WorldWideScience

Sample records for fluidity

  1. Fluidity in the networked society

    DEFF Research Database (Denmark)

    Levinsen, Karin Tweddell

    2011-01-01

    In the globalized economies e-permeation has become a basic condition in our everyday lives. ICT can no longer be understood solely as artefacts and tools and computer-related literacy are no longer restricted to the ability to operate digital tools for specific purposes. The network society......, and therefore also eLearning are characterized by fluidity and the key competence for social actors in this ever changing e-permeated environment is the ability to cope with change - or Castells’ conceptualisation self-programming. Castells’ theory has influenced international definitions of future key...... competencies. Both lifelong learning and digital literacy understood as "bildung" have emerged as central for the definitions of and standards for future key competencies. However, definitions and standards only tell us about the desired destination and outcome of digital competence building. They tell us...

  2. Correlation between ionic conductivity and fluidity of polymer gel ...

    Indian Academy of Sciences (India)

    Unknown

    Ionic conductivity; ion aggregates; FTIR spectroscopy; gels; fluidity. 1. Introduction ... liquid and polymer gel electrolytes have been studied as functions of salt ..... Ratner M A 1987 in Polymer electrolyte reviews (eds) J R. MacCallum and C A ...

  3. Correlation between membrane fluidity cellular development and stem cell differentiation

    KAUST Repository

    Noutsi, Bakiza Kamal

    2016-01-01

    Cell membranes are made up of a complex structure of lipids and proteins that diffuse laterally giving rise to what we call membrane fluidity. During cellular development, such as neuronal differentiation, cell membranes undergo dramatic structural

  4. Tax aggressiveness and corporate social responsibility fluidity in ...

    African Journals Online (AJOL)

    Tax aggressiveness and corporate social responsibility fluidity in Nigerian firms. ... the nexus between shareholding and wider-spectrum stake-holding, where key ... to forge mutually expedient cash flow mechanisms for sustainable corporate ...

  5. Possible evolutionary origins of human female sexual fluidity.

    Science.gov (United States)

    Kanazawa, Satoshi

    2017-08-01

    I propose an evolutionary theory of human female sexual fluidity and argue that women may have been evolutionarily designed to be sexually fluid in order to allow them to have sex with their cowives in polygynous marriage and thus reduce conflict and tension inherent in such marriage. In addition to providing an extensive definition and operationalization of the concept of sexual fluidity and specifying its ultimate function for women, the proposed theory can potentially solve several theoretical and empirical puzzles in evolutionary psychology and sex research. Analyses of the National Longitudinal Study of Adolescent Health (Add Health) confirm the theory's predictions that: (i) women (but not men) who experience increased levels of sexual fluidity have a larger number of children (suggesting that female sexual fluidity, if heritable, may be evolutionarily selected); (ii) women (but not men) who experience marriage or parenthood early in adult life subsequently experience increased levels of sexual fluidity; and (iii) sexual fluidity is significantly positively correlated with known markers of unrestricted sexual orientation among women whereas it is significantly negatively correlated with such markers among men. © 2016 Cambridge Philosophical Society.

  6. Correlation between membrane fluidity cellular development and stem cell differentiation

    KAUST Repository

    Noutsi, Pakiza

    2016-12-01

    Cell membranes are made up of a complex structure of lipids and proteins that diffuse laterally giving rise to what we call membrane fluidity. During cellular development, such as neuronal differentiation, cell membranes undergo dramatic structural changes induced by proteins such as ARC and Cofilin among others in the case of synaptic modification. In this study we used the generalized polarization (GP) property of fluorescent probe Laurdan using two-photon microscopy to determine membrane fluidity as a function of time and for various cell lines. A low GP value corresponds to a higher fluidity and a higher GP value is associated with a more rigid membrane. Four different cell lines were monitored such as hN2, NIH3T3, HEK293 and L6 cells. As expected, NIH3T3 cells have more rigid membrane at earlier stages of their development. On the other hand neurons tend to have the highest membrane fluidity early in their development emphasizing its correlation with plasticity and the need for this malleability during differentiation. This study sheds light on the involvement of membrane fluidity during neuronal differentiation and development of other cell lines.

  7. Fluidity of pea root plasma membranes under altered gravity

    Science.gov (United States)

    Klymchuk, D. O.; Baranenko, V. V.; Vorobyova, T. V.; Dubovoy, V. D.

    This investigation aims to determine whether clinorotation 2 rev min of pea Pisum sativum L seedlings induces the alterations in the physical-chemical properties of cellular membranes including the plasma membrane fluidity The last is an important regulator of functional activity of membrane enzymes The plasma membranes were isolated by aqueous two-phase partitioning from roots of 6-day old pea seedlings The membrane fluidity was examined by fluorescence spectroscopy using pyrene probe The plasma membrane vesicles with known protein concentration were added to the incubation buffer to a final concentration of 50 mu g of protein per ml A small amount by 1 mu l of pyrene solution in 2-propanol was added to the incubation mixture to a final probe concentration 5 mu M at constant mixing Fluorescence spectra were measured using a Perkin-Elmer LS-50 spectrofluorometer Perkin-Elmer England Pyrene was excited at 337 nm and fluorescence intensity of monomers I M and excimers I E were measured at 393 and 470 nm respectively The I E I M ratios were 0 081 pm 0 003 and 0 072 pm 0 004 in preparations obtained from clinorotated and the control seedlings respectively This fact indicates that rotation on the clinostat increases the membrane fluidity Compared with controls clinorotated seedlings have also showed a reduced growth and a higher level of total unsaturated fatty acids determined by gas chromatography The factors that influence on the fluidity of membrane lipids in bilayer appear to be the

  8. Beyond Alphabet Soup: Helping College Health Professionals Understand Sexual Fluidity

    Science.gov (United States)

    Oswalt, Sara B.; Evans, Samantha; Drott, Andrea

    2016-01-01

    Many college students today are no longer using the terms straight, gay, lesbian, bisexual, or transgender to self-identify their sexual orientation or gender identity. This commentary explores research related to fluidity of sexual identities, emerging sexual identities used by college students, and how these identities interact with the health…

  9. Shear viscosity and imperfect fluidity in bosonic and fermionic superfluids

    Science.gov (United States)

    Boyack, Rufus; Guo, Hao; Levin, K.

    2014-12-01

    In this paper we address the ratio of the shear viscosity to entropy density η /s in bosonic and fermionic superfluids. A small η /s is associated with nearly perfect fluidity, and more general measures of the fluidity perfection/imperfection are of wide interest to a number of communities. We use a Kubo approach to concretely address this ratio via low-temperature transport associated with the quasiparticles. Our analysis for bosonic superfluids utilizes the framework of the one-loop Bogoliubov approximation, whereas for fermionic superfluids we apply BCS theory and its BCS-BEC extension. Interestingly, we find that the transport properties of strict BCS and Bogoliubov superfluids have very similar structures, albeit with different quasiparticle dispersion relations. While there is a dramatic contrast between the power law and exponential temperature dependence for η alone, the ratio η /s for both systems is more similar. Specifically, we find the same linear dependence (on the ratio of temperature T to inverse lifetime γ (T ) ) with η /s ∝T /γ (T ) , corresponding to imperfect fluidity. By contrast, near the unitary limit of BCS-BEC superfluids a very different behavior results, which is more consistent with near-perfect fluidity.

  10. Vibration improved the fluidity of aluminum alloys in thin wall ...

    African Journals Online (AJOL)

    user

    The technique to "increase" the metal head during casting and improve the ... The effect of vibration is quantified and incorporated into the fluidity model, such that the ..... Deformation, caused by the expansion and contraction of the thin skin of ...

  11. Gender fluidity and child abuse: A personal view.

    Science.gov (United States)

    Lewis, Charles

    2017-12-01

    Gender fluidity and a failure to respect biological norms may have potentially horrific implications for children and adolescents who express doubt about their bodies. Are transgender activists driving an agenda that will result in inappropriate interventions that block normal development in children and adolescents from which there can be no return? Can the Law protect children and adolescents from harm committed with the intention of helping them?

  12. Membrane fluidity and the radiosensitivity of E. coli K1060

    International Nuclear Information System (INIS)

    Alper, T.; Cramp, W.A.; George, A.; Lunec, J.

    1981-01-01

    Escherichia coli K1060 is deficient in ability to synthesize unsaturated fatty acids, so that the composition of the membrane, and therefore its fluidity, can be changed. A discussion is presented of the results of George et al (1980) concerning the relation of radiosensitivity to membrane fluidity. The following speculations are made: 1) At ice temperatures the membrane of oleic grown bacteria is in the 'gel' state, whereas in elaidic grown bacteria the membrane is in an even more rigid configuration. As a result, lesions produced during irradiation in the presence of oxygen are more lethal than in the more fluid conditions prevailing at room temperature. 2) At room temperature it may be that the bacteria are conditioned by pre-irradiation anoxia so that they become more able to repair damage. When the temperature is decreased to ice levels in bacteria modified by growth in oleic and elaidic acid, reduced membrane fluidity may impair the metabolic activity required for this pre-irradiation conditioning. 3) The lack of temperature effects with the linoleic grown bacteria, that is, no sensitization under aerated conditions and no loss in shoulder under anoxic conditions, is consistent with the lower membrane transitions temperature (fluid to gel) associated with this fatty acid. (U.K.)

  13. The fluidities of digital learning environments and resources

    DEFF Research Database (Denmark)

    Hansbøl, Mikala

    2012-01-01

    The research project “Educational cultures and serious games on a global market place” (2009-2011) dealt with the challenge of the digital learning environment and hence it’s educational development space always existing outside the present space and hence scope of activities. With a reference...... and establishments of the virtual universe called Mingoville.com, the research shows a need to include in researchers’ conceptualizations of digital learning environments and resources, their shifting materialities and platformations and hence emerging (often unpredictable) agencies and educational development...... spaces. Keywords: Fluidity, digital learning environment, digital learning resource, educational development space...

  14. The fluidity of Thai women's gendered and sexual subjectivities.

    Science.gov (United States)

    Thaweesit, Suchada

    2004-05-01

    This paper reports on an ethnographic study of gender and sexuality as factors within contemporary Thai factory women's subjectivities. Competing discourses of what it means to be a woman in contemporary Thai society make women's self-presentations fluid and incoherent. Data from participant-observation and open-ended interviews suggest that the fluidity and inconsistency of women's self-presentations reflect both their negative experiences and oppression within the Thai patriarchal system, and women's strength and resistance to the normative discourses that oppress them. By naming or reinterpreting experiences and desires in their own terms, Thai factory women can redraw elements of their own lives.

  15. Sulfate and Chloride Resistance of High Fluidity Concrete including Fly Ash and GGBS for NPP

    International Nuclear Information System (INIS)

    Noh, Jea Myoung; Cho, Myung Sug

    2010-01-01

    Fly ash mixed concrete has been used for NPP concrete structures in Korea in order to prevent aging and improve durability since the Shin.Kori no.1,2 in 2005. Concentrated efforts to develop technology for the streamlining of construction work and to affect labor savings have been conducted in construction. The application of high fluidity concrete for nuclear power plants has been the research subject with the aim of further rationalization of construction works. Since high fluidity concrete can have the characteristics of high density and high strength without compaction. However, high fluidity concrete can cause thermal cracking by heat of hydration. For this reason, the amount of pozzolan binder should be increased in high fluidity concrete for nuclear power plants. In this study, the resistance of high fluidity concrete on sulfate and chloride was compared with that of the concrete currently using for nuclear power plants

  16. To deal with fluidity in the networked society

    DEFF Research Database (Denmark)

    Levinsen, Karin Tweddell

    2010-01-01

    In the globalized economies e-permeation has become a basic condition in our everyday lives. ICT can no longer be understood solely as artefacts and tools and computer-related literacy are no longer restricted to the ability to operate digital tools for specific purposes. The network society......, and therefore also eLearning are characterized by fluidity and the key competence for social actors in this ever changing e-permeated environment is the ability to cope with change - or Castells’ conceptualisation self-programming. Castells’ theory has influenced international definitions of future key...... competencies. Both lifelong learning and digital literacy understood 'bildun' have emerged as central for the definitions of and standards for future key competencies. However, definitions and standards only tell us about the desired destination and outcome of digital competence building. They tell us nothing...

  17. Study on fluidity of squeeze cast AZ91D magnesium alloy with different wall thicknesses

    Directory of Open Access Journals (Sweden)

    Chen Yun

    2014-03-01

    Full Text Available Rectangular cross-section specimens with different section thicknesses were prepared to study the influences of pouring temperature, mould temperature and squeeze velocity on the fluidity of squeeze cast AZ91D magnesium alloy by means of orthogonal test design method. The results show that pouring temperature, mould temperature and squeeze velocity can significantly affect the fluidity of magnesium alloy specimens with wall thickness no more than 4 mm, and the pouring temperature is the most influential factor on the fluidity of specimens with wall thickness of 1, 2 and 3 mm, while mould temperature is the one for specimens with wall thickness of 4 mm. Increasing pouring temperature between 700 °C and 750 °C is beneficial to the fluidity of AZ91D magnesium alloy, and increasing mould temperature significantly enhances the filling ability of thick (3 and 4 mm section castings. The fluidity of squeeze cast magnesium alloy increases with the increase of wall thickness. It is not recommended to produce magnesium alloy casting with wall thickness of smaller than 3 mm by squeeze cast process due to the poor fluidity. The software DPS was used to generate the regression model, and linear regression equations of the fluidity of squeeze cast AZ91D with different wall thicknesses are obtained using the test results.

  18. Assessment of Membrane Fluidity Fluctuations during Cellular Development Reveals Time and Cell Type Specificity

    KAUST Repository

    Noutsi, Bakiza Kamal; Gratton, Enrico; Chaieb, Saharoui

    2016-01-01

    Cell membrane is made up of a complex structure of lipids and proteins that diffuse laterally giving rise to what we call membrane fluidity. During cellular development, such as differentiation cell membranes undergo dramatic fluidity changes induced by proteins such as ARC and Cofilin among others. In this study we used the generalized polarization (GP) property of fluorescent probe Laurdan using two-photon microscopy to determine membrane fluidity as a function of time and for various cell lines. A low GP value corresponds to a higher fluidity and a higher GP value is associated with a more rigid membrane. Four different cell lines were monitored such as hN2, NIH3T3, HEK293 and L6 cells. Membrane fluidity was measured at 12h, 72h and 92 h. Our results show significant changes in membrane fluidity among all cell types at different time points. GP values tend to increase significantly within 92 h in hN2 cells and 72 h in NIH3T3 cells and only at 92 h in HEK293 cells. L6 showed a marked decrease in membrane fluidity at 72 h and starts to increase at 92 h. As expected, NIH3T3 cells have more rigid membrane at earlier time points. On the other hand, neurons tend to have the highest membrane fluidity at early time points emphasizing its correlation with plasticity and the need for this malleability during differentiation. This study sheds light on the involvement of membrane fluidity during neuronal differentiation and development of other cell lines.

  19. Assessment of Membrane Fluidity Fluctuations during Cellular Development Reveals Time and Cell Type Specificity

    KAUST Repository

    Noutsi, Bakiza Kamal

    2016-06-30

    Cell membrane is made up of a complex structure of lipids and proteins that diffuse laterally giving rise to what we call membrane fluidity. During cellular development, such as differentiation cell membranes undergo dramatic fluidity changes induced by proteins such as ARC and Cofilin among others. In this study we used the generalized polarization (GP) property of fluorescent probe Laurdan using two-photon microscopy to determine membrane fluidity as a function of time and for various cell lines. A low GP value corresponds to a higher fluidity and a higher GP value is associated with a more rigid membrane. Four different cell lines were monitored such as hN2, NIH3T3, HEK293 and L6 cells. Membrane fluidity was measured at 12h, 72h and 92 h. Our results show significant changes in membrane fluidity among all cell types at different time points. GP values tend to increase significantly within 92 h in hN2 cells and 72 h in NIH3T3 cells and only at 92 h in HEK293 cells. L6 showed a marked decrease in membrane fluidity at 72 h and starts to increase at 92 h. As expected, NIH3T3 cells have more rigid membrane at earlier time points. On the other hand, neurons tend to have the highest membrane fluidity at early time points emphasizing its correlation with plasticity and the need for this malleability during differentiation. This study sheds light on the involvement of membrane fluidity during neuronal differentiation and development of other cell lines.

  20. Effects of causality on the fluidity and viscous horizon of quark-gluon plasma

    Science.gov (United States)

    Rahaman, Mahfuzur; Alam, Jan-e.

    2018-05-01

    The second-order Israel-Stewart-M u ̈ller relativistic hydrodynamics was applied to study the effects of causality on the acoustic oscillation in relativistic fluid. Causal dispersion relations have been derived with nonvanishing shear viscosity, bulk viscosity, and thermal conductivity at nonzero temperature and baryonic chemical potential. These relations have been used to investigate the fluidity of quark-gluon plasma (QGP) at finite temperature (T ). Results of the first-order dissipative hydrodynamics have been obtained as a limiting case of the second-order theory. The effects of the causality on the fluidity near the transition point and on the viscous horizon are found to be significant. We observe that the inclusion of causality increases the value of fluidity measure of QGP near Tc and hence makes the flow strenuous. It was also shown that the inclusion of the large magnetic field in the causal hydrodynamics alters the fluidity of QGP.

  1. Lipid engineering reveals regulatory roles for membrane fluidity in yeast flocculation and oxygen-limited growth

    DEFF Research Database (Denmark)

    Degreif, Daniel; de Rond, Tristan; Bertl, Adam

    2017-01-01

    Cells modulate lipid metabolism in order to maintain membrane homeostasis. Here we use a metabolic engineering approach to manipulate the stoichiometry of fatty acid unsaturation, a regulator of cell membrane fluidity, in Saccharomyces cerevisiae. Unexpectedly, reduced lipid unsaturation triggere...

  2. Protein separations using enhanced-fluidity liquid chromatography.

    Science.gov (United States)

    Bennett, Raffeal; Olesik, Susan V

    2017-11-10

    Enhanced-fluidity liquid chromatography (EFLC) methods using methanol/H 2 O/CO 2 and hydrophilic interaction liquid chromatography (HILIC) were explored for the separation of proteins and peptides. EFLC is a separation mode that uses a mobile phase made of conventional solvents combined with liquid carbon dioxide (CO 2 ) in subcritical conditions. The addition of liquid CO 2 enhances diffusivity and decreases viscosity while maintaining mixture polarity, which typically results in reduced time of analysis. TFA additive and elevated temperature were leveraged as key factors in the separation of a 13-analyte intact protein mixture in under 5min. Under these conditions EFLC showed modest improvement in terms of peak asymmetry and analysis time over the competing ACN/H 2 O separation. Protein analytes detected by electrospray ionization - quadrupole time of flight, were shown to be unaffected by the addition of CO 2 in the mobile phase. Herein, the feasibility of separating hydrophilic proteins up to 80kDa (with transferrin) is demonstrated for CO 2 -containing mobile phases. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Effect of grain refinement on the fluidity of two commercial Al-Si foundry alloys

    Science.gov (United States)

    Dahle, A. K.; Tøndel, P. A.; Paradies, C. J.; Arnberg, L.

    1996-08-01

    The effect of grain refinement on the fluidity of AlSi7Mg and AlSi11Mg has been investigated by spiral tests. Two different types of grain refiners have been evaluated. An AlTi5Bl master alloy was added to different Ti contents. Since the commercial alloys had a high initial content of titanium, model alloys were made to investigate the fluidity at low grain refiner additions. Commercial alloys grain refined only by boron additions have also been investigated. The results from the fluidity measurements have been verified by measuring the dendrite coherency point of the different cast alloys. Although different, the two methods show similar trends. The spirals from each fraction grain refiner cast were subsequently investigated metallographically at the tip of the spirals and at a reference point a distance behind, but no obvious difference in structure was observed. For both alloys, an increase in fluidity is observed as the content of grain refiner increases above 0.12 pct Ti, while the fluidity is impaired with increased grain refinement below 0.12 pct Ti. The alloys grain refined with ~0.015 pct B show the highest fraction solid at dendrite coherency, the smallest grain size, and the best fluidity.

  4. Effect of plasma membrane fluidity on serotonin transport by endothelial cells

    International Nuclear Information System (INIS)

    Block, E.R.; Edwards, D.

    1987-01-01

    To evaluate the effect of plasma membrane fluidity of lung endothelial cells on serotonin transport, porcine pulmonary artery endothelial cells were incubated for 3 h with either 0.1 mM cholesterol hemisuccinate, 0.1 mM cis-vaccenic acid, or vehicle (control), after which plasma membrane fluidity and serotinin transport were measured. Fluorescence spectroscopy was used to measure fluidity in the plasma membrane. Serotonin uptake was calculated from the disappearance of [ 14 C]-serotonin from the culture medium. Cholesterol decreased fluidity in the subpolar head group and central and midacyl side-chain regions of the plasma membrane and decreased serotonin transport, whereas cis-vaccenic acid increased fluidity in the central and midacyl side-chain regions of the plasma membrane and also increased serotonin transport. Cis-vaccenic acid had no effect of fluidity in the subpolar head group region of the plasma membrane. These results provide evidence that the physical state of the central and midacyl chains within the pulmonary artery endothelial cell plasma membrane lipid bilayer modulates transmembrane transport of serotonin by these cells

  5. Influence of membrane fluidity on human immunodeficiency virus type 1 entry

    International Nuclear Information System (INIS)

    Harada, Shinji; Yusa, Keisuke; Monde, Kazuaki; Akaike, Takaaki; Maeda, Yosuke

    2005-01-01

    For penetration of human immunodeficiency virus type 1 (HIV-1), formation of fusion-pores might be required for accumulating critical numbers of fusion-activated gp41, followed by multiple-site binding of gp120 with receptors, with the help of fluidization of the plasma membrane and viral envelope. Correlation between HIV-1 infectivity and fluidity was observed by treatment of fluidity-modulators, indicating that infectivity was dependent on fluidity. A 5% decrease in fluidity suppressed the HIV-1 infectivity by 56%. Contrarily, a 5% increase in fluidity augmented the infectivity by 2.4-fold. An increased temperature of 40 deg C or treatment of 0.2% xylocaine after viral adsorption at room temperature enhanced the infectivity by 2.6- and 1.5-fold, respectively. These were inhibited by anti-CXCR4 peptide, implying that multiple-site binding was accelerated at 40 deg C or by xylocaine. Thus, fluidity of both the plasma membrane and viral envelope was required to form the fusion-pore and to complete the entry of HIV-1

  6. Crisis or Fluidity? Florian Znaniecki’s Theory of Civilization

    Directory of Open Access Journals (Sweden)

    Elżbieta Hałas

    2017-01-01

    Full Text Available The preoccupation with the processes of globalization, which has become a key concept in the analysis of the sociocultural condition of postmodernity, has led to a decreased interest in the theory of civilization. The ideological burden of the concept of civilization and its stigmatization by critics of post-Enlightenment modernity also contribute to this current state. However, issues associated with the processes of civilization have once again come to the fore, as shown by the reconstruction of threads associated with civilization in social theory, including sociological works. The views on civilization presented by Weber, Durkheim and Mauss, by their successors Sorokin, Elias and Nelson, down to the contemporary publications of Huntington and Eisenstadt are widely known, whereas works published on this subject in Polish by Florian Znaniecki are not. On a backdrop of the genesis of civilization-associated discourse and its antinomy as regards religion, the article presents Znaniecki’s concept of civilization processes as the social integration of culture, developed on the basis of his theory of cultural and social systems. Two types of human participation in culture are significant here: cultural communities and social groups which create a cultural bond. The de-civilizing processes which Znaniecki described are shown. The article analyzes Znaniecki’s idea of a fluid civilization and the conditions which are necessary for its existence, in the shape of reflexive cultural knowledge as the answer to a cultural crisis. The new type of cultural crisis stems from cultural innovations. The article shows the differences between Znaniecki’s concept of fluidity and Bauman’s liquid modernity. It presents the concept of “civilization of the future” as a pan-human civilization, which requires the formation of a new type of cultural community – the world culture society.

  7. A Study on the Evaluation of Field Application of High-Fluidity Concrete Containing High Volume Fly Ash

    Directory of Open Access Journals (Sweden)

    Yun-Wang Choi

    2015-01-01

    Full Text Available In the recent concrete industry, high-fluidity concrete is being widely used for the pouring of dense reinforced concrete. Normally, in the case of high-fluidity concrete, it includes high binder contents, so it is necessary to replace part of the cement through admixtures such as fly ash to procure economic feasibility and durability. This study shows the mechanical properties and field applicability of high-fluidity concrete using mass of fly ash as alternative materials of cement. The high-fluidity concrete mixed with 50% fly ash was measured to manufacture concrete that applies low water/binder ratio to measure the mechanical characteristics as compressive strength and elastic modulus. Also, in order to evaluate the field applicability, high-fluidity concrete containing high volume fly ash was evaluated for fluidity, compressive strength, heat of hydration, and drying shrinkage of concrete.

  8. Differences in Sexual Orientation Diversity and Sexual Fluidity in Attractions Among Gender Minority Adults in Massachusetts.

    Science.gov (United States)

    Katz-Wise, Sabra L; Reisner, Sari L; Hughto, Jaclyn White; Keo-Meier, Colton L

    2016-01-01

    This study characterized sexual orientation identities and sexual fluidity in attractions in a community-based sample of self-identified transgender and gender-nonconforming adults in Massachusetts. Participants were recruited in 2013 using bimodel methods (online and in person) to complete a one-time, Web-based quantitative survey that included questions about sexual orientation identity and sexual fluidity. Multivariable logistic regression models estimated adjusted risk ratios (aRRs) and 95% confidence intervals (95% CIs) to examine the correlates of self-reported changes in attractions ever in lifetime among the whole sample (n = 452) and after transition among those who reported social gender transition (n = 205). The sample endorsed diverse sexual orientation identities: 42.7% queer, 19.0% other nonbinary, 15.7% bisexual, 12.2% straight, and 10.4% gay/lesbian. Overall, 58.2% reported having experienced changes in sexual attractions in their lifetime. In adjusted models, trans masculine individuals were more likely than trans feminine individuals to report sexual fluidity in their lifetime (aRR = 1.69; 95% CI = 1.34, 2.12). Among those who transitioned, 64.6% reported a change in attractions posttransition, and trans masculine individuals were less likely than trans feminine individuals to report sexual fluidity (aRR = 0.44; 95% CI = 0.28, 0.69). Heterogeneity of sexual orientation identities and sexual fluidity in attractions are the norm rather than the exception among gender minority people.

  9. Membrane fluidity increases during apoptosis of sheep ileal Peyer's patch B cells

    International Nuclear Information System (INIS)

    Jourd'heuil, D.; Aspinall, A.; Reynolds, J.D.; Meddings, J.B.

    1996-01-01

    To investigate specific plasma membrane structural changes associated with apoptosis, whole cells and purified plasma membranes of apoptotic B cells from the ileal Peyer's patch of sheep were analyzed for their 'membrane fluidity'. The ileal Peyer's patch of sheep provided a large number of B cells required for plasma membrane isolation (>5 x 10 9 ). As the incidence of apoptosis increased with time of culture, the fluidity of purified plasma membranes, as measured with the fluorophore DPH (diphenylhexatriene), increased. To evaluate this phenomenon with intact cells, B cells at different apoptotic stages were fractionated on discontinuous Percoll gradients. Similar results were obtained using the fluorophore TMA-DPH (trimethylammoniumdiphenylhexatriene), which has been shown to localize specifically to the plasma membrane. Functionally, the increase in plasma membrane fluidity associated with apoptosis may represent either a mechanism to cycle phosphatidylserine to the outer leaflet, mediating phagocytic recognition of apoptotic cells, or a consequence of this event. (author). 20 refs., 1 tab., 4 figs

  10. Fluidity models in ancient Greece and current practices of sex assignment.

    Science.gov (United States)

    Chen, Min-Jye; McCann-Crosby, Bonnie; Gunn, Sheila; Georgiadis, Paraskevi; Placencia, Frank; Mann, David; Axelrad, Marni; Karaviti, L P; McCullough, Laurence B

    2017-06-01

    Disorders of sexual differentiation such as androgen insensitivity and gonadal dysgenesis can involve an intrinsic fluidity at different levels, from the anatomical and biological to the social (gender) that must be considered in the context of social constraints. Sex assignment models based on George Engel's biopsychosocial aspects model of biology accept fluidity of gender as a central concept and therefore help establish expectations within the uncertainty of sex assignment and anticipate potential changes. The biology underlying the fluidity inherent to these disorders should be presented to parents at diagnosis, an approach that the gender medicine field should embrace as good practice. Greek mythology provides many accepted archetypes of change, and the ancient Greek appreciation of metamorphosis can be used as context with these patients. Our goal is to inform expertise and optimal approaches, knowing that this fluidity may eventually necessitate sex reassignment. Physicians should provide sex assignment education based on different components of sexual differentiation, prepare parents for future hormone-triggered changes in their children, and establish a sex-assignment algorithm. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Emotion Talk in Preschool Same-Sex Friendship Groups: Fluidity over Time and Context.

    Science.gov (United States)

    Kyratzis, Amy

    2001-01-01

    Examined "emotion talk" among 3- and 4-year-old peers in a children's center in different contexts over the academic year. Found that the boys' group evolved norms against expression of being scared with norms downgrading girl characteristics. Boys' and girls' groups showed contextual fluidity in expressing emotion and emotion talk that…

  12. Relational and sexual fluidity in females partnered with male-to-female transsexual persons.

    Science.gov (United States)

    Aramburu Alegría, C

    2013-03-01

    This paper reports on a study examining sexuality in females who remain partnered with male-to-female transsexual persons. Participants' self-view and sexual fluidity following their partners' transition from man to woman is examined. Sixteen females participated in in-depth, semi-structured interviews. An inductive process of data analysis was conducted, using the constant comparative method, an iterative process by which data are compared within and across subjects. Data were collected until thematic saturation was achieved. Four themes related to sexuality emerged: (1) questioning of sexual orientation; (2) sexual orientation categorization; (3) relational fluidity without sexual relations; and (4) relational fluidity with sexual relations. Participants maintained a heterosexual identity, yet modified their self-view to include an identity that reflected their reformed relationship. The majority of the respondents reported sexual lives that were active or evolving. Others remained in relationships that no longer included sexual activity. The study findings highlight the potential fluidity within the sexual and relational lives of females, and can enhance healthcare providers' preparedness and efficacy with diverse populations. Providers are in a unique position to offer resources to patients who identify as sexually or gender-diverse, or who are in relationships with sexually or gender-diverse persons. © 2012 Blackwell Publishing.

  13. Trends in educational fluidity after the fall of socialism in the Czech Republic

    Czech Academy of Sciences Publication Activity Database

    Katrňák, T.; Simonová, Natalie

    2016-01-01

    Roč. 10, č. 3 (2016), s. 49-69 ISSN 1802-4637 R&D Projects: GA ČR GB14-36154G Institutional support: RVO:68378025 Keywords : educational fluidity * cohort analysis * educational inequality Subject RIV: AO - Sociology, Demography OBOR OECD: Sociology

  14. Fluidity models in ancient Greece and current practices of sex assignment

    Science.gov (United States)

    Chen, Min-Jye; McCann-Crosby, Bonnie; Gunn, Sheila; Georgiadis, Paraskevi; Placencia, Frank; Mann, David; Axelrad, Marni; Karaviti, L.P; McCullough, Laurence B.

    2018-01-01

    Disorders of sexual differentiation such as androgen insensitivity and gonadal dysgenesis can involve an intrinsic fluidity at different levels, from the anatomical and biological to the social (gender) that must be considered in the context of social constraints. Sex assignment models based on George Engel’s biopsychosocial aspects model of biology accept fluidity of gender as a central concept and therefore help establish expectations within the uncertainty of sex assignment and anticipate potential changes. The biology underlying the fluidity inherent to these disorders should be presented to parents at diagnosis, an approach that the gender medicine field should embrace as good practice. Greek mythology provides many accepted archetypes of change, and the ancient Greek appreciation of metamorphosis can be used as context with these patients. Our goal is to inform expertise and optimal approaches, knowing that this fluidity may eventually necessitate sex reassignment. Physicians should provide sex assignment education based on different components of sexual differentiation, prepare parents for future hormone-triggered changes in their children, and establish a sex-assignment algorithm. PMID:28478088

  15. Born Both Ways: The Alloparenting Hypothesis for Sexual Fluidity in Women

    Directory of Open Access Journals (Sweden)

    Barry X. Kuhle

    2013-04-01

    Full Text Available Given the primacy of reproduction, same-sex sexual behavior poses an evolutionary puzzle. Why would selection fashion motivational mechanisms to engage in sexual behaviors with members of the same sex? We propose the alloparenting hypothesis, which posits that sexual fluidity in women is a contingent adaptation that increased ancestral women's ability to form pair bonds with female alloparents who helped them rear children to reproductive age. Ancestral women recurrently faced the adaptive problems of securing resources and care for their offspring, but were frequently confronted with either a dearth of paternal resources due to their mates' death, an absence of paternal investment due to rape, or a divestment of paternal resources due to their mates' extra-pair mating efforts. A fluid sexuality would have helped ancestral women secure resources and care for their offspring by promoting the acquisition of allomothering investment from unrelated women. Under this view, most heterosexual women are born with the capacity to form romantic bonds with both sexes. Sexual fluidity is a conditional reproductive strategy with pursuit of men as the default strategy and same-sex sexual responsiveness triggered when inadequate paternal investment occurs or when women with alloparenting capabilities are encountered. Discussion focuses on (a evidence for alloparenting and sexual fluidity in humans and other primates; (b alternative explanations for sexual fluidity in women; and (c fourteen circumstances predicted to promote same-sex sexual behavior in women.

  16. Effects of unripe Citrus hassaku fruits extract and its flavanone glycosides on blood fluidity.

    Science.gov (United States)

    Itoh, Kimihisa; Masuda, Megumi; Naruto, Shunsuke; Murata, Kazuya; Matsuda, Hideaki

    2010-01-01

    The enhancement of blood fluidity may lead to improvements in skin problems resulting from unsmooth circulation or blood stagnation. Since a 50% ethanolic extract (CH-ext) obtained from unripe Citrus hassaku fruits may be a useful ingredient in skin-whitening cosmetics, the present study was designed to examine the effect of CH-ext on blood fluidity. CH-ext concentration-dependently inhibited in vitro collagen-induced rabbit platelet aggregation and in vitro polybrene-induced rat erythrocyte aggregation. The CH-ext showed in vitro fibrinolysis activity in fibrin plate assay. Activity-guided fractionation of the CH-ext using antiplatelet activity, inhibitory activity of erythrocyte aggregation, and fibrinolysis activity revealed that these activities of CH-ext were attributable to naringenin-7-glycoside (prunin). Successive oral administration of CH-ext to rats inhibited the lipopolysaccharide (LPS)-induced decrease of blood platelets and fibrinogen, and LPS-induced increase of fibrin degradation products (FDP) in LPS-induced disseminated intravascular coagulation (DIC) model rats. Effects of CH-ext on blood fluidity were analyzed by a micro channel array flow analyzer (MC-FAN). Preventive oral administration of CH-ext to rats showed dose-dependent reduction of the passage time of whole blood flow of the DIC model rats in comparison with that of the vehicle control rats. These results imply that CH-ext may have effects which improve effects on blood fluidity.

  17. Subcellular membrane fluidity of Lactobacillus delbrueckii subsp. bulgaricus under cold and osmotic stress.

    Science.gov (United States)

    Meneghel, Julie; Passot, Stéphanie; Cenard, Stéphanie; Réfrégiers, Matthieu; Jamme, Frédéric; Fonseca, Fernanda

    2017-09-01

    Cryopreservation of lactic acid bacteria may lead to undesirable cell death and functionality losses. The membrane is the first target for cell injury and plays a key role in bacterial cryotolerance. This work aimed at investigating at a subcellular resolution the membrane fluidity of two populations of Lactobacillus delbrueckii subsp. bulgaricus when subjected to cold and osmotic stresses associated to freezing. Cells were cultivated at 42 °C in mild whey medium, and they were exposed to sucrose solutions of different osmolarities (300 and 1800 mOsm L -1 ) after harvest. Synchrotron fluorescence microscopy was used to measure membrane fluidity of cells labeled with the cytoplasmic membrane probe 1-[4 (trimethylamino) phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH). Images were acquired at 25 and 0 °C, and more than a thousand cells were individually analyzed. Results revealed that a bacterial population characterized by high membrane fluidity and a homogeneous distribution of fluidity values appeared to be positively related to freeze-thaw resistance. Furthermore, rigid domains with different anisotropy values were observed and the occurrence of these domains was more important in the freeze-sensitive bacterial population. The freeze-sensitive cells exhibited a broadening of existing highly rigid lipid domains with osmotic stress. The enlargement of domains might be ascribed to the interaction of sucrose with membrane phospholipids, leading to membrane disorganization and cell degradation.

  18. Differences in Sexual Orientation Diversity and Sexual Fluidity in Attractions among Gender Minority Adults in Massachusetts

    Science.gov (United States)

    Katz-Wise, Sabra L.; Reisner, Sari L.; White, Jaclyn M.; Keo-Meier, Colton L.

    2015-01-01

    This study characterized sexual orientation identities and sexual fluidity in attractions in a community-based sample of self-identified transgender and gender nonconforming adults in Massachusetts. Participants were recruited in 2013 using bi-model methods (online and in-person) to complete a one-time web-based quantitative survey that included questions about sexual orientation identity and sexual fluidity. Multivariable logistic regression models estimated Adjusted Risk Ratios (aRR) and 95% Confidence Intervals (95% CI) to examine the correlates of self-reported changes in attractions ever in lifetime among the whole sample (n=452) and after transition among those who reported social gender transition (n=205). The sample endorsed diverse sexual orientation identities: 42.7% queer, 19.0% other non-binary, 15.7% bisexual, 12.2% straight, 10.4% gay/lesbian. Overall, 58.2% reported having experienced changes in sexual attractions in their lifetime. In adjusted models, trans masculine individuals were more likely than trans feminine individuals to report sexual fluidity in their lifetime (aRR=1.69; 95% CI=1.34, 2.12). Among those who transitioned, 64.6% reported a change in attractions post-transition and trans masculine individuals were less likely than trans feminine individuals to report sexual fluidity (aRR=0.44; 95% CI=0.28, 0.69). Heterogeneity of sexual orientation identities and sexual fluidity in attractions are the norm rather than the exception among gender minority people. PMID:26156113

  19. The effect of alcohols on red blood cell mechanical properties and membrane fluidity depends on their molecular size.

    Science.gov (United States)

    Sonmez, Melda; Ince, Huseyin Yavuz; Yalcin, Ozlem; Ajdžanović, Vladimir; Spasojević, Ivan; Meiselman, Herbert J; Baskurt, Oguz K

    2013-01-01

    The role of membrane fluidity in determining red blood cell (RBC) deformability has been suggested by a number of studies. The present investigation evaluated alterations of RBC membrane fluidity, deformability and stability in the presence of four linear alcohols (methanol, ethanol, propanol and butanol) using ektacytometry and electron paramagnetic resonance (EPR) spectroscopy. All alcohols had a biphasic effect on deformability such that it increased then decreased with increasing concentration; the critical concentration for reversal was an inverse function of molecular size. EPR results showed biphasic changes of near-surface fluidity (i.e., increase then decrease) and a decreased fluidity of the lipid core; rank order of effectiveness was butanol > propanol > ethanol > methanol, with a significant correlation between near-surface fluidity and deformability (r = 0.697; palcohol enhanced the impairment of RBC deformability caused by subjecting cells to 100 Pa shear stress for 300 s, with significant differences from control being observed at higher concentrations of all four alcohols. The level of hemolysis was dependent on molecular size and concentration, whereas echinocytic shape transformation (i.e., biconcave disc to crenated morphology) was observed only for ethanol and propanol. These results are in accordance with available data obtained on model membranes. They document the presence of mechanical links between RBC deformability and near-surface membrane fluidity, chain length-dependence of the ability of alcohols to alter RBC mechanical behavior, and the biphasic response of RBC deformability and near-surface membrane fluidity to increasing alcohol concentrations.

  20. Characterization of membrane lipid fluidity in human embryo cells malignantly transfer med post 238Pu α irradiation

    International Nuclear Information System (INIS)

    Qi Zirong; Sun Ling; Liu Guolian; Shen Zhiyuan

    1992-01-01

    The membrane lipid fluidity of malignantly transformed human embryo cells following 238 Pu α particlce irradiation in vitro has been studied. The results indicate that the ontogenesis depends on irradiation dose (Gy) and the membrane lipid fluidity in malignantly transformed cells is higher than that in normal embryo cells. With the microviscosity (η) of cells plotted against the cell counts, the correlation coefficient (γ) is calculated to be between 0.9936 and 0.9999. Since the malignant transformation of irradiated embryo cells is manifested early on cell membrane lipid, the fluidity of membrane lipid can be used as an oncologic marker

  1. Radiation-Induced Fluidity and Glass-Liquid Transition in Irradiated Amorphous Materials

    International Nuclear Information System (INIS)

    Ojovan, M.I.

    2009-01-01

    This paper describes the fluidity behaviour of continuously irradiated glasses using the Congruent Bond Lattice model in which broken bonds 'configurons' facilitate the flow. Irradiation breaks the bonds creating configurons which at high concentrations provide the transition of material from the glassy to liquid state. An explicit equation of viscosity has been derived which gives results in agreement with experimental data. This equation provides correct viscosity data for non-irradiated materials and shows a significant increase of fluidity in radiation fields. It demonstrates a decrease of activation energy of flow for irradiated glasses. A simple equation for glass-transition temperature was also obtained which shows that irradiated glasses have lower glass transition temperatures and are readily transformed from glassy to liquid state e.g. fluidized in strong radiation fields. (authors)

  2. Hydrostatic pressure decreases membrane fluidity and lipid desaturase expression in chondrocyte progenitor cells.

    Science.gov (United States)

    Montagne, Kevin; Uchiyama, Hiroki; Furukawa, Katsuko S; Ushida, Takashi

    2014-01-22

    Membrane biomechanical properties are critical in modulating nutrient and metabolite exchange as well as signal transduction. Biological membranes are predominantly composed of lipids, cholesterol and proteins, and their fluidity is tightly regulated by cholesterol and lipid desaturases. To determine whether such membrane fluidity regulation occurred in mammalian cells under pressure, we investigated the effects of pressure on membrane lipid order of mouse chondrogenic ATDC5 cells and desaturase gene expression. Hydrostatic pressure linearly increased membrane lipid packing and simultaneously repressed lipid desaturase gene expression. We also showed that cholesterol mimicked and cholesterol depletion reversed those effects, suggesting that desaturase gene expression was controlled by the membrane physical state itself. This study demonstrates a new effect of hydrostatic pressure on mammalian cells and may help to identify the molecular mechanisms involved in hydrostatic pressure sensing in chondrocytes. © 2013 Elsevier Ltd. All rights reserved.

  3. Even a Chronic Mild Hyperglycemia Affects Membrane Fluidity and Lipoperoxidation in Placental Mitochondria in Wistar Rats

    Science.gov (United States)

    Figueroa-García, María del Consuelo; Espinosa-García, María Teresa; Martinez-Montes, Federico; Palomar-Morales, Martín; Mejía-Zepeda, Ricardo

    2015-01-01

    It is known the deleterious effects of diabetes on embryos, but the effects of diabetes on placenta and its mitochondria are still not well known. In this work we generated a mild hyperglycemia model in female wistar rats by intraperitoneal injection of streptozotocin in 48 hours-old rats. The sexual maturity onset of the female rats was delayed around 6–7 weeks and at 16 weeks-old they were mated, and sacrificed at day 19th of pregnancy. In placental total tissue and isolated mitochondria, the fatty acids composition was analyzed by gas chromatography, and lipoperoxidation was measured by thiobarbituric acid reactive substances. Membrane fluidity in mitochondria was measured with the excimer forming probe dipyrenylpropane and mitochondrial function was measured with a Clark-type electrode. The results show that even a chronic mild hyperglycemia increases lipoperoxidation and decreases mitochondrial function in placenta. Simultaneously, placental fatty acids metabolism in total tissue is modified but in a different way than in placental mitochondria. Whereas the chronic mild hyperglycemia induced a decrease in unsaturated to saturated fatty acids ratio (U/S) in placental total tissue, the ratio increased in placental mitochondria. The measurements of membrane fluidity showed that fluidity of placenta mitochondrial membranes increased with hyperglycemia, showing consistency with the fatty acids composition through the U/S index. The thermotropic characteristics of mitochondrial membranes were changed, showing lower transition temperature and activation energies. All of these data together demonstrate that even a chronic mild hyperglycemia during pregnancy of early reproductive Wistar rats, generates an increment of lipoperoxidation, an increase of placental mitochondrial membrane fluidity apparently derived from changes in fatty acids composition and consequently, mitochondrial malfunction. PMID:26630275

  4. Assessment and optimization of thermal and fluidity properties of high strength concrete via genetic algorithm

    Directory of Open Access Journals (Sweden)

    Barış Şimşek

    2016-12-01

    Full Text Available This paper proposes a Response Surface Methodology (RSM based Genetic Algorithm (GA using MATLAB® to assess and optimize the thermal and fluidity of high strength concrete (HSC. The overall heat transfer coefficient, slump-spread flow and T50 time was defined as thermal and fluidity properties of high strength concrete. In addition to above mentioned properties, a 28-day compressive strength of HSC was also determined. Water to binder ratio, fine aggregate to total aggregate ratio and the percentage of super-plasticizer content was determined as effective factors on thermal and fluidity properties of HSC. GA based multi-objective optimization method was carried out by obtaining quadratic models using RSM. Having excessive or low ratio of water to binder provides lower overall heat transfer coefficient. Moreover, T50 time of high strength concrete decreased with the increasing of water to binder ratio and the percentage of superplasticizer content. Results show that RSM based GA is effective in determining optimal mixture ratios of HSC.

  5. Lipid fluidity at different regions in LDL and HDL of β-thalassemia/Hb E patients

    International Nuclear Information System (INIS)

    Morales, Noppawan Phumala; Charlermchoung, Chalermkhwan; Luechapudiporn, Rataya; Yamanont, Paveena; Fucharoen, Suthat; Chantharaksri, Udom

    2006-01-01

    Atherosclerosis-related vascular complications in β-thalassemia/hemoglobin E (β-thal/Hb E) patients may result from iron induced oxidation of lipoproteins. To identify the specific site of oxidative damage, changes in lipid fluidity at different regions in LDL and HDL particle were investigated using two fluorescence probes and two ESR spin probes. The magnitude of increased lipid fluidity in thalassemic lipoproteins was dependent on the location of the probes. In hydrophobic region, the rotational correlation times for 16-doxyl stearic acid and DPH anisotropy were markedly changed in LDL and HDL of the patients. In the surface region, there was only a slight change in the order parameter (S) for 5-doxyl stearic acid and TMA-DPH anisotropy. Lipid fluidity at the core of LDL and HDL showed good correlation with oxidative stress markers, the ratio of CL/CO, and the level of α-tocopherol, suggesting that hydrophobic region of thalassemic lipoprotein was a target site for oxidative damage

  6. Influence of nanoparticle-membrane electrostatic interactions on membrane fluidity and bending elasticity.

    Science.gov (United States)

    Santhosh, Poornima Budime; Velikonja, Aljaž; Perutkova, Šarka; Gongadze, Ekaterina; Kulkarni, Mukta; Genova, Julia; Eleršič, Kristina; Iglič, Aleš; Kralj-Iglič, Veronika; Ulrih, Nataša Poklar

    2014-02-01

    The aim of this work is to investigate the effect of electrostatic interactions between the nanoparticles and the membrane lipids on altering the physical properties of the liposomal membrane such as fluidity and bending elasticity. For this purpose, we have used nanoparticles and lipids with different surface charges. Positively charged iron oxide (γ-Fe2O3) nanoparticles, neutral and negatively charged cobalt ferrite (CoFe2O4) nanoparticles were encapsulated in neutral lipid 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine and negatively charged 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine lipid mixture. Membrane fluidity was assessed through the anisotropy measurements using the fluorescent probe 1,6-diphenyl-1,3,5-hexatriene. Though the interaction of both the types of nanoparticles reduced the membrane fluidity, the results were more pronounced in the negatively charged liposomes encapsulated with positively charged iron oxide nanoparticles due to strong electrostatic attractions. X-ray photoelectron spectroscopy results also confirmed the presence of significant quantity of positively charged iron oxide nanoparticles in negatively charged liposomes. Through thermally induced shape fluctuation measurements of the giant liposomes, a considerable reduction in the bending elasticity modulus was observed for cobalt ferrite nanoparticles. The experimental results were supported by the simulation studies using modified Langevin-Poisson-Boltzmann model. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  7. Effects of Insecticides on the Fluidity of Mitochondrial Membranes of the Diamondback Moth, Plutella xylostella, Resistant and Susceptible to Avermectin

    Science.gov (United States)

    Hu, J.; Liang, P.; Shi, X.; Gao, X.

    2008-01-01

    The effects of various insecticides on the fluidity of mitochondrial membranes and cross-resistance were investigated in the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae) using strains that were both resistant and susceptible to avermectin. The resistant strain of P. xylostella, AV-R, developed 1078-fold resistance to avermetins with a high level of cross-resistance to the analogs of avermectins, ivermectin and emamectin benzoate. It had more than 1000 times greater resistance when compared with the avermectin-susceptible strain, XH-S. Mitochondrial membrane fluidity was measured by detecting fluorescence polarization using DPH (1,6-Diphenyl -1,3,5-hexatriene) as the fluorescence probe. Abamectin, emamectin benzoate, ivermectin, cypermethrin and fenvalerate decreased the fluidity of mitochondrial membranes in the XH-S strain at 25°C. However, fipronil and acephate did not change the fluidity of mitochondrial membrane when the concentration of these insecticides was 1×10-4 mol/L. Membrane fluidity increased as the temperature increased. The thermotropic effect on the polarization value of DPH increased as the insecticide concentration was increased. There was a significant difference of mitochondrial membrane fluidity between both XH-S and AV-R when temperature was less than 25°C and no difference was observed when the temperature was more than 25°C. The low-dose abamectin (0.11 mg/L) in vivo treatment caused a significant change of membrane fluidity in the XH-S strain and no change in the AV-R strain. However, a high-dose abamectin (11.86 mg/L) resulted in 100% mortality of the XH-S strain. In vivo treatment may cause a significant change of membrane fluidity in the AV-R strain PMID:20345311

  8. Reorganization of Azospirillum brasilense cell membrane is mediated by lipid composition adjustment to maintain optimal fluidity during water deficit.

    Science.gov (United States)

    Cesari, A B; Paulucci, N S; Biasutti, M A; Reguera, Y B; Gallarato, L A; Kilmurray, C; Dardanelli, M S

    2016-01-01

    We study the Azospirillum brasilense tolerance to water deficit and the dynamics of adaptive process at the level of the membrane. Azospirillum brasilense was exposed to polyethylene glycol (PEG) growth and PEG shock. Tolerance, phospholipids and fatty acid (FA) composition and membrane fluidity were determined. Azospirillum brasilense was able to grow in the presence of PEG; however, its viability was reduced. Cells grown with PEG showed membrane fluidity similar to those grown without, the lipid composition was modified, increasing phosphatidylcholine and decreasing phosphatidylethanolamine amounts. The unsaturation FAs degree was reduced. The dynamics of the adaptive response revealed a decrease in fluidity 20 min after the addition of PEG, indicating that the PEG has a fluidizing effect on the hydrophobic region of the cell membrane. Fluidity returned to initial values after 60 min of PEG exposure. Azospirillum brasilense is able to perceive osmotic changes by changing the membrane fluidity. This effect is offset by changes in the composition of membrane phospholipid and FA, contributing to the homeostasis of membrane fluidity under water deficit. This knowledge can be used to develop new Azospirillum brasilense formulations showing an adapted membrane to water deficit. © 2015 The Society for Applied Microbiology.

  9. The effect of alcohols on red blood cell mechanical properties and membrane fluidity depends on their molecular size.

    Directory of Open Access Journals (Sweden)

    Melda Sonmez

    Full Text Available The role of membrane fluidity in determining red blood cell (RBC deformability has been suggested by a number of studies. The present investigation evaluated alterations of RBC membrane fluidity, deformability and stability in the presence of four linear alcohols (methanol, ethanol, propanol and butanol using ektacytometry and electron paramagnetic resonance (EPR spectroscopy. All alcohols had a biphasic effect on deformability such that it increased then decreased with increasing concentration; the critical concentration for reversal was an inverse function of molecular size. EPR results showed biphasic changes of near-surface fluidity (i.e., increase then decrease and a decreased fluidity of the lipid core; rank order of effectiveness was butanol > propanol > ethanol > methanol, with a significant correlation between near-surface fluidity and deformability (r = 0.697; p<0.01. The presence of alcohol enhanced the impairment of RBC deformability caused by subjecting cells to 100 Pa shear stress for 300 s, with significant differences from control being observed at higher concentrations of all four alcohols. The level of hemolysis was dependent on molecular size and concentration, whereas echinocytic shape transformation (i.e., biconcave disc to crenated morphology was observed only for ethanol and propanol. These results are in accordance with available data obtained on model membranes. They document the presence of mechanical links between RBC deformability and near-surface membrane fluidity, chain length-dependence of the ability of alcohols to alter RBC mechanical behavior, and the biphasic response of RBC deformability and near-surface membrane fluidity to increasing alcohol concentrations.

  10. [Fluorescence polarization used to investigate the cell membrane fluidity of Saccharomyces cerevisiae treated by pulsed electric field].

    Science.gov (United States)

    Zhang, Ying; Zeng, Xin-An; Wen, Qi-Biao; Li, Lin

    2008-01-01

    To know the lethal mechanism of microorganisms under pulsed electric field treatment, the relationship between the inactivation of Saccharomyces cerevisiae (CICC1308) cell and the permeability and fluidity changes of its cell membrane treated by pulsed electric field (0-25 kV x cm(-1), 0-266 ms) was investigated. With 1,6-diphenyl-1,3,5-hexatriene (DPH) used as a probe, the cell membrane fluidity of Saccharomyces cerevisiae treated by pulsed electric field was expressed by fluorescence polarization. Results showed that the cell membrane fluidity decreases when the electric flied strength is up to 5 kV x cm(-1), and decreases with the increase in electric field strength and treatment time. The plate counting method and ultraviolet spectrophotometer were used to determine the cell viability and to investigate the cell membrane permeability, respectively, treated by pulsed electric field. Results showed that the lethal ratio and the content of protein and nucleic acid leaked from intracellular plasma increased with the increase in the electric field strength and the extension of treatment time. Even in a quite lower electric field of 5 kV x cm(-1) with a tiny microorganism lethal level, the increase in UV absorption value and the decrease in fluidity were significant. It was demonstrated that the cell membrane fluidity decreases with the increase in lethal ratio and cell membrane permeability. The viscosity of cell membrane increases with the decrease in fluidity. These phenomena indicated that cell membrane is one of the most key sites during the pulsed electric field treatment, and the increased membrane permeability and the decreased cell membrane fluidity contribute to the cell death.

  11. Influence of membrane fatty acid composition and fluidity on airborne survival of Escherichia coli.

    Science.gov (United States)

    Ng, Tsz Wai; Chan, Wing Lam; Lai, Ka Man

    2018-04-01

    Finding ways to predict and control the survival of bacterial aerosols can contribute to the development of ways to alleviate a number of crucial microbiological problems. Significant damage in the membrane integrity of Escherichia coli during aerosolization and airborne suspension has been revealed which has prompted the question of how the membrane fatty acid composition and fluidity influence the survival of airborne bacteria. Two approaches of using isogenic mutants and different growth temperatures were selected to manipulate the membrane fatty acid composition of E. coli before challenging the bacteria with different relative humidity (RH) levels in an aerosol chamber. Among the mutants (fabR - , cfa. fadA - ), fabR - had the lowest membrane fluidity index (FI) and generally showed a higher survival than the parental strain. Surprisingly, its resistance to airborne stress was so strong that its viability was fully maintained even after airborne suspension at 40% RH, a harsh RH level to bacterial survival. Moreover, E. coli cultured at 20 °C with a higher FI than that at 30 and 37 °C generally had a lower survival after aerosolization and airborne suspension. Unlike FI, individual fatty acid and cyclopropane fatty acid composition did not relate to the bacterial survival. Lipid peroxidation of the membrane was undetected in all the bacteria. Membrane fluidity plays a stronger role in determining the bacteria survival during airborne suspension than during aerosolization. Certain relationships between FI and bacteria survival were identified, which could help predict the transmission of bacteria under different conditions.

  12. Water droplets' internal fluidity during horizontal motion on a superhydrophobic surface with an external electric field.

    Science.gov (United States)

    Sakai, Munetoshi; Kono, Hiroki; Nakajima, Akira; Sakai, Hideki; Abe, Masahiko; Fujishima, Akira

    2010-02-02

    On a superhydrophobic surface, the internal fluidity of water droplets with different volumes (15, 30 microL) and their horizontal motion in an external electric field were evaluated using particle image velocimetry (PIV). For driving of water droplets on a superhydrophobic coating between parallel electrodes, it was important to place them at appropriate positions. Droplets moved with slipping. Small droplets showed deformation that is more remarkable. Results show that the dielectrophoretic force induced the initial droplet motion and that the surface potential gradient drove the droplets after reaching the middle point between electrodes.

  13. Influence of zinc deficiency on cell-membrane fluidity in Jurkat, 3T3 and IMR-32 cells.

    Science.gov (United States)

    Verstraeten, Sandra V; Zago, M Paola; MacKenzie, Gerardo G; Keen, Carl L; Oteiza, Patricia I

    2004-01-01

    We investigated whether zinc deficiency can affect plasma membrane rheology. Three cell lines, human leukaemia T-cells (Jurkat), rat fibroblasts (3T3) and human neuroblastoma cells (IMR-32), were cultured for 48 h in control medium, in zinc-deficient medium (1.5 microM zinc; 1.5 Zn), or in the zinc-deficient medium supplemented with 15 microM zinc (15 Zn). The number of viable cells was lower in the 1.5 Zn group than in the control and 15 Zn groups. The frequency of apoptosis was higher in the 1.5 Zn group than in the control and 15 Zn groups. Membrane fluidity was evaluated using the 6-(9-anthroyloxy)stearic acid and 16-(9-anthroyloxy)palmitic acid probes. Membrane fluidity was higher in 1.5 Zn cells than in the control cells; no differences were observed between control cells and 15 Zn cells. The effect of zinc deficiency on membrane fluidity at the water/lipid interface was associated with a higher phosphatidylserine externalization. The higher membrane fluidity in the hydrophobic region of the bilayer was correlated with a lower content of arachidonic acid. We suggest that the increased fluidity of the membrane secondary to zinc deficiency is in part due to a decrease in arachidonic acid content and the apoptosis-related changes in phosphatidylserine distribution. PMID:14629198

  14. [The effects of electromagnetic pulse on fluidity and lipid peroxidation of mitochondrial membrane].

    Science.gov (United States)

    Wang, Changzhen; Cong, Jianbo; Xian, Hong; Cao, Xiaozhe; Sun, Cunpu; Wu, Ke

    2002-08-01

    To study the effects of intense electromagnetic pulse(EMP) on the biological effects of mitochondrial membrane. Rat liver mitochondrial suspension was exposed to EMP at 60 kV/m level. The changes of membrane lipid fluidity and membrane protein mobility were detected by ESR and spin label technique. Malondialdehyde(MDA) was detected by spectrophotometer. The mobility of membrane protein decreased significantly(P < 0.05). Correlation time (tau c) of control group was (0.501 +/- 0.077) x 10(-9)s, and tau c of EMP group was (0.594 +/- 0.049) x 10(-9)s, indicating that the mobility of protein was restricted. The fluidity of mitochondrial membrane increased significantly(P < 0.05) at the same time. Order parameter(S) of mitochondrial membrane lipid in control group was 0.63 +/- 0.01, while S of EMP group was 0.61 +/- 0.01(P < 0.05). MDA decreased significantly. The mobility and lipid peroxidation of mitochondrial membrane may be disturbed after EMP exposure.

  15. Numerical analysis of the thermal and fluid flow phenomena of the fluidity test

    Directory of Open Access Journals (Sweden)

    L. Sowa

    2010-01-01

    Full Text Available In the paper, two mathematical and numerical models of the metals alloy solidification in the cylindrical channel of fluidity test, which take into account the process of filling the mould cavity with molten metal, has been proposed. Velocity and pressure fields were obtained by solving the momentum equations and the continuity equation, while the thermal fields were obtained by solving the heat conduction equation containing the convection term. Next, the numerical analysis of the solidification process of metals alloy in the cylindrical mould channel has been made. In the models one takes into account interdependence of the thermal and dynamical phenomena. Coupling of the heat transfer and fluid flow phenomena has been taken into consideration by the changes of the fluidity function and thermophysical parameters of alloy with respect to the temperature. The influence of the velocity or the pressure and the temperature of metal pouring on the solid phase growth kinetics were estimated. The problem has been solved by the finite element method.

  16. Plasma membrane order and fluidity are diversely triggered by elicitors of plant defence.

    Science.gov (United States)

    Sandor, Roman; Der, Christophe; Grosjean, Kevin; Anca, Iulia; Noirot, Elodie; Leborgne-Castel, Nathalie; Lochman, Jan; Simon-Plas, Françoise; Gerbeau-Pissot, Patricia

    2016-09-01

    Although plants are exposed to a great number of pathogens, they usually defend themselves by triggering mechanisms able to limit disease development. Alongside signalling events common to most such incompatible interactions, modifications of plasma membrane (PM) physical properties could be new players in the cell transduction cascade. Different pairs of elicitors (cryptogein, oligogalacturonides, and flagellin) and plant cells (tobacco and Arabidopsis) were used to address the issue of possible modifications of plant PM biophysical properties induced by elicitors and their links to other events of the defence signalling cascade. We observed an increase of PM order whatever the elicitor/plant cell pair used, provided that a signalling cascade was induced. Such membrane modification is dependent on the NADPH oxidase-mediated reactive oxygen species production. Moreover, cryptogein, which is the sole elicitor able to trap sterols, is also the only one able to trigger an increase in PM fluidity. The use of cryptogein variants with altered sterol-binding properties confirms the strong correlation between sterol removal from the PM and PM fluidity enhancement. These results propose PM dynamics as a player in early signalling processes triggered by elicitors of plant defence. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  17. Lipid engineering reveals regulatory roles for membrane fluidity in yeast flocculation and oxygen-limited growth

    Energy Technology Data Exchange (ETDEWEB)

    Degreif, Daniel [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Technical Univ. of Darmstadt (Germany); de Rond, Tristan [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States); Bertl, Adam [Technical Univ. of Darmstadt (Germany); Keasling, Jay D. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Technical Univ. of Denmark, Lyngby (Denmark); Budin, Itay [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Univ. of California, Berkeley, CA (United States)

    2017-03-18

    Cells modulate lipid metabolism in order to maintain membrane homeostasis. In this paper, we use a metabolic engineering approach to manipulate the stoichiometry of fatty acid unsaturation, a regulator of cell membrane fluidity, in Saccharomyces cerevisiae. Unexpectedly, reduced lipid unsaturation triggered cell-cell adhesion (flocculation), a phenomenon characteristic of industrial yeast but uncommon in laboratory strains. We find that ER lipid saturation sensors induce expression of FLO1 – encoding a cell wall polysaccharide binding protein – independently of its canonical regulator. In wild-type cells, Flo1p-dependent flocculation occurs under oxygen-limited growth, which reduces unsaturated lipid synthesis and thus serves as the environmental trigger for flocculation. Transcriptional analysis shows that FLO1 is one of the most highly induced genes in response to changes in lipid unsaturation, and that the set of membrane fluidity-sensitive genes is globally activated as part of the cell's long-term response to hypoxia during fermentation. Finally, our results show how the lipid homeostasis machinery of budding yeast is adapted to carry out a broad response to an environmental stimulus important in biotechnology.

  18. Not changes in membrane fluidity but proteotoxic stress triggers heat shock protein expression in Chlamydomonas reinhardtii.

    Science.gov (United States)

    Rütgers, Mark; Muranaka, Ligia Segatto; Schulz-Raffelt, Miriam; Thoms, Sylvia; Schurig, Juliane; Willmund, Felix; Schroda, Michael

    2017-12-01

    A conserved reaction of all organisms exposed to heat stress is an increased expression of heat shock proteins (HSPs). Several studies have proposed that HSP expression in heat-stressed plant cells is triggered by an increased fluidity of the plasma membrane. Among the main lines of evidence in support of this model are as follows: (a) the degree of membrane lipid saturation was higher in cells grown at elevated temperatures and correlated with a lower amplitude of HSP expression upon a temperature upshift, (b) membrane fluidizers induce HSP expression at physiological temperatures, and (c) membrane rigidifier dimethylsulfoxide dampens heat-induced HSP expression. Here, we tested whether this holds also for Chlamydomonas reinhardtii. We show that heat-induced HSP expression in cells grown at elevated temperatures was reduced because they already contained elevated levels of cytosolic HSP70A/90A that apparently act as negative regulators of heat shock factor 1. We find that membrane rigidifier dimethylsulfoxide impaired translation under heat stress conditions and that membrane fluidizer benzyl alcohol not only induced HSP expression but also caused protein aggregation. These findings support the classical model for the cytosolic unfolded protein response, according to which HSP expression is induced by the accumulation of unfolded proteins. Hence, the membrane fluidity model should be reconsidered. © 2017 John Wiley & Sons Ltd.

  19. Religion and Sexual Identity Fluidity in a National Three-Wave Panel of U.S. Adults.

    Science.gov (United States)

    Scheitle, Christopher P; Wolf, Julia Kay

    2018-05-01

    Research has shown that cross-sectional estimates of sexual identities overlook fluidity in those identities. Research has also shown that social factors, such as competing identities, can influence sexual identity fluidity. We contributed to this literature in two ways. First, we utilized a representative panel of US adults (N = 1034) surveyed in 2010, 2012, and 2014 by the General Social Survey. The addition of a third observation allowed us to examine more complexity in sexual identity fluidity. We found that 2.40% of US adults reported at least one change in sexual identity across the 4 years, with 1.59% reporting one change and 0.81% reporting two changes. Our second contribution came from examining the role of religion, as past research has suggested that religion can destabilize and prolong sexual identity development. We found that lesbian or gay individuals (N = 17), bisexuals (N = 15), and females (N = 585) showed more sexual identity fluidity compared to heterosexuals (N = 1003) and males (N = 450), respectively. Marital status, age, race, and education did not have significant associations with sexual identity fluidity. Regarding the role of religion, we found that participants identifying as more religious in Wave 1 showed more fluidity in sexual identity across later observations. Further analysis showed that higher levels of religiosity make it more likely that lesbian or gay individuals will be fluid in sexual identity, but this is not the case for heterosexual individuals. This finding reinforces past qualitative research that has suggested that religion can extend or complicate sexual minorities' identity development.

  20. Inverse shear viscosity (fluidity) scaled with melting point properties: Almost 'universal' behaviour of heavier alkalis

    International Nuclear Information System (INIS)

    Tankeshwar, K.; March, N.H.

    1997-07-01

    Some numerical considerations relating to the potential of mean force at the melting point of Rb metal are first presented, which argue against the existence of a well defined activation energy for the shear viscosity of this liquid. Therefore, a scaling approach is developed, based on a well established formula for the viscosity η m of sp liquid metals at their melting points T m . This approach is shown to lead to an 'almost' universal plot of scaled fluidity η -1 η m against (T/T m ) 1/2 for the liquid alkali metals, excluding Li. This metal is anomalous because it is a strong scattering liquid, in marked contrast to the other alkali metals. (author). 9 refs, 3 figs, 1 tab

  1. Membrane Fluidity Changes, A Basic Mechanism of Interaction of Gravity with Cells?

    Science.gov (United States)

    Kohn, Florian; Hauslage, Jens; Hanke, Wolfgang

    2017-10-01

    All life on earth has been established under conditions of stable gravity of 1g. Nevertheless, in numerous experiments the direct gravity dependence of biological processes has been shown on all levels of organization, from single molecules to humans. According to the underlying mechanisms a variety of questions, especially about gravity sensation of single cells without specialized organelles or structures for gravity sensing is being still open. Biological cell membranes are complex structures containing mainly lipids and proteins. Functional aspects of such membranes are usually attributed to membrane integral proteins. This is also correct for the gravity dependence of cells and organisms which is well accepted since long for a wide range of biological systems. However, it is as well established that parameters of the lipid matrix are directly modifying the function of proteins. Thus, the question must be asked, whether, and how far plain lipid membranes are affected by gravity directly. In principle it can be said that up to recently no real basic mechanism for gravity perception in single cells has been presented or verified. However, it now has been shown that as a basic membrane parameter, membrane fluidity, is significantly dependent on gravity. This finding might deliver a real basic mechanism for gravity perception of living organisms on all scales. In this review we summarize older and more recent results to demonstrate that the finding of membrane fluidity being gravity dependent is consistent with a variety of published laboratory experiments. We additionally point out to the consequences of these recent results for research in the field life science under space condition.

  2. Increase of radiation damage to potassium-ion permeability in E. coli cells with decrease in membrane fluidity

    International Nuclear Information System (INIS)

    Suzuki, S.

    1980-01-01

    Membrane lipids of an auxotroph of E. coli requiring unsaturated fatty acid were manipulated by supplementing the growth medium with unsaturated fatty acids of different chain lengths and/or configurations, and the radiation damage to K + -permeability of the resulting modified cells was investigated in relation with factors influencing membrane fluidity, such as temperature and procaine. Radiation had greater effects on membranes supplemented with unsaturated fatty acids of the trans configuration with a longer chain than on those of the cis configuration with a shorter chain. Radiation damage also increased with decrease in temperature. Furthermore, procaine-treated membranes showed increased resistance to radiation. All these results indicate that the damage was affected by the physical character of membrane lipids and that it was greater in membranes with decreased fluidity. (author)

  3. Effects of minor scandium on as-cast microstructure, mechanical properties and casting fluidity of ZA84 magnesium alloy

    International Nuclear Information System (INIS)

    Pan Fusheng; Yang Mingbo; Cheng Liang

    2010-01-01

    The effects of minor Sc on the as-cast microstructure, mechanical properties and casting fluidity of the ZA84 magnesium alloy were investigated. The results indicate that the Mg 32 (Al,Zn) 49 phase in the ZA84 alloy is refined with the addition of 0.12-0.35 wt.% Sc, and the formation of the Mg 32 (Al,Zn) 49 phase is suppressed. An increase in Sc amount from 0.12 wt.% to 0.35 wt.% causes the morphology of the Mg 32 (Al,Zn) 49 phase to gradually change from coarse continuous and/or quasi-continuous net to relatively fine quasi-continuous and/or disconnected shapes. In addition, it is shown that the tensile and creep properties of the ZA84 alloy are improved, but the casting fluidity of the alloy is decreased with the addition of 0.12-0.35 wt.% Sc.

  4. "It Has No Color, It Has No Gender, It's Gender Bending": Gender and Sexuality Fluidity and Subversiveness in Drag Performance.

    Science.gov (United States)

    Egner, Justine; Maloney, Patricia

    2016-07-01

    Gender identity is a key question for drag performers. Previous research has shown a lack of consensus about the subversiveness and gender fluidity of drag performers. This article examines the question: How does the relationship between performers and their audience affect the subversive nature and gender representation of drag performers in this study? Furthermore, is this relationship complicated by sexuality? This study uses ethnographic and interview methods, examining experiences of 10 drag performers. Findings indicate mutuality in the relationship between performers and audience. The recursiveness of this relationship provides a constant feedback to the performers in their effort to displace the audience's previously held notions. The performers have fluid understandings of gender and sexuality, often presenting multiple genders in and out of drag. Interactions between performers and their audience indicate their belief in gender fluidity; moreover, the drag performers themselves desire to be subversive and gender and sexually fluid.

  5. Recycling of tailings from Korea Molybdenum Corporation as admixture for high-fluidity concrete.

    Science.gov (United States)

    Jung, Moon Young; Choi, Yun Wang; Jeong, Jae Gwon

    2011-01-01

    The main objective of this study is to develop an eco-friendly and a large recycling technique of flotation Tailings from korea (TK) from metal mines as construction materials such as admixtures for high-fluidity concrete (HFC). TK used in this study was obtained from the Korea Molybdenum Corporation in operation. TK was used as the alternative material to adjust flowability and viscosity of HFC in the form of powder agent which enables adjustment of concrete compressive strength. In this study, we have performed concrete rheological tests and concrete flowability tests to obtain the quality characteristics of TK for using as the admixture in producing HFC. The results indicated that the adequate mix ratio of cement to TK should be 8:2 (vol%). It is more effective to use the TK as admixture to control flowability, viscosity and strength of HFC than the normal concrete. It was found that TK could be recycled construction materials in bulk such as admixture for HFC, in terms of the economic and eco-friendly aspects.

  6. Enhanced fluidity liquid chromatography of inulin fructans using ternary solvent strength and selectivity gradients.

    Science.gov (United States)

    Bennett, Raffeal; Olesik, Susan V

    2018-01-25

    The value of exploring selectivity and solvent strength ternary gradients in enhanced fluidity liquid chromatography (EFLC) is demonstrated for the separation of inulin-type fructans from chicory. Commercial binary pump systems for supercritical fluid chromatography only allow for the implementation of ternary solvent strength gradients which can be restrictive for the separation of polar polymeric analytes. In this work, a custom system was designed to extend the capability of EFLC to allow tuning of selectivity or solvent strength in ternary gradients. Gradient profiles were evaluated using the Berridge function (RF 1 ), normalized resolution product (NRP), and gradient peak capacity (P c ). Selectivity gradients provided the separation of more analytes over time. The RF 1 function showed favor to selectivity gradients with comparable P c to that of solvent strength gradients. NRP did not strongly correlate with P c or RF 1 score. EFLC with the hydrophilic interaction chromatography, HILIC, separation mode was successfully employed to separate up to 47 fructan analytes in less than 25 min using a selectivity gradient. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Tolerance to chitosan by Trichoderma species is associated with low membrane fluidity.

    Science.gov (United States)

    Zavala-González, Ernesto A; Lopez-Moya, Federico; Aranda-Martinez, Almudena; Cruz-Valerio, Mayra; Lopez-Llorca, Luis Vicente; Ramírez-Lepe, Mario

    2016-07-01

    The effect of chitosan on growth of Trichoderma spp., a cosmopolitan genus widely exploited for their biocontrol properties was evaluated. Based on genotypic (ITS of 18S rDNA) characters, four isolates of Trichoderma were identified as T. pseudokoningii FLM16, T. citrinoviride FLM17, T. harzianum EZG47, and T. koningiopsis VSL185. Chitosan reduces radial growth of Trichoderma isolates in concentration-wise manner. T. koningiopsis VSL185 was the most chitosan tolerant isolate in all culture media amended with chitosan (0.5-2.0 mg ml(-1) ). Minimal Inhibitory Concentration (MIC) and Minimal Fungicidal Concentration (MFC) were determined showing that T. koningiopsis VSL185 displays higher chitosan tolerance with MIC value >2000 μg ml(-1) while for other Trichoderma isolates MIC values were around 10 μg ml(-1) . Finally, free fatty acid composition reveals that T. koningiopsis VSL185, chitosan tolerant isolate, displays lower linolenic acid (C18:3) content than chitosan sensitive Trichoderma isolates. Our findings suggest that low membrane fluidity is associated with chitosan tolerance in Trichoderma spp. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Radiation killing of E. coli K1060: role of membrane fluidity, hypothermia and local anaesthetics

    International Nuclear Information System (INIS)

    Yatvin, M.B.; Schmitz, B.J.; Dennis, W.H.

    1980-01-01

    The enhancement of killing by γ irradiation, which is seen when E. coliK1060 are cooled below the transition temperature of their membrane lipids, is blocked by procaine-HCl. These data are consistent with the hypothesis that increased killing associated with irradiation at 0 0 C is the result of membrane microviscosity increases, since procaine is known to fluidize membranes. A cooling enhancement ratio (c.e.r.) is defined as the ratio of radiation D 0 at 22 0 C to its value at 0 0 C. The c.e.r. for oxygen-bubbled cells is 1.5 and for nitrogen-bubbled cells is 2.1. In the presence of 25mM procaine the respective c.e.r. values are 1.08 and 1.29. The oxygen enhancement ratio (o.e.r.) at 22 0 C is 3.43 and at 0 0 C is 2.45. The addition of procaine does not change the o.e.r. Thus, the temperature effect on o.e.r. does not appear to be related to membrane fluidity. (author)

  9. Evidence that survival of γ-irradiated Escherichia coli is influenced by membrane fluidity

    International Nuclear Information System (INIS)

    Yatvin, M.B.

    1976-01-01

    Survival studies have been carried out on an Escherichia coli auxotroph (K-12 strain K1060) defective in both fatty acid degradation and in unsaturated fatty acid biosynthesis. Cultures were grown overnight in media supplemented with either oleic or linolenic acid, and γ-irradiated at two temperatures. Gas chromatography of total cellular fatty acids demonstrated marked differences in the compositions. In the bacteria grown in oleate, plamitate accounted for 35% and oleate 43%, whereas those grown in linolenate had no oleate but contained 56% palmitate and 35% linolenate. The loss (35%) in total DNA radioactivity from ( 3 H)TdR labelled cells after irradiation at room temperature or on ice, was essentially the same in bacteria grown with linoleic or oleic acid medium. The survival of linolenic substituted bacteria was altered little by irradiation at ice-bath temperature, but the oleic-grown bacteria were much more radiosensitive when irradiated and plated from the cold. The temperatures of the membrane phase transitions are such that at ice-bath temperature (approximately 3 to 5 0 C) only the membrane of the linolenate grown bacteria could possibly still be in the liquid (unorganized) state. The results therefore indicate that one of the factors influencing survival of irradiated bacteria may be membrane fluidity, and the membranes are an important factor in determining the extent of damage, 'repair' and ultimate survival in irradiated cells. (U.K.)

  10. Agarose Gel Electrophoresis Reveals Structural Fluidity of a Phage T3 DNA Packaging Intermediate

    Science.gov (United States)

    Serwer, Philip; Wright, Elena T.

    2012-01-01

    We find a new aspect of DNA packaging-associated structural fluidity for phage T3 capsids. The procedure is (1) glutaraldehyde cross-linking of in vivo DNA packaging intermediates for stabilization of structure and then (2) determining of effective radius by two-dimensional agarose gel electrophoresis (2d-AGE). The intermediates are capsids with incompletely packaged DNA (ipDNA) and without an external DNA segment; these intermediates are called ipDNA-capsids. We initially increase production of ipDNA-capsids by raising NaCl concentration during in vivo DNA packaging. By 2d-AGE, we find a new state of contracted shell for some particles of one previously identified ipDNA-capsid. The contracted shell-state is found when ipDNA length/mature DNA length (F) is above 0.17, but not at lower F. Some contracted-shell ipDNA-capsids have the phage tail; others do not. The contracted-shell ipDNA-capsids are explained by premature DNA maturation cleavage that makes accessible a contracted-shell intermediate of a cycle of the T3 DNA packaging motor. The analysis of ipDNA-capsids, rather than intermediates with uncleaved DNA, provides a simplifying strategy for a complete biochemical analysis of in vivo DNA packaging. PMID:22222979

  11. Agarose gel electrophoresis reveals structural fluidity of a phage T3 DNA packaging intermediate.

    Science.gov (United States)

    Serwer, Philip; Wright, Elena T

    2012-01-01

    We find a new aspect of DNA packaging-associated structural fluidity for phage T3 capsids. The procedure is (i) glutaraldehyde cross-linking of in vivo DNA packaging intermediates for the stabilization of structure and then (ii) determining effective radius by two-dimensional agarose gel electrophoresis (2D-AGE). The intermediates are capsids with incompletely packaged DNA (ipDNA) and without an external DNA segment; these intermediates are called ipDNA-capsids. We initially increase the production of ipDNA-capsids by raising NaCl concentration during in vivo DNA packaging. By 2D-AGE, we find a new state of contracted shell for some particles of one previously identified ipDNA-capsid. The contracted shell-state is found when the ipDNA length/mature DNA length (F) is above 0.17, but not at lower F. Some contracted-shell ipDNA-capsids have the phage tail; others do not. The contracted-shell ipDNA-capsids are explained by premature DNA maturation cleavage that makes accessible a contracted-shell intermediate of a cycle of the T3 DNA packaging motor. The analysis of ipDNA-capsids, rather than intermediates with uncleaved DNA, provides a simplifying strategy for a complete biochemical analysis of in vivo DNA packaging. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Bile salt-induced increases in duodenal brush-border membrane proton permeability, fluidity, and fragility

    International Nuclear Information System (INIS)

    Zhao, D.L.; Hirst, B.H.

    1990-01-01

    Rabbit duodenal brush-border membrane vesicles were treated in vitro with deoxycholate, glycodeoxycholate, or taurodeoxycholate. Intravesicular [14C]glucose space at equilibrium, 0.54 microliters/mg protein, was reduced by exposure to the three bile salts in a concentration (0.1-5.0 mM)-dependent manner, equatable with increased membrane fragility. Net proton permeability (Pnet), determined by acridine orange fluorescence quenching, was increased from 6.3 x 10(-4) cm/sec in untreated vesicles, by approximately 120, 150, and 170%, by treatment with bile salts at 0.1, 0.5 and 1.0 mM, respectively. The three bile salts were equipotent. The increases in membrane fragility and Pnet were not accompanied by significant increases in membrane fluidity, as assessed from steady-state and time-resolved diphenylhexatriene fluorescence anisotropy. The data demonstrate direct effects of bile salts on duodenal apical membrane fragility and proton permeability that are likely to be early events in bile salt-induced mucosal damage

  13. Comparison on Heat of Hydration between Current Concrete for NPP and High Fluidity Concrete including Pozzolan Powders

    International Nuclear Information System (INIS)

    Noh, Jea Myoung; Cho, Myung Sug

    2010-01-01

    Nuclear power plant (NPP) concrete structures are exposed to many construction factors that lower the quality of concrete due to densely packed reinforcements and heat of hydration since they are mostly constructed with mass concrete. The concrete currently being used in Korean NPPs is mixed with Type I cement and fly ash. However, there is a demand to improve the performance of concrete with reduced heat of hydration and superior constructability. Many advantages such as improving workability and durability of concrete and decreasing heat of hydration are introduced by replacing cement with pozzolan binders. Therefore, the manufacturing possibility of high fluidity concrete should be investigated through applying multi-component powders blended with pozzolan binders to the concrete structure of NPPs, while the researches on properties, characteristic of hydration, durability and long-term behavior of high fluidity concrete using multi-component cement should be carried out. High fluidity concrete which is made using portland cement and pozzlonan powders such as fly ash and blast furnace slag has better properties on heat of hydration than the concrete currently in use for NPPs

  14. Effect of reinforcement amount, mold temperature, superheat, and mold thickness on fluidity of in-situ Al-Mg2Si composites

    Directory of Open Access Journals (Sweden)

    Reza Vatankhah Barenji

    2018-01-01

    Full Text Available In the present study, the effects of mold temperature, superheat, mold thickness, and Mg2Si amount on the fluidity of the Al-Mg2Si as-cast in-situ composites were investigated using the mathematical models. Composites with different amounts of Mg2Si were fabricated, and the fluidity and microstructure of each were then analyzed. For this purpose, the experiments were designed using a central composite rotatable design, and the relationship between parameters and fluidity were developed using the response surface method. In addition, optical and scanning electron microscopes were used for microstructural observation. The ANOVA shows that the mathematical models can predict the fluidity accurately. The results show that by increasing the mold temperature from 25 °C to 200 °C, superheat from 50 °C to 250 °C, and thickness from 3 mm to 12 mm, the fluidity of the composites decreases, where the mold thickness is more effective than other factors. In addition, the higher amounts of Mg2Si in the range from 15wt.% to 25wt.% lead to the lower fluidity of the composites. For example, when the mold temperature, superheat, and thickness are respectively 100 °C, 150 °C, and 7 mm, the fluidity length is changed in the range of 11.9 cm to 15.3 cm. By increasing the amount of Mg2Si, the morphology of the primary Mg2Si becomes irregular and the size of primary Mg2Si is increased. Moreover, the change of solidification mode from skin to pasty mode is the most noticeable microstructural effect on the fluidity.

  15. Age-dependent effects of He-Ne laser irradiation on the membrane fluidity of human erythrocytes

    Science.gov (United States)

    Kovacs, Eugenia; Savopol, Tudor; Pologea-Moraru, Roxana; Makropoulou, Mersini I.; Serafetinides, Alexander A.

    1997-12-01

    The low power He-Ne laser radiation has been extensively used in past decades as medical device to relieve pain, accelerate wound healing as well as aiming beam in invisible laser beam in invisible laser beam applications. It is not known however if there are any secondary, undesirable effects of He-Ne laser radiation on the irradiated tissue. In this paper we investigate the changes induced in membrane fluidity of human erythrocyte during/upon the interaction with the He-Ne laser beam having the parameters currently used for target aiming in laser surgery.

  16. Evaluation of ionizing radiation effects on recycled polyamide-6 by infrared spectroscopy and measures of fluidity index

    International Nuclear Information System (INIS)

    Evora, Maria Cecilia; Goncalez, Odair Lelis

    2000-01-01

    In this work are presented partial results from a set of experiments and analyses performed at CTA and IPEN laboratories for the characterization of the polyamide-6, recycled and irradiated with a 1.5 MeV electron beam with a 500 kGy dose. The experimental determinations were carried out using infrared spectroscopy with Fourier transform (FTIR), in the medium infrared region (MIR) and in the far infrared region (FAR), to evaluate if exist significant changes in the infrared absorption region of the amide groups due to the polyamide irradiation. Characteristics relative to the measured fluidity index were used to evaluate the irradiated material crosslinking. (author)

  17. Effect of Growth Medium pH of Aeropyrum pernix on Structural Properties and Fluidity of Archaeosomes

    Directory of Open Access Journals (Sweden)

    Ajda Ota

    2012-01-01

    Full Text Available The influence of pH (6.0; 7.0; 8.0 of the growth medium of Aeropyrum pernix K1 on the structural organization and fluidity of archaeosomes prepared from a polar-lipid methanol fraction (PLMF was investigated using fluorescence anisotropy and electron paramagnetic resonance (EPR spectroscopy. Fluorescence anisotropy of the lipophilic fluorofore 1,6-diphenyl-1,3,5-hexatriene and empirical correlation time of the spin probe methylester of 5-doxylpalmitate revealed gradual changes with increasing temperature for the pH. A similar effect has been observed by using the trimethylammonium-6-diphenyl-1,3,5-hexatriene, although the temperature changes were much smaller. As the fluorescence steady-state anisotropy and the empirical correlation time obtained directly from the EPR spectra alone did not provide detailed structural information, the EPR spectra were analysed by computer simulation. This analysis showed that the archaeosome membranes are heterogeneous and composed of several regions with different modes of spin-probe motion at temperatures below 70°C. At higher temperatures, these membranes become more homogeneous and can be described by only one spectral component. Both methods indicate that the pH of the growth medium of A. pernix does not significantly influence its average membrane fluidity. These results are in accordance with TLC analysis of isolated lipids, which show no significant differences between PLMF isolated from A. pernix grown in medium with different pH.

  18. Increased fluidity and oxidation of malarial lipoproteins: relation with severity and induction of endothelial expression of adhesion molecules

    Directory of Open Access Journals (Sweden)

    Looareesuwan Sornchai

    2004-06-01

    Full Text Available Abstract Introduction Oxidative stress has been demonstrated in malaria. The potential oxidative modification of lipoproteins derived from malaria patients was studied. These oxidized lipids may have role in pathogenesis of malaria. Method The plasma lipid profile and existence of oxidized forms of very low density lipoprotein (VLDL, low density lipoprotein (LDL and high density lipoprotein (HDL were investigated in malaria (17 mild and 24 severe patients and 37 control subjects. Thiobarbituric acid reactive substances (TBARs, conjugated dienes, tryptophan fluorescence and fluidity of lipoproteins were determined as markers of oxidation. The biological effect of malarial lipoproteins was assessed by the expression of adhesion molecules on endothelial cells. Results Malarial lipoproteins had decreased cholesterol (except in VLDL and phospholipid. The triglyceride levels were unchanged. The cholesterol/phospholipid ratio of LDL was decreased in malaria, but increased in VLDL and HDL. TBARs and conjugate dienes were increased in malarial lipoproteins, while the tryptophan fluorescence was decreased. The fluidity of lipoproteins was increased in malaria. These indicated the presence of oxidized lipoproteins in malaria by which the degree of oxidation was correlated with severity. Of three lipoproteins from malarial patients, LDL displayed the most pronounced oxidative modification. In addition, oxidized LDL from malaria patients increased endothelial expression of adhesion molecules. Conclusion In malaria, the lipoproteins are oxidatively modified, and the degree of oxidation is related with severity. Oxidized LDL from malarial patients increases the endothelial expression of adhesion molecules. These suggest the role of oxidized lipoproteins, especially LDL, on the pathogenesis of disease.

  19. Factors determining Staphylococcus aureus susceptibility to photoantimicrobial chemotherapy: RsbU activity, staphyloxanthin level and membrane fluidity.

    Directory of Open Access Journals (Sweden)

    Monika Kossakowska-Zwierucho

    2016-07-01

    Full Text Available Photoantimicrobial chemotherapy (PACT constitutes a particular type of stress condition, in which bacterial cells induce a pleiotropic and as yet unexplored effect. In light of this, the key master regulators are of putative significance to the overall phototoxic outcome. In Staphylococcus aureus, the alternative sigma factor σB controls the expression of genes involved in the response to environmental stress. We show that aberration of any sigB operon genes in S. aureus USA300 isogenic mutants causes a pronounced sensitization (>5 log10 reduction in CFU drop to PACT with selected photosensitizers, namely protoporphyrin diarginate, zinc phthalocyanine and rose bengal. This effect is partly due to aberration-coupled staphyloxanthin synthesis inhibition. We identified frequent mutations in RsbU, a σB activator, in PACT-vulnerable clinical isolates of S. aureus, resulting in σB activity impairment. Locations of significant changes in protein structure (IS256 insertion, early STOP codon occurrence, substitutions A230T and A276D were shown in a theoretical model of S. aureus RsbU. As a phenotypic hallmark of PACT-vulnerable S. aureus strains, we observed an increased fluidity of bacterial cell membrane, which is a result of staphyloxanthin content and other yet unidentified factors. Our research indicates σB as a promising target of adjunctive antimicrobial therapy and suggests that enhanced cell membrane fluidity may be an adjuvant strategy in photoantimicrobial chemotherapy.

  20. Coal lithotypes before and after saturation with CO2; insights from micro- and mesoporosity, fluidity, and functional group distribution

    Science.gov (United States)

    Mastalerz, Maria; Drobniak, A.; Walker, R.; Morse, D.

    2010-01-01

    Four lithotypes, vitrain, bright clarain, clarain, and fusain, were hand-picked from the core of the Pennsylvanian Springfield Coal Member (Petersburg Formation) in Illinois. These lithotypes were analyzed petrographically and for meso- and micropore characteristics, functional group distribution using FTIR techniques, and fluidity. High-pressure CO2 adsorption isotherm analyses of these lithotypes were performed and, subsequently, all samples were reanalyzed in order to investigate the effects of CO2. After the high-pressure adsorption isotherm analysis was conducted and the samples were reanalyzed, there was a decrease in BET surface area for vitrain from 31.5m2/g in the original sample to 28.5m2/g, as determined by low-pressure nitrogen adsorption. Bright clarain and clarain recorded a minimal decrease in BET surface area, whereas for fusain there was an increase from 6.6m2/g to 7.9m2/g. Using low-pressure CO2 adsorption techniques, a small decrease in the quantity of the adsorbed CO2 is recorded for vitrain and bright clarain, no difference is observed for clarain, and there is an increase in the quantity of the adsorbed CO2 for fusain. Comparison of the FTIR spectra before and after CO2 injection for all lithotypes showed no differences with respect to functional group distribution, testifying against chemical nature of CO2 adsorption. Gieseler plastometry shows that: 1) softening temperature is higher for the post-CO2 sample (389.5??C vs. 386??C); 2) solidification temperature is lower for the post-CO2 sample (443.5??C vs. 451??C); and 3) the maximum fluidity is significantly lower for the post-CO2 sample (4 ddpm vs. 14 ddpm). ?? 2010 Elsevier B.V.

  1. Fluidity of the dietary fatty acid profile and risk of coronary heart disease and ischemic stroke: Results from the EPIC-Netherlands cohort study.

    Science.gov (United States)

    Sluijs, I; Praagman, J; Boer, J M A; Verschuren, W M M; van der Schouw, Y T

    2017-09-01

    The fluidity of dietary fatty acids consumed has been suggested to inversely affect coronary heart disease (CHD) risk. Lipophilic index (LI) represents overall fluidity of the dietary fatty acid profile. Lipophilic load (LL) represents a combination of overall fluidity and absolute intake of dietary fatty acids. We investigated the relations of dietary LI and LL with risk of CHD and ischemic stroke (iStroke). We used data from the prospective EPIC-NL study, including 36,520 participants aged 20-70 years. LI and LL were calculated using dietary intake data estimated with a validated FFQ. Incident CHD (n = 2348) and iStroke (n = 479) cases were obtained through linkage to national registers during 15 years follow-up. LI and LL were not associated with CHD risk (HRs highest-versus-lowest-quartiles : 0.93 [95%CI: 0.83, 1.04], and 0.92 [95%CI: 0.79, 1.07], respectively), and neither with iStroke risk (HRs 1.15 (95%CI: 0.89, 1.48), and 0.98 (95%CI: 0.70, 1.38), respectively). Original fatty acid classes (SFA, MUFA and PUFA), and LI and LL stratified by these fatty acid classes, were overall not related to CHD and ischemic stroke either. In this Dutch population, neither the overall fluidity of the dietary fatty acid profile (LI), nor the combined fluidity and amount of fatty acids consumed (LL) were related to CHD or iStroke risk. Dietary LI and LL may have limited added value above original fatty acid classes and food sources in establishing the relation of fatty acid consumption with CVD. Copyright © 2017 The Italian Society of Diabetology, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition, and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. All rights reserved.

  2. Membrane fatty acid composition and fluidity are involved in the resistance to freezing of Lactobacillus buchneri R1102 and Bifidobacterium longum R0175.

    Science.gov (United States)

    Louesdon, Séverine; Charlot-Rougé, Séverine; Tourdot-Maréchal, Raphaëlle; Bouix, Marielle; Béal, Catherine

    2015-03-01

    Determinations of membrane fatty acid composition and fluidity were used together with acidification activity and viability measurements to characterize the physiological state after freezing of Lactobacillus buchneri R1102 and Bifidobacterium longum R0175 cells harvested in the exponential and stationary growth phases. For both strains, lower membrane fluidity was achieved in cells harvested in the stationary growth phase. This change was linked to a lower unsaturated-to-saturated fatty acid ratio for both strains and a higher cyclic-to-saturated fatty acid ratio for L. buchneri R1102 alone. These membrane properties were linked to survival and to maintenance of acidification activity of the cells after freezing, which differed according to the strain and the growth phase. Survival of B. longum R0175 was increased by 10% in cells with low membrane fluidity and high relative saturated fatty acid contents, without any change in acidification activity. Acidification activity was more degraded (70 min) in L. buchneri R1102 cells displaying low membrane fluidity and high saturated and cyclic fatty acid levels. Finally, this study showed that membrane modifications induced by the growth phase differed among bacterial strains in terms of composition. By lowering membrane fluidity, these modifications could be beneficial for survival of B. longum R0175 during the freezing process but detrimental for maintenance of acidification activity of L. buchneri R1102. © 2014 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  3. FLUIDITY SPEECH FORMATION AS A QUALITATIVE CHARACTERISTIC OF THE ORAL STATEMENT OF PRESCHOOL AGE CHILDREN WITH STUTTER

    Directory of Open Access Journals (Sweden)

    E. A. Borisova

    2014-01-01

    Full Text Available The research objective is to disclose the subject matter of speech therapy work focused on fluidity speech formation of preschool age children, suffering stutter. Stutter is a difficult disorder of articulation organs suchthat the tempo-rhythmical organisation of statements is distressed that leads to defects and failures of dialogue system, negatively influences on individual development of the child; more specifically it generates the mental stratifications, specific features of emotional-volitional sphere, and causes undesirable qualities ofcharacter such as shyness, indecision, isolation, negativism. The author notes that the problem of early stutter correction among junior preschool-aged children considered as topical and immediate issue. Methods. Concerning the clinical, physiological, psychological and psychologic-pedagogical positions, the author summarizes theoretical framework; an experimentally-practical approbation of an author's method of speech fluidity and stutter abolition of preschool children is described. Stage-by-stage process of correction,spontaneous and non-convulsive speech formation: 1. restraint mode application in order to decrease incorrect verbal output; 2. training exercises to long phonatory and speech expiration; 3. development of coordination and movements rhythm helping to pronounce words and phrases; 4. formation of situational speech, at first consisted of short sentences, then passing to long ones; 5. training to coherent text statements. The research demonstrates data analyses of postexperimental diagnostic examination of stuttering preschool children, proving the efficiency of the author’s applied method. Scientific novelty. The research findings demonstrate a specific approach to correction and stutter abolition of preschool children. Proposed author’s approach consists of complementary to each other directions of speech therapy work which are combines in the following way: coherent speech

  4. Variations in daily intakes of myristic and alpha-linolenic acids in sn-2 position modify lipid profile and red blood cell membrane fluidity.

    Science.gov (United States)

    Dabadie, Henry; Motta, Claude; Peuchant, Evelyne; LeRuyet, Pascale; Mendy, François

    2006-08-01

    The present study evaluated the effects of moderate intakes of myristic acid (MA), at 1.2% and 1.8% of total energy (TE), associated with a 0.9% TE intake of alpha-linolenic acid (ALA) on lipid and fatty acid profiles and red blood cell membrane fluidity. Twenty-nine monks without dyslipidaemia were enrolled in a 1-year nutritional study in which two experimental diets were tested for 3 months each: diet 1, MA 1.2 % and ALA 0.9%; diet 2, MA 1.8% and ALA 0.9%. A control diet (MA 1.2%, ALA 0.4%) was given 3 months before diets 1 and 2. Thus, two different levels of MA (1.2%, 1.8%) and ALA (0.4%, 0.9%) were tested. Intakes of other fatty acids were at recommended levels. Samples were obtained on completion of all three diets. For fluidity analysis, the red blood cells were labelled with 16-doxylstearate and the probe incorporated the membrane where relaxation-correlation time was calculated. Diet 1 was associated with a decrease in total cholesterol, in LDL-cholesterol, in triacylglycerols and in the ratio of total to HDL-cholesterol; ALA and EPA levels were increased in both phospholipids and cholesterol esters. Diet 2 was associated with a decrease in triacylglycerols and in the ratios of total to HDL-cholesterol and of triacylglycerols to HDL-cholesterol, and with an increase in HDL-cholesterol; EPA levels were decreased in phospholipids and cholesterol esters. Red blood cell membrane fluidity was increased in both diets (Pdiet 1, mainly in the oldest subjects. Intakes of myristic acid (1.2%TE) and ALA (0.9%TE), both mainly in the sn-2 position, were associated with favourable lipid and n-3 long-chain fatty acid profiles. These beneficial effects coexisted with particularly high membrane fluidity, especially among the oldest subjects.

  5. Combination of 1H nuclear magnetic resonance spectroscopy and principal component analysis to evaluate the lipid fluidity of flutamide-encapsulated lipid nanoemulsions.

    Science.gov (United States)

    Takegami, Shigehiko; Ueyama, Keita; Konishi, Atsuko; Kitade, Tatsuya

    2018-06-06

    The lipid fluidity of various lipid nanoemulsions (LNEs) without and with flutamide (FT) and containing one of two neutral lipids, one of four phosphatidylcholines as a surfactant, and sodium palmitate as a cosurfactant was investigated by the combination of 1 H nuclear magnetic resonance (NMR) spectroscopy and principal component analysis (PCA). In the 1 H NMR spectra, the peaks from the methylene groups of the neutral lipids and surfactants for all LNE preparations showed downfield shifts with increasing temperature from 20 to 60 °C. PCA was applied to the 1 H NMR spectral data obtained for the LNEs. The PCA resulted in a model in which the first two principal components (PCs) extracted 88% of the total spectral variation; the first PC (PC-1) axis and second PC (PC-2) axis accounted for 73 and 15%, respectively, of the total spectral variation. The Score-1 values for PC-1 plotted against temperature revealed the existence of two clusters, which were defined by the neutral lipid of the LNE preparations. Meanwhile, the Score-2 values decreased with rising temperature and reflected the increase in lipid fluidity of each LNE preparation, consistent with fluorescence anisotropy measurements. In addition, the changes of Score-2 values with temperature for LNE preparations with FT were smaller than those for LNE preparations without FT. This indicates that FT encapsulated in LNE particles markedly suppressed the increase in lipid fluidity of LNE particles with rising temperature. Thus, PCA of 1 H NMR spectra will become a powerful tool to analyze the lipid fluidity of lipid nanoparticles. Graphical abstract ᅟ.

  6. Quality control of Photosystem II: the mechanisms for avoidance and tolerance of light and heat stresses are closely linked to membrane fluidity of the thylakoids

    Directory of Open Access Journals (Sweden)

    Yasusi Yamamoto

    2016-08-01

    Full Text Available When oxygenic photosynthetic organisms are exposed to excessive light and/or heat, Photosystem II is damaged and electron transport is blocked. In these events, reactive oxygen species, endogenous radicals and lipid peroxidation products generated by photochemical reaction and/or heat cause the damage. Regarding light stress, plants first dissipate excessive light energy captured by light-harvesting chlorophyll protein complexes as heat to avoid the hazards, but once light stress is unavoidable, they tolerate the stress by concentrating damage in a particular protein in photosystem II, i.e. the reaction-center binding D1 protein of Photosystem II. The damaged D1 is removed by specific proteases and replaced with a new copy produced through de novo synthesis (reversible photoinhibition. When light intensity becomes extremely high, irreversible aggregation of D1 occurs and thereby D1 turnover is prevented. Once the aggregated products accumulate in Photosystem II complexes, removal of them by proteases is difficult, and irreversible inhibition of Photosystem II takes place (irreversible photoinhibition. Important is that various aspects of both the reversible and irreversible photoinhibition are highly dependent on the membrane fluidity of the thylakoids. Heat stress-induced inactivation of photosystem II is an irreversible process, which may be also affected by the fluidity of the thylakoid membranes. Here I describe why the membrane fluidity is a key to regulate the avoidance and tolerance of Photosystem II on environmental stresses.

  7. Growth and membrane fluidity of food-borne pathogen Listeria monocytogenes in the presence of weak acid preservatives and hydrochloric acid

    Directory of Open Access Journals (Sweden)

    Ioannis eDiakogiannis

    2013-06-01

    Full Text Available This study addresses a major issue in microbial food safety, the elucidation of correlations between acid stress and changes in membrane fluidity of the pathogen Listeria monocytogenes. In order to assess the possible role that membrane fluidity changes play in L. monocytogenes tolerance to antimicrobial acids (acetic, lactic, hydrochloric acid at low pH or benzoic acid at neutral pH, the growth of the bacterium and the gel-to-liquid crystalline transition temperature point (Tm of cellular lipids of each adapted culture was measured and compared with unexposed cells. The Tm of extracted lipids was measured by Differential Scanning Calorimetry (DSC. A trend of increasing Tm values but not of equal extent was observed upon acid tolerance for all samples and this increase is not directly proportional to each acid antibacterial action. The smallest increase in Tm value was observed in the presence of lactic acid, which presented the highest antibacterial action. In the presence of acids with high antibacterial action such as acetic, hydrochloric acid or low antibacterial action such as benzoic acid, increased Tm values were measured. The Tm changes of lipids were also correlated with our previous data about fatty acid changes to acid adaptation. The results imply that the fatty acid changes are not the sole adaptation mechanism for decreased membrane fluidity (increased Tm. Therefore, this study indicates the importance of conducting an in-depth structural study on how acids commonly used in food systems affect the composition of individual cellular membrane lipid molecules.

  8. Growth, fatty acid profile in major lipid classes and lipid fluidity of Aurantiochytrium mangrovei SK-02 As a function of growth temperature.

    Science.gov (United States)

    Chodchoey, Kanokwan; Verduyn, Cornelis

    2012-01-01

    Aurantiochytrium mangrovei Sk-02 was grown in a medium containing glucose (40 g/l), yeast extract (10 g/L) and sea salts (15 g/L) at temperatures ranging from 12 to 35°C. The fastest growth (µmax= 0.15 h(-1)) and highest fatty acid content of 415 mg/g-dry cell weight were found in the cells grown at 30°C. However, the cells grown at 12°C showed the highest percentage of polyunsaturated fatty acid (PUFA) (48.6% of total fatty acid). The percentage of docosahexaenoic acid (DHA) and pentadecanoic acid (C15:0) decreased with an increase in the growth temperature, whereas, palmitic acid (C16:0), stearic acid (C18:0) and DPA (C22:5n6) increased with an increase in the growth temperature. The composition of the major lipid class (%w/w) was slightly affected by the growth temperature. The fluidity of the organelle membrane or intracellular lipid (by DPH measurement) decreased with an increase in the growth temperatures, while the plasma membrane fluidity (by TMA-DPH measurement) could still maintain its fluidity in a wide range of temperatures (15 - 37°C). Furthermore, the distribution of DHA was found to be higher (36 - 54%) in phospholipid (PL) as compared to neutral lipid (NL) (20 - 41%).

  9. F2α-isoprostane, Na+-K+ ATPase and membrane fluidity of placental syncytiotrophoblast cell in preeclamptic women with vitamin E supplementation

    Directory of Open Access Journals (Sweden)

    Franciscus D. Suyatna

    2012-11-01

    Full Text Available Background: The aim of our study was to analyze F2α-isoprostane level, Na+-K+ ATPase activity and placental syncytiotrophoblast cell membrane fluidity in preeclamptic women who received vitamin E supplementation.Methods: The study was conducted between September 2003 and February 2005 at Budi Kemuliaan Maternity Hospital, Central Jakarta. Samples were 6 preeclamptic women with vitamin E supplementation, 6 preeclamptic women without vitamin E supplementation and 6 normal pregnant women. The dose of vitamin E was 200 mg daily. F2α-isoprostane was measured with ELISA reader at λ of 450 nm. Cell membrane fluidity was measured by comparing the molar ratio of total cholesterol and cell membrane phospholipid concentration. The cholesterol was measured by Modular C800 using Roche reagent. Phospholipid was measured by Shimadzu RF5301PC spectrofluorometer (excitation 267 nm, emission 307 nm. Na+-K+ ATPase activity was inhibited by ouabain. Pi production was measured with Fiske and Subbarow method using spectrophotometer at λ of 660 nm. Data was analyzed using F test with one-way ANOVA.Results: Vitamin E supplementation in preeclamptic women decreased the oxidative stress, indicated by significantly lower level of F2α-isoprostane compared to those without vitamin E (26.72 ± 11.21 vs 41.85 ± 7.09 ng/mL, respectively, p = 0.017. Membrane fluidity in syncytiotrophoblast cell of preeclampsia with vitamin E group was maintained at 0.39 ± 0.08 while in those without vitamin E was 0.53 ± 0.14 (p = 0.04. Na+-K+ ATPase activity in syncytiotrophoblast cell membrane was not affected by vitamin E (p = 0.915.Conclusion: Vitamin E supplementation in preeclamptic women decreases F2α-isoprostane level and maintains cell membrane fluidity of syncytiotrophoblast cells; however, it does not increase Na+-K+ ATPase enzyme activity. (Med J Indones. 2012;21:225-9Keywords: F2α-isoprostane, membrane fluidity, Na+-K+ ATPase, preeclampsia, vitamin E

  10. Effect of Ring Size in ω-Alicyclic Fatty Acids on the Structural and Dynamical Properties Associated with Fluidity in Lipid Bilayers.

    Science.gov (United States)

    Poger, David; Mark, Alan E

    2015-10-27

    Fatty acids containing a terminal cyclic group such as cyclohexyl and cycloheptyl are commonly found in prokaryotic membranes, especially in those of thermo-acidophilic bacteria. These so-called ω-alicyclic fatty acids have been proposed to stabilize the membranes of bacteria by reducing the fluidity in membranes and increasing lipid packing and lipid chain order. In this article, molecular dynamics simulations are used to examine the effect of 3- to 7-membered cycloalkyl saturated and unsaturated (cyclopent-2-enyl and phenyl) rings in ω-alicyclic fatty acyl chains on the structure (lipid packing, lipid chain order, and fraction of gauche defects in the chains) and dynamics (lateral lipid diffusion) of a model lipid bilayer. It was found that ω-alicyclic chains in which the ring was saturated reduced lipid condensation and lowered chain order which would be associated with enhanced fluidity. However, this effect was limited. The lateral diffusion of the lipids diminished as the ring size increased. In particular, ω-cyclohexyl and ω-cycloheptyl acyl tails led to a decrease in lipid diffusion. In contrast, ω-alicyclic acyl chains that contain an unsaturated ring promoted membrane fluidity both in terms of changes in membrane structure and lipid diffusion. This may indicate that saturated and unsaturated terminal rings in ω-alicyclic fatty acids fulfill alternative functions within membranes. Overall, the simulations suggest that ω-alicyclic fatty acids in which the terminal ring is saturated might protect the membrane of thermo-acidophilic bacteria from high-temperature and low-pH conditions through a "dynamical barrier" that would limit lipid diffusion and transmembrane diffusion of undesired ions and molecules.

  11. Lessons in Fluidity

    DEFF Research Database (Denmark)

    Dobusch, Leonhard; Schoeneborn, Dennis

    , or partial organizational arrangements, where it is difficult to uphold this distinction. Looking at the case of the hacker collective Anonymous as an extreme example of organization, this paper proposes to adopt a communication-centered perspective in order to better understand the formation...

  12. Fluidity, Identity, and Organizationality

    DEFF Research Database (Denmark)

    Dobusch, Leonhard; Schoeneborn, Dennis

    2015-01-01

    that the organizationality of a social collective is accomplished through “identity claims”—i.e., speech acts that concern what the social collective is or does—and negotiations on whether or not these claims have been made on the collective's behalf. We empirically examine the case of the hacker collective Anonymous...

  13. Relationship between the fluidity of heat-treated coals and molecular weight distributions of their solvent-soluble component; Netsushoritan no yobai kayo seibun no bunshiryo bunpu to ryudosei no kanren

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, T.; Takanohashi, T.; Iino, M. [Tohoku University, Sendai (Japan). Institute for Chemical Reaction Science; Kato, K. [Nippon Steel Co. Ltd., Tokyo (Japan); Fukada, K. [NKK Corp., Tokyo (Japan)

    1996-10-28

    In order to improve the coke manufacturing process, considerations were given on fluidity manifestation mechanism of heat-treated coals from molecular weight distributions of extracts of a solvent mixed with CS2-N-methyl-2-pyrrolidinone (CS2-NMP). The heat treatment was performed in an autoclave under nitrogen atmosphere at a rate of 3{degree}C/min to settings of 200 to 550{degree}C. The resultant heat-treated coal was quenched, and then extracted by using the CS2-NMP mixed solvent. The fluidity was measured by using a Gieseler plastometer. Maximum extraction rate and the highest fluidity are in linear relationship, which suggests that the extracts govern the fluidity. Since heavy caking coal has no difference in the extraction rates due to heat treatment temperature, and its molecular weight distribution trend does not change, the extracted components which have existed primarily in the original coal govern the fluidity. In semi-caking coals, polymer molecular components are extracted in a large quantity at the softening starting temperature, but the quantity decreases as the temperature rises. However, low-molecular components present no quantitative change, while polymer molecular components decompose, decrease in molecular weight, get solubilized with rising temperature, and act as a binder to cause a flow. 7 figs., 1 tab.

  14. A role for protein kinase C in the regulation of membrane fluidity and Ca²(+) flux at the endoplasmic reticulum and plasma membranes of HEK293 and Jurkat cells.

    Science.gov (United States)

    Chen, Lihong; Meng, Qingli; Jing, Xian; Xu, Pingxiang; Luo, Dali

    2011-02-01

    Protein kinase C (PKC) plays a prominent role in the regulation of a variety of cellular functions, including Ca²(+) signalling. In HEK293 and Jurkat cells, the Ca²(+) release and Ca²(+) uptake stimulated by several different activators were attenuated by activation of PKC with phorbol myristate acetate (PMA) or 1-oleoyl-2-acetyl-sn-glycerol (OAG) and potentiated by PKC inhibition with Gö6983 or knockdown of PKCα or PKCβ using shRNA. Immunostaining and Western blotting analyses revealed that PKCα and PKCβII accumulated at the plasma membrane (PM) and that these isoforms, along with PKCβI, also translocated to the endoplasmic reticulum (ER) upon activation with PMA. Measurements of membrane fluidity showed that, like the cell membrane stabilizers bovine serum albumin (BSA) and ursodeoxycholate (UDCA), PMA and OAG significantly reduced the fluidity of both the PM and ER membranes; these effects were blocked in PKC-knockdown cells. Interestingly, both BSA and UDCA inhibited the Ca²(+) responses to agonists to the same extent as PMA, whereas Tween 20, which increases membrane fluidity, raised the internal Ca²(+) concentration. Thus, activation of PKC induces both translocation of PKC to the PM and ER membranes and downregulation of membrane fluidity, thereby negatively modulating Ca²(+) flux. Copyright © 2010 Elsevier Inc. All rights reserved.

  15. Influence of gating design on microstructure and fluidity of thin sections AA320.0 cast hypo-eutectic Al-Si alloy

    Science.gov (United States)

    Ramadan, Mohamed

    2018-05-01

    Influence of gating design especially number of ingrates on microstructure and fluidity of thin sections of 2, 4, 6 mm AA320.0 cast hypo-eutectic Al-Si alloy was evaluated for sand casting molding technique. Increasing the number of ingates improves the microstructe to be fine and more globular. About 87 μm of α-Al grain size, 0.6 α-Al grain sphericity and 37 μm dendrite arm spacing DAS are achieved by using 4 ingates in gating system. Increasing the number of ingates up to 3 increases hardness, filling area and related fluditiy of all cast samples. The minimum thickness of 2.5 mm for each ingate should be considered in order to successfully production of high quality light weight thin sections castings in sand mold.

  16. Coal lithotypes before and after saturation with CO{sub 2}; insights from micro- and mesoporosity, fluidity, and functional group distribution

    Energy Technology Data Exchange (ETDEWEB)

    Mastalerz, M.; Drobniak, A. [Indiana Geological Survey, Indiana University, 611 North Walnut Grove Ave., Bloomington, IN 47405-2208 (United States); Walker, R. [Pearson Coal Petrography, 7300 W. 15th Ave, Gary, IN 46406 (United States); Morse, D. [Illinois State Geological Survey, University of Illinois, Champaign, Illinois, 61820 (United States)

    2010-09-01

    Four lithotypes, vitrain, bright clarain, clarain, and fusain, were hand-picked from the core of the Pennsylvanian Springfield Coal Member (Petersburg Formation) in Illinois. These lithotypes were analyzed petrographically and for meso- and micropore characteristics, functional group distribution using FTIR techniques, and fluidity. High-pressure CO{sub 2} adsorption isotherm analyses of these lithotypes were performed and, subsequently, all samples were reanalyzed in order to investigate the effects of CO{sub 2}. After the high-pressure adsorption isotherm analysis was conducted and the samples were reanalyzed, there was a decrease in BET surface area for vitrain from 31.5 m{sup 2}/g in the original sample to 28.5 m{sup 2}/g, as determined by low-pressure nitrogen adsorption. Bright clarain and clarain recorded a minimal decrease in BET surface area, whereas for fusain there was an increase from 6.6 m{sup 2}/g to 7.9 m{sup 2}/g. Using low-pressure CO{sub 2} adsorption techniques, a small decrease in the quantity of the adsorbed CO{sub 2} is recorded for vitrain and bright clarain, no difference is observed for clarain, and there is an increase in the quantity of the adsorbed CO{sub 2} for fusain. Comparison of the FTIR spectra before and after CO{sub 2} injection for all lithotypes showed no differences with respect to functional group distribution, testifying against chemical nature of CO{sub 2} adsorption. Gieseler plastometry shows that: 1) softening temperature is higher for the post-CO{sub 2} sample (389.5 C vs. 386 C); 2) solidification temperature is lower for the post-CO{sub 2} sample (443.5 C vs. 451 C); and 3) the maximum fluidity is significantly lower for the post-CO{sub 2} sample (4 ddpm vs. 14 ddpm). (author)

  17. High-level iron mitigates fusaricidin-induced membrane damage and reduces membrane fluidity leading to enhanced drug resistance in Bacillus subtilis.

    Science.gov (United States)

    Yu, Wen-Bang; Ye, Bang-Ce

    2016-05-01

    Fusaricidins are a class of cyclic lipopeptide antibiotics that have strong antifungal activities against plant pathogenic fungi and excellent bactericidal activities against Gram-positive bacteria. The mechanism through which fusaricidin exerts its action is not yet entirely clear. To investigate the mode of action of fusaricidin, we determined the physiological and transcriptional responses of Bacillus subtilis to fusaricidin treatment by using a systems-level approach. Our data show that fusaricidin rapidly induced the expression of σ(W) regulon and caused membrane damage in B. subtilis. We further demonstrated that ferric ions play multiple roles in the action of fusaricidin on B. subtilis. Iron deprivation blocked the formation of hydroxyl radical in the cells and significantly inhibited the bactericidal activity of fusaricidin. Conversely, high levels of iron (>2 mM) repressed the expression of BkdR regulon, resulting in a smaller cellular pool of branched-chain precursors for iso- and anteiso-branched fatty acids, which in turn led to a decrease in the proportion of branched-chain fatty acids in the membrane of B. subtilis. This change in membrane composition reduced its bilayer fluidity and increased its resistance to antimicrobial agents. In conclusion, our experiments uncovered some novel interactions and a synergism between cellular iron levels and drug resistance in Gram-positive bacteria. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. 7-ketocholesterol inhibits Na,K-ATPase activity by decreasing expression of its α1-subunit and membrane fluidity in human endothelial cells.

    Science.gov (United States)

    Duran, M J; Pierre, S V; Lesnik, P; Pieroni, G; Bourdeaux, M; Dignat-Georges, F; Sampol, J; Maixent, J M

    2010-11-09

    As cholesterol, oxysterols, can insert the cell membrane and thereby modify the functions of membrane-bound proteins. The Na,K-ATPase is very sensitive to its lipid environment, seems to be involved in important endothelial functions as the regulation of nitric oxide (NO) release. The effects of 7-ketocholesterol , an oxysterol present in oxidized LDL, was investigated on Na,K-ATPase in isolated human endothelial cells. Cells were incubated 24h with lecithin-, cholesterol- or 7-ketocholesterol liposomes (6 μg/ml). K+-stimulated paranitrophenyl phosphatase activity, reflecting Na,K-ATPase activity, was evaluated as well as cell viability and lipoperoxidation. The expression of Na,K-ATPase subunits mRNAs and membrane fluidity were also investigated. As Na,K-ATPase and nitric oxide seem to be related, we determined the production of NO and the expression of endothelial NO synthase mRNAs. Na,K-ATPase activity was strongly decreased by 7-ketocholesterol. This decrease, not related to lipoperoxidation, was correlated with a decreased expression of the Na,K-ATPase α1-subunit messengers and with rigidity of plasma membranes. Cholesterol induced similar effects but was less potent than 7-ketocholesterol. Basal NO production and expression of endothelial NO synthase mRNAs were not modified by 7-ketocholesterol. Our new findings demonstrate that 7-ketocholesterol, used at non toxic doses, was very potent to disrupt the transport of ions by Na,K-ATPase and perturb membrane structure. These data demonstrate that 7-ketocholesterol induces endothelial dysfunction without cell death that may contribute to early events in atherosclerosis.

  19. Plasma 11-deoxycorticosterone (DOC) and mineralocorticoid receptor testicular expression during rainbow trout Oncorhynchus mykiss spermiation: implication with 17alpha, 20beta-dihydroxyprogesterone on the milt fluidity?

    Science.gov (United States)

    Milla, Sylvain; Terrien, Xavier; Sturm, Armin; Ibrahim, Fidaa; Giton, Franck; Fiet, Jean; Prunet, Patrick; Le Gac, Florence

    2008-05-19

    In rainbow trout (Oncorhynchus mykiss), the endocrine control of spermiation is not fully understood. Besides 11ketotestosterone (11KT) and 17alpha, 20beta-dihydroxyprogesterone (MIS), the potential physiological ligand of the mineralocorticoid receptor (MR) 11-deoxycorticosterone (DOC), is a credible candidate in O. mykiss spermiation regulation as spermiation is accompanied with changes in aqueous and ionic flows. In this study, we investigated potential roles of DOC during spermiation 1) by describing changes in blood plasma DOC level, MR mRNA abundance during the reproductive cycle and MR localization in the reproductive tract 2) by investigating and comparing the effects of DOC (10 mg/kg) and MIS (5 mg/kg) supplementations on sperm parameters 3) by measuring the in vitro effect of DOC on testis MIS production. The plasma concentration of DOC increased rapidly at the end of the reproductive cycle to reach levels that were 10-50 fold higher in mature males than in immature fish. MR mRNA relative abundance was lower in maturing testes when compared to immature testes, but increased rapidly during the spermiation period, immediately after the plasma rise in DOC. At this stage, immunohistochemistry localized MR protein to cells situated at the periphery of the seminiferous tubules and in the efferent ducts. Neither DOC nor MIS had significant effects on the mean sperm volume, although MIS treatment significantly increased the percentage of males producing milt. However, a significant reduction in the spermatocrit was observed when DOC and MIS were administrated together. Finally, we detected an inhibitory effect of DOC on testis MIS production in vitro. These results are in agreement with potential roles of DOC and MR during spermiation and support the hypothesis that DOC and MIS mechanisms of action are linked during this reproductive stage, maybe controlling milt fluidity. They also confirm that in O. mykiss MIS is involved in spermiation induction.

  20. Fullerene inhibits benzo(a)pyrene Efflux from Cyprinus carpio hepatocytes by affecting cell membrane fluidity and P-glycoprotein expression.

    Science.gov (United States)

    Chen, Qiqing; Hu, Xialin; Wang, Rui; Yuan, Jin; Yin, Daqiang

    2016-05-01

    P-Glycoprotein (P-gp) can protect cells by pumping out toxic compounds, and has been found widely expressed in fish tissues. Here, we illustrate the P-gp efflux ability for benzo(a)pyrene (BaP) in the hepatocytes of common carp (Cyprinus carpio) after exposing to fullerene aqueous suspension (nC60). The results revealed that nC60 increased the membrane fluidity by decreasing the ratio of saturated to unsaturated fatty acids, and increased the cholesterol contents. These findings, combined with 10-38% and 70-75% down-regulation of P-gp mRNA and protein respectively, suggested that nC60 caused inhibition on P-gp efflux transport system. Therefore, we further investigated the cellular efflux ability for BaP. Results showed unequivocally that nC60 is a potent P-gp inhibitor. The retaining BaP amounts after efflux were elevated by 1.7-2.8 fold during the 10 day exposure. Meanwhile, 5mg/L humic acid (one of the important fractions of natural organic matter, which is ubiquitous in aquatic environment) alleviated the nC60 damage to hepatocytes in terms of oxidative damage, cholesterol increment, and P-gp content reduction; and finally attenuated the suppressed P-gp efflux ability. Collectively, this study provides the first evidence of nC60 toxicity to P-gp functionality in fish and illustrates the possible mechanism of the suppressed P-gp efflux ability for BaP. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. The Fluidity of Feminine Subjectivity——A Study Based on the English Works of Chinese American Women Writers%美国华裔女性主体身份之流变——以华裔女作家英语创作为例

    Institute of Scientific and Technical Information of China (English)

    董秋芳

    2017-01-01

    Based on the English works of significant Chinese American women writers, it is found that the feminine subjectivity of the writers undergoes fluidity in the historical contexts.Those writers took diverse strategies towards racism, patriarchy and cultural differences, and this exerts direct influences on the feminine subjectivity in their works.Presently, with ethnic, cultural differences and gender inequality still in existence, their writings are of great value for the Chinese American women to construct identities.They can also supplement the official history and fight against the hidden hegemony.%从19世纪下半叶以来有代表性的美国华裔女作家的英语创作来看,作家们在应对种族主义、父权制和文化差异时采取了不同的策略,直接影响到其作品中的女性主体身份的定位.华裔女性主体身份在破冰期、模范少数族裔塑造期和多元文化共生期这三个历史阶段分别呈现出两个不同的特点:从冲突对抗到异质共生、从悖离族裔到溯源寻根.当下,文化差异、种族和性别不平等依然存在,作家们的书写对于当代美国华裔女性建构身份、补充历史和对抗霸权主义有积极的现实意义.

  2. Fluidity in autobiographical memories: relationship memories sampled on two occasions.

    Science.gov (United States)

    Drivdahl, Sarah B; Hyman, Ira E

    2014-01-01

    We investigated consistency of relationship memories. College undergraduates described five events (first meeting, first date, first fight, most embarrassing event, and favourite memory) from their current relationship or, if not currently dating, most recent relationship. Three months later, they were asked to describe the same events again. We scored the consistency of these narratives at three levels of analysis: event, basic information and propositions. The participants demonstrated low consistency in their descriptions, particularly at more detailed levels of analysis. Consistency depended somewhat on the events being recalled, with participants being more consistent for commonly retrieved relationship memories such as first dates. We also found that those individuals who continued in a relationship were less consistent than those describing a previous relationship. These still dating couples had increased opportunities to narrate event stories together and to update knowledge about the relationship through new episodes. In this fashion, updating of experiences may have led to more inconsistencies in recall over time. When considered with research on flashbulb memories, our findings indicate that updating and revisions may be general features of autobiographical memory.

  3. Thermal, electrical, mechanical and fluidity properties of polyester ...

    Indian Academy of Sciences (India)

    Bariş Şimşek

    2018-04-13

    Apr 13, 2018 ... of POREC simultaneously is necessary for real-world applications. ... analysis approach containing a design of experiment (DoE) methodology ...... C–S–H gel and mechanical properties: case of ternary Port- land cements ...

  4. To deal with fluidity in the networked society

    DEFF Research Database (Denmark)

    Levinsen, Karin Tweddell

    2010-01-01

    designs for teaching and learning for that purpose. We need research that aims to describe the phenomenology of acquiring digital literacy and self-programming in order to be able to identify relevant learning objectives and scaffolding. Findings from such studies are expected to be relevant for e...

  5. Prokaryote genome fluidity: toward a system approach of the mobilome.

    Science.gov (United States)

    Toussaint, Ariane; Chandler, Mick

    2012-01-01

    The importance of horizontal/lateral gene transfer (LGT) in shaping the genomes of prokaryotic organisms has been recognized in recent years as a result of analysis of the increasing number of available genome sequences. LGT is largely due to the transfer and recombination activities of mobile genetic elements (MGEs). Bacterial and archaeal genomes are mosaics of vertically and horizontally transmitted DNA segments. This generates reticulate relationships between members of the prokaryotic world that are better represented by networks than by "classical" phylogenetic trees. In this review we summarize the nature and activities of MGEs, and the problems that presently limit their analysis on a large scale. We propose routes to improve their annotation in the flow of genomic and metagenomic sequences that currently exist and those that become available. We describe network analysis of evolutionary relationships among some MGE categories and sketch out possible developments of this type of approach to get more insight into the role of the mobilome in bacterial adaptation and evolution.

  6. Vibration improved the fluidity of aluminum alloys in thin wall ...

    African Journals Online (AJOL)

    Misrun is a term used to describe the incomplete filling of the mould cavity. It is a major defect in the investment casting process when used to produce turbine blades, impellers and impulse blades for turbo pumps which have complex profiles, thin walls and sharp edges. From the casting engineering point of view, poor ...

  7. Polymer fluidity influenced by type and amount of filler

    Directory of Open Access Journals (Sweden)

    Stanek Michal

    2016-01-01

    Full Text Available stage of the injection molding process. This paper shows the influence of cavity surface roughness and technological parameters on the flow length of polymers into mold cavity. Application of the measurement results may have significant influence on the production of shaping parts of the injection molds especially in changing the so far used processes and substituting them by less costly production processes which might increase the competitiveness of the tool producers and shorten the time between product plan and its implementation. This research focused into the influence of technological parameters on filling of the injection mold cavity and the flow length respectively.

  8. Membrane fluidity adjustments in ethanol-stressed Oenococcus oeni cells

    NARCIS (Netherlands)

    Silveira, da M.G.; Golovina, E.A.; Hoekstra, F.A.; Rombouts, F.M.; Abee, T.

    2003-01-01

    The effect of ethanol on the cytoplasmic membrane of Oenococcus oeni cells and the role of membrane changes in the acquired tolerance to ethanol were investigated. Membrane tolerance to ethanol was defined as the resistance to ethanol-induced leakage of preloaded carboxyfluorescein (cF) from cells.

  9. On the edge of fluidity: international cooperation in turbulent times

    NARCIS (Netherlands)

    Umans, Laurent

    2016-01-01

    This thesis reflects the results of action-research carried out in development cooperation, policy development and diplomacy. Research was conducted in three communities in Bolivia as well as in the offices of development practitioners, policy makers and diplomats. The research focuses on

  10. Family Drawings before and after Treatment for Child Conduct Problems: Fluidity of Family Dysfunction

    OpenAIRE

    Kloft, Lilian; Hawes, David; Moul, Caroline; Sultan, Sonia; Dadds, Mark

    2017-01-01

    Children’s drawings have previously been found to reflect their representations of family relationships. The present study examined whether evidence-based parent training for child conduct problems impacts on representations of family functioning using the Family Drawing Paradigm (FDP). N = 53 clinic-referred children (aged 3–15) with conduct problems and their families were assessed pre-treatment and at 6-month follow-up on a modified version of the FDP. Analyses of changes in the FDP reveal...

  11. Lipophilic Contaminants Influence Cold Tolerance of Invertebrates through Changes in Cell Membrane Fluidity

    DEFF Research Database (Denmark)

    Holmstrup, Martin; Bouvrais, Hélène; Westh, Peter

    2014-01-01

    Contaminants taken up by living organisms in the environment as a result of anthropogenic contamination can reduce the tolerance of natural stressors, e.g., low temperatures, but the physiological mechanisms behind these interactions of effects are poorly understood. The tolerance to low temperat...

  12. Thermal Regulation of Membrane Lipid Fluidity by a Two-Component System in "Bacillus Subtilis"

    Science.gov (United States)

    Bredeston, L. M.; Marciano, D.; Albanesi, D.; De Mendoza, D.; Delfino, J. M.

    2011-01-01

    This article describes a simple and robust laboratory exercise on the regulation of membrane unsaturated fatty acid composition in bacteria by a decrease in growth temperature. We take advantage of the well characterized Des pathway of "Bacillus subtilis", composed of a [delta]5-desaturase (encoded by the "des" gene) and the canonical…

  13. Development of laboratory test methods to replace the simulated high-temperature grout fluidity test : [summary].

    Science.gov (United States)

    2014-06-01

    Concretes remarkable role in construction depends on its marriage with reinforcing steel. Concrete is very strong in compression, but weak in tension, so reinforcing steel is added to increase tensile strength, yielding structural components capab...

  14. Kidnapping in Taiwan: the significance of geographic proximity, improvisation, and fluidity.

    Science.gov (United States)

    Yang, Shu-Lung; Wu, Bohsiu; Huang, Shih-Long

    2007-06-01

    Kidnapping had been rare in Taiwan until recently. Several high-profile cases in the late 1990s, victimizing both Taiwanese citizens and foreigners, startled the island state. This study is the first systematic examination of the social dynamics involved in kidnapping. Data came from court cases, questionnaires, and in-depth interviews from incarcerated inmates. Results showed that kidnappers' financial crises and friendships with ringleaders were two primary motives. Most kidnapping cases involved a small number of offenders who form an ad hoc kidnapping group. Victims were not randomly chosen and share a geographic tie with the offenders. The process of kidnapping is idiosyncratic in nature, as most kidnappers improvised their plans. The negotiation phase in kidnapping is done hastily, and the amount of ransom is often a compromised result of offenders' needs, victim's family's financial status, timing, and the offenders' perception of risks. Ways to prevent kidnapping are also discussed in this article.

  15. Oligomerization of Bacillus subtilis DesR is required for fine tuning regulation of membrane fluidity.

    Science.gov (United States)

    Najle, Sebastián R; Inda, María E; de Mendoza, Diego; Cybulski, Larisa E

    2009-10-01

    The DesK-DesR two-component system regulates the order of membrane lipids in the bacterium Bacillus subtilis by controlling the expression of the des gene coding for the delta 5-acyl-lipid desaturase. To activate des transcription, the membrane-bound histidine kinase DesK phosphorylates the response regulator DesR. This covalent modification of the regulatory domain of dimeric DesR promotes, in a cooperative fashion, the hierarchical occupation of two adjacent, non-identical, DesR-P binding sites, so that there is a shift in the equilibrium toward the tetrameric active form of the response regulator. However, the mechanism of regulation of DesR activity by phosphorylation and oligomerization is not well understood. We employed deletion analysis and reporter fusions to study the role of the N-terminal domain on DesR activity. In addition, electromobility shift assays were used to analyze the binding capacity of the transcription factor to deletion mutants of the des promoter. We show that DesR lacking the N-terminal domain is still able to bind to the des promoter. We also demonstrate that if the RA site is moved closer to the -35 region of Pdes, the adjacent site RB is dispensable for activation. Our results indicate that the unphosphorylated regulatory domain of DesR obstructs the access of the recognition helix of DesR to its DNA target. In addition, we present evidence showing that RB is physiologically relevant to control the activation of the des gene when the levels of DesR-P reach a critical threshold.

  16. The role of science fiction within the fluidity of slipstream literature

    Directory of Open Access Journals (Sweden)

    Janez Steble

    2015-12-01

    Full Text Available The paper explores the complex and contradictory role of science fiction in slipstream, the type of postmodern non-realistic literature situated between the fantastic genres and the mainstream literary fiction. Because of its unstable status of occupying an interstitial position between multiple literary conventions, the article first deals with an expansive terminology affiliated with slipstream and elucidates upon using a unified term for it. Avantpop, transrealism, and interstitial fiction all help us in understanding the vast postmodern horizon of slipstream. Furthermore, the slipstream's philosophy of cognitive dissonance in comparison to science fiction's is analysed to see the similarities and differences between them. The section is mainly concerned on expanding Darko Suvin's concept of cognition and viewing it as partially compatible with slipstream's estrangement techniques. The final part is focused on the exemplary slipstream novel Vurt by Jeff Noon, a perfect example of science fiction providing material, including latest post-Newtonian paradigms of science, for slipstream to mould it in its own fashion.

  17. Holographic perfect fluidity, Cotton energy-momentum duality and transport properties

    Energy Technology Data Exchange (ETDEWEB)

    Mukhopadhyay, Ayan [Centre de Physique Théorique, Ecole Polytechnique, CNRS UMR 7644,Route de Saclay, 91128 Palaiseau Cedex (France); Institut de Physique Théorique, CEA, CNRS URA 2306,91191 Gif-sur-Yvette (France); Petkou, Anastasios C. [Institute of Theoretical Physics, Department of Physics, Aristotle University of Thessaloniki,54124 Thessaloniki (Greece); Petropoulos, P. Marios; Pozzoli, Valentina [Centre de Physique Théorique, Ecole Polytechnique, CNRS UMR 7644,Route de Saclay, 91128 Palaiseau Cedex (France); Siampos, Konstadinos [Service de Mécanique et Gravitation, Université de Mons, UMONS,20 Place du Parc, 7000 Mons (Belgium)

    2014-04-23

    We investigate background metrics for 2+1-dimensional holographic theories where the equilibrium solution behaves as a perfect fluid, and admits thus a thermodynamic description. We introduce stationary perfect-Cotton geometries, where the Cotton-York tensor takes the form of the energy-momentum tensor of a perfect fluid, i.e. they are of Petrov type D{sub t}. Fluids in equilibrium in such boundary geometries have non-trivial vorticity. The corresponding bulk can be exactly reconstructed to obtain 3+1-dimensional stationary black-hole solutions with no naked singularities for appropriate values of the black-hole mass. It follows that an infinite number of transport coefficients vanish for holographic fluids. Our results imply an intimate relationship between black-hole uniqueness and holographic perfect equilibrium. They also point towards a Cotton/energy-momentum tensor duality constraining the fluid vorticity, as an intriguing boundary manifestation of the bulk mass/nut duality.

  18. Holographic perfect fluidity, Cotton energy-momentum duality and transport properties

    International Nuclear Information System (INIS)

    Mukhopadhyay, Ayan; Petkou, Anastasios C.; Petropoulos, P. Marios; Pozzoli, Valentina; Siampos, Konstadinos

    2014-01-01

    We investigate background metrics for 2+1-dimensional holographic theories where the equilibrium solution behaves as a perfect fluid, and admits thus a thermodynamic description. We introduce stationary perfect-Cotton geometries, where the Cotton-York tensor takes the form of the energy-momentum tensor of a perfect fluid, i.e. they are of Petrov type D t . Fluids in equilibrium in such boundary geometries have non-trivial vorticity. The corresponding bulk can be exactly reconstructed to obtain 3+1-dimensional stationary black-hole solutions with no naked singularities for appropriate values of the black-hole mass. It follows that an infinite number of transport coefficients vanish for holographic fluids. Our results imply an intimate relationship between black-hole uniqueness and holographic perfect equilibrium. They also point towards a Cotton/energy-momentum tensor duality constraining the fluid vorticity, as an intriguing boundary manifestation of the bulk mass/nut duality

  19. The fluidity of biosocial identity and the effects of place, space, and time.

    Science.gov (United States)

    Wiese, Daniel; Rodriguez Escobar, Jeronimo; Hsu, Yohsiang; Kulathinal, Rob J; Hayes-Conroy, Allison

    2018-02-01

    Public and scientific conceptions of identity are changing alongside advances in biotechnology, with important relevance to health and medicine. In particular, biological identity, once predominantly conceived as static (e.g., related to DNA, dental records, fingerprints) is now being recognized as dynamic or fluid, mirroring contemporary understandings of psychological and social identity. The dynamism of biological identity comes from the individual body's unique relationship with the world surrounding it, and therefore may best be described as biosocial. This paper reviews advances in scientific understandings of identity and presents a model that contrasts prior static approaches to biological identity from more recent dynamically-relational ones. This emerging viewpoint is of broad significance to health and medicine, particularly as medicine recognizes the significance of biography - i.e. the multiple, dense interactions imparted on a body across spatio-temporal dimensions - to phenotypic prediction, especially disease risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Sweat : Materiality and Fluidity of Perspiration in in Eighteenth-Century Medicine

    NARCIS (Netherlands)

    Verwaal, Ruben

    2015-01-01

    How can a bodily excretion like sweat, often accompanied with a stench or associated with anxiety and distress, enrich our view of the history of science? This paper argues that following the fluid and flow of sweat has in fact particular advantages, because it provides a unique perspective by

  1. "Home is always home" : (former) street youth in Blantyre, Malawi, and the fluidity of constructing home

    NARCIS (Netherlands)

    Hendriks, T.D.

    2016-01-01

    For many Malawians the concept of home is strongly associated with the rural areas and one's (supposedly rural) place of birth. This 'grand narrative about home', though often reiterated, doesn't necessarily depict lived reality. Malawi's history of movement and labor migration coupled with

  2. Effect of γ-ray irradiation on the structure and melt fluidity of UHMWPE

    International Nuclear Information System (INIS)

    Liu Pengbo; Fan Ping; Xu Wen; Wang Kai

    2005-01-01

    Ultra-high molecular weight polyethylene (UHMWPE) was irradiated in air by 60 Co γ-rays. The effect of γ-ray irradiation on the structure and properties of UHMWPE was studied by FTIR, intrinsic viscosity measurement, melt flow rate (MFR) measurement and mechanical property test. The experimental results show that oxygen-containing groups (mainly carbonyl group) were introduced on the molecular chain of UHMWPE during the irradiation, which caused degradation of UHMWPE. Molecular weight of UHMWPE decreased and melt flow rate increased obviously. Compared with the virgin UHMWPE, MFR of the 100 kGy-irradiated UHMWPE increased from virtually nothing to 4.8 g/10 min. Tensile yield strength and elongation at break of the irradiated UHMWPE samples were improved, whereas notched lzod impact strength of the samples decreased. Compared with the virgin UHMWPE, elongation at break of the UHMWPE samples irradiated to 100 kGy increased from 367% to 801%, and their notched lzod impact strength decreased to 576 J/m from over 1000. (authors)

  3. Nearly perfect fluidity: from cold atomic gases to hot quark gluon plasmas

    International Nuclear Information System (INIS)

    Schaefer, Thomas; Teaney, Derek

    2009-01-01

    Shear viscosity is a measure of the amount of dissipation in a simple fluid. In kinetic theory shear viscosity is related to the rate of momentum transport by quasi-particles, and the uncertainty relation suggests that the ratio of shear viscosity η to entropy density s in units of ℎ/k B is bounded by a constant. Here, ℎ is Planck's constant and k B is Boltzmann's constant. A specific bound has been proposed on the basis of string theory where, for a large class of theories, one can show that η/s ≥ ℎ/(4πk B ). We will refer to a fluid that saturates the string theory bound as a perfect fluid. In this review we summarize theoretical and experimental information on the properties of the three main classes of quantum fluids that are known to have values of η/s that are smaller than ℎ/k B . These fluids are strongly coupled Bose fluids, in particular liquid helium, strongly correlated ultracold Fermi gases and the quark gluon plasma. We discuss the main theoretical approaches to transport properties of these fluids: kinetic theory, numerical simulations based on linear response theory and holographic dualities. We also summarize the experimental situation, in particular with regard to the observation of hydrodynamic behavior in ultracold Fermi gases and the quark gluon plasma.

  4. Fluidity in the Networked Society--Self-Initiated learning as a Digital Literacy Competence

    Science.gov (United States)

    Levinsen, Karin Tweddell

    2011-01-01

    In the globalized economies e-permeation has become a basic condition in our everyday lives. ICT can no longer be understood solely as artefacts and tools and computer-related literacy are no longer restricted to the ability to operate digital tools for specific purposes. The network society, and therefore also eLearning are characterized by…

  5. "Home is always home" : (former) street youth in Blantyre, Malawi, and the fluidity of constructing home

    NARCIS (Netherlands)

    Hendriks, T.D.

    2017-01-01

    For many Malawians the concept of home is strongly associated with the rural areas and one's (supposedly rural) place of birth. This 'grand narrative about home', though often reiterated, doesn't necessarily depict lived reality. Malawi's history of movement and labor migration coupled with

  6. Optimizing the particle size of coal for CWM in view of fluidity. [Biomodal

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, Seiji; Nonaka, Michio; Okano, Yasuhiko; Inoue, Toshio

    1987-10-25

    As is well known, the viscosity of CWM is considerably influenced by the distribution of coal particle sizes and has bearing on particle packing density or porosity. A model for representing the viscosity of CWM in terms of particle porosity and specific surface was designed. Also, experimental verification was conducted for the method of optimizing particle size on a two-stage grinding system. The results are as follows: The viscosity of CWM is influenced not only by the porosity of coal particles, but also by the specific surface; also, it is correlated to the distance between suspended particles. At the two-stage grinding experiments, a particle size distribution leading to a low viscosity was obtained by mixing coarse and fine particles at 4:1. This has demonstrated that the use of an agitating mill for fine particles is of help. (11 figs, 2 tabs, 6 refs)

  7. Living Subjectivity: Time Scales, Language, and the Fluidity of the Self

    DEFF Research Database (Denmark)

    Cowley, Stephen; Madsen, Jens Koed

    2014-01-01

    in general, we extend this argument by looking at multi-scalar temporalities that influence the emergence and potential of the self. In particular, we argue that the self is best understood as a relational entity that immerses contextually in a distributed, non-stable, and temporally multi-scalar manner......, contextually immersed subjectivity is compatible with tracing language and cognition to how cultural resources extend human embodiment (this frames the potential for cognition, subjectivity, and the self). Second, while distributed and fragmented, the construction of temporal experience can become...... an organizing principle for the construction of the self. Through this lens, cognition binds what is learned from introspection with contextual immersion that uses skills in temporal integration. This challenges views of self and cognition as stable internal phenomena and, conversely, shows that philosophy...

  8. The dilemmas of indefiniteness: Utopia, fluidity and subjectivity in Stone, by Adam Roberts

    Directory of Open Access Journals (Sweden)

    André Cabral de Almeida Cardoso

    2017-06-01

    Full Text Available http://dx.doi.org/10.5007/2175-8026.2017v70n2p107 Ae, the narrator-protagonist of the novel Stone, by Adam Roberts, is the only criminal in a post-human utopian society in which the use of nanotechnology has allowed humanity to reach its plenitude. Isolated from the rest of society, one day Ae is offered freedom and wealth if he agrees to kill the population of a whole planet. After accepting this offer, Ae must try to fulfil his mission at the same time that he questions himself and tries to discover who his employers are. In developing the conflict between this deviant individual and the utopia in which he lives, Stone examines the limits of the utopia itself, which is based on the idea of flux and indefiniteness. The novel also explores the models of subjectivity created in the context of this utopia. The notion of utopia as a well-defined social project is replaced by the image of utopian bodies, influenced by technologies that challenge the definitions of the human and of the post-human. In establishing this network of tensions and indefiniteness, the novel offers the possibility that the marginalized sociopath might be the only one capable of examining in depth the reality of a world anesthetized by its own comfort.

  9. The dilemmas of indefiniteness: Utopia, fluidity and subjectivity in Stone, by Adam Roberts

    OpenAIRE

    André Cabral de Almeida Cardoso; Carla de Figueiredo Portilho

    2017-01-01

    http://dx.doi.org/10.5007/2175-8026.2017v70n2p107 Ae, the narrator-protagonist of the novel Stone, by Adam Roberts, is the only criminal in a post-human utopian society in which the use of nanotechnology has allowed humanity to reach its plenitude. Isolated from the rest of society, one day Ae is offered freedom and wealth if he agrees to kill the population of a whole planet. After accepting this offer, Ae must try to fulfil his mission at the same time that he questions himself and trie...

  10. The Bible Student’s Sacrifice: Gender Fluidity and Consecrated Identity in Evangelical America, 1879-1916

    Directory of Open Access Journals (Sweden)

    Timothy Robert Noddings

    2012-11-01

    Full Text Available American feminist scholars have often represented gender in nineteenth-century evangelical Protestantism as a binary conflict between oppositional ‘male’ and ‘female’ categories of identity and experience. Drawing on the theoretical work of Jeanne Boydston, this article argues that gender within evangelical religion is better understood as a ‘system of distinctions’ that could be articulated in a variety of ways, some of which violated the gendered division of masculine/feminine. The American Bible Student movement, as a fervent millennialist organization, demanded that its members sacrifice their individuality to become ‘harvest workers’ for Christ. This sacrifice temporarily provided Students with a degree of freedom to construct spiritual identities that combined ‘masculine’ and ‘feminine’ signifiers, de-stabilizing the binary meaning of gender. After 1897, a series of internal challenges and schisms re-solidified the gender line, associating stability with the limiting of women’s power within both church and home.

  11. Type-1 cannabinoid receptors reduce membrane fluidity of capacitated boar sperm by impairing their activation by bicarbonate.

    Directory of Open Access Journals (Sweden)

    Barbara Barboni

    Full Text Available BACKGROUND: Mammalian spermatozoa acquire their full fertilizing ability (so called capacitation within the female genital tract, where they are progressively exposed to inverse gradients of inhibiting and stimulating molecules. METHODOLOGY/PRINCIPAL FINDINGS: In the present research, the effect on this process of anandamide, an endocannabinoid that can either activate or inhibit cannabinoid receptors depending on its concentration, and bicarbonate, an oviductal activatory molecule, was assessed, in order to study the role exerted by the type 1 cannabinoid receptor (CB1R in the process of lipid membrane remodeling crucial to complete capacitation. To this aim, boar sperm were incubated in vitro under capacitating conditions (stimulated by bicarbonate in the presence or in the absence of methanandamide (Met-AEA, a non-hydrolysable analogue of anandamide. The CB1R involvement was studied by using the specific inhibitor (SR141716 or mimicking its activation by adding a permeable cAMP analogue (8Br-cAMP. By an immunocytochemistry approach it was shown that the Met-AEA inhibits the bicarbonate-dependent translocation of CB1R from the post-equatorial to equatorial region of sperm head. In addition it was found that Met-AEA is able to prevent the bicarbonate-induced increase in membrane disorder and the cholesterol extraction, both preliminary to capacitation, acting through a CB1R-cAMP mediated pathway, as indicated by MC540 and filipin staining, EPR spectroscopy and biochemical analysis on whole membranes (CB1R activity and on membrane enriched fraction (C/P content and anisotropy. CONCLUSIONS/SIGNIFICANCE: Altogether, these data demonstrate that the endocannabinoid system strongly inhibits the process of sperm capacitation, acting as membrane stabilizing agent, thus increasing the basic knowledge on capacitation-related signaling and potentially opening new perspectives in diagnostics and therapeutics of male infertility.

  12. Ambivalence and Fluidity in the Teenage Smoking and Quitting Experience: Lessons from a Qualitative Study at an English Secondary School

    Science.gov (United States)

    Buswell, Marina; Duncan, Peter

    2013-01-01

    Objective: To evaluate a school-based stop smoking pilot project and to understand the teenage experience of smoking and quitting within that context. Design: Flexible design methods. Setting: A Kent (United Kingdom [UK]) secondary school. Methods: Semi-structured interviews analyzed following a grounded theory approach. Results: The main themes…

  13. Localized fluidity modes and the topology of the constant-potential-energy hypersurfaces of Lennard-Jones matter

    DEFF Research Database (Denmark)

    Cotterill, Rodney M J; Madsen, J.

    1986-01-01

    Sections of configuration space for Lennard-Jones matter were obtained by probing all the normal-mode energy profiles, following diagonalization of the dynamical matrix for a 240-particle system. For the crystal and sufficiently cold glass, these are single welled, whereas increasing numbers...... of double wells occur as the glass is warmed toward the fluid. This indicates that there might be a fundamental difference between the topologies of the constant-potential-energy hypersurfaces of crystalline and noncrystalline Lennard-Jones matter....

  14. Of woods and webs: possible alternatives to the tree of life for studying genomic fluidity in E. coli

    Directory of Open Access Journals (Sweden)

    Lapointe François-Joseph

    2011-07-01

    Full Text Available Abstract Background We introduce several forest-based and network-based methods for exploring microbial evolution, and apply them to the study of thousands of genes from 30 strains of E. coli. This case study illustrates how additional analyses could offer fast heuristic alternatives to standard tree of life (TOL approaches. Results We use gene networks to identify genes with atypical modes of evolution, and genome networks to characterize the evolution of genetic partnerships between E. coli and mobile genetic elements. We develop a novel polychromatic quartet method to capture patterns of recombination within E. coli, to update the clanistic toolkit, and to search for the impact of lateral gene transfer and of pathogenicity on gene evolution in two large forests of trees bearing E. coli. We unravel high rates of lateral gene transfer involving E. coli (about 40% of the trees under study, and show that both core genes and shell genes of E. coli are affected by non-tree-like evolutionary processes. We show that pathogenic lifestyle impacted the structure of 30% of the gene trees, and that pathogenic strains are more likely to transfer genes with one another than with non-pathogenic strains. In addition, we propose five groups of genes as candidate mobile modules of pathogenicity. We also present strong evidence for recent lateral gene transfer between E. coli and mobile genetic elements. Conclusions Depending on which evolutionary questions biologists want to address (i.e. the identification of modules, genetic partnerships, recombination, lateral gene transfer, or genes with atypical evolutionary modes, etc., forest-based and network-based methods are preferable to the reconstruction of a single tree, because they provide insights and produce hypotheses about the dynamics of genome evolution, rather than the relative branching order of species and lineages. Such a methodological pluralism - the use of woods and webs - is to be encouraged to analyse the evolutionary processes at play in microbial evolution. This manuscript was reviewed by: Ford Doolittle, Tal Pupko, Richard Burian, James McInerney, Didier Raoult, and Yan Boucher

  15. Accounting for structural and exchange mobility in models of status attainment: Social fluidity in five European countries.

    Science.gov (United States)

    Menés, Jorge Rodríguez

    2017-01-01

    This paper proposes a new method to distinguish structural from exchange mobility in status attainment models with interval endogenous variables. In order to measure structural mobility, the paper proposes to trace occupational and educational changes across generations using information provided by children about their fathers. The validity of the method is assessed by comparing the effects of father's socio-economic status and education on son's status and educational attainments, net of occupational upgrading and educational expansion, in five European countries: Britain, Denmark, Germany, Norway, and Spain, using data from the 2005 EU-SILC survey. The results show that the effect of father's on son's ISEI weakens greatly in all countries after considering occupational upgrading, and that much of father's influence over sons occurs by directing them towards occupations with good economic prospects. Useful extensions to the method are discussed in the conclusions. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Cytotoxic Lipopeptide Muscotoxin A, Isolated from Soil Cyanobacterium Desmonostoc muscorum, Permeabilizes Phospholipid Membranes by Reducing Their Fluidity

    Czech Academy of Sciences Publication Activity Database

    Tomek, P.; Hrouzek, Pavel; Kuzma, Marek; Sýkora, Jan; Fišer, R.; Černý, J.; Novák, Petr; Bártová, Simona; Šimek, Petr; Hof, Martin; Kavan, Daniel; Kopecký, Jiří

    2015-01-01

    Roč. 28, č. 2 (2015), s. 216-224 ISSN 0893-228X R&D Projects: GA ČR GPP503/12/P614; GA MŠk(CZ) LH11129; GA MŠk ED2.1.00/03.0110; GA MŠk(CZ) ED1.1.00/02.0109 Institutional support: RVO:61388971 ; RVO:61388955 ; RVO:60077344 Keywords : BLUE-GREEN-ALGA * CYCLIC-PEPTIDES * LYNGBYA SP Subject RIV: EE - Microbiology, Virology; EE - Microbiology, Virology (UFCH-W); EE - Microbiology, Virology (BC-A) Impact factor: 3.025, year: 2015

  17. Fruit metabolite networks in engineered and non-engineered tomato genotypes reveal fluidity in a hormone and agroecosystem specific manner.

    Science.gov (United States)

    Fatima, Tahira; Sobolev, Anatoly P; Teasdale, John R; Kramer, Matthew; Bunce, Jim; Handa, Avtar K; Mattoo, Autar K

    Metabolomics provides a view of endogenous metabolic patterns not only during plant growth, development and senescence but also in response to genetic events, environment and disease. The effects of the field environment on plant hormone-specific metabolite profiles are largely unknown. Few studies have analyzed useful phenotypes generated by introducing single or multiple gene events alongside the non-engineered wild type control at field scale to determine the robustness of the genetic trait and its modulation in the metabolome as a function of specific agroecosystem environments. We evaluated the influence of genetic background (high polyamine lines; low methyl jasmonate line; low ethylene line; and isogenic genotypes carrying double transgenic events) and environments (hairy vetch, rye, plastic black mulch and bare soil mulching systems) on the metabolomic profile of isogenic reverse genetic mutations and selected mulch based cropping systems in tomato fruit. Net photosynthesis and fruit yield were also determined. NMR spectroscopy was used for quantifying metabolites that are central to primary metabolism. We analyzed both the first moment (means) of metabolic response to genotypes and agroecosystems by traditional univariate/multivariate methods, and the second moment (covariances) of responses by creating networks that depicted changes in correlations of paired metabolites. This particular approach is novel and was necessary because our experimental material yielded highly variable metabolic responses that could not be easily understood using the traditional analytical approaches for first moment statistics. High endogenous spermidine and spermine content exhibited strong effects on amino acids, Krebs cycle intermediates and energy molecules (ADP + ATP) in ripening fruits of plants grown under different agroecosystem environments. The metabolic response to high polyamine genotypes was similar to the response to hairy vetch cover crop mulch; supported by the pattern of changes in correlation between metabolites. Changes in primary metabolites of genotypes mutated for the deficiency of ethylene or methyl jasmonate were unique under all growth conditions and opposite of high polyamine genotype results. The high polyamine trait was found to dominate the low ethylene and low jasmonate mutations under field conditions. For several metabolites low ethylene and low methyl jasmonate genotypes had an inverse relationship. Collectively, these results affirm that interactions between metabolite pathways and growth environments are affected by genotype, and influence the metabolite quality of a crop. This study portrays how metabolite relationships change, both in mean and in correlation, under different genotypic and environmental conditions. Although these networks are surprisingly dynamic, we also find examples of selectively conserved associations.

  18. Influence of freezing stress on morphological alteration and biofilm formation by Listeria monocytogenes: relationship with cell surface hydrophobicity and membrane fluidity.

    Science.gov (United States)

    Miladi, Hanene; Ammar, Emna; Ben Slama, Rihab; Sakly, Nawfel; Bakhrouf, Amina

    2013-11-01

    The morphological changes and adhesive property of three Listeria monocytogenes strains submitted to freezing stress (-20 °C) were studied. The atomic force micrographs showed a reduction in the cell size and an evolution to coccoid shape. The phenotypic slime production of L. monocytogenes and the expression of the adhesive gene were investigated before and after 10 months of incubation in salmon at -20°. Our results showed that after ten months, stressed stains become more adherent and able to produce slime. In addition, we noted that this pathogen presents same physiological changes to adapt to starvation conditions. The cellular fatty acids composition of adhered and floating cells of three L. monocytogenes strains was taken into consideration. The stressed strains presented different chain lengths and therefore an increase in the hydrophobicity level. Moreover, we noted that the adhesive property of L. monocytogenes strains affects the Benzalkonium chloride bacterial sensitivity which increased after biofilm formation.

  19. Differential Adaptations of Methicillin-Resistant Staphylococcus aureus to Serial In Vitro Passage in Daptomycin: Evolution of Daptomycin Resistance and Role of Membrane Carotenoid Content and Fluidity

    Directory of Open Access Journals (Sweden)

    Nagendra N. Mishra

    2012-01-01

    Full Text Available Previous studies showed serial 20 d in vitro passage of MRSA strain MW2 in sublethal daptomycin (DAP resulted in diverse perturbations in both cell membrane (CM and cell wall (CW characteristics, including increased CM rigidity; increased CW thickness; “gain-in-function” single nucleotide polymorphisms (SNPs in the mprF locus (i.e., increased synthesis and translocation of lysyl-phosphatidylglycerol (L-PG; progressive accumulation of SNPs in yyc and rpo locus genes; reduced carotenoid production; cross-resistance to innate host defense peptides. The current study was designed to characterize the reproducibility of these phenotypic and genotypic modifications following in vitro serial passages of the same parental strain. After a second 20d serial in vitro passage of parental MW2, emergence of DAP-R was associated with evolution of several phenotypes closely mirroring previous passage outcomes. However, in contrast to the initial serial passage strain set, we observed (i only modest increase in L-PG synthesis and no increase in L-PG outer CM translocation; (ii significantly increased carotenoid synthesis (P<0.05; (iii a different order of SNP accumulations (mprF≫rpoB≫yycG; (iv a different cadre and locations of such SNPs. Thus, MRSA strains are not “pre-programmed” to phenotypically and/or genotypically adapt in an identical manner during induction of DAP resistance.

  20. Bloom's "Normal" (2002) and Tarttelin's "Golden Boy" (2013): Teaching Gender Fluidity Written across Time and Text

    Science.gov (United States)

    LeSavoy, Barbara

    2016-01-01

    The author is in a faculty position in women and gender studies (WGST) at a comprehensive public university in western New York. In this article, the author summarize theories of identity and voice as backdrop for inquiry, transitioning to a systematic discussion of teaching about sex and gender identity to differently positioned learners, drawing…

  1. Bulk Fluidity and Apparent Wall Slip of Aqueous Kaolin Suspensions Studied Using the Cone-Cone (KK) Sensor: Effect of the Sensor Surface Quality.

    Czech Academy of Sciences Publication Activity Database

    Pěnkavová, Věra; Tihon, Jaroslav; Wein, Ondřej

    2017-01-01

    Roč. 533, NOV 20 (2017), s. 338-346 ISSN 0927-7757 EU Projects: Foundation for Science and Technology(XE) MP1305 Institutional support: RVO:67985858 Keywords : aqueous kaolin suspensions * rotational AWS viscometry * apparent wall slip Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 2.714, year: 2016

  2. Bulk Fluidity and Apparent Wall Slip of Aqueous Kaolin Suspensions Studied Using the Cone-cone (KK) Sensor: The Effect of Concentration and Temperature.

    Czech Academy of Sciences Publication Activity Database

    Pěnkavová, Věra; Tihon, Jaroslav; Wein, Ondřej

    2016-01-01

    Roč. 511, DEC 20 (2016), s. 272-284 ISSN 0927-7757 R&D Projects: GA MŠk(CZ) LD13018 Grant - others:COST- European Coperation in Science and Technology(XE) MP1305; COST- European Coperation in Science and Technology(XE) MP1106 Program:LD COST Institutional support: RVO:67985858 Keywords : aqueous kaolin suspensions * apparent wall slip * cone-cone (KK) sensor Subject RIV: CI - Industrial Chemistry , Chemical Engineering Impact factor: 2.714, year: 2016

  3. The Complexities of Adolescent Dating and Sexual Relationships: Fluidity, Meaning(s), and Implications for Young Adults' Well-Being

    Science.gov (United States)

    Manning, Wendy D.; Longmore, Monica A.; Copp, Jennifer; Giordano, Peggy C.

    2014-01-01

    The complexity of adolescents' dating and sexual lives is not easily operationalized with simple indicators of dating or sexual activity. While building on prior work that emphasizes the "risky" nature of adolescents' intimate relationships, we assess whether a variety of indicators reflecting the complexity of…

  4. Influence of Changes in Water-to-Cement Ratio, Alkalinity, Concrete Fluidity, Voids, and Type of Reinforcing Steel on the Corrosion Potential of Steel in Concrete.

    Science.gov (United States)

    2014-04-01

    "Research on steel corrosion has demonstrated that the concentrations of chloride and hydroxide ion at the concrete/steel : interface influence the susceptibility of the steel to corrosive attack. This study used electrochemical means and changes in ...

  5. Biosynthesis of omega-alicyclic fatty acids induced by cyclic precursors and change of membrane fluidity in thermophilic bacteria Geobacillus stearothermophilus and Meiothermus ruber

    Czech Academy of Sciences Publication Activity Database

    Siřišťová, L.; Luhový, R.; Sigler, Karel; Řezanka, Tomáš

    2011-01-01

    Roč. 15, č. 3 (2011), 423-429 ISSN 1431-0651 Institutional research plan: CEZ:AV0Z50200510 Keywords : Thermophilic bacteria * Geobacillus * Meiothermus Subject RIV: EE - Microbiology, Virology Impact factor: 2.941, year: 2011

  6. Effect of body build on the validity of predicted body fat from body mass index and bioelectrical impedance

    NARCIS (Netherlands)

    Snijder, M.B.; Kuyf, B.E.M.; Deurenberg, P.

    1999-01-01

    Background: Membrane fluidity is an important aspect of cellular physiology which may be manipulated by diet. Methods: We studied the effect of dietary fish oil on the membrane composition of erythrocytes and cheek cells, and on membrane fluidity of erythrocytes as assessed by fluorescence recovery

  7. Rooster sperm plasma membrane protein and phospholipid organization and reorganization attributed to cooling and cryopreservation

    Science.gov (United States)

    Cholesterol to phospholipid ratio is used as a representation for membrane fluidity, and predictor of cryopreservation success but results are not consistent across species and ignore the impact of membrane proteins. Therefore, this research explored the modulation of membrane fluidity and protein ...

  8. Effect of Permeation Enhancers on the Release Behavior and ...

    African Journals Online (AJOL)

    HP

    International Pharmaceutical Abstract, Chemical Abstracts, Embase, Index Copernicus, EBSCO, African. Index Medicus ... inhibition of norepinephrine and serotonin uptake. ..... structural organization and increase in their fluidity and partial ...

  9. Goodbye Career, Hello Success.

    Science.gov (United States)

    Komisar, Randy

    2000-01-01

    Success in today's economy means throwing out the old career rules. The "noncareer" career is driven by passion for the work and has the fluidity and flexibility needed in the contemporary workplace. (JOW)

  10. Fulltext PDF

    Indian Academy of Sciences (India)

    Unknown

    mental temperature, the fluidity of bacterial cell-membranes decreases and ... Listeria monocytogenes is a food-borne pathogen that grows at refri- geration ... acid in the growth of Listeria monocytogenes at low temperatures; Appl. Environ.

  11. Quercetin modulates activities of Taiwan cobra phospholipase A2 ...

    Indian Academy of Sciences (India)

    2012-04-25

    Apr 25, 2012 ... Quercetin incorporation led to a reduction in PLA2 enzymatic activity and membrane-damaging activity ... membrane physical properties such as membrane fluidity or ..... eral blood mononuclear cells from diabetes patients.

  12. The radiation effects on lipid bilayers

    International Nuclear Information System (INIS)

    Ikigai, Hajime; Matsuura, Tomio; Narita, Noboru; Ozawa, Atsushi.

    1980-01-01

    The Radiation effects on lipid bilayers are studied by the electron spin resonance. Egg lecithin liposomes and human erythrocytes are labeled with spin probes (5 SAL, 12 SAL). Effects of membrane fluidity by X-Ray (or ultraviolet) irradiation are measured by change of the order parameter S. The results obtained are as follows: 1) A similar tendency is observed on the order parameter S between X-Ray irradiated egg lecithin liposomes and human erythrocytes. 2) The rapid changes of the membrane fluidity are observed below 1 krad. The fluctuation of membrane fluidity decreases above 1 krad, consequently the membrane has a tendency changing to a rigid state at low dose area. 3) It is suggested that the more effective radicals are hydroxyl radicals and superoxide radicals. 4) The effects of ultraviolet irradiation with hydrogen peroxide show that hydroxyl radicals lead to changes of membrane fluidity. (author)

  13. Pengaruh unsur Tembaga (Cu terhadap fluiditas paduan Al-Si 11.8 wt% (ADC 12 dengan metode Vacuum Suction Test

    Directory of Open Access Journals (Sweden)

    Bambang Suharno

    2012-11-01

    Full Text Available Al-Si 11.8 wt% alloy which classified to eutectic Al-Si composition usually used to produce a flat casting product with high pressure die casting process. Alloying element become an important things to determine behavior and characteristic of aluminum. Copper added into aluminum to improve strength and hardness, but there has no many studies on the effect of copper on fluidity. This fluidity study is using vacuum suction test method and the microstructure is observed with SEM/EDS. Spectrometer test has been used to find out chemical composition of sample. The result of this study shows that with copper addition from 2.25 wt% to 3.11 wt%, the fluidity value has increased 24.11% on 680oC pouring temperature. On 3.11 wt% copper composition, fluidity value has increased 14.38% from 640oC pouring temperature to 700oC pouring temperature.

  14. Study on melting conditions of radioactive miscellaneous solid waste. Contract research

    International Nuclear Information System (INIS)

    Fukui, Toshiki; Nakashio, Nobuyuki; Isobe, Motoyasu; Otake, Atsushi; Wakui, Takuji; Nakashima, Mikio; Hirabayashi, Takakuni

    2001-02-01

    Improvement of fluidity of molten slag is one of the most important factors for plasma melting treatment of low level radioactive miscellaneous wastes generated from nuclear facilities. In general, it is considered that elevating molten slag temperature of addition of flux is of certain use in improvement of fluidity of molten slag. However, these ways are not necessarily suitable from the viewpoints of refractory erosion or reduction of waste volume. In this report, we suggested that fluidity of molten slag could be improved by controlling chemical compositions of molten slag. On the Basic of the investigation using phase diagram and viscosity data, FeO was selected as a key component for improving fluidity: Viscosity and melting point of molten slag decreased with increasing relative concentration of FeO in molten slag. Accordingly, we concluded that it is important to adjust basicity of molten slag for melting treatment of low-level radioactive miscellaneous solid wastes. (author)

  15. to view fulltext PDF

    Indian Academy of Sciences (India)

    Unknown

    larly during leaf and flower senescence and also during fruit ripening. This provides an .... PA binding is also known to affect membrane fluidity and thus PAs may ..... prokaryotes, algae, plants and fungi; in Polyamines: Basic and clinical ...

  16. Development of low weight self-levelling mortars

    International Nuclear Information System (INIS)

    Padilla, A; Panama, I; Toledo, A; Flores, A

    2015-01-01

    This work shows the development of self levelling mortars, using micro bubbles based on aluminium silicate with a density of 0.25 g/cm 3 . Mortars formulations are composed by 8 different components in order to achieve properties balance between fresh and solid state. The mean objective is development light weight mortars with high fluidity and compression strength using micro bubbles and some additives. Formulations were designed employing Taguchi DOE of 8 variables and 3 states. Result analysis according to Taguchi method lets indentify the preponderant effect of each variable on the cited properties. Several formulations reached fluidity higher than 250%, with compression strength around 100 kg/cm 2 and a low volumetric weigh. Obtained volumetric weights are 20% less than commercial self levelling mortars weight. Finally some relations are presented such: as relation water/cement with fluidity, and micro bubble content versus mortars volumetric weight, and finally compression strength versus the volumetric weight of mortars

  17. Casting characteristics of Al-Mg alloy 535 cast in permanent moulds

    International Nuclear Information System (INIS)

    Fasoyinu, F.A.; Thomson, J.; Cousineau, D.; Castles, T.; Sahoo, M.

    2002-01-01

    Aluminum alloy 535 could be used for automotive and marine applications because of its good corrosion resistance against mild alkaline and salt spray exposure. The majority of components from this alloy are usually produced by sand casting because it is prone to hot shortness and has poor fluidity when poured in permanent moulds. In an attempt to improve its castability in permanent moulds, casting characteristics such as casting fluidity and hot tear resistance have been studied. In addition, the effectiveness of titanium, boron, scandium, zirconium and a combination of selected elements from this group as grain refiners were evaluated. It s shown that alloy 535 exhibits good casting fluidity when poured with adequate metal superheat and that there is significant improvement in hot tear resistance following grain refinement. (author)

  18. Effects of semen preservation on boar spermatozoa head membranes.

    Science.gov (United States)

    Buhr, M M; Canvin, A T; Bailey, J L

    1989-08-01

    Head plasma membranes were isolated from the sperm-rich fraction of boar semen and from sperm-rich semen that had been subjected to three commercial preservation processes: Extended for fresh insemination (extended), prepared for freezing but not frozen (cooled), and stored frozen for 3-5 weeks (frozen-thawed). Fluorescence polarization was used to determine fluidity of the membranes of all samples for 160 min at 25 degrees C and also for membranes from the sperm-rich and extended semen during cooling and reheating (25 to 5 to 40 degrees C, 0.4 degrees C/min). Head plasma membranes from extended semen were initially more fluid than from other sources (P less than 0.05). Fluidity of head membranes from all sources decreased at 25 degrees C, but the rate of decrease was significantly lower for membranes from cooled and lower again for membranes from frozen-thawed semen. Cooling to 5 degrees C reduced the rate of fluidity change for plasma membranes from the sperm-rich fraction, while heating over 30 degrees C caused a significantly greater decrease. The presence of Ca++ (10 mM) lowered the fluidity of the head plasma membranes from sperm-rich and extended semen over time at 25 degrees C but did not affect the membranes from the cooled or frozen-thawed semen. The change in head plasma membrane fluidity at 25 degrees C may reflect the dynamic nature of spermatozoa membranes prior to fertilization. Extenders, preservation processes and temperature changes have a strong influence on head plasma membrane fluidity and therefore the molecular organization of this membrane.

  19. [Effect of extracted ZG from gardenia on Hep-2 cell membrane post infected with parainfluenza virus type 1 (PIV-1)].

    Science.gov (United States)

    Guo, Shan-Shan; Huang, Yang; Zhao, Ye; Gao, Ying-Jie; Gong, Wen-Feng; Cui, Xiao-Lan

    2007-09-01

    In order to study the anti-viral mechanism of extracted ZG from Gardenia, the effect of extracted ZG on Hep-2 cell membrane potential, Na -K+-ATPase activity and membrane fluidity post infected with parainfluenza virus type 1 (PIV-1) was observed. Acetylcholine which was fluorescent labeled with DiBAC4 (3) was taken as positive control to observe the changes of membrane potential and was measured by flow cytometer. The phosphorus determination method and spectrophotometer were used to measure the Na+-K+-ATPase activity of Hep-2 cell membrane post PIV-1 infection. Hep-2 cell membrane phospholipids was labeled with fluorescent NBD-C6-HPC and membrane fluidity was measured by confocal laser scanning microscope. The results demonstated that after PIV-1 infection the Hep-2 cell membrane potential decreased significantly and the membrane was in the state of hyperpolarization, Na+-K+-ATPase activity increased and membrane fluidity decreased significantly. There was no apparent interferring effect of extracted ZG on the changes of membrane potential and Na+-K+-ATPase activity post PIV-1 infection, while membrane fluidity was improved significantly. Acetylcholine improved the state of hyperpolarization. The changes of membrane potential, Na -K+-ATPase activity and membrane fluidity might be the biomechanism of PIV-1 infectoin. The extracted ZG improved membrane fluidity to prevent from PIV-1 infection by protecting the cell membrane, which was probably the mechanism of anti-PIV-1 activity of the extracted ZG, but ZG probably had nothing to do with membrane potential and Na+-K+-ATPase activity.

  20. Service climate as a mediator of organizational empowerment in customer-service employees.

    Science.gov (United States)

    Mendoza-Sierra, Maria Isabel; Orgambídez-Ramos, Alejandro; Carrasco-González, Ana María; León-Jariego, José Carlos

    2014-01-01

    The aim of this study is to examine the mediating role of the service climate between organizational empowerment (i.e., dynamic structural framework, control of workplace decisions, fluidity in information sharing) and service quality (functional and relational). 428 contact employees from 46 hotels participated in the survey. Correlations demonstrated that dynamic structural framework, control decisions, and fluidity in information sharing are related to both functional and relational service quality. Regression analyses and Sobel tests revealed that service climate totally mediated the relationship between all three dimensions of organizational empowerment and relational service quality. Implications for practice and future research are discussed.

  1. Membrane damage induced in cultured human skin fibroblasts by UVA irradiation

    International Nuclear Information System (INIS)

    Gaboriau, F.; Morliere, P.; Marquis, I.; Moysan, A.; Geze, M.; Dubertret, L.

    1993-01-01

    Irradiation of cultured human skin fibroblasts with ultraviolet light from 320 to 400 nm (UVA) leads to a decrease in the membrane fluidity exemplified by an enhanced fluorescence anisotropy of the lipophilic fluorescent probe 1-[4-trimethylamino)-phenyl]-6-phenylhexa-1,3,5-triene. This UVA-induced decrease in fluidity is associated with lactate dehydrogenase leakage in the supernatant. Vitamin E, an inhibitor of lipid peroxidation, exerts a protective effect on both phenomena. Therefore, this UVA-induced damage in membrane properties may be related to lipid peroxidation processes. Moreover, exponentially growing cells are more sensitive to these UVA-induced alterations than confluent cells. (Author)

  2. Dislocation kinetics and the acoustic-wave approximation for liquids

    International Nuclear Information System (INIS)

    Stout, R.B.

    1983-03-01

    A dislocation-dependent model for liquids describes the lattice deformation and the fluidity deformation as additive deformations. The lattice deformation represents distortions of an atom's potential energy structure and is a recoverable deformation response. The fluidity deformation represents discontinuous repositioning of atoms by dislocation kinetics in the lattice structure and is a nonrecoverable deformation response. From this model, one concludes that in liquids the acoustic-wave approximation is a description of a recoverable oscillation deformation that has dissipation because of dislocation kinetics. Other more-complex waves may exist, but such waves would rapidly disappear because of the small thermodynamic potential for dislocation kinetics in liquids

  3. Structural modifications of vesicular aggregates following gamma-irradiation

    International Nuclear Information System (INIS)

    Mantaka-Marketou, A.E.; Domasou, A.S.

    1991-01-01

    The structural changes of the didodecyldimethylammonium bromide (DDAB) vesicular bilayers after γ-irradiation and under conditions where mainly OH radicals are present are reported. Alterations of the vesicular structure, such as polarity and fluidity, were detected after a dose of 0.65 kGy. A higher dose of ∼14kGy cause important damage to the well organized molecular structure and this is manifested by an important augmentation of the fluidity and polarity of the Stern region of the aggregates. Increased water penetration into the bilayer of the vesicle is probably the reason for these changes and electron micrographs support this hypothesis. (author)

  4. THE RHEOLOGY OF THE BLOOD. V.

    Science.gov (United States)

    Bingham, E C

    1945-07-20

    A study has been made of those proteins which might offer exceptions to the law that the fluidity of a protein solution is a linear function of the volume concentration; viz., egg albumin, serum albumin, pseudoglobulin, euglobulin, gelatin, and sodium caseinogenate. Solutions of egg albumin below 20 per cent by weight obey the above law but somewhat below 30 per cent the fluidities begin to be too high, presumably due to the contribution to the fluidity made by the deformation of the particles as they come into contact, as the fluidity approaches zero. The fluidity of serum albumin solutions shows a similar behavior, being exceptional above 15 per cent in weight. Pseudoglobulin and euglobulin give fluidity-concentration curves (Fig. 4) which are linear up to about 2.5 per cent each in a total range of 20 and 14 per cent respectively. From this singular point both compounds show a second range which is linear. Pseudoglobulin is the only substance whose solutions seem to show a third linear range. We have also used the data of Chick and Martin for sodium caseinogenate and found evidence for two linear régimes. It is desirable at this time to call attention to the measurements of the flow of glycogen solutions by Botazzi and d'Errico (14) which in Fluidity and See PDF for Structure plasticity, page 207, are expressed in rhes. The data show two linear fluidity curves of different slopes. In this case it was definitely known that the data for each curve were measured with different viscometers which suggested the possibility of an error in viscometry entering in to confuse the issue. We have no suspicions as to the reliability of the data studied in this paper; we only wish to caution the readers that our hypotheses based on these data must be regarded with due reserve until confirmed. We have found a formula (11) based on the supposed linear relation between logarithmic fluidities and concentration which is convenient to use within the range, but close examination

  5. Biophysical and lipofection studies of DOTAP analogs.

    Science.gov (United States)

    Regelin, A E; Fankhaenel, S; Gürtesch, L; Prinz, C; von Kiedrowski, G; Massing, U

    2000-03-15

    In order to investigate the relationship between lipid structure and liposome-mediated gene transfer, we have studied biophysical parameters and transfection properties of monocationic DOTAP analogs, systematically modified in their non-polar hydrocarbon chains. Stability, size and (by means of anisotropy profiles) membrane fluidity of liposomes and lipoplexes were determined, and lipofection efficiency was tested in a luciferase reporter gene assay. DOTAP analogs were used as single components or combined with a helper lipid, either DOPE or cholesterol. Stability of liposomes was a precondition for formation of temporarily stable lipoplexes. Addition of DOPE or cholesterol improved liposome and lipoplex stability. Transfection efficiencies of lipoplexes based on pure DOTAP analogs could be correlated with stability data and membrane fluidity at transfection temperature. Inclusion of DOPE led to rather uniform transfection and anisotropy profiles, corresponding to lipoplex stability. Cholesterol-containing lipoplexes were generally stable, showing high transfection efficiency at low relative fluidity. Our results demonstrate that the efficiency of gene transfer mediated by monocationic lipids is greatly influenced by lipoplex biophysics due to lipid composition. The measurement of fluorescence anisotropy is an appropriate method to characterize membrane fluidity within a defined system of liposomes or lipoplexes and may be helpful to elucidate structure-activity relationships.

  6. A digital humanities approach to the history of science: eugenics revisited in hidden debates by means of semantic text mining

    NARCIS (Netherlands)

    Huijnen, P.; Laan, F.; de Rijke, M.; Pieters, T.; Nadamoto, A.; Jatowt, A.; Wierzbicki, A.; Leidner, J.L.

    2014-01-01

    Comparative historical research on the the intensity, diversity and fluidity of public discourses has been severely hampered by the extraordinary task of manually gathering and processing large sets of opinionated data in news media in different countries. At most 50,000 documents have been

  7. A Digital Humanities Approach to the History of Science Eugenics Revisited in Hidden Debates by Means of Semantic Text Mining

    NARCIS (Netherlands)

    Huijnen, Pim; Laan, Fons; de Rijke, Maarten; Pieters, Toine

    2014-01-01

    Comparative historical research on the the intensity, diversity and fluidity of public discourses has been severely hampered by the extraordinary task of manually gathering and processing large sets of opinionated data in news media in different countries. At most 50,000 documents have been

  8. Combined Diffusion Tensor Imaging and Transverse Relaxometry in Early-Onset Bipolar Disorder

    Science.gov (United States)

    Gonenc, Atilla; Frazier, Jean A.; Crowley, David J.; Moore, Constance M.

    2010-01-01

    Objective: Transverse relaxation time (T2) imaging provides the opportunity to examine membrane fluidity, which can affect a number of cellular functions. The objective of the present work was to examine T2 abnormalities in children with unmodified DSM-IV-TR bipolar disorder (BD) in bilateral cingulate-paracingulate (CPC) white matter. Method: A…

  9. Influence des bulles gazeuses et des préparations fermentatives ...

    African Journals Online (AJOL)

    English Abstract. Molasses is the product of the manufacture of sugar cane or beet whose composition changes depending on the climatic conditions of de production of the raw materials and of the process of manufacture set up by the sugar refinery. It comes as a thick, homogenous, and brown liquid. Its fluidity is limited by ...

  10. Contribution à la formulation d\\'une pâte autoplaçante à base de ...

    African Journals Online (AJOL)

    A self consolidating concrete could be prepared while passing the scale of the paste to the one of the concrete while injecting some aggregates (sand and gravel). The rheology of the paste is studied according to dosages made of cement, in limestone filler, in superplasticizer and in water. Workability and fluidity of the ...

  11. "If Only I Did Not Have That Label Attached to Me": Foregrounding Self-Positioning and Intersectionality in the Experiences of Immigrant and Refugee Youth

    Science.gov (United States)

    Fruja Amthor, Ramona

    2017-01-01

    In order to bring forth the specific intricacies of the migration experience among comparatively understudied immigrant and refugee youth, this article bridges an intersectionality framework with multicultural education scholars' calls to flexibility and fluidity in conceptualizing culture and identity. Drawing on in-depth interviews, the analysis…

  12. Being in Community: A Food Security Themed Approach to Public Scholarship

    Science.gov (United States)

    Harrison, Barbara; Nelson, Connie; Stroink, Mirella

    2013-01-01

    For six years the Food Security Research Network at Lakehead University, Canada, has been engaged in an interdisciplinary theme-based service-learning initiative focusing on food security. Informed by complexity theory, the contextual fluidity partnership model brings community partners, students, and faculty into a nexus through which new…

  13. Stearic acid spin labels in lipid bilayers :  insight through atomistic simulations

    NARCIS (Netherlands)

    Stimson, L.M.; Dong, L.; Karttunen, M.E.J.; Wisniewska, A.; Dutka, M.; Róg, T.

    2007-01-01

    Spin-labeled stearic acid species are commonly used for electron paramagnetic resonance (EPR) studies of cell membranes to investigate phase transitions, fluidity, and other physical properties. In this paper, we use large-scale molecular dynamics simulations to investigate the position and behavior

  14. Injection molding of Y-TZP powders prepared by colloidal processing

    International Nuclear Information System (INIS)

    Kimura, Y.; Mineshita, O.; Kaga, T.; Tokinaga, T.; Obitsu, M.

    1991-01-01

    TZP powders containing 3mol% Y 2 O 3 were prepared from ZrOCl 2 solution via an aqueous colloidal suspension of ZrO 2 . Processing variables were optimized to obtain powders suitable for injection molding. Wettability of powders with binders, fluidity of melting compound, removal of binder from green body, and properties of sintered body were investigated

  15. The Perceived Impact of Conflict on Adolescent Relationships.

    Science.gov (United States)

    Laursen, Brett

    1993-01-01

    Examined adolescents' perceptions of their daily conflicts in relationships with mothers, fathers, siblings, friends, romantic partners, and other peers and adults. Most adolescent conflicts were perceived as benign events with few positive or negative consequences for the relationship. Results suggest that adolescents recognize the fluidity and…

  16. okoronkwo, ike francis

    African Journals Online (AJOL)

    Valued Acer Customer

    chain of events. Among these is a mass participation of people into an emerging global culture ... the enormous fluidities of location and identity, are the imperatives of existence of our age. .... searched for a plastic reality a year later and this became the beginning of sourcing imagery from electronic ..... Superpower in Africa.

  17. On the potential application of polar and temperate marine microalgae for EPA and DHA production

    NARCIS (Netherlands)

    Boelen, P.; van Dijk, R.; Sinninghe Damsté, J.S.; Rijpstra, W.I.C.; Buma, A.G.J.

    2013-01-01

    Long chain polyunsaturated fatty acids (LC-PUFAs) such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are considered essential omega-3 fatty acids in human nutrition. In marine microalgae EPA and/or DHA are allegedly involved in the regulation of membrane fluidity and thylakoid

  18. EFFECTS OF DIETARY CORN AND OLIVE OIL VERSUS COCONUT FAT ON BILIARY CHOLESTEROL SECRETION IN RATS

    NARCIS (Netherlands)

    SMIT, MJ; WOLTERS, H; TEMMERMAN, AM; KUIPERS, F; BEYNEN, AC; VONK, RJ

    1994-01-01

    We have studied the effects of dietary corn and olive oil versus coconut fat on bile formation and fluidity of hepatic plasma membranes in rats. After 4 weeks of feeding the purified diets containing 9% (w/w) of the test fats, there was no difference in plasma cholesterol concentration between the

  19. The uncomfortable context

    DEFF Research Database (Denmark)

    Houmøller, Kathrin; Bernays, Sarah

    2011-01-01

    A reflexive account of the influence of context and time on accessing and understanding young people's experiences of parental substance misuse. The account draws on the case of Emily, a 13 year-old girl, to illustrate the dilemmas involved in capturing the fluidity of young people's coping over ...

  20. Sphingolipid levels crucially modulate lateral microdomain organization of plasma membrane in living yeast

    Czech Academy of Sciences Publication Activity Database

    Večeř, J.; Veselá, Petra; Malínský, Jan; Herman, P.

    2014-01-01

    Roč. 588, č. 3 (2014), s. 443-449 ISSN 0014-5793 R&D Projects: GA ČR GAP205/12/0720 Institutional support: RVO:68378041 Keywords : membrane microdomain * lipid order * fluidity Subject RIV: BO - Biophysics Impact factor: 3.169, year: 2014

  1. The VLE as a Trojan Mouse: Policy, Politics and Pragmatism

    Science.gov (United States)

    Brown, Mark; Paewai, Shelley; Suddaby, Gordon

    2010-01-01

    This paper argues that selecting a new Learning Management System (LMS) is a strategic decision about the future direction of your institution. However, the development of a robust methodology for the selection of a new LMS is particularly challenging given the fluidity of the e-learning environment. This is especially so when both quantitative…

  2. Changing rooster sperm membranes to facilitate cryopreservation

    Science.gov (United States)

    Cryopreservation damages rooster sperm membranes. Part of this damage is due to membrane transitioning from the fluid to the gel state as temperature is reduced. This damage may be prevented by increasing membrane fluidity at low temperatures by incorporating cholesterol or unsaturated lipids into t...

  3. Effect of strong electrolytes on edible oils part II: vViscosity of maize ...

    African Journals Online (AJOL)

    The electrolytes behave as structure breaker. The effect of temperature was also determined in terms of fluidity parameters, energy of activation, latent heat of vaporization, molar volume of oil and free energy change of activation for viscous flow. Journal of Applied Sciences and Environmental Management Vol. 10 (3) 2006: ...

  4. Effect of strong electrolytes on edible oils part III: viscosity of canola ...

    African Journals Online (AJOL)

    ... in the positive values of B-coefficient. Fluidity parameters were also evaluated and the change in these values with temperature and concentration of oil shows that the electrolytes behave as structure breaker. The energy of activation, latent heat of vaporization and molar volume of oil were also evaluated and discussed.

  5. Na(+),K(+)-ATPase of human placenta during gestational hypertension: a biochemical-biophysical study

    Czech Academy of Sciences Publication Activity Database

    Rabini, R. A.; Zolese, G.; Staffolani, R.; Lucarelli, G.; Amler, Evžen; Cester, N.; Mazzanti, L.

    1996-01-01

    Roč. 91, č. 6 (1996), s. 719-723 ISSN 0143-5221 Institutional research plan: CEZ:AV0Z5011922 Keywords : activation energy * fluidity * gestational hypertension Subject RIV: CE - Biochemistry Impact factor: 2.154, year: 1996

  6. Queering Constructs: Proposing a Dynamic Gender and Sexuality Model

    Science.gov (United States)

    Jourian, T. J.

    2015-01-01

    Higher education educators commonly understand social identities, including gender, to be fluid and dynamic. Lev's (2004) model of four components of sexual identity is commonly used to demonstrate the fluidity of sex, gender, and sexuality for individuals, but it does little to address the fixedness of those constructs. Through a multipronged…

  7. KRW/USD Exchange Rate Volatility and Efficient Risk Management

    Directory of Open Access Journals (Sweden)

    Sang-Yong Joo

    1999-03-01

    Full Text Available This thesis analyzes the relationship between the exchange rate of Korean Won and US dollar and the amount of foreign exchange, and studies the direction of the amendment of the risk control of foreign exchange. The GARCH (Generalized Auto Regressive Conditional Heteroscedasticity model which visually embodies the auto-regress of the wave of exchange rate shows that the amount of trade will enhance the fluidity of the exchange rate, that is, the various expects of the participators of the market affect the amount of trade and the fluidity, so in the process of trading, the trader who is in the dry tree of information bears more trading expenditure. It is predicted that the liberalization of foreign exchange rate and fluctuated exchange rate system will jointly bring the enhancement of the fluidity of the exchange rate and the amount of exchange trade. The change of this system will bring the rise of participators in foreign exchange market; meanwhile, it will also initiate superfluous fluidity of foreign exchange market. In order to overcome this problem, the government needs to implement the development strategy of the understructure of the foreign exchange market and the enterprises need to carry through systemic exchange rate risk control.

  8. Religion, social mobility and education in Scotland.

    Science.gov (United States)

    Paterson, Lindsay; Iannelli, Cristina

    2006-09-01

    The relationship among religion, education and social mobility in Scotland is analysed statistically using the Scottish Household Survey of 2001. The large sample size allows much greater statistical power for this purpose than any previous source, and thus allows a more reliable assessment of claims that the stratifying effect of religion in Scotland may have declined. The questions investigated are as follows. What are the religious differences in the distributions of class origins and class destinations, in the movement between these (absolute mobility), and in the association of these (relative mobility, or social fluidity)? Do changes in social fluidity across cohorts vary among people with different religious affiliation? Are there religious differences in the association of origins and education, in the association of education and destinations, or in the role of education in social fluidity, and do any of these vary over cohorts? The conclusions are that, in younger cohorts, there is no religious difference in social status, and that in older cohorts Catholics are generally of lower status than Protestants and the non-religious. Social fluidity does not, however, vary among religious groups, even for older cohorts, and does not change over time. The reason for convergence in social status of religious groups over time is probably the equalizing of educational attainment among the groups: there is no evidence for any of the cohorts that the labour-market rewards to education differ by religion.

  9. Plasma cholesterol and sodium in some Nigerians | Ighoroje ...

    African Journals Online (AJOL)

    Cholesterol moderates the fluidity of cell membrane and this in turn controls the transmembrane movement of Na+. We have thus attempted to investigate the relationship of serum cholesterol and Na+ concentrations in some Nigerians. Blood samples were obtained from 122 healthy adult Nigerians and the plasma ...

  10. "Change4Life for Your Kids": Embodied Collectives and Public Health Pedagogy

    Science.gov (United States)

    Evans, Bethan; Colls, Rachel; Horschelmann, Kathrin

    2011-01-01

    Recent work in human geography has begun to explore the fluidity of bodily boundaries and to foreground the connectedness of bodies to other bodies/objects/places. Across multiple subdisciplinary areas, including health, children's and feminist geographies, geographers have begun to challenge the notion of a singular, bounded body by highlighting…

  11. "A Writer More than . . . A Child": A Longitudinal Study Examining Adolescent Writer Identity

    Science.gov (United States)

    Lammers, Jayne C.; Marsh, Valerie L.

    2018-01-01

    This article reconsiders theoretical claims of identity fluidity, stability, and agency through a longitudinal case study investigating one adolescent's writing over time and across spaces. Qualitative data spanning her four years of high school were collected and analyzed using a grounded theory approach with literacy-and-identity theory…

  12. Preparation, Characterization and Performances of Powdered Polycarboxylate Superplasticizer with Bulk Polymerization

    Directory of Open Access Journals (Sweden)

    Xiao Liu

    2014-08-01

    Full Text Available A polycarboxylate superplasticizer (PCE was synthesized in a non-solvent system with bulk polymerization and then was pulverized into powdered form to achieve a rapid transportation and convenient preparation. PCE synthesized by using isopentenyl polyethylene glycol (TPEG or isobutenyl polyethylene glycol (IPEG as a macromonomer exhibited the best fluidities and retaining properties at 80 °C and 75 °C, respectively. Besides, azobisisobutyronitrile (AIBN was suitable as an initiator, and the fumaric acid was suitable as the third monomer. The test results of 1H nuclear magnetic resonance (1H NMR confirmed the occurrences of polymerization, and the measurement results of molecular weight and distribution showed that PCE molecular weight characteristics were in accordance with their fluidity properties in cement paste. The application performances in cement showed that PCEs with the best paste fluidity retentions had the longest final setting time and the shortest setting time interval, and the PCEs with good fluidity properties can obviously delay the hydration process and lower the hydration heat. Accordingly, this is a novel, energy-saving and economical method to prepare powdered PCE in the field of concrete admixtures.

  13. Journal of Research in National Development

    African Journals Online (AJOL)

    The Journal of Research in National Development aims to encourage interdisciplinary ... Favorite articles are quantitative, empirical and developmentally biased. .... Tax aggressiveness and corporate social responsibility fluidity in Nigerian firms ... By Country · List All Titles · Free To Read Titles This Journal is Open Access.

  14. Four Models of Sharing Economy Platforms

    DEFF Research Database (Denmark)

    Constantiou, Ioanna; Marton, Attila; Tuunainen, Virpi Kristiina

    2017-01-01

    the resulting four sharing economy models "Franchiser," "Principal," "Chaperone" and "Gardener." Each model focuses on a different value proposition and strategic intent, but they all exploit the growing fluidity of organizational boundaries. Understanding the sharing economy in these terms enables businesses...

  15. Interaction of procyanidin B-3 with membrane lipids Fluorescence, DSC and FTIR studies

    Czech Academy of Sciences Publication Activity Database

    Cyboran-Mikolajczyk, S.; Zylka, R.; Jurkiewicz, Piotr; Pruchnik, H.; Oszmianski, J.; Hof, M.; Kleszczynska, H.

    2017-01-01

    Roč. 1859, č. 8 (2017), s. 1362-1371 ISSN 0005-2736 Institutional support: RVO:61388955 Keywords : FTIR * Fluidity * Hydration * dmpc Subject RIV: CF - Physical ; Theoretical Chemistry OBOR OECD: Physical chemistry Impact factor: 3.498, year: 2016

  16. An Overview of Microbiology Research in Japan, with Notes on Medical History, Education and Health Care.

    Science.gov (United States)

    1981-07-01

    the electron microscope to Japan, and discovery of vitamin B-decomposing bacteria (R. Kimura ). The Department of Microbiology recently underwent...the aid of monoclonal antibodies which have neutralizing activity. 22 Dr. Kimura is investigating the properties of Vibrio haemolyticus toxins, another...immunogenicity of the liposomes is the membrane fluidity, which can be regulated by modulating cholesterol content. Assistant Professor Hisashi Narimatsu

  17. Queering Black Racial Identity Development

    Science.gov (United States)

    Johnson, Alandis A.; Quaye, Stephen John

    2017-01-01

    We used queer theory to encourage readers to think differently about previous theories about Black racial identity development. Queer theory facilitates new and deeper understandings of how Black people develop their racial identities, prompting more fluidity and nuance. Specifically, we present a queered model of Black racial identity development…

  18. Will Global Warming Cause a Rise in Sea Level? A Simple Activity about the States of Water

    Science.gov (United States)

    Oguz, Ayse

    2009-01-01

    In this activity, a possible problem related to global warming is clarified by the principle of states of water. The activity consists of an experiment that includes three scientific principles: Archimedes' Principle, the Law of Conservation of Matter, and the fluidity of liquids. The experiment helps students raise questions and open new horizons…

  19. Flexibility and security: an asymmetrical relationship? The uncertain relevance of flexicurity policies for segmented labour markets and residual welfare regimes

    NARCIS (Netherlands)

    Mouriki, A.

    2009-01-01

    Against a background of growing international competition and of pervasive uncertainty and fluidity, flexicurity policies are being actively promoted in the EU policy agenda as a useful policy tool to address the needs of business to respond to rapid changes, while providing workers with a safety

  20. 49 CFR 1180.10 - Service assurance plans.

    Science.gov (United States)

    2010-10-01

    ... negative impacts. (c) Yard and terminal operations. The operational fluidity of yards and terminals is key... revised and how these revisions would affect service to customers. As part of this analysis, applicants... operations. They should also describe improvements related to future growth, and indicate the relationship of...

  1. Omega-3 Fatty Acid Supplementation for the Treatment of Children with Attention-Deficit/Hyperactivity Disorder Symptomatology: Systematic Review and Meta-Analysis

    Science.gov (United States)

    Bloch, Michael H.; Qawasmi, Ahmad

    2011-01-01

    Objective: Several studies have demonstrated differences in omega-3 fatty acid composition in plasma and in erythrocyte membranes in patients with attention-deficit/hyperactivity disorder (ADHD) compared with unaffected controls. Omega-3 fatty acids have anti-inflammatory properties and can alter central nervous system cell membrane fluidity and…

  2. Youth Participatory Action Research (YPAR) 2.0: How Technological Innovation and Digital Organizing Sparked a Food Revolution in East Oakland

    Science.gov (United States)

    Akom, Antwi; Shah, Aekta; Nakai, Aaron; Cruz, Tessa

    2016-01-01

    This article argues that technological innovation is transforming the flow of information, the fluidity of social action, and is giving birth to new forms of bottom up innovation that are capable of expanding and exploding old theories of reproduction and resistance because "smart mobs," "street knowledge," and "social…

  3. Symposium: "Crash": Rhetorically Wrecking Discourses of Race, Tolerance, and White Privilege

    Science.gov (United States)

    Nunley, Vorris L.

    2007-01-01

    From within the milieu of race and identity fatigue emerges "Crash." Winner of three Academy Awards, including Best Picture, "Crash" addresses how the fluidity of identity is pooled, ebbed, blocked, directed, dammed up. How identity and subjectivity are dammed up and mediated through the force of the anxieties, fears, and frustrations of people…

  4. A New Destination for "The Flying Bus"?: The Implications of Orlando-Rican Migration for Luis Rafael Sanchez's "La guagua aerea"

    Science.gov (United States)

    Barreneche, Gabriel Ignacio; Lombardi, Jane; Ramos-Flores, Hector

    2012-01-01

    Puerto Rican author Luis Rafael Sanchez's "La guagua aerea" explores the duality, hybridity, and fluidity of US-Puerto Rican identity through the frequent travel of migrants between New York City (the traditional destination city for Puerto Rican migrants) and the island. In recent years, however, the "flying bus" has adopted a…

  5. Application of shortened heat treatment cycles on A356 automotive brake calipers with respective globular and dendritic microstructures

    CSIR Research Space (South Africa)

    Moller, H

    2010-09-01

    Full Text Available The conventional casting alloy A356 is probably one of the most popular alloys used for semi-solid metal (SSM) forming. This is due to its high fluidity and good castability. This alloy can be heat treated alternatively to the T4, T5 or T6 temper...

  6. The threshold of indifference; rethinking immobility in explaining cross-border labour mobility

    NARCIS (Netherlands)

    Velde, B.M.R. van der; Houtum, H.J. van

    2004-01-01

    In the current aftermath the post-modern era more and more scholars within social studies are working with the concept of mobility, sometimes metaphorically termed liquidity or fluidity, to denote and typify the present assumed debordering and interwovenness of our current society. At the heart of

  7. Toward a Dialectical Model of Family Gender Discourse: Body, Identity, and Sexuality.

    Science.gov (United States)

    Blume, Libby Balter; Blume, Thomas W.

    2003-01-01

    Proposes a dialectical model representing gender discourse in families. A brief review of literature in sociology, psychology, and gender studies focuses on three dialectical issues: nature versus culture, similarity versus difference, and stability versus fluidity. Deconstructing gender theories from a postmodern feminist perspective, the authors…

  8. Effects of fluconazole on the secretome, the wall proteome, and wall integrity of the clinical fungus Candida albicans

    NARCIS (Netherlands)

    Sorgo, A.G.; Heilmann, C.J.; Dekker, H.L.; Bekker, M.; Brul, S.; de Koster, C.G.; de Koning, L.J.; Klis, F.M.

    2011-01-01

    Fluconazole is a commonly used antifungal drug that inhibits Erg11, a protein responsible for 14α-demethylation during ergosterol synthesis. Consequently, ergosterol is depleted from cellular membranes and replaced by toxic 14α-methylated sterols, which causes increased membrane fluidity and drug

  9. Lipid-protein interactions. The leucine transport system of Lactococcus lactis.

    NARCIS (Netherlands)

    Veld, Geertruida Elisabeth in 't

    1992-01-01

    In summary, it is concluded, that a functionally reconstituted leucine transport system of L. lactis is affected by bilayer features in the following order of importance: lipid headgroup (H+-bonding) › acyl chain carbon number (thickness) › cholesterol (fluidity) › acyl chain unsaturation (indirect

  10. A Ratchet Lens: Black Queer Youth, Agency, Hip Hop, and the Black Ratchet Imagination

    Science.gov (United States)

    Love, Bettina L.

    2017-01-01

    This article explores the utilization of the theory of a Black ratchet imagination as a methodological perspective to examine the multiple intersections of Black and queer identity constructions within the space of hip hop. In particular, I argue for the need of a methodological lens that recognizes, appreciates, and struggles with the fluidity,…

  11. The Multi/Plural Turn, Postcolonial Theory, and Neoliberal Multiculturalism: Complicities and Implications for Applied Linguistics

    Science.gov (United States)

    Kubota, Ryuko

    2016-01-01

    In applied linguistics and language education, an increased focus has been placed on plurality and hybridity to challenge monolingualism, the native speaker norm, and the modernist view of language and language use as unitary and bounded. The multi/plural turn parallels postcolonial theory in that they both support hybridity and fluidity while…

  12. Demons Registration of CT Volume and CBCT Projections for Adaptive Radiotherapy: Avoiding CBCT Reconstruction

    DEFF Research Database (Denmark)

    Bjerre, Troels; Aznar, M.; Munck af Rosenschöld, P.

    2012-01-01

    with adaptive fluidity (smoothing kernel width). For forward/back-projection, the separable footprints algorithm with trapezoid functions was applied. The similarity between the simulated and measured projections was measured as the SSD. Results: The figure shows a slice of; the CT volume (reference), the CT...

  13. Quality control of Photosystem II: reversible and irreversible protein aggregation decides the fate of Photosystem II under excessive illumination

    Directory of Open Access Journals (Sweden)

    Yasusi eYamamoto

    2013-10-01

    Full Text Available In response to excessive light, the thylakoid membranes of higher plant chloroplasts show dynamic changes including the degradation and reassembly of proteins, a change in the distribution of proteins, and large-scale structural changes such as unstacking of the grana. Here, we examined the aggregation of light-harvesting chlorophyll-protein complexes and Photosystem II core subunits of spinach thylakoid membranes under light stress with 77K chlorophyll fluorescence; aggregation of these proteins was found to proceed with increasing light intensity. Measurement of changes in the fluidity of thylakoid membranes with fluorescence polarization of diphenylhexatriene showed that membrane fluidity increased at a light intensity of 500–1,000 µmol photons m-2 s-1, and decreased at very high light intensity (1,500 µmol photons m-2 s-1. The aggregation of light-harvesting complexes at moderately high light intensity is known to be reversible, while that of Photosystem II core subunits at extremely high light intensity is irreversible. It is likely that the reversibility of protein aggregation is closely related to membrane fluidity: increases in fluidity should stimulate reversible protein aggregation, whereas irreversible protein aggregation might decrease membrane fluidity. When spinach leaves were pre-illuminated with moderately high light intensity, the qE component of non-photochemical quenching and the optimum quantum yield of Photosystem II increased, indicating that Photosystem II/ light-harvesting complexes rearranged in the thylakoid membranes to optimize Photosystem II activity. Transmission electron microscopy revealed that the thylakoids underwent partial unstacking under these light stress conditions. Thus, protein aggregation is involved in thylakoid dynamics and regulates photochemical reactions, thereby deciding the fate of Photosystem II.

  14. Phase separation of the plasma membrane in human red blood cells as a potential tool for diagnosis and progression monitoring of type 1 diabetes mellitus.

    Science.gov (United States)

    Maulucci, Giuseppe; Cordelli, Ermanno; Rizzi, Alessandro; De Leva, Francesca; Papi, Massimiliano; Ciasca, Gabriele; Samengo, Daniela; Pani, Giovambattista; Pitocco, Dario; Soda, Paolo; Ghirlanda, Giovanni; Iannello, Giulio; De Spirito, Marco

    2017-01-01

    Glycosylation, oxidation and other post-translational modifications of membrane and transmembrane proteins can alter lipid density, packing and interactions, and are considered an important factor that affects fluidity variation in membranes. Red blood cells (RBC) membrane physical state, showing pronounced alterations in Type 1 diabetes mellitus (T1DM), could be the ideal candidate for monitoring the disease progression and the effects of therapies. On these grounds, the measurement of RBC membrane fluidity alterations can furnish a more sensitive index in T1DM diagnosis and disease progression than Glycosylated hemoglobin (HbA1c), which reflects only the information related to glycosylation processes. Here, through a functional two-photon microscopy approach we retrieved fluidity maps at submicrometric scale in RBC of T1DM patients with and without complications, detecting an altered membrane equilibrium. We found that a phase separation between fluid and rigid domains occurs, triggered by systemic effects on membranes fluidity of glycation and oxidation. The phase separation patterns are different among healthy, T1DM and T1DM with complications patients. Blood cholesterol and LDL content are positively correlated with the extent of the phase separation patterns. To quantify this extent a machine learning approach is employed to develop a Decision-Support-System (DSS) able to recognize different fluidity patterns in RBC. Preliminary analysis shows significant differences(pBlood cells is a potential tool for diagnosis and progression monitoring of type 1 diabetes mellitus, and could allow customization and the selection of medical treatments in T1DM in clinical settings, and enable the early detection of complications.

  15. Phase separation of the plasma membrane in human red blood cells as a potential tool for diagnosis and progression monitoring of type 1 diabetes mellitus.

    Directory of Open Access Journals (Sweden)

    Giuseppe Maulucci

    Full Text Available Glycosylation, oxidation and other post-translational modifications of membrane and transmembrane proteins can alter lipid density, packing and interactions, and are considered an important factor that affects fluidity variation in membranes. Red blood cells (RBC membrane physical state, showing pronounced alterations in Type 1 diabetes mellitus (T1DM, could be the ideal candidate for monitoring the disease progression and the effects of therapies. On these grounds, the measurement of RBC membrane fluidity alterations can furnish a more sensitive index in T1DM diagnosis and disease progression than Glycosylated hemoglobin (HbA1c, which reflects only the information related to glycosylation processes. Here, through a functional two-photon microscopy approach we retrieved fluidity maps at submicrometric scale in RBC of T1DM patients with and without complications, detecting an altered membrane equilibrium. We found that a phase separation between fluid and rigid domains occurs, triggered by systemic effects on membranes fluidity of glycation and oxidation. The phase separation patterns are different among healthy, T1DM and T1DM with complications patients. Blood cholesterol and LDL content are positively correlated with the extent of the phase separation patterns. To quantify this extent a machine learning approach is employed to develop a Decision-Support-System (DSS able to recognize different fluidity patterns in RBC. Preliminary analysis shows significant differences(p<0.001 among healthy, T1DM and T1DM with complications patients. The development of an assay based on Phase separation of the plasma membrane of the Red Blood cells is a potential tool for diagnosis and progression monitoring of type 1 diabetes mellitus, and could allow customization and the selection of medical treatments in T1DM in clinical settings, and enable the early detection of complications.

  16. Development of granular powder manufacturing technology by spray pyrolysis

    International Nuclear Information System (INIS)

    Katoh, Yoshiyuki; Kawase, Keiichi; Takahashi, Yoshiharu; Todokoro, Akio

    1996-01-01

    For shortening of mixed-oxide (MOX) fuel manufacturing process and improvement in treatment of MOX-powder, we have been developing the granular powder production technology. Since the granular powders have excellent fluidity owing to the spherical shape, there is the possibility of modifying scattering and adcering of the powder in the process equipment. In this paper, spray pyrolysis process in adopted as the process of manufacturing the granular powders and the basic feasibility study has been carried out. The experimental results show that the manufactured granular powders have excellent fluidity and the diameter of the powders is controllable. Furthermore, high density pellets are formed by sintering the powders. Thus, it is clarified that this process is promising for the actual MOX fuel fabrication. (author)

  17. PAQR-2 regulates fatty acid desaturation during cold adaptation in C. elegans.

    Directory of Open Access Journals (Sweden)

    Emma Svensk

    Full Text Available C. elegans PAQR-2 is homologous to the insulin-sensitizing adiponectin receptors in mammals, and essential for adaptation to growth at 15°C, a low but usually acceptable temperature for this organism. By screening for novel paqr-2 suppressors, we identified mutations in genes involved in phosphatidylcholine synthesis (cept-1, pcyt-1 and sams-1 and fatty acid metabolism (ech-7, hacd-1, mdt-15, nhr-49 and sbp-1. We then show genetic evidence that paqr-2, phosphatidylcholines, sbp-1 and Δ9-desaturases form a cold adaptation pathway that regulates the increase in unsaturated fatty acids necessary to retain membrane fluidity at low temperatures. This model is supported by the observations that the paqr-2 suppressors normalize the levels of saturated fatty acids, and that low concentrations of detergents that increase membrane fluidity can rescue the paqr-2 mutant.

  18. PAQR-2 regulates fatty acid desaturation during cold adaptation in C. elegans.

    Science.gov (United States)

    Svensk, Emma; Ståhlman, Marcus; Andersson, Carl-Henrik; Johansson, Maja; Borén, Jan; Pilon, Marc

    2013-01-01

    C. elegans PAQR-2 is homologous to the insulin-sensitizing adiponectin receptors in mammals, and essential for adaptation to growth at 15°C, a low but usually acceptable temperature for this organism. By screening for novel paqr-2 suppressors, we identified mutations in genes involved in phosphatidylcholine synthesis (cept-1, pcyt-1 and sams-1) and fatty acid metabolism (ech-7, hacd-1, mdt-15, nhr-49 and sbp-1). We then show genetic evidence that paqr-2, phosphatidylcholines, sbp-1 and Δ9-desaturases form a cold adaptation pathway that regulates the increase in unsaturated fatty acids necessary to retain membrane fluidity at low temperatures. This model is supported by the observations that the paqr-2 suppressors normalize the levels of saturated fatty acids, and that low concentrations of detergents that increase membrane fluidity can rescue the paqr-2 mutant.

  19. Development of highly workable concrete, 'Neuro-crete'. Part 1. ; Basic properties of Neuro-crete and application to large-scale structures with heavy-reinforcement. Koryudo concrete (Neuro crete) no kaihatsu. 1. ; Neuro crete no kiso bussei to kamitsu haikin wo yusuru doboku kozobutsu eno tekiyo

    Energy Technology Data Exchange (ETDEWEB)

    Miura, N; Chikamatsu, R; Sogo, S; Haga, T; Iriya, K; Taniguchi, M [Obayashi Corp., Tokyo (Japan)

    1993-08-10

    This paper introduces a highly workable concrete, 'Neuro-crete' developed for the purpose of simplifying construction of concrete structures and improving their guality. This concrete has a feature that it can reduce or eliminate a compacting process. Resistance to separation of coarse aggregate from mortar (separation resistance) is required. A difference of the material from conventional concrete is an increased unit particulate amount (binder + inert particulate). The binders may include cement, blast furnace slag particulate, flyash, silica fume, and expander. The inert particulate may be limestone powder. Kinds and mixing ratio of binders are important in improving fluidity. The separation resistivity is largely affected by a water-cement ratio and a water-binder ratio. A flow distance limit exists to maintain the fluidity without decreasing the compression strength after curing. The internal structure having become denser suppresses progress of neutralization or salt penetration. Drying contraction is equivalent to or less than the conventional concrete. 5 refs., 30 figs., 3 tabs.

  20. Analytical studies into radiation-induced starch damage in black and white peppers

    International Nuclear Information System (INIS)

    Sharif, M.M.; Farkas, J.

    1993-01-01

    Temperature dependence of the apparent viscosity of heat-generalized suspensions of untreated and irradiated pepper samples has been investigated. There was a close linear correlation between the logarithm of ''fluidity'' (reciprocal of the apparent viscosity) and the reciprocal absolute temperature of the measurement. The slope of the regression line (the temperature dependence of fluidity) increased with the radiation dose. Gelatinization thermograms of aqueous suspensions of ground pepper samples were obtained by differential scanning calorimetry. Temperature characteristics of heat-gelatinization endotherms showed no significant differences between untreated and irradiated samples. A calorimetric method for damaged starch, the estimation of reducing power, and the alcohol-induced turbidity of aqueous extracts showed statistically significant increases of starch damage at doses higher than 4 kGy. These indices of starch-depolymerization have been changed less dramatically by irradiation than the apparent viscosity of the heat-gelatinized suspensions. (author)

  1. Expression of urokinase receptors by human trophoblast. A histochemical and ultrastructural analysis

    DEFF Research Database (Denmark)

    Multhaupt, H A; Mazar, A; Cines, D B

    1994-01-01

    BACKGROUND: Through their ability to invade endometrium, remodel the uterine spiral arteries, and sustain placental blood fluidity, trophoblast cells play a central role in establishing and maintaining the integrity of the uteroplacental vasculature. The expression of urokinase receptors by troph......BACKGROUND: Through their ability to invade endometrium, remodel the uterine spiral arteries, and sustain placental blood fluidity, trophoblast cells play a central role in establishing and maintaining the integrity of the uteroplacental vasculature. The expression of urokinase receptors...... at the leading edge of migrating extravillous trophoblast cells. Receptors were also abundantly expressed during the first and second trimesters of gestation by villous trophoblast, where they were located on apical villous projections and within intracellular vacuoles, a subset of which were lysosomes...

  2. Development of Thin Section Zinc Die Casting Technology

    Energy Technology Data Exchange (ETDEWEB)

    Goodwin, Frank [International Lead Zinc Research Org., Inc., Durham, NC (United States)

    2013-10-31

    A new high fluidity zinc high pressure die casting alloy, termed the HF alloy, was developed during laboratory trials and proven in industrial production. The HF alloy permits castings to be achieved with section thicknesses of 0.3 mm or less. Technology transfer activities were conducted to develop usage of the HF high fluidity alloy. These included production of a brochure and a one-hour webinar on the HF alloy. The brochure was then sent to 1,184 product designers in the Interzinc database. There was excellent reception to this mailing, and from this initial contact 5 technology transfer seminars were conducted for 81 participants from 30 companies across a wide range of business sectors. Many of the successful applications to date involve high quality surface finishes. Design and manufacturing assistance was given for development of selected applications.

  3. The actin homologue MreB organizes the bacterial cell membrane.

    Science.gov (United States)

    Strahl, Henrik; Bürmann, Frank; Hamoen, Leendert W

    2014-03-07

    The eukaryotic cortical actin cytoskeleton creates specific lipid domains, including lipid rafts, which determine the distribution of many membrane proteins. Here we show that the bacterial actin homologue MreB displays a comparable activity. MreB forms membrane-associated filaments that coordinate bacterial cell wall synthesis. We noticed that the MreB cytoskeleton influences fluorescent staining of the cytoplasmic membrane. Detailed analyses combining an array of mutants, using specific lipid staining techniques and spectroscopic methods, revealed that MreB filaments create specific membrane regions with increased fluidity (RIFs). Interference with these fluid lipid domains (RIFs) perturbs overall lipid homeostasis and affects membrane protein localization. The influence of MreB on membrane organization and fluidity may explain why the active movement of MreB stimulates membrane protein diffusion. These novel MreB activities add additional complexity to bacterial cell membrane organization and have implications for many membrane-associated processes.

  4. Barium sulphate preparations for use in double contrast examination of the upper gastrointestinal tract

    International Nuclear Information System (INIS)

    Anderson, W.; Harthill, J.E.; James, W.B.; Montgomery, D.

    1980-01-01

    Physical properties relevant to upper gastrointestinal radiology have been compared for five barium sulphate preparations and related to radiographic results. Evaluation of particles (size and stability) and whole suspension (dispersibility and fluidity) resulted in ranking of the preparations generally in accord with that based on radiological experience in double contrast examinations of the stomach. Experiments with extirpated pig stomach revealed a tendency for large particles in a low viscosity barium sulphate suspension to settle in mucosal grooves. This is believed to contribute to good radiographic definition of both the areae gastricae and small lesions. Particle size is therefore important and susceptibility to flocculation, a possible cause of random change in size during use, was assessed by measuring particle electrophoretic mobility under varying conditions; quantitative differences in suspension flow and dispersibility were also demonstrated. Fluidity and dispersibility together with rapid sedimentation of suitably sized particles resistant to flocculation underlie the successful use of low viscosity high density barium sulphate suspensions. (U.K.)

  5. Improvement of castable for tundish lining; Tandeisshu you futeikei taikabutsu no kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Takashi, Fujita.; Tanikawa, Kanji. [Kobe Steel Ltd., Kobe (Japan); Kamio, Hidetoshi.; Sugimoto, Masayuki.; Hosokawa, Kiyohiro.; Furukawa, Kunio. [Harima Ceramic Corp., Hyogo (Japan)

    1998-12-01

    To apply castable refractory, which contains 60% of calcined alumina composition, to Tundish Lining, composition of the castable refractory - content of alumina cement(AC), silica flour(SF) and residual expansion material was investigated and fluidity, modurus of rupture in bending(MOR) and stability in volume were improved. Because low AC content lowers MOR, SF content was increased. MOR measured after drying and after burning at 800 degree C got large when SF addition is increased, as well as of AC. Increased addition of SF made MOR measured after burning at 1000 degree C large but increasing of AC had no effect on it. Increasing of residual expansion material made differential change of linear change small, and resulted in good stability in volume, however, too much addition caused low fluidity. Field test in 20 metric tons Tundish Lining showed improvements in the life of refractory to 1.7 times longer and reduced cost of lining by 49%. (NEDO)

  6. Multiracial in Middle School: The Influence of Classmates and Friends on Changes in Racial Self-Identification.

    Science.gov (United States)

    Echols, Leslie; Ivanich, Jerreed; Graham, Sandra

    2017-11-27

    In the present research, the influence of racial diversity among classmates and friends on changes in racial self-identification among multiracial youth was examined (n = 5,209; M age  = 10.56 years at the beginning of sixth grade). A novel individual-level measure of diversity among classmates based on participants' course schedules was utilized. The findings revealed that although there was some fluidity in multiracial identification at the beginning of middle school, changes in multiracial identification were more evident later in middle school. In addition, although diversity among classmates and friends both increased the likelihood of multiracial identification in the beginning of middle school, only diversity among friends mattered later in middle school, when fluidity in multiracial identification was at its peak. © 2017 The Authors. Child Development © 2017 Society for Research in Child Development, Inc.

  7. The influence of form release agent application to the quality of concrete surfaces

    International Nuclear Information System (INIS)

    Klovas, A; Daukšys, M

    2013-01-01

    The main aim of this article was to obtain concrete surface quality changes by the usage of different form release agent application. Secondly, to determine blemishes of concrete surfaces and divide them according to combined method provided by two documents and by using computer program: CIB Report No. 24 T olerances on blemishes of concrete , GOST 13015.0–83 and I mageJ . Two different concrete compositions were made: BA1 (low fluidity, vibration is needed) and BA8 (high fluidity, vibration is not needed). Three castings with each formwork were conducted. Water emulsion based form release agent was used. Different applications (normal and excessive) of form release agent were used on the formwork

  8. Physisorbed Polymer-Tethered Lipid Bilayer with Lipopolymer Gradient

    Directory of Open Access Journals (Sweden)

    Christoph A. Naumann

    2012-11-01

    Full Text Available Physisorbed polymer-tethered lipid bilayers consisting of phospholipids and lipopolymers represent an attractive planar model membrane platform, in which bilayer fluidity and membrane elastic properties can be regulated through lipopolymer molar concentration. Herein we report a method for the fabrication of such a planar model membrane system with a lateral gradient of lipopolymer density. In addition, a procedure is described, which leads to a sharp boundary between regions of low and high lipopolymer molar concentrations. Resulting gradients and sharp boundaries are visualized on the basis of membrane buckling structures at elevated lipopolymer concentrations using epifluorescence microscopy and atomic force microscopy. Furthermore, results from spot photobleaching experiments are presented, which provide insight into the lipid lateral fluidity in these model membrane architectures. The presented experimental data highlight a planar, solid-supported membrane characterized by fascinating length scale-dependent dynamics and elastic properties with remarkable parallels to those observed in cellular membranes.

  9. A Digital Humanities Approach to the History of Science Eugenics Revisited in Hidden Debates by Means of Semantic Text Mining

    OpenAIRE

    Huijnen, Pim; Laan, Fons; de Rijke, Maarten; Pieters, Toine

    2014-01-01

    Comparative historical research on the the intensity, diversity and fluidity of public discourses has been severely hampered by the extraordinary task of manually gathering and processing large sets of opinionated data in news media in different countries. At most 50,000 documents have been systematically studied in a single comparative historical project in the subject area of heredity and eugenics. Digital techniques, like the text mining tools WAHSP and BILAND we have developed in two succ...

  10. Membrane properties of Enchytraeus albidus originating from contrasting environments: a comparative analysis

    Czech Academy of Sciences Publication Activity Database

    Fisker, K. V.; Bouvrais, H.; Overgaard, J.; Schöttner, Konrad; Ipsen, J. H.; Holmstrup, M.

    2015-01-01

    Roč. 185, č. 4 (2015), s. 389-400 ISSN 0174-1578 R&D Projects: GA MŠk(CZ) EE2.3.30.0032 Institutional support: RVO:60077344 Keywords : membrane fluidity * fluorescence anisotropy * bending rigidity Subject RIV: ED - Physiology Impact factor: 1.884, year: 2015 http://link.springer.com/article/10.1007%2Fs00360-015-0895-7

  11. Coupling of lipid membrane elasticity and in-plane dynamics

    Science.gov (United States)

    Tsang, Kuan-Yu; Lai, Yei-Chen; Chiang, Yun-Wei; Chen, Yi-Fan

    2017-07-01

    Biomembranes exhibit liquid and solid features concomitantly with their in-plane fluidity and elasticity tightly regulated by cells. Here, we present experimental evidence supporting the existence of the dynamics-elasticity correlations for lipid membranes and propose a mechanism involving molecular packing densities to explain them. This paper thereby unifies, at the molecular level, the aspects of the continuum mechanics long used to model the two membrane features. This ultimately may elucidate the universal physical principles governing the cellular phenomena involving biomembranes.

  12. Cluster Sampling Bias in Government-Sponsored Evaluations: A Correlational Study of Employment and Welfare Pilots in England

    OpenAIRE

    Vaganay, Arnaud

    2016-01-01

    For pilot or experimental employment programme results to apply beyond their test bed, researchers must select 'clusters' (i.e. the job centres delivering the new intervention) that are reasonably representative of the whole territory. More specifically, this requirement must account for conditions that could artificially inflate the effect of a programme, such as the fluidity of the local labour market or the performance of the local job centre. Failure to achieve representativeness results ...

  13. Biguanides Inhibit Complex I, II and IV of Rat Liver Mitochondria and Modify Their Functional Properties

    Czech Academy of Sciences Publication Activity Database

    Drahota, Zdeněk; Páleníčková, E.; Endlicher, R.; Milerová, Marie; Brejchová, Jana; Vošahlíková, Miroslava; Svoboda, Petr; Kazdová, L.; Kalous, M.; Červinková, Z.; Cahová, M.

    2014-01-01

    Roč. 63, č. 1 (2014), s. 1-11 ISSN 0862-8408 R&D Projects: GA MŠk(CZ) LL1204; GA ČR(CZ) GAP207/12/0919 Grant - others:Univerzita Karlova(CZ) PRVOUK P37/02 Institutional support: RVO:67985823 Keywords : metformin * phenformin * mitochondrial enzymes * mitochondrial permeability transition pore * membrane fluidity Subject RIV: ED - Physiology Impact factor: 1.293, year: 2014

  14. The new disease model of alcoholism.

    OpenAIRE

    Wallace, J

    1990-01-01

    The new biopsychosocial disease model of alcoholism is examined from the perspective of recent biologic research. Studies of animal and human genetic predispositions suggest the presence of genetic influences over drinking behavior as well as biologic risk factors related to deficiencies in various neurochemicals. Ethanol affects the fluidity of cell membrane lipids, eventually causing membrane dysfunction. It also adversely affects the activity of two enzymes, monoamine oxidase and adenylate...

  15. The radioinduced membranes injuries as biological dose indicators: mechanisms of studies and practical applications; Les dommages membranaires radio-induits comme bio-indicateurs de dose: etudes des mecanismes et applications pratiques

    Energy Technology Data Exchange (ETDEWEB)

    Vincent-Genod, Lucie

    2001-10-15

    After an accidental overexposure, the assessment of the received dose in biological dosimetry is performed by a method based on the effects of irradiation on the DNA molecule. But this technique shows some limitations; therefore we tried to find new bio-sensors of radiation exposure. We have pointed out that membrane is a critical target of ionising radiation after an in vitro and in vivo overexposure. In vitro, these modifications were involved in the radio-induced apoptotic pathway. The measure of membrane fluidity allowed us to obtain an overall view of cellular membrane. Moreover, in vivo, by changing the lipid nutritional status of animals, our results displayed the important role played by membrane lipid composition in radio-induced membrane alterations. Besides, membrane effects were adjusted by the extracellular physiological control, and in particular by the damages on membrane fatty acid pattern. Finally, we have tested the use of membrane fluidity index as a bio-sensor of radiation exposure on in vivo models and blood samples from medical total body irradiated patients. The results achieved on animal models suggested that the membrane fluidity index was a bio-sensor of radiation exposure. Nevertheless, the observations realised on patients highlight that the effect of the first dose fraction of the radiotherapy treatment had some difficulties to be noticed. Indeed, the combined treatment: chemotherapy and radiotherapy disturbed the membrane fluidity index measures. To conclude, whereas this parameter was not a bio-sensor of irradiation exposure usable in biological dosimetry, it may allow us to assess the radio-induced damages and their cellular but also tissue impacts. (author)

  16. Illicit networks targeting the nexus between terrorists, proliferators, and narcotraffickers

    OpenAIRE

    Dietz, Rebekah K.

    2010-01-01

    Approved for public release; distribution is unlimited Globalization and the liberal international marketplace have provided fertile ground for the rise of transnational and non-state actors. Unfortunately, while states and businesses have profited from the increased fluidity of borders and the rise of global commerce, so have the criminal organizations that threaten national and international security. These illicit networks are stateless; they conduct their business in failed or failing ...

  17. Reversible bulk-phase change of anthroyl compounds for photopatterning based on photodimerization in the molten state and thermal back reaction.

    Science.gov (United States)

    Kihara, Hideyuki; Yoshida, Masaru

    2013-04-10

    As new organic materials for rewritable photopatterning, 2-anthroyl and 9-anthroyl ester compounds were synthesized. Their bulk-phase changes (we use "bulk-phase change" as complete phase change in a mass of a material neither in a surface nor in a small quantity in this study) triggered by photodimerization under melting conditions (melt-photodimerization) and subsequent thermal back reactions were investigated. All the anthroyl compounds exhibited melting points lower than ca. 160 °C, and they were nearly quantitatively converted to the corresponding photodimers by UV irradiation at temperatures of ∼5 °C higher than their respective melting points. We found that there were two kinds of bulk-phase change behaviors through the photoreaction. Two of the anthroyl compounds remained isotropic and lost fluidity during the melt-photodimerization. The obtained photodimers exhibited robust solid-state amorphous phases at room temperature. In contrast, the other three anthroyl compounds showed crystallization during the melt-photodimerization. The resulting photodimers changed from isotropic to crystalline phases, even at high temperature. Various experiments revealed that the bulk phase of the photodimers was affected not by the existence of regioisomers but by their fluidity at the photoirradiation temperature. The latter three photodimers retained enough fluidity, reflecting their high molecular mobilities at the photoirradiation temperature at which the isothermal crystallization occurred. The other two products were not able to crystallize due to low fluidity, resulting in amorphous phases. We also found that all the photodimers reverted to the corresponding monomers by thermal back reaction and recovered their initial photochemical and thermal properties. Using these reversible bulk-phase changes of the anthroyl compounds, we successfully demonstrated rewritable photopatterning in not only negative images but also positive ones, based on the optical contrast

  18. The radioinduced membranes injuries as biological dose indicators: mechanisms of studies and practical applications

    International Nuclear Information System (INIS)

    Vincent-Genod, Lucie

    2001-10-01

    After an accidental overexposure, the assessment of the received dose in biological dosimetry is performed by a method based on the effects of irradiation on the DNA molecule. But this technique shows some limitations; therefore we tried to find new bio-sensors of radiation exposure. We have pointed out that membrane is a critical target of ionising radiation after an in vitro and in vivo overexposure. In vitro, these modifications were involved in the radio-induced apoptotic pathway. The measure of membrane fluidity allowed us to obtain an overall view of cellular membrane. Moreover, in vivo, by changing the lipid nutritional status of animals, our results displayed the important role played by membrane lipid composition in radio-induced membrane alterations. Besides, membrane effects were adjusted by the extracellular physiological control, and in particular by the damages on membrane fatty acid pattern. Finally, we have tested the use of membrane fluidity index as a bio-sensor of radiation exposure on in vivo models and blood samples from medical total body irradiated patients. The results achieved on animal models suggested that the membrane fluidity index was a bio-sensor of radiation exposure. Nevertheless, the observations realised on patients highlight that the effect of the first dose fraction of the radiotherapy treatment had some difficulties to be noticed. Indeed, the combined treatment: chemotherapy and radiotherapy disturbed the membrane fluidity index measures. To conclude, whereas this parameter was not a bio-sensor of irradiation exposure usable in biological dosimetry, it may allow us to assess the radio-induced damages and their cellular but also tissue impacts. (author)

  19. Sex-Dependent Changes in Striatal Dopamine Transport in Preadolescent Rats Exposed Prenatally and/or Postnatally to Methamphetamine

    Czech Academy of Sciences Publication Activity Database

    Šírová, J.; Krištofíková, Z.; Vrajová, M.; Fujakova-Lipski, M.; Řípová, D.; Klaschka, Jan; Šlamberová, R.

    2016-01-01

    Roč. 41, č. 8 (2016), s. 1911-1923 ISSN 0364-3190 Grant - others:GA MŠk(CZ) ED2.1.00/03.0078; GA ČR(CZ) GA14-03708S; Univerzita Karlova(CZ) Prvouk P34; GA UK(CZ) 88315; SVV(CZ) 260277/2016 Institutional support: RVO:67985807 Keywords : methamphetamine * dopamine transporte * sex differences * membrane fluidity Subject RIV: FH - Neurology Impact factor: 2.581, year: 2016

  20. Effect of various enhancers on transdermal penetration of indomethacin and urea, and relationship between penetration parameters and enhancement factors.

    Science.gov (United States)

    Ogiso, T; Iwaki, M; Paku, T

    1995-04-01

    The enhancing capacity of various chemicals, which are widely recognized as enhancers, for the transdermal penetration into full-thickness rat skin of a model lipophilic drug [indomethacin (IND)] and a hydrophilic permeant (urea) was estimated by an in vitro technique. In addition, the fluidity of the stratum corneum lipids, the partitioning of IND into skin, the lipid (ceramides) extraction from the stratum corneum by enhancers, and the IND solubility in enhancer vehicle were measured and related to the enhancing capacity. In vitro permeation experiments with hairless rat skin unequivocally revealed that the enhancers varied in abilities to enhance the fluxes of both agents. Laurocapram, isopropylmyristate (IPM), sodium oleate, and cineol increased fluxes of both agents to a great extent, but N-methyl-2-pyrrolidone (NMP), N,N-diethyl-m-tolamide (DEET), and oleyl oleate were less effective acclerants. Many enhancers increased the fluidity of the lipids [with a threshold of approximately 0.6-0.8 ns at 37 degrees C in the rotational correlation time (tau c)], the skin partitioning of IND, the extraction of ceramides from the cornified cells, and the thermodynamic activity of IND in vehicle (calculated from the solubility) to varying extents. A good correlation was observed between the increase in the fluidity of stratum corneum lipids and the partitioning of IND into skin, between the increase in the fluidity and the flux or the decrease in lag time for IND, between the removal of ceramides and the skin partitioning of IND, and between the removal of ceramides and the flux of urea (p < 0.05 in all cases).(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Molecular view of the interaction between iota-carrageenan and a phospholipid film and its role in enzyme immobilization.

    Science.gov (United States)

    Nobre, Thatyane M; de Sousa e Silva, Heurison; Furriel, Rosa P M; Leone, Francisco A; Miranda, Paulo B; Zaniquelli, Maria Elisabete D

    2009-05-28

    Proteins incorporated into phospholipid Langmuir-Blodgett (LB) films are a good model system for biomembranes and enzyme immobilization studies. The specific fluidity of biomembranes, an important requisite for enzymatic activity, is naturally controlled by varying phospholipid compositions. In a model system, instead, LB film fluidity may be varied by covering the top layer with different substances able to interact simultaneously with the phospholipid and the protein to be immobilized. In this study, we immobilized a carbohydrate rich Neurospora crassa alkaline phosphatase (NCAP) in monolayers of the sodium salt of dihexadecylphosphoric acid (DHP), a synthetic phospholipid that provides very condensed Langmuir films. The binding of NCAP to DHP Langmuir-Blodgett (LB) films was mediated by the anionic polysaccharide iota-carrageenan (iota-car). Combining results from surface isotherms and the quartz crystal microbalance technique, we concluded that the polysaccharide was essential to promote the interaction between DHP and NCAP and also to increase the fluidity of the film. An estimate of DHP:iota-car ratio within the film also revealed that the polysaccharide binds to DHP LB film in an extended conformation. Furthermore, the investigation of the polysaccharide conformation at molecular level, using sum-frequency vibrational spectroscopy (SFG), indicated a preferential conformation of the carrageenan molecules with the sulfate groups oriented toward the phospholipid monolayer, and both the hydroxyl and ether groups interacting preferentially with the protein. These results demonstrate how interfacial electric fields can reorient and induce conformational changes in macromolecules, which may significantly affect intermolecular interactions at interfaces. This detailed knowledge of the interaction mechanism between the enzyme and the LB film is relevant to design strategies for enzyme immobilization when orientation and fluidity properties of the film provided by the

  2. Dimensions of somatization and hypochondriasis.

    Science.gov (United States)

    Ford, C V

    1995-05-01

    A significantly large group of patients who communicate their psychosocial distress in the form of physical symptoms are called somatizers. They tend to overuse medical services. The syndromes with which they present have indistinct boundaries, and there tends to be some fluidity of their symptomatic presentations. Underlying psychiatric disorders such as mood disorders, anxiety disorders (including obsessive compulsive disorder), and personality disorders are frequently present.

  3. Calculation of the density of liquid radon

    International Nuclear Information System (INIS)

    Herreman, W.

    1980-01-01

    Eleven condensed gases were investigated to relate their critical molar volume Vsub(c) to their molar volume Vsub(o)(Vsub(o) is the molar volume where the fluidity phi = 0). From this relationship the critical density of radon was calculated psub(c) = 1613 kg m -3 . From this principle of corresponding states for viscosity and with this value for psub(c) the density for the saturated liquid state of radon was predicted. (author)

  4. Lifestyle mobilities: The crossroads of travel, leisure and migration

    OpenAIRE

    Cohen, Scott; Duncan, T; Thulemark, M

    2013-01-01

    This article examines how the mobilities paradigm intersects with physically moving as an on-going lifestyle choice. We conceptualise a lens of ‘lifestyle mobilities’ that challenges discrete notions of, and allows for a wider grasp of the increasing fluidity between travel, leisure and migration. We demonstrate how contemporary lifestyle-led mobility patterns contribute to and illustrate a breakdown in conventional binary divides between work and leisure, and a destabilisation of concepts of...

  5. KRW/USD Exchange Rate Volatility and Efficient Risk Management

    OpenAIRE

    Sang-Yong Joo; Chae-Shick Chung; Young-Woo Lee

    1999-01-01

    This thesis analyzes the relationship between the exchange rate of Korean Won and US dollar and the amount of foreign exchange, and studies the direction of the amendment of the risk control of foreign exchange. The GARCH (Generalized Auto Regressive Conditional Heteroscedasticity) model which visually embodies the auto-regress of the wave of exchange rate shows that the amount of trade will enhance the fluidity of the exchange rate, that is, the various expects of the participators of the ma...

  6. 'Change4Life for your kids' : embodied collectives and public health pedagogy.

    OpenAIRE

    Evans, B.; Colls, R.; Horschelmann, K.

    2011-01-01

    Recent work in human geography has begun to explore the fluidity of bodily boundaries and to foreground the connectedness of bodies to other bodies/objects/places. Across multiple subdisciplinary areas, including health, children's and feminist geographies, geographers have begun to challenge the notion of a singular, bounded body by highlighting the importance of, for example, relations of care and intergenerationality to everyday embodied experiences; remembered past/anticipated future bodi...

  7. Studying structurally-mechanical characteristics suppositories with amlodipine

    Directory of Open Access Journals (Sweden)

    Fadi Al Zedan

    2013-02-01

    Full Text Available Rheological behaviour suppositories with amlodipine on lypofiles to a basis are studied and character of temperature effect on their structurally-mechanical properties is positioned. It is revealed that the temperature of carrying out of technological operations of homogenization and overflow suppositories 50-55ºС is optimum, providing necessary fluidity suppositories masses at hypodispersion in it reacting and aids.

  8. Correlation of polyunsaturated fatty acids with the cold adaptation of Rhodotorula glutinis.

    Science.gov (United States)

    He, Jing; Yang, Zhaojie; Hu, Binbin; Ji, Xiuling; Wei, Yunlin; Lin, Lianbing; Zhang, Qi

    2015-11-01

    This study aimed to investigate the correlation between the cold adaptation of Rhodotorula glutinis YM25079 and the membrane fluidity, content of polyunsaturated fatty acids and mRNA expression level of the Δ(12)-desaturase gene. The optimum temperature for YM25079 growth was analysed first, then the composition changes of membrane lipid in YM25079 were detected by GC-MS and membrane fluidity was evaluated by 1-anilinonaphthalene-8-sulphonate (ANS) fluorescence. Meanwhile, the encoding sequence of Δ(12)-fatty acid desaturase in YM25079 was cloned and further transformed into Saccharomyces cerevisiae INVScl for functional analysis. The mRNA expression levels of Δ(12)-fatty acid desaturase at 15°C and 25°C were analysed by real-time PCR. YM25079 could grow at 5-30°C, with the optimum temperature of 15°C. The membrane fluidity of YM25079 was not significantly reduced when the culture temperature decreased from 25°C to 15°C, but the content of polyunsaturated fatty acids (PUFAs), including linoleic acid and α-Linolenic acid increased significantly from 29.4% to 55.39%. Furthermore, a novel Δ(12)-fatty acid desaturase gene YM25079RGD12 from YM25079 was successfully identified and characterized, and the mRNA transcription level of the Δ(12)-desaturase gene was about five-fold higher in YM25079 cells grown at 15°C than that at 25°C. These results suggests that the cold adaptation of Rhodotorula glutinis YM25079 might result from higher expression of genes, especially the Δ(12)-fatty acid desaturase gene, during polyunsaturated fatty acids biosynthesis, which increased the content of PUFAs in the cell membrane and maintained the membrane fluidity at low temperature. Copyright © 2015 John Wiley & Sons, Ltd.

  9. Physical model of the heat flow 'q' in to the rock massifs in the Kochani depression

    International Nuclear Information System (INIS)

    Karakashev, Deljo

    2006-01-01

    The numerous regional geologic and hydrogeological eplorations carried out in the Kochani depression by the end of the last century and those carried out lately indicate that the area possesses large thermal potentiality. The physical analysis presents one physical model who eplain the thermal flow who fluidity yielding in to the rock massive in the Kochani depression. The models offer a clear picture on the geothermal energy, which becomes important for the economies in developing and developed countries.

  10. Fourier Transform Infrared Imaging Shows Reduced Unsaturated Lipid Content in the Hippocampus of a Mouse Model of Alzheimer’s Disease

    OpenAIRE

    Leskovjan, Andreana C.; Kretlow, Ariane; Miller, Lisa M.

    2010-01-01

    Polyunsaturated fatty acids are essential to brain functions such as membrane fluidity, signal transduction, and cell survival. It is also thought that low levels of unsaturated lipid in the brain may contribute to Alzheimer’s disease (AD) risk or severity. However, it is not known how accumulation of unsaturated lipids is affected in different regions of the hippocampus, which is a central target of AD plaque pathology, during aging. In this study, we used Fourier Transform Infrared Imaging ...

  11. Intensification of transferring the Kazakhstan high-congealed oil: challenges and advances

    Energy Technology Data Exchange (ETDEWEB)

    Maimakov, Tayhan P.; Boiko, Galinal; Lyubchenko, Nina P. [High education institute «UNAT», Almaty (Kazakhstan); Shaihutdinov, Yerengaip M. [Kazakh national technical university, Almaty (Kazakhstan)

    2008-07-01

    It were investigated the rheohgica! parameters of South-Turgay region crude oils at presence of novel pour point depressant additive DP-43/2005. It has shown that additive improves pour point and rheohgica; properties of crude oil mixture Kumkol-Akshabidak, inhibits wax deposition and can provide safe conditions of crude oil mixture transportation through pipeline at the cold season of year. Keywords: oil, temperature of fluidity loss, rheology, viscosity, oligomer depressor dopants.

  12. Development, Stability and Legitimacy: Minority Education Reform in Myanmar

    Science.gov (United States)

    2014-10-30

    institutional theory is not sufficiently dynamic to account for the number of variables and general fluidity of politics to achieve the level of...download =54:presentation. Peters, B. Guy. “ Institutional Theory : Problems and Prospects.” Institute for Advanced Studies, 2000. Accessed 16...institution theory. 41 B. Guy Peters, Institutional Theory : Problems and Prospects (Institute for Advanced Studies: 2000), accessed 16 September 2014

  13. Anesthetic consideration in a postchemotherapy pediatric patient for segmental mandibulectomy with free fibula reconstruction

    Directory of Open Access Journals (Sweden)

    Amit Kumar Mittal

    2017-01-01

    Full Text Available We report successful anesthetic management of a postchemotherapy pediatric patient having Ewing's Sarcoma mandible who underwent segmental mandibulectomy with free fibula reconstruction. The main challenges were securing difficult airway due to fragile mandible and maintenance of ideal blood rheostatic properties in an attempt to ensure optimal fluidity in microcirculation for the viability of flap. Other aspects of care like prevention of postoperative thrombosis of anastomotic vessels and need of tracheostomy for postoperative elective ventilation are being discussed.

  14. Involvement of membrane lipids in radiation damage to potassium-ion permeability of Escherichia coli

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, S [Tokyo Univ. (Japan). Inst. for Medical Science; Akamatsu, Y

    1978-02-01

    Radiation damage to K/sup +/ permeability of an unsaturated fatty acid auxotroph of E.coli grown with oleate or linolenate was investigated at different temperatures. A remarkable effect of radiation was observed at 0/sup 0/C with cells that had been grown in linolenate at 42/sup 0/C. This indicates that, besides protein, membrane lipids at least are involved in the radiation damage. The damage also seems to be affected by the fluidity of membrane lipids.

  15. Pelletizing of NaF granules as adsorbent for fluorides of nuclear fuel materials, (1)

    International Nuclear Information System (INIS)

    Kimura, Syojiro; Tsutsui, Tenson; Kanagawa, Akira.

    1976-01-01

    The pelletizing of NaF granules on laboratory scale used for recovery and purification of fluorides of nuclear fuel materials are investigated, particularity experimental studies on how to pelletize, fluidity of granules and flow rate of the granules in mortar of tablet machine are carried out. As result, added quantity of H 2 O as binder at granulation process of spherical NaF granule influence to yield of NaF granules. The proper quantity of H 2 O to NaF powder is about 18--19%. Friction coefficient of unfixed shape NaF granule is higher than that of spherical granule, in opposition, density of the former granule is lower. So fluidity of unfixed shape NaF granule is low, flow rate of the granules through feeder of tablet machine is slow, and arching on mortar of the tablet machine occurs. Then, some further operation for getting better fluidity needs for pelletizing of NaF granules using unfixed shape granule. The other hand, using spherical NaF granule, continuous pelletizing by commercial tablet machine can be carried out. (auth.)

  16. Vitamin E supplementation protects erythrocyte membranes from oxidative stress in healthy Chinese middle-aged and elderly people.

    Science.gov (United States)

    Sun, Yongye; Ma, Aiguo; Li, Yong; Han, Xiuxia; Wang, Qiuzhen; Liang, Hui

    2012-05-01

    Elderly people are subject to higher levels of oxidative stress than are young people. Vitamin E, as a powerful antioxidant residing mainly in biomembranes, may provide effective protection against oxidative membrane damage and resultant age-related deterioration, especially in the elderly. We hypothesized that appropriate levels of vitamin E supplementation would protect erythrocyte membranes from oxidative stress and thus improve membrane fluidity in healthy middle-aged and elderly people. To test this, we conducted a 4-month double-blind, randomized trial in which 180 healthy subjects (55-70 years old) were randomly divided into 4 groups: group C (control), and 3 treatment groups in which daily doses of 100 mg (VE1), 200 mg (VE2), and 300 mg (VE3) dl-α-tocopheryl acetate were administered. We measured plasma α-tocopherol concentration, malondialdehyde, and superoxide dismutase levels, erythrocyte hemolysis, and erythrocyte membrane fluidity at the beginning and end of the trial. After 4 months supplementation, plasma α-tocopherol concentrations in the 3 treatment groups had increased by 71%, 78%, and 95%, respectively (all P stress in healthy middle-aged to elderly people, at least in part by improving erythrocyte membrane fluidity and reducing erythrocyte hemolysis. Copyright © 2012 Elsevier Inc. All rights reserved.

  17. Mushy Zone Properties and Castability of Aluminium Foundry Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dahle, A.K.

    1996-01-01

    The growing application and market share of aluminium castings demand better understanding of the mechanisms of defect formation during casting. Although casting is a cost-effective production route, inadequate reproducibility and quality of the cast structure often restrict the utilization of castings. This doctoral thesis aims to (1) determine how the solidification conditions affect the rheological behaviour in the partially solidified state, (2) to measure how alterations in solidification variables influence castability, and (3) to investigate the relationship between mushy zone rheology and castability. The development of mechanical strength in the mushy zone was measured as a function of chemical composition. Measurements of the dendrite coherency point provided accurate determination of the point where the dendrite network is established. The strength measurements confirm that the dendrites are largely independent and free-floating before dendrite coherency. The point and rate of strength development in the subsequently established interdendritic network strongly depend on the size and morphology of the dendrites and fraction solid. The castability investigation was limited to evaluations of fluidity and feeding. Fluidity measurements showed a complex effect of increased grain refinement. Alterations of the concentration and type of main alloying element gave a direct relationship between mushy zone rheology and fluidity. The range of the operating feeding mechanisms during solidification is directly related to the rheological properties of the mushy zone. 251 refs., 77 refs., 25 tabs.

  18. Influence of Temperature and Storing Time on Selected Red Wine Physical Properties

    Directory of Open Access Journals (Sweden)

    Peter Hlaváč

    2016-01-01

    Full Text Available Presented article is focused on red wine rheological and thermal properties. Effects of temperature and short term storage on density, rheological parameters and thermal parameters were investigated. First measurement was done at the beginning of storage and then the same sample was measured again after one week of storing. Density was measured by densimeter Mettler Toledo DM 40 at different temperatures. For dynamic viscosity measurement was used rotational viscometer Anton Paar DV-3P. The kinematic viscosity and fluidity were determined according to the definitions. Thermal parameters were measured by instrument Isomet 2104. Temperature dependencies of wine dynamic and kinematic viscosity had decreasing exponential shape and temperature dependencies of fluidity had an increasing exponential shape. Temperature dependencies of red wine thermal conductivity and diffusivity had increasing linear character. Decreasing polynomial functions were obtained for temperature dependencies of red wine density. The values of dynamic and kinematic viscosity, thermal conductivity and diffusivity, and density of red wine were a little bit higher after short term storing, which can be expressed by changed amount of water caused by evaporation. Due to the same reasons were values of fluidity little bit lower after storage.

  19. Antidiabetic and Neuroprotective Effects of Trigonella Foenum-graecum Seed Powder in Diabetic Rat Brain

    Directory of Open Access Journals (Sweden)

    P. Kumar

    2012-01-01

    Full Text Available Trigonella foenum-graecum seed powder (TSP has been reported to have hypoglycemic and hyperinsulinemic action. The objective of the study was to examine the antidiabetic and neuroprotective role of TSP in hyperglycemiainduced alterations in blood glucose, insulin levels and activities of membrane linked enzymes (Na+K+ATPase, Ca2+ATPase, antioxidant enzymes (superoxide dismutase, glutathione S-transferase, calcium (Ca2+ levels, lipid peroxidation, membrane fluidity and neurolipofuscin accumulation in the diabetic rat brain. Female Wistar rats weighing between 180 and 220 g were made diabetic by a single injection of alloxan monohydrate (15 mg/100 g body weight, diabetic rats were given 2 IU insulin, per day with 5% TSP in the diet for three weeks. A significant increase in lipid peroxidation was observed in diabetic brain. The increased lipid peroxidation following chronic hyperglycemia was accompanied with a significant increase in the neurolipofuscin deposition and Ca2+ levels with decreased activities of membrane linked ATPases and antioxidant enzymes in diabetic brain. A decrease in synaptosomal membrane fluidity may influence the activity of membrane linked enzymes in diabetes. The present study showed that TSP treatment can reverse the hyperglycemia induced changes to normal levels in diabetic rat brain. TSP administration amended effect of hyperglycemia on alterations in lipid peroxidation, restoring membrane fluidity, activities of membrane bound and antioxidant enzymes, thereby ameliorating the diabetic complications.

  20. Procaine-mediated modification of membranes and of the response to x irradiation and hyperthermia in mammalian cells

    International Nuclear Information System (INIS)

    Yau, T.M.

    1979-01-01

    Procaine, a membrane-specific agent, was found to protect the response of oxygenated mammalian cells toward x irradiation in vitro. In addition, the drug also potentiates hyperthermic killing of cells. In an effort to gain further insights into the mechanisms underlying the action of procaine as a modifier of cell injury in x-irradiated and heated cells, the effects of procaine on cellular morphology, membrane fluidity, and cellular electrokinetic properties were studied. It was found that procaine can reversibly influence the cellular morphology. Using scanning electron microscopy, we were able to demonstrate the presence of numerous smooth blebs on the cell surface of either normal or SV40-transformed 3T3 mouse fibroblasts treated with procaine. When 1,6-diphenyl-1,3,5-hexatriene was used as a membrane probe, the overall fluidity of cell membranes from 3T3 cells grown as monolayers or L5178Y lymphoma cells grown in suspensions was not significantly changed by procaine; however, when perylene was used as a probe, the overall fluidity of cell membranes of procaine-treated cells was found to increase significantly. Lastly, procaine was found to alter the electrophoretic mobility of cells. These results indicate that procaine may exert its modification of radiation- and heat-induced effects via a still elusive membrane-mediated mechanism(s). It is anticipated that membrane-active agents with different specificities may be employed as tools to probe the role of membranes in the radiation or heat response of cells

  1. Effects of Coal Gangue on Cement Grouting Material Properties

    Science.gov (United States)

    Liu, J. Y.; Chen, H. X.

    2018-05-01

    The coal gangue is one of the most abundant industrial solid wastes and pollute source of air and water. The use of coal gangue in the production of cement grouting material comforms to the basic state policy of environment protection and the circular using of natural resources. Through coal gangue processing experiment, coal gangue cement grouting materials making test, properties detection of properties and theoretical analysis, the paper studied the effects of coal gangue on the properties of cement grouting materials. It is found that at the range of 600 to 700 °C, the fluidity and the compressive and flexural strengths of the cement grouting materials increase with the rising up of the calcination temperatures of coal gangue. The optimum calcination temperature is around 700 °C. The part substitution of cement by the calcined coal gangue in the cement grouting material will improve the mechanical properties of the cement grouting material, even thought it will decrease its fluidity. The best substitution amount of cement by coal gangue is about 30%. The fluidity and the long term strength of the ordinary silicate cement grouting material is obviously higher than that of the sulphoaluminate cement one as well as that of the silicate-sulphoaluminate complex cement one.

  2. Lactobacillus casei combats acid stress by maintaining cell membrane functionality.

    Science.gov (United States)

    Wu, Chongde; Zhang, Juan; Wang, Miao; Du, Guocheng; Chen, Jian

    2012-07-01

    Lactobacillus casei strains have traditionally been recognized as probiotics and frequently used as adjunct culture in fermented dairy products where lactic acid stress is a frequently encountered environmental condition. We have investigated the effect of lactic acid stress on the cell membrane of L. casei Zhang [wild type (WT)] and its acid-resistant mutant Lbz-2. Both strains were grown under glucose-limiting conditions in chemostats; following challenge by low pH, the cell membrane stress responses were investigated. In response to acid stress, cell membrane fluidity decreased and its fatty acid composition changed to reduce the damage caused by lactic acid. Compared with the WT, the acid-resistant mutant exhibited numerous survival advantages, such as higher membrane fluidity, higher proportions of unsaturated fatty acids, and higher mean chain length. In addition, cell integrity analysis showed that the mutant maintained a more intact cellular structure and lower membrane permeability after environmental acidification. These results indicate that alteration in membrane fluidity, fatty acid distribution, and cell integrity are common mechanisms utilized by L. casei to withstand severe acidification and to reduce the deleterious effect of lactic acid on the cell membrane. This detailed comparison of cell membrane responses between the WT and mutant add to our knowledge of the acid stress adaptation and thus enable new strategies to be developed aimed at improving the industrial performance of this species under acid stress.

  3. Effect of Pulsed Electric Field on Membrane Lipids and Oxidative Injury of Salmonella typhimurium.

    Science.gov (United States)

    Yun, Ou; Zeng, Xin-An; Brennan, Charles S; Han, Zhong

    2016-08-22

    Salmonella typhimurium cells were subjected to pulsed electric field (PEF) treatment at 25 kV/cm for 0-4 ms to investigate the effect of PEF on the cytoplasmic membrane lipids and oxidative injury of cells. Results indicated that PEF treatment induced a decrease of membrane fluidity of Salmonella typhimurium (S. typhimuriumi), possibly due to the alterations of fatty acid biosynthesis-associated gene expressions (down-regulation of cfa and fabA gene expressions and the up-regulation of fabD gene expression), which, in turn, modified the composition of membrane lipid (decrease in the content ratio of unsaturated fatty acids to saturated fatty acids). In addition, oxidative injury induced by PEF treatment was associated with an increase in the content of malondialdehyde. The up-regulation of cytochrome bo oxidase gene expressions (cyoA, cyoB, and cyoC) indicated that membrane damage was induced by PEF treatment, which was related to the repairing mechanism of alleviating the oxidative injury caused by PEF treatment. Based on these results, we achieved better understanding of microbial injury induced by PEF, suggesting that micro-organisms tend to decrease membrane fluidity in response to PEF treatment and, thus, a greater membrane fluidity might improve the efficiency of PEF treatment to inactivate micro-organisms.

  4. Effect of Nanosilica on the Fresh Properties of Cement-Based Grouting Material in the Portland-Sulphoaluminate Composite System

    Directory of Open Access Journals (Sweden)

    Shengli Li

    2016-01-01

    Full Text Available The effect of NS particle size and content on the fresh properties of the grouting material based on the portland-sulphoaluminate composite system was analyzed. The experimental results indicated that air content increased and apparent density decreased, with increased NS content, but the NS particle sizes have minimal effect on the air content and apparent density. The setting time of mortar was significantly shortened, with increased NS content; however, NS particle sizes had little influence on the setting time. The effect of fluidity on the mortars adding NS with particle size of 30 nm is larger than NS with particle sizes of 15 and 50 nm and the fluidity decreased with increased NS content, but the fluidity of mortars with the particle sizes of 15 and 50 nm is almost not affected by the NS content. XRD analysis shows that the formation of ettringite was promoted and the process of hydration reaction of cement was accelerated with the addition of NS. At the microscopic level, the interfacial transition zone (ITZ of the grouting material became denser and the formation of C-S-H gel was promoted after adding NS.

  5. Infrared spectroscopy of fluid lipid bilayers.

    Science.gov (United States)

    Hull, Marshall C; Cambrea, Lee R; Hovis, Jennifer S

    2005-09-15

    Infrared spectroscopy is a powerful technique for examining lipid bilayers; however, it says little about the fluidity of the bilayer-a key physical aspect. It is shown here that it is possible to both acquire spectroscopic data of supported lipid bilayer samples and make measurements of the membrane fluidity. Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FT-IR) is used to obtain the spectroscopic information and fluorescence recovery after photobleaching (FRAP) is used to determine the fluidity of the samples. In the infrared spectra of lipid bilayers composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine, the following major peaks were observed; nu(as)(CH3) 2954 cm(-1), nu(s)(CH3) 2870 cm(-1), nu(as)(CH2) 2924 cm(-1), nu(s)(CH2) 2852 cm(-1), nu(C=O) 1734 cm(-1), delta(CH2) 1463-1473 cm(-1), nu(as)(PO2-) 1226 cm(-1), nu(s)(PO2-) 1084 cm(-1), and nu(as)(N+(CH3)3) 973 cm(-1). The diffusion coefficient of the same lipid bilayer was measured to be 3.5 +/- 0.5 micom(2)/s with visual recovery also noted through use of epifluorescence microscopy. FRAP and visual data confirm the formation of a uniform, mobile supported lipid bilayer. The combination of ATR-FT-IR and FRAP provides complementary data giving a more complete picture of fully hydrated model membrane systems.

  6. Interaction of cationic carbosilane dendrimers and their complexes with siRNA with erythrocytes and red blood cell ghosts.

    Science.gov (United States)

    Wrobel, Dominika; Kolanowska, Katarzyna; Gajek, Arkadiusz; Gomez-Ramirez, Rafael; de la Mata, Javier; Pedziwiatr-Werbicka, Elżbieta; Klajnert, Barbara; Waczulikova, Iveta; Bryszewska, Maria

    2014-03-01

    We have investigated the interactions between cationic NN16 and BDBR0011 carbosilane dendrimers with red blood cells or their cell membranes. The carbosilane dendrimers used possess 16 cationic functional groups. Both the dendrimers are made of water-stable carbon-silicon bonds, but NN16 possesses some oxygen-silicon bonds that are unstable in water. The nucleic acid used in the experiments was targeted against GAG-1 gene from the human immunodeficiency virus, HIV-1. By binding to the outer leaflet of the membrane, carbosilane dendrimers decreased the fluidity of the hydrophilic part of the membrane but increased the fluidity of the hydrophobic interior. They induced hemolysis, but did not change the morphology of the cells. Increasing concentrations of dendrimers induced erythrocyte aggregation. Binding of short interfering ribonucleic acid (siRNA) to a dendrimer molecule decreased the availability of cationic groups and diminished their cytotoxicity. siRNA-dendrimer complexes changed neither the fluidity of biological membranes nor caused cell hemolysis. Addition of dendriplexes to red blood cell suspension induced echinocyte formation. Copyright © 2013 Elsevier B.V. All rights reserved.

  7. Optimization and characterization of liposome formulation by mixture design.

    Science.gov (United States)

    Maherani, Behnoush; Arab-tehrany, Elmira; Kheirolomoom, Azadeh; Reshetov, Vadzim; Stebe, Marie José; Linder, Michel

    2012-02-07

    This study presents the application of the mixture design technique to develop an optimal liposome formulation by using the different lipids in type and percentage (DOPC, POPC and DPPC) in liposome composition. Ten lipid mixtures were generated by the simplex-centroid design technique and liposomes were prepared by the extrusion method. Liposomes were characterized with respect to size, phase transition temperature, ζ-potential, lamellarity, fluidity and efficiency in loading calcein. The results were then applied to estimate the coefficients of mixture design model and to find the optimal lipid composition with improved entrapment efficiency, size, transition temperature, fluidity and ζ-potential of liposomes. The response optimization of experiments was the liposome formulation with DOPC: 46%, POPC: 12% and DPPC: 42%. The optimal liposome formulation had an average diameter of 127.5 nm, a phase-transition temperature of 11.43 °C, a ζ-potential of -7.24 mV, fluidity (1/P)(TMA-DPH)((¬)) value of 2.87 and an encapsulation efficiency of 20.24%. The experimental results of characterization of optimal liposome formulation were in good agreement with those predicted by the mixture design technique.

  8. The effect of MLS laser radiation on cell lipid membrane.

    Science.gov (United States)

    Pasternak, Kamila; Wróbel, Dominika; Nowacka, Olga; Pieszyński, Ireneusz; Bryszewska, Maria; Kujawa, Jolanta

    2018-03-14

    Authors of numerous publications have proved the therapeutic effect of laser irradiation on biological material, but the mechanisms at cellular and subcellular level are not yet well understood. The aim of this study was to assess the effect of laser radiation emitted by the MLS M1 system (Multiwave Locked System) at two wavelengths (808 nm continuous and 905 nm pulsed) on the stability and fluidity of liposomes with a lipid composition similar to that of human erythrocyte membrane or made of phosphatidylocholine. Liposomes were exposed to low-energy laser radiation at surface densities 195 mW/cm2 (frequency 1,000 Hz) and 230 mW/cm2 (frequency 2,000 Hz). Different doses of radiation energy in the range 0-15 J were applied. The surface energy density was within the range 0.46 - 4.9 J/cm 2. The fluidity and stability of liposomes subjected to such irradiation changed depending on the parameters of radiation used. Since MLS M1 laser radiation, depending on the parameters used, affects fluidity and stability of liposomes with the lipid content similar to erythrocyte membrane, it may also cause structural and functional changes in cell membranes.

  9. Fluiditas Antara Maskulinitas Dan Femininitas: Representasi Waria Dalam Film Dokumenter Dan Fiksi

    Directory of Open Access Journals (Sweden)

    Maimunah Maimunah

    2012-06-01

    Full Text Available Dunia Waria menjadi salah satu tema yang muncul dalam perkembangan film Indonesia pasca Orde Baru. Penelitian ini mengkaji dua film dokumenter dan sebuah film fiksi yaitu Betty Bencong Slebor karya Benyamin Sueb (1978 serta dua film dokumenter Renita­Renita karya Tony Trimarsanto (2006 dan Ngudal Piwulang Wandu karya Kukuh Yudha Karnanta (2009. Meng­ gunakan metode penelitian kualitatif dan teori queer dalam membaca media film, hasil penelitian ini menunjukkan bahwa dari ketiga film tersebut terlihat perbedaan dalam memaknai tubuh dan gender. Tokoh Sholeh dalam Ngudal Piwulang Wandu berharap suatu hari nanti kembali menjadi lanang sejati, menikah secara heteroseksual dan memiliki anak. Renita membayangkan tubuh dan identitas gender sebagai perempuan sempurna, sedangkan Betty terlihat menikmati interplay antara tubuh feminine dan maskulinnya. Tubuh dalam konteks ini dapat dilihat sebagai suatu con­ tinuum, perpaduan antara femininitas dan maskulinitas, bukan suatu entitas yang statis. Perbe­ daan ketiga tokoh utama dalam memandang tubuh, seksualitas, dan gender mereka juga mere­ fleksikan bahwa tidak ada identitas dan entitas tunggal dari waria. Abstract: The growing visibility of waria/male to female transgender has become one of the do­ dominant features in Indonesia’s contemporary film industry. The research examines three waria films: Tony Trimarsanto’s Renita­Renita (2006, Kukuh Yudha Karnanta’s Ngudal Piwulang Wan­ du (2009, and Benyamin Sueb’s Betty Bencong Slebor (1978. Two basic research questions are, firstly: how is the fluidity of masculinity and femininity represented; secondly how do the waria per­ceive themselves (self­identity in a heterosexual culture. Queer film theory will be used in analyzing the film diegesis. The research finds the fluidity and continuum of the waria main characters in de­fining the meaning of the self and their bodies. This fluidity offers a playful negotiation to the essen

  10. Measurement and study of density, surface tension, and viscosity of quaternary ammonium-based ionic liquids ([N222(n)]Tf2N)

    International Nuclear Information System (INIS)

    Ghatee, Mohammad Hadi; Bahrami, Maryam; Khanjari, Neda

    2013-01-01

    Highlights: • Characterization of high purity synthesized alkyl quaternary ammonium ionic liquids. • Measurement of temperature dependent surface tension, density, viscosity and critical point. • Systematic increase of surface energy and surface entropy having plateau at high chain length. • Accurate application of VFT and fluidity equations to temperature dependent viscosities. • Particular variation of fluidity exponent with a plateau at high alkyl chain length. -- Abstract: In this work five quaternary ammonium-based ionic liquids with bis(trifluoromethylsulfonyl)imide anion were synthesized and their density, viscosity and surface tensions were measured in the temperature range (298 to 373) K. Surface tensions were measured by capillary rise method using a homemade capillary apparatus, in which the liquid/vapor can be brought into equilibrium practically. Measurements of viscosities and surface tensions were performed under water–vapor free atmosphere. The surface tension of quaternary ammonium-based ILs decreases as the alkyl chain length increases. Also surface energy and surface entropy are found as increasing functions of alkyl chain length with a plateau at high lengths in the surface. The viscosities measured by capillary viscometer fit in VFT equation, indication of non-Arrhenius ionic liquids. Viscosities are also fitted quite accurately in the relation we have developed recently as the fluidity equation with the characteristics exponent ϕ. Values of ϕ for ionic liquids are close to one another and tend to the limiting value, almost 0.328, asymptotically as the alkyl chain length increases. The critical temperatures predicted via the temperature dependent surface tensions decrease with increasing alkyl chain length of the cation. The trend of predicted critical temperature of these ionic liquids conforms to those of imidazolium-based ILs

  11. Physiological and biochemical effects of 17β estradiol in aging female rat brain.

    Science.gov (United States)

    Kumar, Pardeep; Taha, Asia; Kale, R K; Cowsik, S M; Baquer, Najma Zaheer

    2011-07-01

    Aging in females and males is considered as the end of natural protection against age related diseases like osteoporosis, coronary heart disease, diabetes, Alzheimer's disease and Parkinson's disease. These changes increase during menopausal condition in females when the level of estradiol is decreased. The objective of this study was to observe the changes in activities of monoamine oxidase, glucose transporter-4 levels, membrane fluidity, lipid peroxidation levels and lipofuscin accumulation occurring in brains of female rats of 3 months (young), 12 months (adult) and 24 months (old) age groups, and to see whether these changes are restored to normal levels after exogenous administration of estradiol (0.1 μg/g body weight for 1 month). The results obtained in the present work revealed that normal aging was associated with significant increases in the activity of monoamine oxidase, lipid peroxidation levels and lipofuscin accumulation in the brains of aging female rats, and a decrease in glucose transporter-4 level and membrane fluidity. Our data showed that estradiol treatment significantly decreased monoamine oxidase activity, lipid peroxidation and lipofuscin accumulation in brain regions of aging rats, and a reversal of glucose transporter-4 levels and membrane fluidity was achieved, therefore it can be concluded from the present findings that estradiol's beneficial effects seemed to arise from its antilipofuscin, antioxidant and antilipidperoxidative effects, implying an overall anti-aging action. The results of this study will be useful for pharmacological modification of the aging process and applying new strategies for control of age related disorders. Copyright © 2011 Elsevier Inc. All rights reserved.

  12. Cleavage and crosslinking of polymeric coal structures during pyrolysis. Final report

    Energy Technology Data Exchange (ETDEWEB)

    McMillen, D.F.; Malhotra, R.

    1992-02-01

    The ultimate objective of this project was to develop a better understanding of volatiles production to help optimize the yield and character of condensable coproducts during coal pyrolysis or mild gasification. The specific objectives were to (1) Develop pyrolysis procedures that minimize secondary reactions; and (2) Develop coal pretreatments that current knowledge suggests will prorate bond scission or prevent retrograde reactions. Our approach was to study the pyrolysis of coals and tar-loaded coals by using several techniques that span a range of heating rates and pressures. Slow-heating pyrolyses were performed at low pressures in the inlet of a field ionization mass spectrometer and at atmospheric pressures in a thermogravimetric analyzer. Moderately rapid-heating pyrolyses were performed in a vacuum TGA apparatus and in sealed silica ampules heated in a molten-salt bath. The fastest heating rates were achieved with laser pyrolysis at about 30,000 X/s. The high tar yield seen in this work where the entire volume of the coal particle becomes hot and fluid at very nearly the same time, taken together with the evident non-vapor transport of the tar under these conditions, emphasizes the importance of better understanding the development of fluidity during coal heating. This specifically includes the profound effects--long-recognized but poorly understood that mild oxidation has in suppressing coal fluidity. It also includes the more recently recognized fact that heating in the presence of an inert gas produced substantially greater fluidity than does heating in the presence of combustion gases, even if the conditions are very fuel rich and all the oxygen itself has already been consumed when the coal particles are encountered.

  13. Cleavage and crosslinking of polymeric coal structures during pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    McMillen, D.F.; Malhotra, R.

    1992-02-01

    The ultimate objective of this project was to develop a better understanding of volatiles production to help optimize the yield and character of condensable coproducts during coal pyrolysis or mild gasification. The specific objectives were to (1) Develop pyrolysis procedures that minimize secondary reactions; and (2) Develop coal pretreatments that current knowledge suggests will prorate bond scission or prevent retrograde reactions. Our approach was to study the pyrolysis of coals and tar-loaded coals by using several techniques that span a range of heating rates and pressures. Slow-heating pyrolyses were performed at low pressures in the inlet of a field ionization mass spectrometer and at atmospheric pressures in a thermogravimetric analyzer. Moderately rapid-heating pyrolyses were performed in a vacuum TGA apparatus and in sealed silica ampules heated in a molten-salt bath. The fastest heating rates were achieved with laser pyrolysis at about 30,000 X/s. The high tar yield seen in this work where the entire volume of the coal particle becomes hot and fluid at very nearly the same time, taken together with the evident non-vapor transport of the tar under these conditions, emphasizes the importance of better understanding the development of fluidity during coal heating. This specifically includes the profound effects--long-recognized but poorly understood that mild oxidation has in suppressing coal fluidity. It also includes the more recently recognized fact that heating in the presence of an inert gas produced substantially greater fluidity than does heating in the presence of combustion gases, even if the conditions are very fuel rich and all the oxygen itself has already been consumed when the coal particles are encountered.

  14. Bile salts stimulate mucin secretion by cultured dog gallbladder epithelial cells independent of their detergent effect.

    Science.gov (United States)

    Klinkspoor, J H; Yoshida, T; Lee, S P

    1998-05-15

    1. Bile salts stimulate mucin secretion by the gallbladder epithelium. We have investigated whether this stimulatory effect is due to a detergent effect of bile salts. 2. The bile salts taurocholic acid (TC) and tauroursodeoxycholic acid (TUDC) and the detergents Triton X-100 (12.5-400 microM) and Tween-20 (0.1-3.2 mM) were applied to monolayers of cultured dog gallbladder epithelial cells. Mucin secretion was studied by measuring the secretion of [3H]N-acetyl-d-glucosamine-labelled glycoproteins. We also attempted to alter the fluidity of the apical membrane of the cells through extraction of cholesterol with beta-cyclodextrin (2.5-15 mM). The effect on TUDC-induced mucin secretion was studied. Cell viability was assessed by measuring lactate dehydrogenase (LDH) leakage or 51Cr release. 3. In contrast with the bile salts, the detergents were not able to cause an increase in mucin secretion without causing concomitant cell lysis. Concentrations of detergent that increased mucin release (>100 microM Triton X-100, >0.8 mM Tween-20), caused increased LDH release. Incubation with beta-cyclodextrin resulted in effective extraction of cholesterol without causing an increase in 51Cr release. However, no effect of the presumed altered membrane fluidity on TUDC (10 mM)-induced mucin secretion was observed. 4. The stimulatory effect of bile salts on mucin secretion by gallbladder epithelial cells is not affected by the fluidity of the apical membrane of the cells and also cannot be mimicked by other detergents. We conclude that the ability of bile salts to cause mucin secretion by the gallbladder epithelium is not determined by their detergent properties.

  15. Influence of thermoplastic properties on coking pressure generation: Part 1 - A study of single coals of various rank

    Energy Technology Data Exchange (ETDEWEB)

    John J. Duffy; Merrick R. Mahoney; Karen M. Steel [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre

    2010-07-15

    In this study a number of high coking pressure coals with different fluidities were evaluated alongside a number of low pressure coals also with differing fluidities. This was to establish rheological parameters within which a coal may be considered potentially dangerous with regards to coking pressure. The results have confirmed and elaborated on previous findings which show that parallel plate displacement ({Delta}L) and axial force profiles can be used to distinguish between high and low pressure coals, with peak values indicating cell rupture and subsequent pore network formation. This is thought to correspond with plastic layer compaction in the coke oven. For low pressure coals pore coalescence occurs quite early in the softening process when viscosity/elasticity are decreasing and consequently a large degree of contraction/collapse is observed. For higher pressure coals the process is delayed since pore development and consequently wall thinning progress at a slower rate. If or when a pore network is established, a lower degree of contraction/collapse is observed because the event occurs closer to resolidification, where viscosity and elasticity are increasing. For the higher fluidity, high coking pressure coals, a greater degree of swelling is observed prior to cell rupture, and this is considered to be the primary reason for the high coking pressure observed with these coals. An additional consequence of these events is that high pressure coals are likely to contain a higher proportion of closed cells both at and during resolidification, reducing permeability in both the semi-coke and high temperature plastic layers, respectively. Using a rheological mapping approach to follow viscoelastic changes during carbonisation it has been possible to identify specific regions associated with dangerous coals. 76 refs., 11 figs., 3 tabs.

  16. Understanding the mechanisms behind coking pressure: Relationship to pore structure

    Energy Technology Data Exchange (ETDEWEB)

    John J. Duffy; M. Castro Diaz; Colin E. Snape; Karen M. Steel; Merrick R. Mahoney [University of Nottingham, Nottingham (United Kingdom). Nottingham Fuel and Energy Centre, School of Chemical, Environmental and Mining Engineering

    2007-09-15

    Three low volatile coals A, B and C with oven wall pressures of 100 kPa, 60 kPa and 20 kPa respectively were investigated using high-temperature rheometry, {sup 1}H NMR, thermogravimetric analysis and SEM, with the primary aim to better understand the mechanisms behind the coking pressure phenomenon. Rheometer plate displacement measurements ({Delta}L) have shown differences in the expansion and contraction behaviour of the three coals, which seem to correlate with changes in rheological properties; while SEM images have shown that the expansion process coincides with development of pore structure. It is considered that the point of maximum plate height ({Delta}L{sub max}) prior to contraction may be indicative of a cell opening or pore network forming process, based on analogies with other foam systems. Such a process may be considered important for coking pressure since it provides a potential mechanism for volatile escape, relieving internal gas pressure and inducing charge contraction. For coal C, which has the highest fluidity {delta}L{sub max} occurs quite early in the softening process and consequently a large degree of contraction is observed; while for the lower fluidity coal B, the process is delayed since pore development and consequently wall thinning progress at a slower rate. When {Delta}L{sub max} is attained, a lower degree of contraction is observed because the event occurs closer to resolidification where the increasing viscosity/elasticity can stabilise the expanded pore structure. For coal A which is relatively high fluidity, but also high coking pressure, a greater degree of swelling is observed prior to cell rupture, which may be due to greater fluid elasticity during the expansion process. This excessive expansion is considered to be a potential reason for its high coking pressure. 58 refs., 15 figs., 1 tab.

  17. Exogenous and endogenous lipids of human hair.

    Science.gov (United States)

    Coderch, L; Oliver, M A; Martínez, V; Manich, A M; Rubio, L; Martí, M

    2017-11-01

    The aim of this study was to characterize the external and internal lipids of Caucasian hair and their influence in different hair properties such as moisture content, hydrophobic character, and mechanical properties. Lipid extraction and their analysis by thin layer chromatography with flame ionization detector were carried out. Lipid rearrangement and water sorption and desorption evaluation of these fibers with and without lipids will also be determined using different techniques such as differential scanning calorimetry, thermogravimetric analysis and dynamic vapor sorption, mainly to evaluate permeation changes of these hair fibers possibly related to the fluidity of the lipids extracted. Caucasian fibers were found to be well hydrated, and moisture diminution was observed mainly for the external lipid extracted fibers. Unexpectedly, the lipid extraction promoted an increase in the break tenacity of the Caucasian fibers. The hydrophobic character of the fiber surfaces indicates the marked hydrophobicity of all fibers. Delipidization promotes only a slight diminution of their hydrophobic properties. Water uptake and desorption studies indicate an important water regain for Caucasian fibers. The external extracted hair fibers presented a diminution of maximum water regain, which surprisingly increases with the following internal lipid extraction. This can be due to a higher water desorption found only for external extracted fibers. The relationship between fluidity of lipids extracted and hair fiber water diffusion were established. Extraction of internal lipids of Caucasian fibers, which have a higher unsaturated lipid content than external lipids of the same hair fiber, leads to a lower water permeability of the fiber. On the capillar formulations should be considered the importance of lipid fluidity to modify the permeability of the fiber. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  18. Growth-Environment Dependent Modulation of Staphylococcus aureus Branched-Chain to Straight-Chain Fatty Acid Ratio and Incorporation of Unsaturated Fatty Acids.

    Science.gov (United States)

    Sen, Suranjana; Sirobhushanam, Sirisha; Johnson, Seth R; Song, Yang; Tefft, Ryan; Gatto, Craig; Wilkinson, Brian J

    2016-01-01

    The fatty acid composition of membrane glycerolipids is a major determinant of Staphylococcus aureus membrane biophysical properties that impacts key factors in cell physiology including susceptibility to membrane active antimicrobials, pathogenesis, and response to environmental stress. The fatty acids of S. aureus are considered to be a mixture of branched-chain fatty acids (BCFAs), which increase membrane fluidity, and straight-chain fatty acids (SCFAs) that decrease it. The balance of BCFAs and SCFAs in USA300 strain JE2 and strain SH1000 was affected considerably by differences in the conventional laboratory medium in which the strains were grown with media such as Mueller-Hinton broth and Luria broth resulting in high BCFAs and low SCFAs, whereas growth in Tryptic Soy Broth and Brain-Heart Infusion broth led to reduction in BCFAs and an increase in SCFAs. Straight-chain unsaturated fatty acids (SCUFAs) were not detected. However, when S. aureus was grown ex vivo in serum, the fatty acid composition was radically different with SCUFAs, which increase membrane fluidity, making up a substantial proportion of the total (37%) and BCFAs (>36%) making up the rest. Staphyloxanthin, an additional major membrane lipid component unique to S. aureus, tended to be greater in content in cells with high BCFAs or SCUFAs. Cells with high staphyloxanthin content had a lower membrane fluidity that was attributed to increased production of staphyloxanthin. S. aureus saves energy and carbon by utilizing host fatty acids for part of its total fatty acids when growing in serum, which may impact biophysical properties and pathogenesis given the role of SCUFAs in virulence. The nutritional environment in which S. aureus is grown in vitro or in vivo in an infection is likely to be a major determinant of membrane fatty acid composition.

  19. Phase-field modeling of mixing/demixing of regular binary mixtures with a composition-dependent viscosity

    Science.gov (United States)

    Lamorgese, A.; Mauri, R.

    2017-04-01

    We simulate the mixing (demixing) process of a quiescent binary liquid mixture with a composition-dependent viscosity which is instantaneously brought from the two-phase (one-phase) to the one-phase (two-phase) region of its phase diagram. Our theoretical approach follows a standard diffuse-interface model of partially miscible regular binary mixtures wherein convection and diffusion are coupled via a nonequilibrium capillary force, expressing the tendency of the phase-separating system to minimize its free energy. Based on 2D simulation results, we discuss the influence of viscosity ratio on basic statistics of the mixing (segregation) process triggered by a rapid heating (quench), assuming that the ratio of capillary to viscous forces (a.k.a. the fluidity coefficient) is large. We show that, for a phase-separating system, at a fixed value of the fluidity coefficient (with the continuous phase viscosity taken as a reference), the separation depth and the characteristic length of single-phase microdomains decrease monotonically for increasing values of the viscosity of the dispersed phase. This variation, however, is quite small, in agreement with experimental results. On the other hand, as one might expect, at a fixed viscosity of the dispersed phase both of the above statistics increase monotonically as the viscosity of the continuous phase decreases. Finally, we show that for a mixing system the attainment of a single-phase equilibrium state by coalescence and diffusion is retarded by an increase in the viscosity ratio at a fixed fluidity for the dispersed phase. In fact, for large enough values of the viscosity ratio, a thin film of the continuous phase becomes apparent when two drops of the minority phase approach each other, which further retards coalescence.

  20. Influence of initial microstructure of aluminium alloy charge after its melting on the hard metal inherited structure

    Directory of Open Access Journals (Sweden)

    Г. О. Іванов

    2016-07-01

    Full Text Available Metal properties heredity in the chain- initial hard state > liquid state > final solidified state has always been interesting for metallurgists. It is known that after the primary melting of charge there occurs microheterogenеous non-equilibrium melt with crystal-like groups of atoms and disordered area in it. With increase in temperature the melt approaches the equilibrium microhomogeneous state. The aim of this work is to study the charge microstructure influence on melt fluidity in the light of quasi-crystal model of liquid structure. Influence of isothermal heating on fluidity of aluminium melt, smelted from fine-grained and coarse-grained charge has been investigated. It has been stated that for coarse-grained metal additional melting of crystallization «genes» takes place in 1,4-quick time, as compared to fine-grained. The coefficients of exponential function for our experimental data have been calculated. It has been stated that the exponent depends on the charge microstructure, and multiplier depends on the soaking temperature. On the basis of A. Einstein equation for the calculation of liquid viscosity from the known fraction of admixtures and clean liquid viscosity an analogical equation for fluidity and calculation of quasi-crystals volume share in the melt have been derived. It has been found that the charge grain size affects the speed of quasi-crystals additional melting in the melt. The reference amount of quasi-crystals at the initial moment of large- and fine-grained charge melting has been calculated from our metallographic, experimental and estimated data

  1. Security Problems of Communicative Strategies

    Directory of Open Access Journals (Sweden)

    Elena B. Perelygina

    2011-01-01

    Full Text Available The main directions of safety formation in communication strategies are connected with their adaptation to the conditions of social and psychological variability. Building up a communicative strategy is a versatile process, in which it is necessary to consider a wide spectrum of social and psychological parameters, especially topical in the modern period of social development. Forms of social interactions in schematic formats of contemporary social and economic revolution are reduced, social and functional potentials are depleted, mass society is further differentiating, the pace of historic changes is growing, all this determines the necessity to prepare changes in personality structures to the dynamics of social and fluidity.

  2. Migration of actinide elements in representative US soils

    International Nuclear Information System (INIS)

    Sheppard, J.C.; Campbell, M.J.; Kittrick, J.A.; Hardt, T.L.

    1981-01-01

    Diffusion data indicate the Am, Cm, and Np migrate 1.2, 0.8, and 26 centimeters, respectively, in a thousand years. Thus, excluding mass transport by moving water or wind, actinide elements, such as Cm, Am, and Np that find their way to the soil-squatic environment are relatively immobile. Measured diffusion coefficients, corrected for distribution between the aqueous and soil phases, tortuosity, negative absorption, and relative fluidity are in reasonable agreement with aqueous diffusion coefficients. However, agreement depends strongly on measurement method used to determine distribution ratios

  3. Streaming: A Media Hydrography of Televisual Flows

    Directory of Open Access Journals (Sweden)

    Ghislain Thibault

    2015-09-01

    Full Text Available This paper focuses on the continuities, rather than the ruptures, between digital television and past media forms. It situates the metaphor of “streaming” in contrast to and connection with previous fluid metaphors that have been used to describe different models of media transmission. From the early use of aqueous vocabulary that shaped popular and scientific understandings of electricity transmission to the seminal studies of mass communication concerning the flows of information, images of fluidity have long shaped cultural understandings of the inner logics of media infrastructures. Building on the work of media archaeologist Erkki Huhtamo, I approach these metaphors as “recurrent topoi” in media culture.

  4. INFLUENCE OF STORING AND TEMPERATURE ON RHEOLOGIC AND THERMOPHYSICAL PROPERTIES OF WHISKY SAMPLES

    Directory of Open Access Journals (Sweden)

    Peter Hlavac

    2013-09-01

    Full Text Available Temperature and storing time can be included between the most significant parameters that influence physical properties of food. This article deals with selected rheologic and thermophysical properties of alcohol drink whisky. Our research was oriented on measuring of rheologic and thermophysical characteristics of whisky. There were measured two types of whisky Grant s and Jim Beam from two different producers, both samples had 40 percent of alcohol content. During the experiments were analyzed rheologic parameters as dynamic viscosity, kinematic viscosity and fluidity and thermophysical parameters as thermal conductivity, thermal diffusivity and volume specific heat. Selected parameters were measured in temperature range 5 to 27 C. Measurements were done on whisky samples in different days during the storage. Measuring of dynamic viscosity was performed by digital rotational viscometer Anton Paar. Principle of measuring is based on dependency of sample resistance against the probe rotation. Density of whisky samples was determined by pycnometric method. Average density at given temperature along with dynamic viscosity value was used at calculation of kinematic viscosity and fluidity was also determined. Measuring of thermophysical parameters was performed by instrument Isomet 2104 Measurement by Isomet is based on analysis of the temperature response of the measured sample to heat flow impulses. Relations of rheologic and thermophysical parameters to the temperature were made and influence of storing time was discussed. From obtained results is clear that dynamic and kinematic viscosity is decreasing exponentially with temperature and fluidity has increasing exponential progress. We found out that both whisky samples had at the beginning and after one week of storage very similar values of rheologic parameters. Very small difference in rheologic parameters of whisky samples was found after two weeks of storing. Values of dynamic and kinematic

  5. Crisis? What Crisis? Political articulation and government in the March of Tuscany through placita and diplomas from Guy of Spoleto to Berengar II

    Directory of Open Access Journals (Sweden)

    Igor Santos Salazar

    2016-09-01

    Full Text Available In the last decades, much work have been done to deconstruct the mechanisms of government in Early Medieval Europe. In that task, the interpretation of the settlement of disputes and royal/imperial diplomas as the basis of the central government strategies in local spheres has been underlined by recent historiography. Following this methodology, the aim of this article is, thus, to analyze the mechanisms of governance in the March of Tuscany in a time characterized by political fluidity, focusing in the role played by the kings and lay and ecclesiastical aristocracies in the construction of complex political systems.

  6. Synchronic Seriality: The Dissolving of Diegetic Borders Through Metalepsis

    Directory of Open Access Journals (Sweden)

    Paige M. Piper

    2015-12-01

    Full Text Available In dialogue with Gérard Genette’s literary concept of metalepsis to television, this paper considers instances of meta-textual actor/character portrayals in serial narratives to show that meta-narrative intrusion fosters a greater empathetic link between the spectator and character, whilst simultaneously inviting the viewer to appreciate the technique as an artifice-aware gesture. The fluidity of diegetic borders brought on by the conflation of performer/performance replicates Baudrillard’s simulacra, creating a synchronic form of seriality and transcending rigid genre classifications.

  7. Radiation-induced changes in membrane hydrophobicity in liposomes

    International Nuclear Information System (INIS)

    Nakazawa, Tohru; Nagatsuka, Shinichiro; Yukawa, Osami

    1985-01-01

    Effects of γ-radiation on the physical state of membranes were examined with liposomes of lecithin (phosphatidylcholine) from soybean and rat liver microsomes using spin labeling method. There was a slight increase in the membrane fluidity after irradiation. However, a marked decrease in the membrane hydrophobicity by irradiation was observed in the peripheral region in both types of membranes, in parallel with an increase in the lipid peroxidation. These results suggest that irradiation mainly causes a decrease in the membrane hydrophobicity through lipid peroxidation. (author)

  8. Effects of Current Guides Destruction at Ultra-fast Acceleration of Macrobodies

    Science.gov (United States)

    Kataev, V. N.; Boriskin, A. S.; Golosov, S. N.; Demidov, V. A.; Klimashov, M. V.; Korolev, P. V.; Makartsev, G. F.; Pikar, A. S.; Russkov, A. S.; Shapovalov, E. V.; Shibitov, Yu. M.

    2006-08-01

    The paper is devoted to discussion of current guides destruction effects in different accelerators: thermal-electric and electro-magnetic rail accelerator at macrobodies acceleration value of 108-109 m/s2. Experimental results with thermal-electric accelerators powering from megajoule capacitor battery and helical magneto-cumulative generator MCG-100 at currents up to 3.5 MA are analyzed. The process of rails destruction at railgun at pressure magnetic field excess over the limit of metal fluidity is presented. Methods of efficiency coefficient increase of capacitive storage energy transmission to kinetic energy of accelerating body are discussed.

  9. Development of friction welding method by electric servo motors; Dendo servo shiki masatsu assetsuho no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, H; Onuma, M; Hasegawa, T; Sakamoto, T [Toyota Motor Corp., Aichi (Japan)

    1997-10-01

    The standard friction welding has two methods; the brake method and the inertia method. We have developed a new friction welding method with the electric servo motor system. The forming of plastic fluidity layers of interface is evaluated quantitatively with the feedback control characteristics. The new method has enabled to reduce the heat effect and the burr of friction welding. In the method, we could reduce the getting heat energy, from one-third to half less than the previous methods. 6 refs., 16 figs.

  10. La teoria letteraria di Freud

    Directory of Open Access Journals (Sweden)

    Raffaele Pinto

    2013-06-01

    Full Text Available From the moment in which the neurotic symptom appears as an imaginary disguise for the psychic trauma, literature becomes for Freud the ideal object of analysis in order to rebuild the experiences of the unconscious mind. Since both are regulated by the imaginative function of the mind, symptom and literature alike, can be described as symbolic and discursive constructs of the instinctual drive (pulsional, but with one essential difference: the symptom (and the dream, the lapsus, the witz is, above all, an expression of the individual unconscious, while literature expresses the social unconscious; the door between one dimension and the other being in a state of constant fluidity.

  11. NON-PHARMACOLOGICAL CONCEPTS OF ENDOTHELIAL DYSFUNCTION IMPROVEMENT

    Directory of Open Access Journals (Sweden)

    Mirjana Bakic

    2007-04-01

    Full Text Available Endothelium plays an important role in maintaining normal vascular tonus and blood fluidity reducing thrombocyte activity and adhesion of leukocytes as well as limiting response of vascular inflammation. However, in certain pathological conditions such as hypercholesterolemia, hypertension, and diabetes, endothelium improves vasoconstriction, inflammation and thrombocytic events.Non-pharmacological concept is based on recognition of genetic factors, environmental factors, or combination of risk factors for the occurrence of endothelial dysfunction, general and individual education of the significance of adequate nutrition, physical activity and regulation of body weight, regular check-ups and the application of antioxidants which can regulate and protect several aspects of endothelial functions.

  12. Physicochemical properties of binary solutions of propylene carbonate-acetonitrile in the range of 253.15-313.15 K

    Science.gov (United States)

    Tyunina, E. Yu.; Chekunova, M. D.

    2017-05-01

    The density, dynamic viscosity, and dielectric constant of propylene carbonate solutions with acetonitrile are measured over the composition of a mixed solvent at temperatures of 253.15, 273.15, 293.15, and 313.15 K. The molar volume, molar viscosity, and molar capacity of a mixture of propylene carbonate-acetonitrile and an excess amount of it are calculated. The effect the temperature and composition of the mixture have on the excess molar properties is discussed. A linear correlation is observed between the values of the molar fluidity, capacity, polarization, and molar volume of the studied system.

  13. The effect of cooling to different subzero temperatures on dog sperm cryosurvival.

    Science.gov (United States)

    Alcantar-Rodriguez, A; Medrano, A

    2017-06-01

    The objective was to assess the effect of cooling to different subzero temperatures around ice formation (-5°C) on dog sperm cryosurvival and plasma membrane fluidity. Semen was centrifuged, and sperm were resuspended in a Tris-egg yolk medium (3% glycerol). Diluted sperm were cooled from 22 to 5°C, and then, a Tris-egg yolk medium containing 7% glycerol was added (final concentration of 5% glycerol and 200 × 10 6  cells/ml). Sperm were packaged in 0.5-ml plastic straws, and equilibration was done 16 hr at 5°C before freezing. I. Straws (n = 47) at 5°C were exposed to nitrogen vapours to determine the freezing point. II. Other straws (from different ejaculates) processed as mentioned, were further cooled to -3, -5 or -7°C and immediately rewarmed in a water bath at 37°C. Motility, plasma membrane functionality and acrosome integrity were assessed. III. Other straws (from different ejaculates) processed as mentioned were further cooled to -3 or -5°C, frozen over nitrogen vapours and stored in liquid nitrogen for one month. Straws were thawed in a water bath at 38°C for 30 s. Motility, plasma membrane functionality, plasma membrane integrity, acrosome integrity, capacitation status and plasma membrane fluidity were assessed. Ice nucleation temperature was -14.3 ± 2.05°C (mean ± SD); cooling to +5, -3, -5 and -7°C, without freezing, produces no differences on sperm quality between target temperatures; cooling to +5, -3, and -5°C produced no differences on sperm survival and plasma membrane fluidity after freeze-thawing. In conclusion, cooling of dog spermatozoa to different subzero temperatures did not improve sperm cryosurvival and had no effect on plasma membrane fluidity after thawing. © 2017 Blackwell Verlag GmbH.

  14. MANAGEMENT OF INVENTORIES IN AN ENTEPRISE IN THE CONTEXT OF PRODUCTION CONTINUITY

    Directory of Open Access Journals (Sweden)

    Izabela EMERLING

    2014-04-01

    Full Text Available Inventories are a very important category in the accounting of every enterprise. Inventory management is one of the major decision‐making areas for the company’s management board. Proper inventory management allows reducing total costs and increasing the quality of production, which is the goal of an integrated management system. Proper financial management can also positively affect the maintenance of liquidity in the company. The purpose of this article is to present issues related to inventory management in a company in the context of continuity of production and fluidity of a subject.

  15. Tendances Carbone n. 12 Mar. 2007

    International Nuclear Information System (INIS)

    2007-01-01

    This newsletter presents first some lessons learnt from the European emissions trading system (market fluidity, administrative and political framework, careful but voluntaristic development of the system). Then it makes a synthesis of the European CO 2 market over the last 13 months: traded volumes, spot prices, climate indexes (temperature, precipitations), economic activity indicators (industrial production index, business leaders' confidence index, changes in energy prices, CO 2 quotas allocated to European Union countries, and detailed indicators of CO 2 market, climate, economic activity and energy prices. (J.S.)

  16. High Cholesterol/Low Cholesterol: Effects in Biological Membranes: A Review.

    Science.gov (United States)

    Subczynski, Witold K; Pasenkiewicz-Gierula, Marta; Widomska, Justyna; Mainali, Laxman; Raguz, Marija

    2017-12-01

    Lipid composition determines membrane properties, and cholesterol plays a major role in this determination as it regulates membrane fluidity and permeability, as well as induces the formation of coexisting phases and domains in the membrane. Biological membranes display a very diverse lipid composition, the lateral organization of which plays a crucial role in regulating a variety of membrane functions. We hypothesize that, during biological evolution, membranes with a particular cholesterol content were selected to perform certain functions in the cells of eukaryotic organisms. In this review, we discuss the major membrane properties induced by cholesterol, and their relationship to certain membrane functions.

  17. A new doubly discrete analogue of smoke ring flow and the real time simulation of fluid flow

    International Nuclear Information System (INIS)

    Pinkall, Ulrich; Springborn, Boris; Weissmann, Steffen

    2007-01-01

    Modelling incompressible ideal fluids as a finite collection of vortex filaments is important in physics (super-fluidity, models for the onset of turbulence) as well as for numerical algorithms used in computer graphics for the real time simulation of smoke. Here we introduce a time-discrete evolution equation for arbitrary closed polygons in 3-space that is a discretization of the localized induction approximation of filament motion. This discretization shares with its continuum limit the property that it is a completely integrable system. We apply this polygon evolution to a significant improvement of the numerical algorithms used in computer graphics

  18. "I know you!": The Implications of Knowing In Joyce Carol Oates's Marya: A Life

    Directory of Open Access Journals (Sweden)

    Josephene T.M. Kealey

    2015-05-01

    Full Text Available Joyce Carol Oates’s Preface to the Franklin Library 1st Edition of her 1986 novel Marya: A Life is a theoretical reading guide. In her explanations for the possible autobiographical components discernible in her book, Oates challenges readers to question their ability to know a character, to know an author’s intentions, even to know the self. Oates’s ideas about the fluidity of identity and the dangers of claiming “to know” an other or the self are explored in this story.

  19. Arenas de dragado marino como nueva fuente para materiales de construcción

    OpenAIRE

    Limeira de Araujo, Jussara; Agulló Fité, Luís; Etxeberria Larrañaga, Miren

    2012-01-01

    This work deals with the use of dredged marine sand (DMS) in pastes and mortars as construction material. Different materials from two Spanish ports were used: DMS-0 from Sant Carles de la Ràpita and DMS-A, DMS-B and DMS-C from Barcelona. The aim of the study was to assess DMS as addition (its influence on cohesion and fluidity) or as a fine granular corrector (its influence on compressive strength) in different mixes of cement paste and mortars, respectively. Two experimental stages were car...

  20. Tendances Carbone n. 12 Mar. 2007; Tendances Carbone n. 12 mars 2007

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    This newsletter presents first some lessons learnt from the European emissions trading system (market fluidity, administrative and political framework, careful but voluntaristic development of the system). Then it makes a synthesis of the European CO{sub 2} market over the last 13 months: traded volumes, spot prices, climate indexes (temperature, precipitations), economic activity indicators (industrial production index, business leaders' confidence index, changes in energy prices, CO{sub 2} quotas allocated to European Union countries, and detailed indicators of CO{sub 2} market, climate, economic activity and energy prices. (J.S.)

  1. Viscous optical clearing agent for in vivo optical imaging

    Science.gov (United States)

    Deng, Zijian; Jing, Lijia; Wu, Ning; lv, Pengyu; Jiang, Xiaoyun; Ren, Qiushi; Li, Changhui

    2014-07-01

    By allowing more photons to reach deeper tissue, the optical clearing agent (OCA) has gained increasing attention in various optical imaging modalities. However, commonly used OCAs have high fluidity, limiting their applications in in vivo studies with oblique, uneven, or moving surfaces. In this work, we reported an OCA with high viscosity. We measured the properties of this viscous OCA, and tested its successful performances in the imaging of a living animal's skin with two optical imaging modalities: photoacoustic microscopy and optical coherence tomography. Our results demonstrated that the viscous OCA has a great potential in the study of different turbid tissues using various optical imaging modalities.

  2. Effect of gamma irradiation on membranes of normal and pathological erythrocytes (beta-thalassemia)

    International Nuclear Information System (INIS)

    Sportelli, L.; Bonincontro, A.; Cametti, C.; Consiglio Nazionale delle Ricerche, Rome

    1987-01-01

    The influence of ionizing radiation on the membrane of human normal erythrocytes has extensively been studied and a variety of effects including changes in the cation fluxes or in non-electrolytes permeability, in membrane fluidity, in peroxidation of unsaturated lipids as well as chemical composition or structural modifications has been observed. However, only few studies deal with the effects of ionizing radiation on pathological red blood cells. In this work, we have investigated by means of electron spin resonance (ESR) spectroscopy the effects of 60 Co γ-radiation on the normal and homozygous β-thalassemic human erythrocyte membranes. (orig.)

  3. Numerical modeling of magnetic induction and heating in injection molding tools

    DEFF Research Database (Denmark)

    Guerrier, Patrick; Hattel, Jesper Henri

    2013-01-01

    the temperatures as close as possible to the cavity surface, by means of an integrated induction heating system in the injection molding tool, to improve the fluidity of the polymer melt hereby ensuring that the polymer melt will continue to flow until the mold cavity is completely filled. The presented work uses......Injection molding of parts with special requirements or features such as micro- or nanostructures on the surface, a good surface finish, or long and thin features results in the need of a specialized technique to ensure proper filling and acceptable cycle time. The aim of this study is to increase...

  4. USE OF THE DEVICE TO INCREASE THE PLASTIC PROPERTIES OF COLD-SHAPED FITTINGS

    Directory of Open Access Journals (Sweden)

    T. A. Akhmetov

    2016-01-01

    Full Text Available The subjects of influence of the relationship of a limit of fluidity and full relative lengthening at the maximum load on deformation energy before destruction are considered in the article. Use of the block to decrease of internal tension in production of cold-shaped fittings allows to increase significantly its plastic properties, i. e. a power factor. At the same time combination of such device with the straightening unit similar to one used in production of thin wire and also minimization of specific reduction opens prospects for obtaining all necessary parameters of the fittings of a class «B» produced by cold rolling. 

  5. Lexical shifts, substantive changes, and continuity in State of the Union discourse, 1790-2014.

    Science.gov (United States)

    Rule, Alix; Cointet, Jean-Philippe; Bearman, Peter S

    2015-09-01

    This study reveals that the entry into World War I in 1917 indexed the decisive transition to the modern period in American political consciousness, ushering in new objects of political discourse, a more rapid pace of change of those objects, and a fundamental reframing of the main tasks of governance. We develop a strategy for identifying meaningful categories in textual corpora that span long historic durées, where terms, concepts, and language use changes. Our approach is able to account for the fluidity of discursive categories over time, and to analyze their continuity by identifying the discursive stream as the object of interest.

  6. Lexical shifts, substantive changes, and continuity in State of the Union discourse, 1790–2014

    Science.gov (United States)

    Rule, Alix; Cointet, Jean-Philippe; Bearman, Peter S.

    2015-01-01

    This study reveals that the entry into World War I in 1917 indexed the decisive transition to the modern period in American political consciousness, ushering in new objects of political discourse, a more rapid pace of change of those objects, and a fundamental reframing of the main tasks of governance. We develop a strategy for identifying meaningful categories in textual corpora that span long historic durées, where terms, concepts, and language use changes. Our approach is able to account for the fluidity of discursive categories over time, and to analyze their continuity by identifying the discursive stream as the object of interest. PMID:26261302

  7. Highly selective fusion and accumulation of hybrid liposomes into primary effusion lymphoma cells along with induction of apoptosis

    Energy Technology Data Exchange (ETDEWEB)

    Towata, Tomomi [Division of Applied Life Science, Graduate School of Engineering, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082 (Japan); Division of Hematopoiesis, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811 (Japan); Komizu, Yuji [Division of Applied Life Science, Graduate School of Engineering, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082 (Japan); Suzu, Shinya [Division of Hematopoiesis, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811 (Japan); Ueoka, Ryuichi, E-mail: ueoka@life.sojo-u.ac.jp [Division of Applied Life Science, Graduate School of Engineering, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082 (Japan); Okada, Seiji, E-mail: okadas@kumamoto-u.ac.jp [Division of Hematopoiesis, Center for AIDS Research, Kumamoto University, 2-2-1 Honjo, Kumamoto 860-0811 (Japan)

    2010-03-12

    Primary effusion lymphoma (PEL) is an aggressive neoplasm caused by human herpes virus-8 infection, and is generally resistant to chemotherapy. Hybrid liposomes, composed of dimyristoylphosphatidylcholine (DMPC) and polyoxyethylene (21) dodecyl ether (C{sub 12}(EO){sub 21}) (HL-21), were rapidly accumulated in the membrane of PEL cells. HL-21 also increased membrane fluidity of PEL cells, and induced caspase-3 activation along with cell death. These results suggest that HL-21 should be an effective and attractive regent for PEL treatment.

  8. “Mobile” Phones: The Time/Space and Society/Individual in the Liquid Modernity

    Directory of Open Access Journals (Sweden)

    Arthur Hou-ming Huang

    2015-07-01

    Full Text Available This paper attempts to understand the impact of mobile phones by taking note of both the technological characteristics of mobile phones and the culture of the liquid modernity. Our contention is that the quality of “instant connectivity” of mobile phones and the “ambivalence” between individual and society beneath the liquid modernity jointly bring about the phenomena which cannot be explicated by “perpetual contact”. These phenomena we attempt to investigate include the softening of time/space frameworks, the blurring of the demarcation between public and private spheres, and the fluidity of the relations between individual and society.

  9. Optimal distribution of science funding

    Science.gov (United States)

    Huang, Ding-wei

    2018-07-01

    We propose a new model to investigate the theoretical implications of a novel funding system. We introduce new parameters to model the accumulated advantage. We assume that all scientists are equal and follow the same regulations. The model presents three distinct regimes. In regime (I), the fluidity of funding is significant. The funding distribution is continuous. The concentration of funding is effectively suppressed. In both regimes (II) and (III), a small group of scientists emerges as a circle of elites. Large funding is acquired by a small number of scientists.

  10. "NOTHING IS AGREED UNTIL EVERYTHING IS AGREED": INSTITUTIONALIZING RADICAL DISAGREEMENT AND DEALING WITH THE PAST IN NORTHERN IRELAND

    DEFF Research Database (Denmark)

    McQuaid, Sara Dybris

    2018-01-01

    constitutional futures. It demonstrates that in the absence of an overarching framework for dealing with the past in Northern Ireland, the model is coming into view as accumulated, piecemeal, pluralistic, complex and often contradictory efforts, emerging in the tensions between radical disagreement and attempts...... at reconciliation, between community initiatives and policy discourses, in what may be called a protracted peace process. The chapter argues that navigating this paradox of fixity and fluidity has crucially involved somewhat futile attempts at separating distinct lines of truth and justice in coming to terms...

  11. Mobexpert - Reprezentări Semiotice ale unui Stil de Viaţă

    Directory of Open Access Journals (Sweden)

    Camelia-Mihaela Cmeciu

    2009-07-01

    Full Text Available The lack of space triggers, in postmodernism, the creativity of the furniture designers. The tendency of abundance and of filling the traditional space with ancient objects is replaced with a certain fluidity of some simple structures which will turn into an indexical sign of a certain life style. Having as theoretical background the semiotic framework of Jean-Marie Floch ([1995] 2000, Jean Baudrillard ([1968] 1996 and the representatives of the Groupe μ (1992, the aim of this paper is to analyse the four semiotic valorizations on which an advertisement of Mobexpert is structured.

  12. Hemorheological abnormalities in human arterial hypertension

    Science.gov (United States)

    Lo Presti, Rosalia; Hopps, Eugenia; Caimi, Gregorio

    2014-05-01

    Blood rheology is impaired in hypertensive patients. The alteration involves blood and plasma viscosity, and the erythrocyte behaviour is often abnormal. The hemorheological pattern appears to be related to some pathophysiological mechanisms of hypertension and to organ damage, in particular left ventricular hypertrophy and myocardial ischemia. Abnormalities have been observed in erythrocyte membrane fluidity, explored by fluorescence spectroscopy and electron spin resonance. This may be relevant for red cell flow in microvessels and oxygen delivery to tissues. Although blood viscosity is not a direct target of antihypertensive therapy, the rheological properties of blood play a role in the pathophysiology of arterial hypertension and its vascular complications.

  13. Cromatografia unificada Unified chromatography

    Directory of Open Access Journals (Sweden)

    Carin von Mühlen

    2004-10-01

    Full Text Available The scope of this study encompasses an overview of the principles of unified chromatography as well as the principles of chromatographic techniques as applied to unified systems, which include gas chromatography, liquid chromatography, supercritical fluid chromatography, high temperature and high pressure liquid chromatography, micro-liquid chromatography, enhanced fluidity chromatography, and solvating gas chromatography. Theoretical considerations and individual instrumental parameters such as mobile phase, sample introduction system, columns, and detection system are also discussed. Future applications of this separation approach are discussed.

  14. NEW CONTRIBUTIONS TO READING DIFFICULTIES INTERVENTION

    Directory of Open Access Journals (Sweden)

    VÍCTOR SANTIUSTE BERMEJO

    2005-01-01

    Full Text Available This article presents a synthesis of the intervention programs and strategies to treat reading difficulties. The synthesisincludes a review of the last published articles on the issue, both in Spanish and English. It also presents the visits todifferent Language Rehabilitation Centers in the Community of Madrid including the approaches applied in thesecenters. Besides the description of the general intervention strategies applied to reading problems, some of theprograms to treat specific difficulties of words decoding and recognizing are explained, and the programs to treatreading comprehension and fluidity.

  15. The intersectional body

    DEFF Research Database (Denmark)

    Elg, Camilla; Jensen, Sune Qvotrup

    2012-01-01

    from Merleau-Ponty’s thinking about human experience as always already being part of the physical world, and from the concept of mimesis which denotes that we are always as human beings spontaneously engaged with sociality, implying both the accumulation of practical sense and radical conditionality......-additive analyses might be managed as the body is by definition non-additive. 2, Considerations about fluidity and changeability might be refocused, as a central characteristic of the body is its intertia. 3, Thinking about power relations might be recast as attention is drawn to how power relations are embodied...

  16. Physicochemical and biological characterization of 1,2-dialkoylamidopropane-based lipoplexes for gene delivery.

    Science.gov (United States)

    Aljaberi, Ahmad; Saleh, Suhair; Abu Khadra, Khalid M; Kearns, Molinda; Savva, Michalakis

    2015-04-01

    Elucidation of the molecular and formulation requirements for efficient lipofection is a prerequisite to enhance the biological activity of cationic lipid-mediated gene delivery systems. To this end, the in vitro lipofection activity of the ionizable asymmetric 1,2-dialkoylamidopropane-based derivatives bearing a single primary amine group as the cationic head group was evaluated. The electrostatic interactions of these cationic lipids with plasmid DNA in serum-free medium were investigated by means of gel electrophoresis retardation and Eth-Br quenching assays. The effect of the inclusion of the helper lipid DOPE in the formulation on these interactions was also considered. The physicochemical properties of these lipids in terms of bilayer fluidity and extent of ionization were investigated using fluorescence anisotropy and surface potential techniques, respectively. The results showed that only the active lipid, 1,2lmp[5], existed in a liquid crystalline state at physiological temperature. Moreover, the extent of ionization of this lipid in assemblies was significantly higher that it's saturated analogues. Inclusion of the helper lipid DOPE improved the encapsulation and association between 1,2lmp[5] and plasmid DNA, which was reflected by the significant boost of lipofection activity of the 1,2lmp[5]/DOPE formulation as compared to the lipid alone. In conclusion, membrane fluidity and sufficient protonation of ionizable cationic lipid are required for efficient association and encapsulation of plasmid DNA and elicit of improved in vitro lipofection activity. Copyright © 2015 Elsevier B.V. All rights reserved.

  17. Performance Comparison between Neutralization Tailings and Flotation Tailings Used for Backfill Mix and Mechanism Analysis

    Directory of Open Access Journals (Sweden)

    Bin Han

    2016-01-01

    Full Text Available A comparison test of different tailings used for underground backfill was conducted, using neutralized tailings from BIOX and flotation tailings of Jinfeng Mine. Laboratory comparison test results show that, with neutralized tailings, when the cement dosage is at 19%, backfill UCS after 7 days, 14 days, and 28 days are 105%–163%, 80%–102%, and 33%–43%, respectively, which are higher than those of flotation tailings. When the cement dosage is at 12%, backfill UCS after 7 days, 14 days, and 28 days are 58%–77%, 50%–60%, and 28%–51%, respectively, which are higher than those of flotation tailings. Slurry fluidity of neutralized tailings is lower than that of flotation tailings, while, in these two tailings, the difference of slump and diffusivity values is less than 6%, which is not a significant difference in slurry fluidity. The reason for neutralized tailings showing higher UCS is as follows: during backfill curing, neutralization tailings produce abundant crystals of CaSO4·2H2O in interlaced structure which helps in combining aggregates closely; CaSO4·2H2O hydrates with C3A C4AF contained in the cement and forms clavate cement bacillus which works as a micro reinforcing steel bar. The test proved that neutralized tailings are more optimal for backfilling.

  18. [Description and evaluation of creative thinking in preterm low birth weight infants].

    Science.gov (United States)

    Parisi, L; Di Filippo, T; Firrigno, L; La Grutta, S; Testa, D; Roccella, M

    2007-04-01

    Since the 1950s, the problem of how to evaluate creativity has been addressed in studies on the definition of measurement criteria and on the relationship between intelligence and creative thinking. Many revealed cognitive and relational disorders in preterm infants, particularly in preterm very low birth weight infants (birth weight 2500 g. The test battery included: Torrance Test of Creative Thinking (TCTT); WISC-R intelligence test; Goodenough Human Figure Drawing Test. Statistical analysis (Mann-Whitney U test) showed a statistically significant difference (P>0.05) between the 2 groups; scores for figure originality, figure fluidity and figure elaboration were consistently higher in the control group. Within the low birth weight group, there was a significant correlation (Spearman r) between verbal IQ and verbal fluidity and verbal flexibility subscale scores and between IQ performance and figure elaboration. Scores on the figure drawing tests showed higher creative ability in the control group. In children born preterm with low birth weight, emotive dynamics and flow of affection may influence the channels of communication between child and family. The low figure originality subscale scores support the hypothesis that psychodynamic and relational factors (worry about the preterm condition, overprotective behaviour by parents and others) could lead to diminished autonomy, flexibility and manipulatory interest in the child.

  19. The Categorical Stability of Gambling Motives Among Community-Recruited Gamblers: A Longitudinal Assessment.

    Science.gov (United States)

    McGrath, Daniel S; Konkolÿ Thege, Barna

    2018-03-01

    Over the past decade, several motivational models have been proposed to explain the role of motives in gambling disorder. In the model captured by the four-factor Gambling Motives Questionnaire Financial (GMQ-F), gamblers are described as being primarily motivated to gamble for 'coping', 'enhancement', 'social', and 'financial' reasons. Although this model has received significant empirical support; to date, research assessing the role of motives in gambling disorder has been primarily cross-sectional in nature. Thus, the extent to which gambling motives remain stable over time has yet to be explored. In the current study, the stability versus fluidity of self-assessed gambling motives was investigated using the Quinte Longitudinal Study, a longitudinal dataset of gambling behaviour collected over 5 years. Gambling motives of 2795 gamblers were examined over all five annual assessments. The total proportion of gamblers who stayed in the same primary motive category across each of the 5 consecutive assessments was 22%, indicating substantial fluidity in category membership. Substantial movement between categories was seen for each GMQ-F group, as well as an additional group of non-classified motives. Logistic regression analyses suggest that greater resistance to gambling fallacies significantly predicted stability between the baseline assessment and a follow-up 1 year later, but gambling severity did not. Potential limitations in the study design and opportunities for future research are discussed.

  20. Studies of coal slurries property; Slurry no seijo ni kansuru kento

    Energy Technology Data Exchange (ETDEWEB)

    Kawabata, M.; Aihara, Y.; Imada, K. [Nippon Steel Corp., Tokyo (Japan); Nogami, Y.; Inokuchi, K. [Mitsui SRC Development Co. Ltd., Tokyo (Japan); Sakaki, T.; Shibata, M.; Hirosue, H. [Kyushu National Industrial Research Institute, Saga (Japan)

    1996-10-28

    It was previously found that the increase of slurry temperature provides a significant effect of slurry viscosity reduction for the coal slurry with high concentration of 50 wt%. To investigate the detailed influence of slurry temperature for the coal slurry with concentration of 50 wt%, influence of temperature on the successive change of apparent viscosity was observed at the constant shear rate. When the concentration of coal was increased from 45 wt% to 50 wt%, viscosity of the slurry was rapidly increased. When heated above 70{degree}C, the apparent viscosity decreased during heating to the given temperature, but it increased successively after reaching to the given temperature. The apparent viscosity showed higher value than that of the initial viscosity. The coal slurry with concentration of 50 wt% showed the fluidity of Newtonian fluid at the lower shear rate region, but showed the fluidity of pseudo-plastic fluid at the higher shear rate region. The slurry having high apparent viscosity by the successive change showed higher apparent viscosity with increasing the higher even by changing the shear rate. 1 ref., 4 figs.

  1. Influence of packing and dispersion of particles on the cement content of concretes

    Directory of Open Access Journals (Sweden)

    B. L. DAMINELI

    Full Text Available Abstract Due to environmental issues, the concrete chain seeks to reduce CO2 emissions. However, growing demand from developing countries causes the increase of CO2 emissions in production to exceed decreases generated by industrial actions, such as improving kilns and clinker replacement. New strategies are important. Changes in the concrete formulation, making it more efficient, can help if these changes produce concrete with the same performance and lower cement consumption. In this regard, the improvement of packing and dispersion of particles increases this efficiency. The better the packing, the lower the volume of voids between particles, thereby requiring lower fluid content (water to permit flow. The dispersion of the particles also decreases the water content for the same fluidity. The less the water content, the smaller the water/cement (w/c ratio, and the greater the resistance. Thus, both strategies increase the efficiency by uncoupling obtaining fluidity from the water content. This study investigated the influence of packing and dispersion on the efficiency of cement use in concrete. The increase of packing and the complete dispersion of fine particles has been shown to improve efficiency, as measured by the ratio between binder consumption and compressive strength (the performance parameter used in most practical applications.

  2. Arachidonic acid in health and disease with focus on hypertension and diabetes mellitus: A review

    Directory of Open Access Journals (Sweden)

    Undurti N. Das

    2018-05-01

    Full Text Available Arachidonic acid (AA 20:4n-6 is an essential component of cell membranes and modulates cell membrane fluidity. AA is metabolized by cyclo-oxygenase (COX, lipoxygenase (LOX and cytochrome P450 enzymes to form several metabolites that have important biological actions. Of all the actions, role of AA in the regulation of blood pressure and its ability to prevent both type 1 and type 2 diabetes mellitus seems to be interesting. Studies showed that AA and its metabolites especially, lipoxin A4 (LXA4 and epoxyeicosatrienoic acids (EETs, potent anti-inflammatory metabolites, have a crucial role in the pathobiology of hypertension and diabetes mellitus. AA, LXA4 and EETs regulate smooth muscle function and proliferation, voltage gated ion channels, cell membrane fluidity, membrane receptors, G-coupled receptors, PPARs, free radical generation, nitric oxide formation, inflammation, and immune responses that, in turn, participate in the regulation blood pressure and pathogenesis of diabetes mellitus. In this review, role of AA and its metabolites LXA4 and EETs in the pathobiology of hypertension, pre-eclampsia and diabetes mellitus are discussed. Based on several lines of evidences, it is proposed that a combination of aspirin and AA could be of benefit in the prevention and management of hypertension, pre-eclampsia and diabetes mellitus. Keywords: Arachidonic acid, Lipoxin A4, Hypertension, Pre-eclampsia, Diabetes mellitus, Inflammation, Cytokines, Free radicals, Nitric oxide

  3. Influence of lecithin-lipid composition on physico-chemical properties of nanoliposomes loaded with a hydrophobic molecule.

    Science.gov (United States)

    Bouarab, Lynda; Maherani, Behnoush; Kheirolomoom, Azadeh; Hasan, Mahmoud; Aliakbarian, Bahar; Linder, Michel; Arab-Tehrany, Elmira

    2014-03-01

    In this work, we studied the effect of nanoliposome composition based on phospholipids of docosahexaenoic acid (PL-DHA), salmon and soya lecithin, on physico-chemical characterization of vector. Cinnamic acid was encapsulated as a hydrophobic molecule in nanoliposomes made of three different lipid sources. The aim was to evaluate the influence of membrane lipid structure and composition on entrapment efficiency and membrane permeability of cinnamic acid. These properties are important for active molecule delivery. In addition, size, electrophoretic mobility, phase transition temperature, elasticity and membrane fluidity were measured before and after encapsulation. The results showed a correlation between the size of the nanoliposome and the entrapment. The entrapment efficiency of cinnamic acid was found to be the highest in liposomes prepared from salmon lecithin. The nanoliposomes composed of salmon lecithin presented higher capabilities as a carrier for cinnamic acid encapsulation. These vesicles also showed a high stability which in turn increases the membrane rigidity of nanoliposome as evaluated by their elastic properties, membrane fluidity and phase transition temperature. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Effect of metal properties of casts of steel-15Kh1M1FL on the crack resistance at 565 deg C

    International Nuclear Information System (INIS)

    Gladshtejn, V.I.; Sheshenev, M.F.

    1976-01-01

    Results are given of prolonged tests of the metal of industrial casts with various fluidity limits. It has been shown experimentally that a quite satisfactory crack resistance is characteristic of a metal with a fluidity limit in the range 30-50 kgf/mm 2 . Metallographic studies have been conducted. Upon variation of the structure and properties of the 15Kh1M1FL steel during operation, the rate of growth of small cracks (up to 2.0 mm) decreases almost by 3 orders of ten (from 1.4x10 -4 to 2.0x10 -7 mm/hour). Subsequent structural changes during prolonged operation (over 50000 hours) result in a gradual increase in the rate of crack growth. At the same time resistance towards appearance of the impermissible high rate of the crack growth, Ksub(10sup(-3)), diminishes monotonically with the operation time. The metal of industrial 15Kh1M1FL steel casts has good crack resistance (Ksub(10sup(-3)) =30-70 kgf/mmsup(3/2) and Vsub(ef) =) kgf/mm 2 ) and a satisfactory local plasticity (critical opening being no more than 0.20 mm for 10 3 hours)

  5. Quality design of belite–melilite clinker

    Energy Technology Data Exchange (ETDEWEB)

    Kurokawa, Daisuke, E-mail: daisuke_kurokawa@taiheiyo-cement.co.jp [R and D center, Taiheiyo Cement Corporation, Chiba 285-8655 (Japan); Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan); Honma, Kenichi; Hirao, Hiroshi [R and D center, Taiheiyo Cement Corporation, Chiba 285-8655 (Japan); Fukuda, Koichiro [Department of Materials Science and Engineering, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

    2013-12-15

    We have developed a new cement clinker, consisting mainly of belite and melilite, which is capable of increasing the amount of recycled waste as a part of its raw materials. We analyzed clinkers with a wide range of compositions, and clarified the quantitative relationship between the chemical and mineral compositions. Clinkers consisting mostly of belite and melilite were successfully obtained at the CaO/SiO{sub 2} mass ratio of 1.7 to 1.9. Test cements were prepared using these clinkers and mixed with OPC for the evaluation of fluidity and strength. The belite–melilite cement was found to have good fluidity, and the belite–melilite cement mixed with OPC at up to 30% exhibited a satisfactory long term strength equivalent to the OPC, demonstrating the potential as an alternative to OPC. Electron probe microanalysis revealed the relatively high concentration of diphosphorus pentaoxide in belite, suggesting this component might contribute to the strength enhancement of the cement. -- Highlights: •A new cement clinker consisting mainly of belite and melilite was designed. •The clinker enables the use of various recycled wastes as part of its raw materials. •The relationship between the chemical and mineral compositions was clarified. •This cement mixed with OPC at up to 30% exhibited a good quality equivalent to OPC.

  6. Homeoviscous adaptation and the regulation of membrane lipids

    DEFF Research Database (Denmark)

    Ernst, Robert; Ejsing, Christer S; Antonny, Bruno

    2016-01-01

    Biological membranes are complex and dynamic assemblies of lipids and proteins. Poikilothermic organisms including bacteria, fungi, reptiles, and fish do not control their body temperature and must adapt their membrane lipid composition in order to maintain membrane fluidity in the cold. This ada......Biological membranes are complex and dynamic assemblies of lipids and proteins. Poikilothermic organisms including bacteria, fungi, reptiles, and fish do not control their body temperature and must adapt their membrane lipid composition in order to maintain membrane fluidity in the cold....... This adaptive response was termed homeoviscous adaptation and has been frequently studied with a specific focus on the acyl chain composition of membrane lipids. Massspectrometry-based lipidomics can nowadays provide more comprehensive insights into the complexity of lipid remodeling during adaptive responses...... such as neurons maintain unique lipid compositions with specific physicochemical properties. To date little is known about the sensory mechanisms regulating the acyl chain profile in such specialized cells or during adaptive responses. Here we summarize our current understanding of lipid metabolic networks...

  7. Properties of Plasma Membrane from Pea Root Seedlings under Altered Gravity

    Science.gov (United States)

    Klymchuk, D.; Baranenko, V.; Vorobyova, T. V.; Kurylenko, I.; Chyzhykova, O.; Dubovoy, V.

    In this study, the properties of pea (Pisum sativum L.) plasma membrane were examined to determine how the membrane structure and functions are regulated in response to clinorotation (2 rev/min) conditions. Membrane preparations enriched by plasma membrane vesicles were obtained by aqueous two-phase partitioning from 6-day seedling roots. The specific characteristics of H^+-ATPase, lípid composition and peroxidation intensity as well as fluidity of lipid bilayer were analysed. ATP hydrolytic activity was inhibited by ortovanadate and was insensitive to aside and nitrate in sealed plasma membrane vesicles isolated from both clinorotated and control seedlings. Plasma membrane vesicles from clinorotated seedlings in comparison to controls were characterised by increase in the total lipid/protein ratio, ATP hydrolytic activity and intensifying of lipid peroxidation. Sitosterol and campesterol were the predominant free sterol species. Clinorotated seedlings contained a slightly higher level of unsaturated fatty acid than controls. Plasma membrane vesicles were labelled with pyrene and fluorescence originating from monomeric (I_M) molecules and excimeric (I_E) aggregates were measured. The calculated I_E/I_M values were higher in clinorotated seedlings compared with controls reflecting the reduction in membrane microviscosity. The involvement of the changes in plasma membrane lipid content and composition, fluidity and H^+-ATPase activity in response of pea seedlings to altered gravity is discussed.

  8. Lipids of Prokaryotic Origin at the Base of Marine Food Webs

    Directory of Open Access Journals (Sweden)

    Maria José Caramujo

    2012-11-01

    Full Text Available In particular niches of the marine environment, such as abyssal trenches, icy waters and hot vents, the base of the food web is composed of bacteria and archaea that have developed strategies to survive and thrive under the most extreme conditions. Some of these organisms are considered “extremophiles” and modulate the fatty acid composition of their phospholipids to maintain the adequate fluidity of the cellular membrane under cold/hot temperatures, elevated pressure, high/low salinity and pH. Bacterial cells are even able to produce polyunsaturated fatty acids, contrarily to what was considered until the 1990s, helping the regulation of the membrane fluidity triggered by temperature and pressure and providing protection from oxidative stress. In marine ecosystems, bacteria may either act as a sink of carbon, contribute to nutrient recycling to photo-autotrophs or bacterial organic matter may be transferred to other trophic links in aquatic food webs. The present work aims to provide a comprehensive review on lipid production in bacteria and archaea and to discuss how their lipids, of both heterotrophic and chemoautotrophic origin, contribute to marine food webs.

  9. Stability of Sexual Attractions Across Different Timescales: The Roles of Bisexuality and Gender.

    Science.gov (United States)

    Diamond, Lisa M; Dickenson, Janna A; Blair, Karen L

    2017-01-01

    We examined the stability of same-sex and other-sex attractions among 294 heterosexual, lesbian, gay, and bisexual men and women between the ages of 18 and 40 years. Participants used online daily diaries to report the intensity of each day's strongest same-sex and other-sex attraction, and they also reported on changes they recalled experiencing in their attractions since adolescence. We used multilevel dynamical systems models to examine individual differences in the stability of daily attractions (stability, in these models, denotes the tendency for attractions to "self-correct" toward a person-specific setpoint over time). Women's attractions showed less day-to-day stability than men's, consistent with the notion of female sexual fluidity (i.e., heightened erotic sensitivity to situational and contextual influences). Yet, women did not recollect larger post-adolescent changes in sexual attractions than did men, and larger recollected post-adolescent changes did not predict lower day-to-day stability in the sample as a whole. Bisexually attracted individuals recollected larger post-adolescent changes in their attractions, and they showed lower day-to-day stability in attractions to their "less-preferred" gender, compared to individuals with exclusive same-sex or exclusive other-sex attractions. Our results suggest that both gender and bisexuality have independent influences on sexual fluidity, but these influences vary across short versus long timescales, and they also differ for attractions to one's "more-preferred" versus "less-preferred" gender.

  10. Characterization of linoleate 10-hydratase of Lactobacillus plantarum and novel antifungal metabolites

    Directory of Open Access Journals (Sweden)

    Yuan Yao Chen

    2016-10-01

    Full Text Available Lactobacilli convert linoleic acid to the antifungal compound 10-hydroxy-12-octadecenoic acid (10-HOE by linoleate 10-hydratase (10-LAH. However, the effect of this conversion on cellularmembrane physiology and properties of the cell surface have not been demonstrated. Moreover, L. plantarum produces 13-hydroxy-9-octadecenoic acid (13-HOE in addition to 10-HOE, but the antifungal activity of 13-HOE was unknown. Phylogenetic analyses conducted in this study did not differentiate between 10-LAH and linoleate 13-hydratase (13-LAH. Thus, linoleate hydratases (LAHs must be characterized through their differences in their activities of linoleate conversion. Four genes encoding putative LAHs from lactobacilli were cloned, heterologous expressed, purified and identified as FAD-dependent 10-LAH. The unsaturated fatty acid substrates stimulated the growth of lactobacilli. We also investigated the role of 10-LAH in ethanol tolerance, membrane fluidity and hydrophobicity of cell surfaces in lactobacilli by disruption of 10-lah. Compared with the L. plantarum 10-lah deficient strain, 10-LAH in wild-type strain did not exert effect on cell survival and membrane fluidity under ethanol stress, but influenced the cell surface hydrophobicity. Moreover, deletion of 10-LAH in L. plantarum facilitated purification of 13-HOE and demonstration of its antifungal activity against Penicillium roquefortii and Aspergillus niger.

  11. Polymalic Acid Tritryptophan Copolymer Interacts with Lipid Membrane Resulting in Membrane Solubilization

    Directory of Open Access Journals (Sweden)

    Hui Ding

    2017-01-01

    Full Text Available Anionic polymers with membrane permeation functionalities are highly desirable for secure cytoplasmic drug delivery. We have developed tritryptophan containing copolymer (P/WWW of polymalic acid (PMLA that permeates membranes by a mechanism different from previously described PMLA copolymers of trileucine (P/LLL and leucine ethyl ester (P/LOEt that use the “barrel stave” and “carpet” mechanism, respectively. The novel mechanism leads to solubilization of membranes by forming copolymer “belts” around planar membrane “packages.” The formation of such packages is supported by results obtained from studies including size-exclusion chromatography, confocal microscopy, and fluorescence energy transfer. According to this “belt” mechanism, it is hypothesized that P/WWW first attaches to the membrane surface. Subsequently the hydrophobic tryptophan side chains translocate into the periphery and insert into the lipid bilayer thereby cutting the membrane into packages. The reaction is driven by the high affinity between the tryptophan residues and lipid side chains resulting in a stable configuration. The formation of the membrane packages requires physical agitation suggesting that the success of the translocation depends on the fluidity of the membrane. It is emphasized that the “belt” mechanism could specifically function in the recognition of abnormal cells with high membrane fluidity and in response to hyperthermia.

  12. The molecular-scale arrangement and mechanical strength of phospholipid/cholesterol mixed bilayers investigated by frequency modulation atomic force microscopy in liquid

    International Nuclear Information System (INIS)

    Asakawa, Hitoshi; Fukuma, Takeshi

    2009-01-01

    Cholesterols play key roles in controlling molecular fluidity in a biological membrane, yet little is known about their molecular-scale arrangements in real space. In this study, we have directly imaged lipid-cholesterol complexes in a model biological membrane consisting of dipalmitoylphosphatidylcholine (DPPC) and cholesterols by frequency modulation atomic force microscopy (FM-AFM) in phosphate buffer solution. FM-AFM images of a DPPC/cholesterol bilayer in the liquid-ordered phase showed higher energy dissipation values compared to those measured on a nanoscale DPPC domain in the gel phase, reflecting the increased molecular fluidity due to the insertion of cholesterols. Molecular-resolution FM-AFM images of a DPPC/cholesterol bilayer revealed the existence of a rhombic molecular arrangement (lattice constants: a = 0.46 nm, b = 0.71 nm) consisting of alternating rows of DPPC and cholesterols as well as the increased defect density and reduced molecular ordering. The mechanical strength of a DPPC/cholesterol bilayer was quantitatively evaluated by measuring a loading force required to penetrate the membrane with an AFM tip. The result revealed the significant decrease of mechanical strength upon insertion of cholesterols. Based on the molecular-scale arrangement found in this study, we propose a model to explain the reduced mechanical strength in relation to the formation of lipid-ion networks.

  13. Molecular mechanism of the viscosity of aqueous glucose solutions

    Science.gov (United States)

    Bulavin, L. A.; Zabashta, Yu. F.; Khlopov, A. M.; Khorol'skii, A. V.

    2017-01-01

    Experimental relations are obtained for the viscosity of aqueous glucose solutions in the temperature range of 10-80°C and concentration range 0.01-2.5%. It is found that the concentration dependence of fluidity is linear when the concentration is higher than a certain value and varies at different temperatures. The existence of such a dependence indicates that the mobilities of solvent and solute molecules are independent of the concentration of solutions. This assumption is used to construct a theoretical model, in which the structure of an aqueous glucose solution is presented as a combination of two weakly interacting networks formed by hydrogen bonds between water molecules and between glucose molecules. Theoretical relations are obtained using this model of network solution structure for the concentration and temperature dependence of solution viscosity. Experimental data are used to calculate the activation energies for water ( U w = 3.0 × 10-20 J) and glucose molecules ( U g = 2.8 × 10-20 J). It is shown that the viscosity of a solution in such a network structure is governed by the Brownian motion of solitons along the chains of hydrogen bonds. The weak interaction between networks results in the contributions to solution fluidity made by the motion of solitons in both of them being almost independent.

  14. Multiscale analysis of the correlation of processing parameters on viscidity of composites fabricated by automated fiber placement

    Science.gov (United States)

    Han, Zhenyu; Sun, Shouzheng; Fu, Yunzhong; Fu, Hongya

    2017-10-01

    Viscidity is an important physical indicator for assessing fluidity of resin that is beneficial to contact resin with the fibers effectively and reduce manufacturing defects during automated fiber placement (AFP) process. However, the effect of processing parameters on viscidity evolution is rarely studied during AFP process. In this paper, viscidities under different scales are analyzed based on multi-scale analysis method. Firstly, viscous dissipation energy (VDE) within meso-unit under different processing parameters is assessed by using finite element method (FEM). According to multi-scale energy transfer model, meso-unit energy is used as the boundary condition for microscopic analysis. Furthermore, molecular structure of micro-system is built by molecular dynamics (MD) method. And viscosity curves are then obtained by integrating stress autocorrelation function (SACF) with time. Finally, the correlation characteristics of processing parameters to viscosity are revealed by using gray relational analysis method (GRAM). A group of processing parameters is found out to achieve the stability of viscosity and better fluidity of resin.

  15. Interaction of toremifene with dipalmitoyl-phosphatidyl-glycerol in monolayers at the air–water interface followed by fluorescence microscopy in Langmuir–Blodgett films

    International Nuclear Information System (INIS)

    Romão, Rute I.S.; Maçôas, Ermelinda; Martinho, José M.G.; Gonçalves da Silva, Amélia M.P.S.

    2013-01-01

    Langmuir monolayers of dipalmitoyl-phosphatidyl-glycerol (DPPG) containing toremifene (TOR), an antiestrogen drug derivative of tamoxifen, were prepared in order to study the interaction of the drug with the cell membrane. TOR is not surface active but it remains at the interface in DPPG rich monolayers anchored by electrostatic interaction with the anionic DPPG up to the equimolar composition. The fluidity of mixed monolayers increases up to the TOR mole fraction X TOR = 0.3, remaining practically invariant for higher compositions. Brewster angle microscopy shows that the TOR disturbs the DPPG organization and the liquid condensed (LC) domains of DPPG become undetectable for X TOR ≥ 0.4. Laser scanning confocal fluorescence microscopy images of the LB films doped with rhodamine B-piperazine amide dye confirm the progressive reduction in size of LC domains, from which TOR and rhodamine are excluded. The incorporation of TOR in DPPG monolayers up to the equimolar composition supports the formation of a TOR:DPPG complex (1:1) due to electrostatic interactions between the negatively charged polar groups of DPPG and protonated TOR. - Highlights: • Toremifene (TOR) in dipalmitoyl-phosphatidyl-glycerol (DPPG) monolayers • Electrostatic interactions between DPPG and TOR form a 1:1 complex. • TOR increases the fluidity of DPPG monolayers. • Incorporation of TOR in the fluid phase of DPPG followed by fluorescence imaging

  16. Haemato-protective influence of dietary fenugreek (Trigonella foenum-graecum L.) seeds is potentiated by onion (Allium cepa L.) in streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Pradeep, Seetur R; Srinivasan, Krishnapura

    2018-02-01

    We have recently reported the beneficial modulation of metabolic abnormalities and oxidative stress in diabetic rats by dietary fenugreek seeds and onion. This investigation evaluated the protective influence of dietary fenugreek seeds (100 g kg -1 ) and onion (30 g kg -1 ) on erythrocytes of streptozotocin-induced diabetic rats, through modulation of reduced haematological indices and antisickling potency. This study also evaluated the altered erythrocyte membrane lipid profile and beneficial countering of increased lipid peroxidation, osmotic fragility, along with reduced membrane fluidity and deformability, nitric oxide production and echinocyte formation. Dietary fenugreek seeds and onion appeared to counter the deformity and fragility of erythrocytes partially in diabetic rats by their antioxidant potential and hypocholesterolemic property. The antisickling potency of these spices was accomplished by a substantial decrease in echinocyte population and AGEs in diabetic rats. Further insight into the factors that might have reduced the fluidity of erythrocytes in diabetic rats revealed changes in the cholesterol: phospholipid ratio, fatty acid profile, and activities of membrane-bound enzymes. Dietary fenugreek seeds and onion offered a beneficial protective effect to the red blood cells, the effect being higher with fenugreek + onion. This is the first report on the hemato-protective influence of a nutraceutical food component in diabetic situation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  17. The molecular-scale arrangement and mechanical strength of phospholipid/cholesterol mixed bilayers investigated by frequency modulation atomic force microscopy in liquid

    Energy Technology Data Exchange (ETDEWEB)

    Asakawa, Hitoshi; Fukuma, Takeshi [Frontier Science Organization, Kanazawa University, Kakuma-machi, 920-1192 Kanazawa (Japan)], E-mail: hi_asa@staff.kanazawa-u.ac.jp, E-mail: fukuma@staff.kanazawa-u.ac.jp

    2009-07-01

    Cholesterols play key roles in controlling molecular fluidity in a biological membrane, yet little is known about their molecular-scale arrangements in real space. In this study, we have directly imaged lipid-cholesterol complexes in a model biological membrane consisting of dipalmitoylphosphatidylcholine (DPPC) and cholesterols by frequency modulation atomic force microscopy (FM-AFM) in phosphate buffer solution. FM-AFM images of a DPPC/cholesterol bilayer in the liquid-ordered phase showed higher energy dissipation values compared to those measured on a nanoscale DPPC domain in the gel phase, reflecting the increased molecular fluidity due to the insertion of cholesterols. Molecular-resolution FM-AFM images of a DPPC/cholesterol bilayer revealed the existence of a rhombic molecular arrangement (lattice constants: a = 0.46 nm, b = 0.71 nm) consisting of alternating rows of DPPC and cholesterols as well as the increased defect density and reduced molecular ordering. The mechanical strength of a DPPC/cholesterol bilayer was quantitatively evaluated by measuring a loading force required to penetrate the membrane with an AFM tip. The result revealed the significant decrease of mechanical strength upon insertion of cholesterols. Based on the molecular-scale arrangement found in this study, we propose a model to explain the reduced mechanical strength in relation to the formation of lipid-ion networks.

  18. Fiscal 2000 survey report. Survey of long-term energy technology strategy and the like (Research on actualities of Japanese industries' research and development potential); 2000 nendo choki energy gijutsu senryaku nado ni kansuru chosa hokokusho. Sangyo gijutsu senryaku sakutei kiban chosa (Nippon kigyo no kenkyu kaihatsuryoku no jittai ni kansuru chosa kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    For working out propositions on what the country should do and on what improvement industries should make for the strengthening of industries' competitive power on the market, analyses were conducted into the objects of research and development, organizations engaged in research and development activities, methods of evaluation, and the like. In concrete terms, studies were made on industries' roles in research and development activities and on the actualities of basic research and development potential, and then a survey was conducted through questionnaires and interviews about (1) tasks relating to corporation management and research and development potential, (2) development of research dedicated talent and its fluidity, and (3) problems feared to get worse in the future. Questionnaires were sent to 217 corporations or 577 people of whom 37.6% responded. Each item is described below. Under item (1), it is pointed out that basic research has shrunk as a whole, that pressure is on the increase urging that research directly increase profit, and that theme selection is made to match the business model. Under item (2), it is stated that post-doctorate researchers' knowledge is respected but that recruitment is another matter, and that fluidity of researchers between corporations will increase. Under item (3), it is pointed out that researchers are increasingly inferior in quality and that brain drain out of Japan is feared. (NEDO)

  19. Achievement report on developing coal liquefaction technologies in fiscal 1998 - edition B. Development of bituminous coal liquefaction technology (studies by using pilot plant) 1/2; 1998 nendo sekitan ekika gijutsu kaihatsu seika hokokusho B. 1/2. Rekiseitan ekika gijutsu no kaihatsu (pilot plant ni yoru kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    With an objective to improve the environment by substituting petroleum energy by coal, and by reducing emission of SOx and NOx, research and development has been performed on coal liquefaction technologies. This paper summarizes the achievements thereof in fiscal 1998. In the operation study RUN-5, the operation was carried out by using the Tanito Harum coal of Indonesia, and raising the slurry concentration to 50% by weight. The operation stability when the high concentration slurry was used was verified, and the liquefying reaction column fluidity property data, and the material balance and heat balance data were acquired by using the NAT method. In the RUN-6 and 7, for the purpose of verifying the applicability of the NEDOL process to the wide range of coal types as the process feature, the Adaro coal of Indonesia and the Ikejima coal of Japan were used, and the operation at high slurry concentration was performed at 80% load and under the standard NEDOL conditions. The operation stability when the upper and lower limit coals was used was verified, and the operability at high slurry concentration was identified. At the same time, the liquefying reaction column fluidity property data, and the material balance and heat balance data were acquired. The development targets established by the Industrial Technology Council have all been achieved. (NEDO)

  20. Thermophysical Properties of Fluid Latent Heat Storage Material using Urea-Water Mixture

    Science.gov (United States)

    Hokamura, Taku; Ohkubo, Hidetoshi; Ashizawa, Kiyonori

    This study is concerned with the measurement of thermophysical properties of a urea-water mixture with the aim of adopting the mixture as a latent heat storage material for air-conditioning systems. The urea-water mixture is made of natural substances and has a good fluidity. The urea concentration in the mixture was controlled by measuring the refractive index of the mixture. Being a multi-component substance, a urea-water solution has a liquid-solid co-existent phase on a phase-diagram. Therefore, the liquidus temperature was measured to establish a relationship between the fraction of the solid-phase and temperature. Furthermore, apparent values of specific heat and coefficient of viscosity were measured in the two-phase region where the solid phase is ice. The apparent specific heat and coefficient of viscosity were measure by using an adiabatic calorimeter and a stirring torque meter respectively. The results revealed that the urea-water mixture can probably be used as a latent heat storage material of good fluidity.

  1. Pull-Out Strength and Bond Behavior of Prestressing Strands in Prestressed Self-Consolidating Concrete

    Directory of Open Access Journals (Sweden)

    Wu-Jian Long

    2014-10-01

    Full Text Available With the extensive use of self-consolidating concrete (SCC worldwide, it is important to ensure that such concrete can secure uniform in-situ mechanical properties that are similar to those obtained with properly consolidated concrete of conventional fluidity. Ensuring proper stability of SCC is essential to enhance the uniformity of in-situ mechanical properties, including bond to embedded reinforcement, which is critical for structural engineers considering the specification of SCC for prestressed applications. In this investigation, Six wall elements measuring 1540 mm × 2150 mm × 200 mm were cast using five SCC mixtures and one reference high-performance concrete (HPC of normal consistency to evaluate the uniformity of bond strength between prestressing strands and concrete as well as the distribution of compressive strength obtained from cores along wall elements. The evaluated SCC mixtures used for casting wall elements were proportioned to achieve a slump flow consistency of 680 ± 15 mm and minimum caisson filling capacity of 80%, and visual stability index of 0.5 to 1. Given the spreads in viscosity and static stability of the SCC mixtures, the five wall elements exhibited different levels of homogeneity in in-situ compressive strength and pull-out bond strength. Test results also indicate that despite the high fluidity of SCC, stable concrete can lead to more homogenous in-situ properties than HPC of normal consistency subjected to mechanical vibration.

  2. Mechanical coupling of microtubule-dependent motor teams during peroxisome transport in Drosophila S2 cells.

    Science.gov (United States)

    De Rossi, María Cecilia; Wetzler, Diana E; Benseñor, Lorena; De Rossi, María Emilia; Sued, Mariela; Rodríguez, Daniela; Gelfand, Vladimir; Bruno, Luciana; Levi, Valeria

    2017-12-01

    Intracellular transport requires molecular motors that step along cytoskeletal filaments actively dragging cargoes through the crowded cytoplasm. Here, we explore the interplay of the opposed polarity motors kinesin-1 and cytoplasmic dynein during peroxisome transport along microtubules in Drosophila S2 cells. We used single particle tracking with nanometer accuracy and millisecond time resolution to extract quantitative information on the bidirectional motion of organelles. The transport performance was studied in cells expressing a slow chimeric plus-end directed motor or the kinesin heavy chain. We also analyzed the influence of peroxisomes membrane fluidity in methyl-β-ciclodextrin treated cells. The experimental data was also confronted with numerical simulations of two well-established tug of war scenarios. The velocity distributions of retrograde and anterograde peroxisomes showed a multimodal pattern suggesting that multiple motor teams drive transport in either direction. The chimeric motors interfered with the performance of anterograde transport and also reduced the speed of the slowest retrograde team. In addition, increasing the fluidity of peroxisomes membrane decreased the speed of the slowest anterograde and retrograde teams. Our results support the existence of a crosstalk between opposed-polarity motor teams. Moreover, the slowest teams seem to mechanically communicate with each other through the membrane to trigger transport. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Devulcanization of ground tire rubber: Physical and chemical changes after different microwave exposure times

    Directory of Open Access Journals (Sweden)

    P. S. Garcia

    2015-11-01

    Full Text Available Microwave devulcanization is known to be a promising and an efficient rubber recycling method which makes possible for the rubber to regain its fluidity, and makes it capable of being remolded and revulcanized. The focus of this work is to understand the physical and chemical changes that occur in the ground tire rubber after different microwave exposure periods. For this purpose chemical, thermal, rheological and morphological analyses were performed on the tire rubber, which contains natural rubber (NR and styrene-butadiene rubber (SBR as polymeric material. The results showed that the microwave treatment promoted the breaking of sulfur cross-links and consequently increased the rubber fluidity. However, long periods of exposure led to degradation and modification of some properties. At nanoscale, the deformation of the devulcanized NR domain under stress was observed, and the morphology obtained appears to be a droplet dispersion morphology. The most exposed samples presented only one glass transition temperature, and from this it was concluded that the treatment may have played an important role in the compatibilization of the elastomeric blend. Based on the results, it is required to control the microwave exposure time and polymeric degradation in order to achieve a regenerated rubber with satisfactory properties.

  4. Effects of ioxaglate to blood rheology

    International Nuclear Information System (INIS)

    Schmid-Schoenbein, H.; Teitel, P.; Tietz, G.; Oezlen, A.

    1984-01-01

    Almen and Aspelin have shown that the use of non-ionic radio contrast media allows to increase the iodine concentration (which is desirable because of its effect on radio opacity) without a very large increase in osmolarity (which is undesirable because it impaires the fluidity of erythrocytes). This latter effect can also be diminished by reducing the osmolarity of a dimeric contrast medium as it has been achieved by incorporating more iodine atoms into the molecule in the case of Ioxaglate (Hexabrix). In various microrheological test systems, the fluidity of packed red cell suspension, the corrected filtration rate though 5 μm pores and the relative apparent viscosity of blood - contrast media mixtures (1 to 50% concentration) were determined in experiments comparing this compound with Urografin 76 of the same iodine content. In all systems, the former showed lesser rheological effects. In whole blood viscometry, this can be detected only after appropriate corrections for the effects of the two contrast media on hematocrit and plasma viscosity. Owing to a more pronounced water shift from the cells to the plasma, Urografin tends to reduce the viscosity of the plasma-contrast media mixture. The concomitant reduction in MCV and hematocrit level tends to screen the macrorheological effect of the dehydrated cells becomes immediately obvious when the viscometric data are corrected for hematocrit value and plasma viscosity effects. (orig.)

  5. On the possibility to affect the course of glycaemia, insulinaemia, and perceived hunger/satiety to bread meals in healthy volunteers.

    Science.gov (United States)

    Ekström, Linda M N K; Björck, Inger M E; Ostman, Elin M

    2013-04-25

    Frequent hyperglycaemia is associated with oxidative stress and subclinical inflammation, and thus increased risk of cardiovascular disease. Possibilities of modulating glycaemia, insulinaemia and perceived satiety for bread products were investigated, with emphasis on the course of glycaemia expressed as a glycaemic profile (defined as the duration of the glucose curve above the fasting concentration divided by the incremental glucose peak). For this purpose white wheat bread was supplemented with whole grain corn flour with an elevated amylose content and different types and levels of guar gum. The bread products were characterised in vitro for release of starch degradation products and content of resistant starch. Fibre related fluidity following enzyme hydrolysis was also studied. By combining medium weight guar gum and whole grain corn flour with an elevated amylose content, the course of glycaemia, insulinaemia and subjective appetite ratings were improved compared to the reference white wheat bread. In addition, the combination beneficially influenced the content of resistant starch. Fluidity measurements showed potential to predict the glycaemic profile.

  6. Interaction Study of an Amorphous Solid Dispersion of Cyclosporin A in Poly-Alpha-Cyclodextrin with Model Membranes by 1H-, 2H-, 31P-NMR and Electron Spin Resonance

    Directory of Open Access Journals (Sweden)

    Jean-Claude Debouzy

    2014-01-01

    Full Text Available The properties of an amorphous solid dispersion of cyclosporine A (ASD prepared with the copolymer alpha cyclodextrin (POLYA and cyclosporine A (CYSP were investigated by 1H-NMR in solution and its membrane interactions were studied by 1H-NMR in small unilamellar vesicles and by 31P 2H NMR in phospholipidic dispersions of DMPC (dimyristoylphosphatidylcholine in comparison with those of POLYA and CYSP alone. 1H-NMR chemical shift variations showed that CYSP really interacts with POLYA, with possible adduct formation, dispersion in the solid matrix of the POLYA, and also complex formation. A coarse approach to the latter mechanism was tested using the continuous variations method, indicating an apparent 1 : 1 stoichiometry. Calculations gave an apparent association constant of log Ka = 4.5. A study of the interactions with phospholipidic dispersions of DMPC showed that only limited interactions occurred at the polar head group level (31P. Conversely, by comparison with the expected chain rigidification induced by CYSP, POLYA induced an increase in the fluidity of the layer while ASD formation led to these effects almost being overcome at 298 K. At higher temperature, while the effect of CYSP seems to vanish, a resulting global increase in chain fluidity was found in the presence of ASD.

  7. Development of a New Type of Green Switch Air Entraining Agent for Wet-Mix Shotcrete and Its Engineering Application

    Directory of Open Access Journals (Sweden)

    Guoming Liu

    2016-01-01

    Full Text Available Air entraining agent (AEA can bring a lot of microbubbles into fresh concrete for improving its fluidity; however, high fluidity has adverse effect on the shootability of wet-mix shotcrete. In order to solve the contradictory issue, the paper developed a new type of green switch air entraining agent (GSAE that can improve both the pumpability and shootability. The single-admixture and combination tests containing foaming ability and surface tension were performed with Deer agitator and automatic tension meter. The new AEA was developed with two constituents A and B. A was prepared with Sapindus mukorossi(S-1, dodecyl trimethyl ammonium chloride(1231, and polyacrylamide. B was prepared with lauryl sodium sulfate (K12 and silicone oil. The mass mix proportion was S-1 : 1231 : polyacrylamide : K12 : silicone oil = 1 : 0.33 : 0.2 : 0.33 : 0.47. The application method of GSAE proposed that A was premixed with fresh concrete and then B was added at nozzle. Experimental investigation showed that the optimal mixing amount of GSAE was 0.1%–0.2% relative to cement. All performance measured of wet-mix shotcrete with 0.12% GSAE met the first-grade product requirements of the China National Standard. Compared with the conventional type of AEA, the proposed GSAE is capable of effectively improving pumpability and shootability.

  8. Superior PSZ-SOD Gap-Fill Process Integration Using Ultra-Low Dispensation Amount in STI for 28 nm NAND Flash Memory and Beyond

    Directory of Open Access Journals (Sweden)

    Chun Chi Lai

    2015-01-01

    Full Text Available The gap-fill performance and process of perhydropolysilazane-based inorganic spin-on dielectric (PSZ-SOD film in shallow trench isolation (STI with the ultra-low dispensation amount of PSZ-SOD solution have been investigated in this study. A PSZ-SOD film process includes liner deposition, PSZ-SOD coating, and furnace curing. For liner deposition, hydrophilic property is required to improve the contact angle and gap-fill capability of PSZ-SOD coating. Prior to PSZ-SOD coating, the additional treatment on liner surface is beneficial for the fluidity of PSZ-SOD solution. The superior film thickness uniformity and gap-fill performance of PSZ-SOD film are achieved due to the improved fluidity of PSZ-SOD solution. Following that up, the low dispensation rate of PSZ-SOD solution leads to more PSZ-SOD filling in the trenches. After PSZ-SOD coating, high thermal curing process efficiently promotes PSZ-SOD film conversion into silicon oxide. Adequate conversion from PSZ-SOD into silicon oxide further increases the etching resistance inside the trenches. Integrating the above sequence of optimized factors, void-free gap-fill and well-controlled STI recess uniformity are achieved even when the PSZ-SOD solution dispensation volume is reduced 3 to 6 times compared with conventional condition for the 28 nm node NAND flash and beyond.

  9. Temperature and storing time influence on selected physical properties of milk and acidophilus milk

    Directory of Open Access Journals (Sweden)

    Monika Božiková

    2013-01-01

    Full Text Available This article deals with thermophysical parameters as: temperature, thermal conductivity, diffusivity and rheologic parameters as: dynamic, kinematic viscosity and fluidity of milk and acidophilus milk. For thermophysical parameters measurements was used Hot Wire method and for rheologic parameters measurements was used single – spindle viscometer. In the first series of measurements we measured relations between thermophysical and rheologic parameters in temperature range (5–25 °C for milk and acidophilus milk. Relations of all physical parameters of milk to the temperature showed influence of relative fat content. Effect of storage on milk and acidophilus milk is shown in the text. All measured relations for milk and acidophilus milk during temperature stabilisation had linear increasing progress with high coefficients of determination in the range (0.991–0.998. It was shown that increasing relative fat content has decreasing influence on milk thermal conductivity. Relations of rheologic parameters as dynamic and kinematic viscosity to the temperature had decreasing exponential progress, while relation of fluidity to the temperature had increasing exponential shape with high coefficients of determination in the range (0.985–0.994.. Mathematical description of the dependencies is summarised by regression equations and all coefficients are in presented tables.

  10. Degradation and impact of phthalate plasticizers on soil microbial communities

    Energy Technology Data Exchange (ETDEWEB)

    Cartwright, C.D.; Thompson, I.P.; Burns, R.G.

    2000-05-01

    To assess the impact of phthalates on soil microorganisms and to supplement the environmental risk assessment for these xenobiotics, soil was treated with diethyl phthalate (DEP) or di (2-ethyl hexyl) phthalate (DEHP) at 0.1 to 100 mg/g. Bioavailability and membrane disruption were proposed as the characteristics responsible for the observed fate and toxicity of both compounds. Diethyl phthalate was biodegraded rapidly in soil with a half-life of 0.75 d at 20 C, and was not expected to persist in the environment. The DEHP, although biodegradable in aqueous solution, was recalcitrant in soil, because of poor bioavailability and was predicted to account for the majority of phthalate contamination in the environment. Addition of DEP or DEHP to soil at a concentration similar to that detected in nonindustrial environments had no impact on the structural diversity or functional diversity (BIOLOG) of the microbial community. At concentrations representative of a phthalate spill, DEP reduced numbers of both total culturable bacteria and pseudomonads within 1 d. This was due to disruption of membrane fluidity by the lipophilic phthalate, a mechanism not previously attributed to phthalates. However, DEHP had no effect on the microbial community or membrane fluidity, even at 100 mg/g, and was predicted to have no impact on microbial communities in the environment.

  11. Protection against oxidative damage in human erythrocytes and preliminary photosafety assessment of Punica granatum seed oil nanoemulsions entrapping polyphenol-rich ethyl acetate fraction.

    Science.gov (United States)

    Baccarin, Thaisa; Mitjans, Montserrat; Lemos-Senna, Elenara; Vinardell, Maria Pilar

    2015-12-25

    The main purpose of the present study is to evaluate the ability of nanoemulsion entrapping pomegranate peel polyphenol-rich ethyl acetate fraction (EAF) prepared from pomegranate seed oil and medium chain triglyceride to protect human erythrocyte membrane from oxidative damage and to assess preliminary in vitro photosafety. In order to evaluate the phototoxic effect of nanoemulsions, human red blood cells (RBCs) are used as a biological model and the rate of haemolysis and photohaemolysis (5 J cm(-2) UVA) is assessed in vitro. The level of protection against oxidative damage caused by the peroxyl radical generator AAPH in human RBCs as well as its effects on bilayer membrane characteristics such as fluidity, protein profile and RBCs morphology are determined. EAF-loaded nanoemulsions do not promote haemolysis or photohaemolysis. Anisotropy measurements show that nanoemulsions significantly retrain the increase in membrane fluidity caused by AAPH. SDS-PAGE analysis reveals that AAPH induced degradation of membrane proteins, but that nanoemulsions reduce the extension of degradation. Scanning electron microscopy examinations corroborate the interaction between AAPH, nanoemulsions and the RBC membrane bilayer. Our work demonstrates that Punica granatum nanoemulsions are photosafe and protect RBCs against oxidative damage and possible disturbance of the lipid bilayer of biomembranes. Moreover it suggests that these nanoemulsions could be promising new topical products to reduce the effects of sunlight on skin. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. γ-Radiation (0-150 kGy) Effects on HDPE/LDPE Blends

    International Nuclear Information System (INIS)

    Albano, C.

    2006-01-01

    In the present work, irradiation with 60 C o source was employed to study the effect of γ-rays on some physical properties of HDPE/LDPE blends (0/100, 10/90, 25/75, 50/50, 75/25, 100/0), using various doses: 0, 50, 150 kGy. The blends were prepared by extrusion and plates were compression molded employing fast and slow cooling methods from the melt. Density, degree of crystallinity and mechanical properties were dependant on the cooling rate used and blend composition. Better properties were found for HDPE-rich blends. Mechanical properties showed no significant variations in tensile modulus and yield stress. Instead, a decrease in elongation at break, due to molecular crosslinking or branching reaction effects, with the raise of radiation dose was obtained. Density measurements and differential scanning calorimetry results failed to exhibit significant changes with radiation dose. Some qualitative aspects included changes in endotherms shape. These were attributed to the variation of in crystallite sizes, probably due to structural changes originated by crosslinking and chain scission reactions occurring as a result of γ-rays exposure. On the other hand, there was an abrupt reduction of the melt flow index (MFI) from the range of 16-9 dg/min for 0 kGy to non-fluidity for an exposure of 150 kGy; this behavior is another sign of high crosslinking, impairing the viscous fluidity of the blends

  13. Influence of time addition of superplasticizers on the rheological properties of fresh cement pastes

    International Nuclear Information System (INIS)

    Aiad, Ismail

    2003-01-01

    It is well known that the fluidity and the fluidity loss of fresh cement pastes are affected by the kind and the time of addition of organic admixtures. The influence of the time addition of two chemical admixtures, namely, melamine formaldehyde sulfonate (MFS) and naphthalene formaldehyde sulfonate (NFS), on the rheological properties of ordinary Portland and sulfate-resisting cement pastes through the first 120 min of hydration was investigated. The admixture addition was delayed by 0, 5, 10, 15, 20, and 25 min. Shear stress and apparent viscosity of the cement pastes were determined at different shear rates (3-146 s -1 ) and hydration times of 30, 60, 90, and 120 min. The concentration of Ca 2+ and the combined water content of the cement pastes were determined after 120 min. Yield stress and plastic viscosity values were also determined by using the Bingham model. The results show that an increase in the addition time of the admixture reduces the shear stress, the yield stress, and the plastic viscosity of the cement pastes at the early ages (15 min) as well as at later early ages (120 min). The optimum delaying time of admixture addition is found to be 10-15 min. This time does not depend on the cement and superplasticizer type

  14. Effect of shear stress and free radicals induced by ultrasound on erythrocytes

    International Nuclear Information System (INIS)

    Kondo, T.; Fukushima, Y.; Kon, H.; Riesz, P.

    1989-01-01

    The present study was undertaken to elucidate the mechanism of hemolysis induced by ultrasound. Ar or N2O gas was used to distinguish between cavitation with or without free radical formation (hydroxyl radicals and hydrogen atoms). Free radical formation was examined by the method of spin trapping combined with ESR. After sonication of erythrocyte suspensions, several structural and functional parameters of the erythrocyte membrane--hemolysis, membrane fluidity, membrane permeability, and membrane deformability--were examined. Although free radical formation was observed in the erythrocyte suspensions sonicated in the presence of Ar, no free radical formation was observed in the presence of N2O. However, the hemolysis behavior induced by ultrasound was similar in the presence of Ar or N2O. The membrane fluidity, permeability, and deformability of the remaining unlysed erythrocytes after sonication in the presence of Ar or N2O were unchanged and identical to those of the control cells. On the other hand, after gamma irradiation (700 Gy), the hemolysis behavior was quite different from that after sonication, and the membrane properties were significantly changed. These results suggest that hemolysis induced by sonication was due to mechanical shearing stress arising from cavitation, and that the membrane integrity of the remaining erythrocytes after sonication was the same as that of control cells without sonication. The triatomic gas, N2O, may be useful for ultrasonically disrupting cells without accompanying free radical formation

  15. Interaction of toremifene with dipalmitoyl-phosphatidyl-glycerol in monolayers at the air–water interface followed by fluorescence microscopy in Langmuir–Blodgett films

    Energy Technology Data Exchange (ETDEWEB)

    Romão, Rute I.S. [Centro de Química Estrutural, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Maçôas, Ermelinda [Centro de Química-Física Molecular and IN — Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Martinho, José M.G. [Centro de Química-Física Molecular and IN — Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Departamento de Engenharia Química, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Gonçalves da Silva, Amélia M.P.S., E-mail: ameliags@ist.utl.pt [Centro de Química Estrutural, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal); Departamento de Engenharia Química, Instituto Superior Técnico, Universidade Técnica de Lisboa, Av. Rovisco Pais, P-1049-001 Lisboa (Portugal)

    2013-05-01

    Langmuir monolayers of dipalmitoyl-phosphatidyl-glycerol (DPPG) containing toremifene (TOR), an antiestrogen drug derivative of tamoxifen, were prepared in order to study the interaction of the drug with the cell membrane. TOR is not surface active but it remains at the interface in DPPG rich monolayers anchored by electrostatic interaction with the anionic DPPG up to the equimolar composition. The fluidity of mixed monolayers increases up to the TOR mole fraction X{sub TOR} = 0.3, remaining practically invariant for higher compositions. Brewster angle microscopy shows that the TOR disturbs the DPPG organization and the liquid condensed (LC) domains of DPPG become undetectable for X{sub TOR} ≥ 0.4. Laser scanning confocal fluorescence microscopy images of the LB films doped with rhodamine B-piperazine amide dye confirm the progressive reduction in size of LC domains, from which TOR and rhodamine are excluded. The incorporation of TOR in DPPG monolayers up to the equimolar composition supports the formation of a TOR:DPPG complex (1:1) due to electrostatic interactions between the negatively charged polar groups of DPPG and protonated TOR. - Highlights: • Toremifene (TOR) in dipalmitoyl-phosphatidyl-glycerol (DPPG) monolayers • Electrostatic interactions between DPPG and TOR form a 1:1 complex. • TOR increases the fluidity of DPPG monolayers. • Incorporation of TOR in the fluid phase of DPPG followed by fluorescence imaging.

  16. Consequences of transition from liquid chromatography to supercritical fluid chromatography on the overall performance of a chiral zwitterionic ion-exchanger.

    Science.gov (United States)

    Wolrab, Denise; Frühauf, Peter; Gerner, Christopher; Kohout, Michal; Lindner, Wolfgang

    2017-09-29

    Major differences in the chromatographic performance of a zwitterion ion-exchange type (ZWIX) chiral stationary phase (CSP) in supercritical fluid chromatography (SFC) and high-performance liquid chromatography (HPLC) have been observed. To explain these differences, transition from HPLC to SFC conditions has been performed. The amount of a protic organic modifier in supercritical carbon dioxide (scCO 2 ) was stepwise increased and the effect of this change studied using acidic, basic and ampholytic analytes. At the same time, the effect of various basic additives to the mobile phase and transient acidic buffer species, formed by the reaction of scCO 2 with the organic modifier and additives, was assessed. Evidence is provided that a transient acid together with the intrinsic counter-ions present in the ZWIX selector structure drive the elution of analytes even when no buffer is employed. We show that the tested analytes can be enantioseparated under both SFC and HPLC conditions; the best conditions for the resolution of ampholytes are in the so-called enhanced-fluidity mobile phase region. As a consequence, subcritical fluid and enhanced-fluidity mobile phase regions seem to be chromatographic modes with a high potential for operating ZWIX CSPs. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Kinetics of apoptotic markers in exogeneously induced apoptosis of EL4 cells.

    Science.gov (United States)

    Jessel, Robert; Haertel, Steffen; Socaciu, Carmen; Tykhonova, Svetlana; Diehl, Horst A

    2002-01-01

    We investigated the time-dependence of apoptotic events in EL4 cells by monitoring plasma membrane changes in correlation to DNA fragmentation and cell shrinkage. We applied three apoptosis inducers (staurosporine, tubericidine and X-rays) and we looked at various markers to follow the early-to-late apoptotic events: phospholipid translocation (identified through annexin V-fluorescein assay and propidium iodide), lipid package (via merocyanine assay), membrane fluidity and anisotropy (via fluorescent measurements), DNA fragmentation by the fluorescence-labeling test and cell size measurements. The different apoptotic inducers caused different reactions of the cells: staurosporine induced apoptosis most rapidly in a high number of cells, tubercidine triggered apoptosis only in the S phase cells, while X-rays caused a G2/M arrest and subsequently apoptosis. Loss of lipid asymmetry is promptly detectable after one hour of incubation time. The phosphatidylserine translocation, decrease of lipid package and anisotropy, and the increase of membrane fluidity appeared to be based on the same process of lipid asymmetry loss. Therefore, the DNA fragmentation and the cell shrinkage appear to be parallel and independent processes running on different time scales but which are kinetically inter-related. The results indicate different signal steps to apoptosis dependent on inducer characteristics but the kinetics of "early-to-late" apoptosis appears to be a fixed program.

  18. Pull-Out Strength and Bond Behavior of Prestressing Strands in Prestressed Self-Consolidating Concrete.

    Science.gov (United States)

    Long, Wu-Jian; Khayat, Kamal Henri; Lemieux, Guillaume; Hwang, Soo-Duck; Xing, Feng

    2014-10-10

    With the extensive use of self-consolidating concrete (SCC) worldwide, it is important to ensure that such concrete can secure uniform in-situ mechanical properties that are similar to those obtained with properly consolidated concrete of conventional fluidity. Ensuring proper stability of SCC is essential to enhance the uniformity of in-situ mechanical properties, including bond to embedded reinforcement, which is critical for structural engineers considering the specification of SCC for prestressed applications. In this investigation, Six wall elements measuring 1540 mm × 2150 mm × 200 mm were cast using five SCC mixtures and one reference high-performance concrete (HPC) of normal consistency to evaluate the uniformity of bond strength between prestressing strands and concrete as well as the distribution of compressive strength obtained from cores along wall elements. The evaluated SCC mixtures used for casting wall elements were proportioned to achieve a slump flow consistency of 680 ± 15 mm and minimum caisson filling capacity of 80%, and visual stability index of 0.5 to 1. Given the spreads in viscosity and static stability of the SCC mixtures, the five wall elements exhibited different levels of homogeneity in in-situ compressive strength and pull-out bond strength. Test results also indicate that despite the high fluidity of SCC, stable concrete can lead to more homogenous in-situ properties than HPC of normal consistency subjected to mechanical vibration.

  19. CFB粉煤灰作水泥混合材时与聚羧酸减水剂的相容性研究%Study on compatibility of CFB fly ash as cement admixture with polycarboxylate superplasticizer

    Institute of Scientific and Technical Information of China (English)

    赵少鹏; 陆加越; 刘建忠; 周明凯

    2017-01-01

    The compatibility between CFB fly ash and polycarboxylic superplasticizer was studied by the flow ability of cement paste and total organic carbon adsorption methods.The influence of compatibility with CFB ash was discussed by changing types of gypsum,reducing the ignition loss of CFB fly ash,compounding mineral admixtures and inorganic salt.The results show that,there has little influence on compatibility with superplasticizer by changing types of gypsum or adding mineral admixtures.Reducing the loss of fly ash can lead to the lower absorption of water reducer,as a result,the initial fluidity of cement paste increases gradually and the fluidity loss of 1 h reduces.Adding phosphate retarder has the best influence on compatibility,the initial fluidity of cement paste rises to 260mm from 200mm,and it still has good flow property after 1 h.%采用净浆流动度、总有机碳吸附法研究了CFB粉煤灰水泥与聚羧酸减水剂的相容性,探讨了改变石膏种类,降低CFB粉煤灰的烧失量,复掺矿物掺合料及外掺无机盐等措施对CFB粉煤灰水泥与减水剂相容性的影响.结果表明:改变石膏种类及复掺混合材对减水剂相容性的改善效果较小;降低CFB粉煤灰的烧失量能有效减小CFB粉煤灰对减水剂分子的吸附量,增大水泥浆体的初始流动度,且减小经时损失;外掺磷酸盐对减水剂相容性的改善效果显著,初始流动度由200 mm提高到了260 mm,1h后仍然具有较好的流动性.

  20. Cryopreservation of canine semen - new challenges.

    Science.gov (United States)

    Farstad, W

    2009-07-01

    Egg yolk (EY) protects cell membranes against cold shock, and it prevents or restores the loss of phospholipids from the membrane. EY has been widely used in semen extenders. It has been added to Tris-Glucose buffer and has been widely used for cooling and cryopreservation of canine semen. EY is not a defined entity, but a complex biological compound containing proteins, vitamins, phospholipids, glucose and antioxidants which are all potentially useful for cell membrane integrity. Unfortunately, it also is a biologically hazardous compound. Hence, whole EY needs to be replaced by other chemically defined components for semen processing in dogs. Freezing poor semen does not improve its quality, so attention must be focused on how to cope with dogs whose semen does not freeze well, and on designing individual freezing extenders for semen from such males. Furthermore, differences have been found among canid species in the ability of their spermatozoa to withstand freezing. There are differences in sperm membrane fatty acid composition among species, which may explain part of these differences. If the presence of long-chained polyunsaturated fatty acids contributes to increased membrane fluidity, this relationship may be biphasic, i.e. either too much membrane fluidity, or too little, could compromise successful sperm cryopreservation. An increase in fluidity of the outer leaflet of the plasma membrane has been shown in frozen thawed dog spermatozoa. The protective effect of exogenous lipids may lie in close association with the membrane rather than in modification or rearrangement of the membrane. This also points at lipids as an important, if not entirely new group of substances, which may substitute standard EY-based diluents in preserving sperm survival during freezing. EY-derived phospholipids or lecithin could be used to replace whole EY. Vegetable lecithin is currently investigated to avoid using substances of animal origin. EY also contains antioxidants which

  1. [Status of vitamin A, vitamin B2, iron and an-oxidantive activity in anemic pregnant women in China].

    Science.gov (United States)

    Yang, Fang; Ma, Ai-Guo; Zhang, Xiu-Zhen; Jiang, Dian-Chen

    2006-05-01

    To investigate the status of vitamin A(VA), vitamin B2 (VB2), iron and anoxidative function in anemic and non-anemic pregnant women. 426 anemic and 36 non-anemic pregnant women were included in the study. The survey of 24-hour's diet recall of pregnant women was made to evaluate intake of iron, VB2, folic acid, etc by the nutrition software provided by Beijing 301 hospital, iron and VA were measured by Radioimmunoassay (RIA) and by high-pressure liquid chromatography. VB2 status was detected using the assay for erythrocyte glutathione reductase (Egr; EC 1.6.4.2) activity. SOD and GSH-Px activities and MDA were determined using commercial kits. Peripheral blood erythrocyte membrane fluidity was detected by using 1,6-diphenyl-1,3,5-hexatriene as a probe, the degree of fluorescence polarization (P) at 25 degrees C of disrupted cells plasma membranes were compared for a variety of systems. Median intakes of protein and vitamin C met the current Chinese RNIs for pregnancy, whereas intakes of(VA) and VB2 were well below the recommendations. Intake of iron were above 90%, but the main sources of iron are vegetables. Plasma VA (1.25 micromol/L) and iron (20.57 microg/L) were lower, BGRAC (1.79) was higher than that in non-anemia group (VA 1.57 micromol/L, SF 33.16 microg/L, BGRAC 1.52). The level of plasma SOD (77.1U/ml) and the activity of GSH-Px (61.9U) were lower than those in non-anemia group (92.2U/ml, 71.6U, P membrane (P = 0.2622, eta = 2.7465) fluidity were higher than those non-anemia group(MDA = 3.78 nmol/ ml, P = 0.2360, eta = 2.3658). Plasam VA, VB2 and iron, antioxidantcapacity and erythrocyte membrane fluidity were decreased in the anemic pregnant women.

  2. Incidence of ZrO2 on the physical chemical properties at high temperatures of cast powder

    International Nuclear Information System (INIS)

    Brandaleze, E; Martin, A; Santini, L; Benavidez, E; Gonzalez Oliver, C

    2006-01-01

    The cast powders normally used in the continuous casting process in many steel mills contain a great number of oxides. The chemical composition of these materials determines the behavior of the powders in operating conditions and their corrosive effect on the submerged dips. Specifically, these powders require certain levels of fluidity in order to guarantee lubrication in the cast. No less important is the tendency to crystallization due to the formation of crystalline phases in the layer of cast powder during cooling, since the proportion of crystalline phases influences the cast's heat extraction conditions. Another aspect to be aware of is that industrial production requirements demand greater availability of the equipment and, therefore, prolonging the duration of the dipping is of considerable interest. An understanding of the phenomena in the processing conditions should start with a knowledge of the effects of the variations in the chemical composition of these powders. This work presents the influence of the added zircon oxide (ZrO 2 ) on the fluidity and crystallization of commercial cast powders. Fluidity tests were performed with the sloped plane method and with micro-structural observations of these samples in order to observe their degree of crystallization. Corrosion tests were carried out to know what attack mechanisms are used on the dips. According to the results, the addition of zircon oxide causes an increase in both the viscosity and the proportion of crystals. So the potential addition of this oxide in the commercial powders, as an innovation in the steel company's operating practices, would cause less heat extraction from the cast steel and a lower level of lubrication. Maintaining the current processing conditions (casting speed, flow of refrigeration water, etc.) could produce serious disorder in the process and in the quality of the final product. Considering just the aspect of durability of the aluminum-graphite dips, the corrosion trials

  3. The development of composition and technology for the capsulated drug based on bee pollen and honey powder. Announcement 3.

    Directory of Open Access Journals (Sweden)

    B. Т. Kudrik

    2016-12-01

    Full Text Available Aim. To develop experimentally and to substantiate theoretically both in pharmaceutical and industrial conditions the technology of manufacturing for capsules with the immunomodulatory action (provisional name «Api-Immuno-Vit» basing on pharmacotechnological and physical-chemical studies. Also to study the effect of excipients, the residual moisture and the particle size of capsules on technological parameters of mixtures quality, as well as to substantiate the choice of the size for solid gelatin capsules. Material and methods. The study objects were the experimental samples of the mixtures of «Api-Immuno-Vit» capsules with such active pharmaceutical ingredients (API as bee pollen (DSTU 7074:2009, GOST 31776-2012 and honey powder (TU U 10.8-39834691-001:2015, as well as aerosil and mannitol, which were used as excipients. Results. The pharmacotechnological tests of the experimental samples of the mixtures (particle size distribution, moisture content, fluidity, bulk density and tapped density, angle of repose, uniformity of mixing were carried out using the conventional methods given in the State Pharmacopoeia of Ukraine. The influence of particle size distribution of the granulate on technological parameters of the mixture quality in capsules has been studied. It has been found that the increase of residual moisture leads to decrease of fluidity, and therefore, the residual moisture of the mixture for encapsulation should be less than 1.5%. It has been also noted that during the experiment the presence of large and medium fractions is important for the particle size distribution since fluidity and the bulk density of the mixtures significantly reduce if the fine fraction in more than 30% in amount. Сonclusions. The results of the experimental studies were used in developing the flowchart of «Api-Immuno-Vit» capsules manufacturing. Taking into account the physical-chemical properties and the pharmacotechnological tests the flowchart of

  4. [Coordinating complex nursing care: building a guidance tool for cancer patients, to direct them towards the coordination nurse].

    Science.gov (United States)

    Froger, Raphael; Allenet, Benoit; Guillem, Pascale

    2017-03-01

    Introduction : following the 2009-2013 Cancer Plan, the experimental oncology nursing coordination (IDEC) showed a positive impact on the fluidity of care pathways. The 2014-2019 cancer plan guides their mission to complex cases. The objective of this study is to build a tool to facilitate the recruitment of patients likely to experience a complex path. Method : two phases have formed this research. The first one collected the elements of the dimensions that can predict the complexity of the care path, by focus group. The second consisted of reduction and selection of priority items and to estimate their importance by the Delphi method. Results : from the 12 selected items, two are recognized as a significant risk scoring, seven probably correlated with a complex pathway and three unrelated to the complexity of the pathways. Discussion : later this instrument would be validated by a test sample to evaluate its psychometric properties, metrological and feasibility.

  5. Novel use of levodopa in human immunodeficiency virus encephalopathy-mediated parkinsonism in an adult

    Directory of Open Access Journals (Sweden)

    M F Devine

    2018-01-01

    Full Text Available We report a case of a 36-year-old man with a medical history of human immunodeficiency virus (HIV infection who presented with hypomimia, hypophonia, bradykinesia, rigidity, and freezing of gait. His clinical presentation and magnetic resonance imaging were consistent with HIV encephalopathy with involvement of the bilateral basal ganglia and diffuse leukoencephalopathy. We initiated a trial of carbidopa-levodopa. The dose was escalated to 1050 mg levodopa daily. Amantadine was also started. The patient was closely monitored for behavioral, neurological, or systemic side effects. He tolerated therapy well without adverse effects. The patient's neurological status significantly improved with levodopa, including hypomimia, hypophonia, bradykinesia, and fluidity of gait. This case demonstrates that carbidopa-levodopa can be safely utilized to manage parkinsonism in an adult patient with HIV encephalopathy.

  6. Svrchovanost povrchu. O distribuci smyslu v jedné literární recenzi // The sovereignty of the surface

    Directory of Open Access Journals (Sweden)

    Jakub Blecha

    2016-11-01

    Full Text Available The article starts from an interpretation of the famous review of James Joyce’s Ulysses by Carl Gustav Jung called “Ulysses: A Monologue”. It focuses mainly on the comparison of the semiological assumptions of the two authors. Although both are aware of the principle of openness and fluidity of the text, it is evident, that their hypotheses, submitted to justify this view, do not have the same efficiency. The article can be also read as an attempt to articulate the so called „serial method“, i. e. the Deleuzian critique of the concept of representation from the Logic of Sense. From this point of view, the article could be considered a contribution to the poststructuralist discussion of the concept of sense.

  7. Radiation shielding concrete

    International Nuclear Information System (INIS)

    Kunishima, Shigeru.

    1990-01-01

    The radiation shielding concretes comprise water, cement, fine aggregates consisting of serpentines and blown mist slags, coarse aggregates consisting of serpentines and kneading materials. Since serpentines containing a relatively great amount of water of crystallization in rocks as coarse aggregates and fine aggregates, the hydrogen content in the radiation shielding concretes is increased and the neutron shielding effect is improved. In addition, since serpentines are added as the fine aggregates and blown mists slags of a great specific gravity are used, the specific gravity of the shielding concretes is increased to improve the γ-ray shielding effect. Further, by the use of the kneading material having a water reducing effect and fluidizing effect, and by the bearing effect of the spherical blown mist slags used as the fine aggregates, concrete fluidity can be increased. Accordingly, workability of the radiation shielding concretes can be improved. (T.M.)

  8. Bacterial strategies of resistance to antimicrobial peptides.

    Science.gov (United States)

    Joo, Hwang-Soo; Fu, Chih-Iung; Otto, Michael

    2016-05-26

    Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'. © 2016 The Author(s).

  9. Experimental Study on Hot Metal Desulfurization Using Sintered Red Mud-Based Flux

    Science.gov (United States)

    Li, Fengshan; Zhang, Yanling; Guo, Zhancheng

    2017-09-01

    This research presents the results of laboratory and pilot-scale tests conducted on the use of sintered red mud (RM)-based flux in the hot metal desulfurization (HMD) process. Al2O3/Na2O in RM can decrease the melting point of lime-based slag and can work as a flux in the HMD process. Good slag fluidity was observed throughout the process, and high desulfurization rates ( 80%) with a low final S content (pilot-scale test results indicated that a desulfurization rate as high as 91% and a S content <0.0099% could be acquired when RM:lime = 1:1, verifying the feasibility of using sintered RM-based flux in HMD. The data obtained provide important information for promoting the large-scale application of sintered RM in steelmaking.

  10. Superior Performance Nanocomposites from Uniformly Dispersed Octadecylamine Functionalized Multi-Walled Carbon Nanotubes

    KAUST Repository

    Chen, Ye

    2015-12-08

    Polyetherimide (PEI) is a widely applied as engineering plastic in the electronics, aerospace, and automotive industries but the disadvantages of extremely low conductivity, atmospheric moisture absorption, and poor fluidity at high temperature limits its application. Herein, commercial multi-walled carbon nanotubes (MWCNTs) were modified with a long alkyl chain molecule, octadecylamine (ODA), to produce a uniform dispersion in commercial PEI matrices. Both covalent and noncovalent modification of MWCNTs with ODA, were prepared and compared. Modified MWCNTs were incorporated in PEI matrices to fabricate nanocomposite membranes by a simple casting method. Investigating mechanical properties, thermal stability, and conductivity of the polyetherimide (PEI)/MWCNT composites showed a unique combination of properties, such as high electrical conductivity, high mechanical properties, and high thermal stability at a low content of 1.0 wt % loading of ODA modified MWCNTs. Moreover, electrical resistivity decreased around 10 orders of magnitude with only 0.5 wt % of modified MWCNTs.

  11. L’immram nell’Irlanda del XX secolo Una lettura comparativa dei romanzi di Flann O’Brien

    Directory of Open Access Journals (Sweden)

    Vito Carrassi

    2013-03-01

    Full Text Available This paper seeks to offer a unitary vision of Flann O’Brien’s novels through a comparative reading with the immram, a genre from the Irish literary tradition with which O’Brien’s work bears numerous meaningful affinities and analogies. Particular attention is devoted to the Immram curaig Máele Dúin, whose fundamental characteristics we find, in variable measure and manner, in O’Brien’s novels. The intolerance of linearity of plot, the digressive spirit and progression of the narration, the taste for literary artifice and meta-literary play, the centrality of the theme of guilt and above all the complete fluidity of time-space confines which are violated and continually re-defined are essential elements of O’Brien’s narrative which can be recognized, albeit in nuce, in the immram.

  12. Effect of Trace Be and Sc Additions on the Mechanical Properties of A357 Alloys

    Directory of Open Access Journals (Sweden)

    Yu-Chih Tzeng

    2018-03-01

    Full Text Available The effect of the addition of Be and Sc on the microstructure and mechanical properties of A357 alloy were systematically investigated. The results show that the addition of small amounts of Be and Sc could change the acicular structure of iron-bearing intermetallic compounds to harmless compact Al-Fe-Si and Sc-Fe iron-bearing intermetallic compounds. Compact iron-bearing intermetallic compounds could improve fluidity, causing a reduction in interdendritic shrinkage during solidification. The addition of 0.05 wt % Be enhanced the quality index of the A357 alloy by 11% and increased the notch-yield ratio of fracture toughness by 4.5%. In contrast, the addition of 0.05 wt % Sc increased the quality index and the notch to yield ratio of fracture toughness up to 17% and 9%, respectively. Therefore, the microstructure and mechanical properties of the A357 alloy could be improved by substituting Be with Sc.

  13. Ni{sub 3}Al technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Santella, M.L.; Alexander, D.J. [Oak Ridge National Laboratory, TN (United States)] [and others

    1995-05-01

    Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for (1)high-strength castable composition for turbochargers, furnace furniture, and hot-die applications; (2) castability (fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) hot fabricability of cast ingots. All of the issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes work completed to address some of these issues during the fourth quarter of FY 1994.

  14. Tin-silver and tin-copper alloys for capillarity joining-soft soldering-of copper piping

    International Nuclear Information System (INIS)

    Duran, J.; Amo, J. M.; Duran, C. M.

    2001-01-01

    It is studied the influence of the type of alloy used as filling material on the defects of the soldering joints in copper piping installations, which induce the fluid leak of the systems. The different eutectic temperatures and solidus-liquidus ranges of these alloys, require the setting of the soldering heat input in each case to obtain the suitable capillarity features and alloying temperatures to achieve for the correct formation of the bonding. Most defects in the joints are demonstrated to be generated by bad dossification of thermal inputs, which led depending on the filler alloy used to variations in its fluidity that may produce penetration failures in the bonds or insufficient consistency for the filling of the joints. (Author) 7 refs

  15. Measurement and Analysis of the Diffusible Hydrogen in Underwater Wet Welding Joint

    Directory of Open Access Journals (Sweden)

    Kong Xiangfeng

    2016-01-01

    Full Text Available The diffusible hydrogen in steel weldments is one of the main reasons that led to hydrogen assisted cracking. In this paper, the results of literatures survey and preliminary tests of the diffusible hydrogen in underwater wet welding joint were presented. A fluid-discharge method of for measuring the diffusible hydrogen in weldment was introduced in detail. Two kinds of underwater welding electrode diffusible hydrogen are 26.5 mL/100g and 35.5 mL/100g by fluid-discharge method, which are high levels. The diffusible hydrogen of underwater welding is higher than atmospheric welding, and the result is closely related to welding material. The best way to control the diffusible hydrogen is adjusting welding material and improving fluidity of slag.

  16. Exploiting the pliability and lateral mobility of Pickering emulsion for enhanced vaccination

    Science.gov (United States)

    Xia, Yufei; Wu, Jie; Wei, Wei; Du, Yiqun; Wan, Tao; Ma, Xiaowei; An, Wenqi; Guo, Aiying; Miao, Chunyu; Yue, Hua; Li, Shuoguo; Cao, Xuetao; Su, Zhiguo; Ma, Guanghui

    2018-02-01

    A major challenge in vaccine formulations is the stimulation of both the humoral and cellular immune response for well-defined antigens with high efficacy and safety. Adjuvant research has focused on developing particulate carriers to model the sizes, shapes and compositions of microbes or diseased cells, but not antigen fluidity and pliability. Here, we develop Pickering emulsions--that is, particle-stabilized emulsions that retain the force-dependent deformability and lateral mobility of presented antigens while displaying high biosafety and antigen-loading capabilities. Compared with solid particles and conventional surfactant-stabilized emulsions, the optimized Pickering emulsions enhance the recruitment, antigen uptake and activation of antigen-presenting cells, potently stimulating both humoral and cellular adaptive responses, and thus increasing the survival of mice upon lethal challenge. The pliability and lateral mobility of antigen-loaded Pickering emulsions may provide a facile, effective, safe and broadly applicable strategy to enhance adaptive immunity against infections and diseases.

  17. Rheological behavior of oil and biodiesel from Moringa oleifera

    International Nuclear Information System (INIS)

    Díaz Domínguez, Yosvany; Tabio García, Danger; Rondón Macías, Maylin; Fernández Santana, Elina; Rodríguez Muñoz, Susana; Piloto‐Rodríguez, Ramón

    2017-01-01

    The seeds of Moringa oleifera contain between 30 and 45% of oil, which has motivated the development of investigations with a view to their possible use. The present work aims to determine the rheological behavior of Moringa oleifera oil and biodiesel. The synthesis of biodiesel from crude Moringa oleifera oil was made using methanol with presence of sodium hydroxide. The average yield of this stage was 93%. The results of the rheological study shown that the viscosity at 40°C of Moringa oleifera oil is independent of the shear rate, which corresponds to the behavior of a Newtonian fluid. However, for biodiesel it was demonstrated that there is a dependence of the viscosity with the shear rate (non-Newtonian fluid). This result is corroborated by the fluidity curve, assuring that Moringa oleifera biodiesel behaves as a dilating fluid. (author)

  18. Physiological and biochemical aspects of the effect of ionizing radiations on the lung parenchyma

    International Nuclear Information System (INIS)

    Pasquier, Christian.

    1975-03-01

    Concerning the biochemical reactions of the lung parenchyma to irradiation the following points have been developed. Role of biochemically active substances (histamine, serotonin, kinins, catecholamines, prostaglandins) in the early reaction of the lung to irradiation, their common feature being their vascular impact point. Lung irradiation and lipids (fatty acids and lipid metabolism in general); irradiation, by raising the proportion of unsaturated at the expense of saturated fatty acids, may give rise to serious physiological respiratory disorders. Lung irradiation and blood fluidity (fibrinolytic activity, heparin, platelet factors). Pulmonary interstitium and irradiation (of the three interstitium components collagen plays a preferential part). Irradiation and immunological lung reaction (reasons behind the immunological theory, immunological assistance, immunological mechanism of pulmonary reactions towards pollutants). Enzymatic lung radiolesion indicators. Three kinds of physiological changes have been considered. Vascular physiology disturbances caused by the initial biochemical reactions; anomalies of physiological or functional trials, images of the lesion formed; disorders of the cell physiology of carcinogenesis [fr

  19. Laboratory hemostasis: milestones in Clinical Chemistry and Laboratory Medicine.

    Science.gov (United States)

    Lippi, Giuseppe; Favaloro, Emmanuel J

    2013-01-01

    Hemostasis is a delicate, dynamic and intricate system, in which pro- and anti-coagulant forces cooperate for either maintaining blood fluidity under normal conditions, or else will prompt blood clot generation to limit the bleeding when the integrity of blood vessels is jeopardized. Excessive prevalence of anticoagulant forces leads to hemorrhage, whereas excessive activation of procoagulant forces triggers excessive coagulation and thrombosis. The hemostasis laboratory performs a variety of first, second and third line tests, and plays a pivotal role in diagnostic and monitoring of most hemostasis disturbances. Since the leading targets of Clinical Chemistry and Laboratory Medicine include promotion of progress in fundamental and applied research, along with publication of guidelines and recommendations in laboratory diagnostics, this journal is an ideal source of information on current developments in the laboratory technology of hemostasis, and this article is aimed to celebrate some of the most important and popular articles ever published by the journal in the filed of laboratory hemostasis.

  20. Performance and Compatibility of Phosphonate-Based Superplasticizers for Concrete

    Directory of Open Access Journals (Sweden)

    Luigi Coppola

    2017-07-01

    Full Text Available The paper deals with the effectiveness of an innovative phosphonate-based superplasticizer (PNH for ready mixed concrete. Concrete specimens were manufactured by considering a constant initial workability, equal to 220 mm slump at the end of the mixing procedure. Workability was measured at 0, 30, and 60 min to evaluate the workability retention performances of the innovative superplasticizer. Compressive tests at 1, 7, and 28 days were carried out to evaluate the influence of the phosphonate-based superplasticizer on concrete setting and hardening. The concrete mixes were designed by considering 13 different cements to assess the superplasticizer-cement compatibility. The PNH-based admixture showed a better performance in terms of water reduction and workability retention with respect to napthalenesulphonate based admixtures (NSF; however, a higher dosage of PNH with respect to polycarboxylate ethers (PCEs was needed to get the same initial fluidity.

  1. Overturning dogma: tolerance of insects to mixed-sterol diets is not universal.

    Science.gov (United States)

    Behmer, Spencer T

    2017-10-01

    Insects cannot synthesize sterols de novo, but like all eukaryotes they use them as cell membrane inserts where they influence membrane fluidity and rigidity. They also use a small amount for metabolic purposes, most notably as essential precursors for steroid hormones. It has been a long-held view that most insects require a small amount of specific sterol (often cholesterol) for metabolic purposes, but for membrane purposes (where the bulk of sterols are used) specificity in sterol structure was less important. Under this model, it was assumed that insects could tolerate mixed-sterol diets as long as a small amount of cholesterol was available. In the current paper this dogma is overturned, using data from plant-feeding insects that were fed mixed-sterol diets with different amounts and ratios of dietary sterols. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. High-efficiency water-loaded microwave antenna in ultra-high-frequency band

    Science.gov (United States)

    Gong, Zilun; Bartone, Chris; Yang, Fuyi; Yao, Jie

    2018-03-01

    High-index dielectrics are widely used in microwave antennas to control the radiation characteristics. Liquid water, with a high dielectric index at microwave frequency, is an interesting material to achieving tunable functionalities. Here, we demonstrate a water-loaded microwave antenna system that has high loss-tolerance and wideband tunability enabled by fluidity. Our simulation and experimental results show that the resonance frequency can be effectively tuned by the size of loading water. Furthermore, the antenna systems with water loading can achieve high radiation efficiency (>90%) in the ultra-high-frequency (0.3-3 GHz) band. This work brings about opportunities in realistic tunable microwave antenna designs enabled by liquid.

  3. Influence of superplasticizer on microstructure of a 40 MPa strength concrete

    International Nuclear Information System (INIS)

    Teixeira, Sandra M.F.; Menezes, Raquel Maria R.O.; Figueiredo, Roberto B.; Aguilar, Maria Teresa P.; Franca, Fabricio Carlos; Bezerra, Augusto Cesar da S.

    2016-01-01

    The self compacting concrete has high fluidity and deformability. Studies analyze its performance through compressive strength, mortar content and / or water cement factor, which does not allow the evaluation of superplasticante influence the microstructure of these concretes. In this work, we evaluated the influence of superplasticizer comparing the phases present in a self-compacting concrete 40 MPa and at a same conventional compressive strength, same water / cement and mortar content. Therefore, scanning techniques were employed by electron microscope low vacuum using backscattered electrons and thermal analysis. The observed results show no significant differences in the microstructure of the two composites, ie the superplasticizer does not alter the microstructure of the self-compacting concrete. However, thermal analysis indicates that the present self-compacting concrete greater calcium hydroxide content which may suggest a lower content of such dry cement concrete. (author)

  4. Evaluation of the shrinkage and creep of medium strength self compacting concrete

    Science.gov (United States)

    De La Cruz, C. J.; Ramos, G.; Hurtado, W. A.

    2017-02-01

    The difference between self compacting concrete (SCC) and conventional concrete (CC) is in fresh state, is the high fluidity at first and the need for vibration at second, but in hardened state, both concretes must comply with the resistance specified, in addition to securing the safety and functionality for which it was designed. This article describes the tests and results for shrinkage and creep at some medium strength Self Compacting Concrete with added sand (SCC-MSs) and two types of cement. The research was conducted at the Laboratorio de Tecnología de Estructuras (LTE) of the Universitat Politécnica de Catalunya (UPC), in dosages of 200 liters; with the idea of evaluating the effectiveness of implementation of these new concretes at elements designed with conventional concrete (CCs).

  5. Sawdust Ash as Powder Material for Self-Compacting Concrete Containing Naphthalene Sulfonate

    Directory of Open Access Journals (Sweden)

    Augustine U. Elinwa

    2014-01-01

    Full Text Available Tests are carried out to determine the fluidity of Ashaka Portland cement paste and its compatibility with sawdust ash (SDA as powder material for self-compacting cement (SCC mixtures. Results of the investigation showed that saturation was achieved at w/c ratios of 0.4 and 0.42, at dosages of naphthalene sulfonate superplasticizers of 3.5% and 2%, respectively. The optimum replacement level for the SCC mixture was 10 wt.% of cement by SDA and 2% of the superplasticizer dosage. The achieved spread and flow time were 26 cm and 8 seconds and are within the specified range of 24 cm to 26 cm and 7 to 11 seconds, respectively. Statistical inference showed that the mix, w/c, and the interaction between the mix and w/c ratio are significant.

  6. High impact polystyrene (HIPS). Predicting its molecular, morphological and mechanical properties

    International Nuclear Information System (INIS)

    Luciani, C; Estenoz, D; Morales, G; Meira, G

    2004-01-01

    A mathematical model that is able to predict the molecular and morphological structure of high impact polystyrene (HIPS) and the Fluidity Index (MFI) is presented. The model is divided into two parts: a) the estimation of the material's molecular and morphological properties, simulating the polymerization process in discontinuous mass based on the recipe and the conditions of synthesis; and b) the prediction of rheological variables (viscosity at low deformation speeds and relaxation time), and of the MFI, based on average molecular and morphological variables. The model also combines with empirical correlations proposed in the literature [1] in order to estimate impact strength (IS). The predictions for a), b) and impact strength were co-validated by independent data and resulted in a good fit (CW)

  7. Older lesbian sexuality: identity, sexual behavior, and the impact of aging.

    Science.gov (United States)

    Averett, Paige; Yoon, Intae; Jenkins, Carol L

    2012-01-01

    In response to the very limited and mostly outdated literature on older lesbian sexuality, this exploratory study examined older lesbian sexual identity, romantic relationships, the impact of aging, and experiences of discrimination within these contexts. Utilizing an online survey that recruited via numerous online lesbian communities and snowball sampling, 456 lesbians over the age of 50 responded to closed, Likert scale, and open-ended questions that provided a preliminary understanding of older lesbian sexuality. The results indicated that older lesbians have experienced fluidity in past romantic and sexual relationships, as well as in erotic fantasies, despite strong identification with being lesbian. The findings also indicate a decreased focus on sexuality in the context of relationships, with more focus on stability and continuity. Future research is needed that provides greater specificity and detail about older lesbian conceptions of sexual behavior and sexual identity labels, as well as specific sexual behaviors.

  8. Water-bearing explosives thickened with a partially hydrolyzed acrylamide polymer

    Energy Technology Data Exchange (ETDEWEB)

    Lyerly, W.M.

    1971-11-23

    Thickened water-bearing explosives are provided which do not segregate and are water-resistant over a wide range of viscosities. Preferred compositions have a unique combination of pourability and fluidity coupled with resistance to water and segregation which makes them particularly suitable in small diameter holes and in holes partially filled with water. Accordingly, water-bearing explosive compositions also are provided which consist of inorganic oxidizing salt, fuel, and water, which improvement consists of thickening the compositions with the combination of polyacrylamide and cross-linked galactomannan. The weight ratio of the polyacrylamide to galactomanan is from about ratio 0.1:1 to 10:1, and preferably 1:1 to 5:1. (1 claim)

  9. Antimony Influence on Shape of Eutectic Silicium in Al-Si Based Alloys

    Directory of Open Access Journals (Sweden)

    Bolibruchová D.

    2017-12-01

    Full Text Available Liquid AI-Si alloys are usually given special treatments before they are cast to obtain finer or modified matrix and eutectic structures, leading to improved properties. For many years, sodium additions to hypoeutectic and eutectic AI-Si melts have been recognized as the most effective method of modifying the eutectic morphology, although most of the group IA or IIA elements have significant effects on the eutectic structure. Unfortunately, many of these approaches also have associated several founding difficulties, such as fading, forming dross in presence of certain alloying elements, reduced fluidity, etc. ln recent years, antimony additions to AI-Si castings have attracted considerable attention as an alternative method of refining the eutectic structure. Such additions eliminate many of the difficulties listed above and provide permanent (i.e. non-fading refining ability. In this paper, the authors summarize work on antimony treatment of Al-Si based alloys.

  10. Uncertainty and control in the context of a category-five tornado.

    Science.gov (United States)

    Afifi, Walid A; Afifi, Tamara D; Merrill, Annie

    2014-10-01

    The purpose of this qualitative descriptive study was to illuminate the experience and management of uncertainty during a natural disaster. Interviews were conducted with 26 survivors of a category-five tornado that entirely demolished the small, rural town of Greensburg, Kansas. Three primary themes were found in the survivors' accounts. First, the survivors experienced rapidly shifting levels and kinds of uncertainty as they proceeded through the stages of the disaster. Second, the fluidity of much-needed information added to uncertainty. Third, the feeling of lack of control over outcomes of the disaster and its aftermath was pervasive and was often managed through reliance on communal coping. Recommendations for disaster-related intervention programs are suggested. © 2014 Wiley Periodicals, Inc.

  11. Effect of temperature on the level of corrosion caused by heavy petroleum on AISI 304 and AISI 444 stainless steel

    Directory of Open Access Journals (Sweden)

    João Paulo Sampaio Eufrásio Machado

    2006-06-01

    Full Text Available This work presents a study on the influence of national heavy petroleum in the corrosion of the AISI 444 and AISI 304 stainless steels in simulated refining operation conditions. The petroleum was first characterized through physicochemical analysis (density, fluidity point, viscosity, sulfur concentration. In an attempt to understand the corrosion effect of temperature and of the type of heating the referred types of steel thermal treatments were carried out at three levels of temperature (200, 300 and 400 °C. The procedure was done in conditions close to those in the distillation column. Heat was gradually increased from room temperature, and directly heated to working temperature. Each treatment took 4 hours to be completed. Scanning electronic microscopy (SEM and the analysis of X rays dispersive energy (EDX were used after the trials to characterize the samples. The results show that treatment temperature, as well as the type of heating, has distinct influences on each type of steel.

  12. Maneiras de ser, maneiras de sentir do indivíduo hipermoderno Way of being, hypermodern individual's way of feeling

    Directory of Open Access Journals (Sweden)

    Claudine Haroche

    2004-12-01

    Full Text Available A fluidez das sociedades contemporâneas, intrinsecamente destituídas de limites, provoca modificações das estruturas, suscetíveis de colocar em causa a possibilidade mesma de estruturação, até mesmo da existência do eu. Indaga-se, aqui, se as maneiras - mais fundamentalmente a capacidade de sentir -, declinaram "em se sentir", separadas doravante do fato de experimentar sentimentos, não seriam agora sinônimo de sensação.The fluidity of the contemporary society, intrinsically destituted by limitations, induces structural modifications, susceptible of putting in grounds the same possibility of structuralization, even so at the existence of the I. It is questioned here if the reasons - most fundamentally the capacity of feeling - declined to "feeling", separated from the experimentation of feeling, wouldn't them be, now, synonym of sensation.

  13. Global cities and cultural experimentation

    DEFF Research Database (Denmark)

    Rojas Gaviria, Pilar; Emontspool, Julie

    2015-01-01

    Purpose: Studying the cultural dynamics of expatriate amateur theater in Brussels, this paper investigates multicultural marketplace development in contemporary global cities. Design/methodology/approach: The paper performs an interpretive analysis of the expatriate amateur scene in Brussels from...... an ethnographic perspective, combining observations of rehearsals and performances, in-depth interviews with actors, directors and audience, and secondary data. Findings: The fluidity of global cities allows their inhabitants to engage in collective creative processes of cultural experimentation, performing...... to the important role of global cities for cultural experimentation. Such cities are not only an interesting market for culturally diverse products, but also learning hubs. Managers willing to address multicultural marketplaces might target these markets with dynamic cultural offers that ensure a balance between...

  14. Temperature dependence of positronium reactivities with charge transfer molecules in bilayer membranes

    International Nuclear Information System (INIS)

    Jean, Y.C.; Yu, C.; Wang, Y.Y.; Yeh, Y.Y.

    1984-01-01

    Rate constants for positronium atoms reacting chemically with charge-transfer molecules such as p-benzoquinone, nitrobenzene, and coenzyme Q-10 in a model bilayer membrane, dipalmitoylphosphatidylcholine (DPPC), have been measured at temperatures between 23 and 65 0 C. A strong variation of the positronium chemical reactivities, k/sub Ps/ was observed in these systems: k/sub Ps/ increases with increasing temperature until the pretransition temperature of the membrane reaches a maximum value near the main transition temperature and decreases at temperatures higher than the main transition temperature. This variation is interpreted in terms of fluidity and permeability changes associated with the phase transitions of membranes and in terms of charge-transfer-complex formation between the solubilized molecules and the polar head of the membrane. These results demonstrate that positronium and its annihilation characteristics can be employed to investigate charge transport phenomena and microstructural changes of real biological membranes

  15. Proton and carbon-13 nuclear magnetic resonance studies of the effects of retinal on the dynamic structure and stability of lipid bilayer

    International Nuclear Information System (INIS)

    Inoue, Yoshio; Hanafusa, Yoshito; Toda, Masakazu; Chujo, Riichiro

    1982-01-01

    The effects of retinal and vitamin A on the dynamic structure and stability of hen egg yolk lecithin bilayers have been studied by means of carbon-13 and proton NMR spectroscopies. 13 C spin-lattice relaxation and paramagnetic ion permeability studies on lecithin bilayers indicate a marked decrease in flexibility of the lipid acyl chain and a breakdown of membrane impermeableness to ion by the intercalated all-trans- and 11-cis-retinal, whereas the effect of incorporated vitamin A on the fluidity of bilayers is small and its impermeableness to ion remains effective even in the presence of higher concentration of vitamin A. The experimental results are discussed in connection with the mechanism of the permeability change in photoreceptive disk membrane. (author)

  16. Increasing the compressive strength of portland cement concrete using flat glass powder

    Energy Technology Data Exchange (ETDEWEB)

    Miranda Junior, Edson Jansen Pedrosa de; Bezerra, Helton de Jesus Costa Leite; Politi, Flavio Salgado; Paiva, Antonio Ernandes Macedo, E-mail: edson.jansen@ifma.edu.br [Instituto Federal de Educacao, Ciencia e Tecnologia do Maranha (IFMA), Sao Luis, MA (Brazil). Dept. de Mecanica e Materiais

    2014-08-15

    This paper analyzes the compressive strength of Portland cement concrete in response to the incorporation of 5%, 10% and 20% of flat glass powder in place of sand, at w/c (water/cement) ratios of 0.50, 0.55 and 0.58. A statistical analysis of variance (ANOVA) was performed after 7, 14 and 28 days of curing. The compressive strength test results indicate that the concrete containing a w/c ratio of 0.50 can be used for structural applications, regardless of the waste glass content, as can that with a w/c ratio of 0.55 containing 20% of waste glass. We suggest that the use of flat glass powder in place of sand in the above mentioned percentages is feasible for the production of an environmentally appropriate and structurally applicable concrete. However, the concrete's fluidity and void content must be taken into account. (author)

  17. Where Kinsey, Christ, and Tila Tequila meet: discourse and the sexual (non)-binary.

    Science.gov (United States)

    Callis, April S

    2014-01-01

    Drawing on 80 interviews and 17 months of participant observation in Lexington, Kentucky, this article details how individuals drew on three areas of national and local discourse to conceptualize sexuality. Media, popular science, and religious discourses can be viewed as portraying sexuality bifocally--as both a binary of heterosexual/homosexual and as a non-binary that encompasses fluidity. However, individuals in Lexington drew on each of these areas of discourse differently. Religion was thought to produce a binary vision of sexuality, whereas popular science accounts were understood as both binary and not. The media was understood as portraying non-binary identities that were not viable, thus strengthening the sexual binary. These differing points of view led identities such as bisexual and queer to lack cultural intelligibility.

  18. The emergence of understanding in a computer model of concepts and analogy-making

    Science.gov (United States)

    Mitchell, Melanie; Hofstadter, Douglas R.

    1990-06-01

    This paper describes Copycat, a computer model of the mental mechanisms underlying the fluidity and adaptability of the human conceptual system in the context of analogy-making. Copycat creates analogies between idealized situations in a microworld that has been designed to capture and isolate many of the central issues of analogy-making. In Copycat, an understanding of the essence of a situation and the recognition of deep similarity between two superficially different situations emerge from the interaction of a large number of perceptual agents with an associative, overlapping, and context-sensitive network of concepts. Central features of the model are: a high degree of parallelism; competition and cooperation among a large number of small, locally acting agents that together create a global understanding of the situation at hand; and a computational temperature that measures the amount of perceptual organization as processing proceeds and that in turn controls the degree of randomness with which decisions are made in the system.

  19. Bonding Characteristics of Macrosynthetic Fiber in Latex-Modified Fiber-Reinforced Cement Composites as a Function of Carbon Nanotube Content

    Directory of Open Access Journals (Sweden)

    Ji-Hong Jean

    2016-01-01

    Full Text Available The effect of carbon nanotube content (0, 0.5, 1.0, 1.5, and 2.0% of the cement weight on the bonding properties of macrosynthetic fiber in latex-modified hybrid fiber cement-based composites (LMHFRCCs was evaluated. The slump value, compressive strength, and bonding strength were measured for each LMHFRCC. As the carbon nanotube content increased to 1.5%, the bonding properties of the macrosynthetic fiber improved. However, the bonding performance deteriorated at a carbon nanotube content of 2.0%. A decrease in the fluidity of the mix negatively affected the dispersion of the nanotubes in the LMHFRCCs. The addition of carbon nanotubes also affected the relative bonding strength independently of the improvement in compressive strength. Microscopic analysis of the macrosynthetic fiber surfaces was used to understand changes in the bonding behavior.

  20. Tranio Transformed: Social Anxieties and Social Metamorphosis in The Taming of the Shrew

    Directory of Open Access Journals (Sweden)

    Sonya L. Brockman

    2015-03-01

    Full Text Available The article discusses Elizabethan anxieties about the increasing fluidity of social status through an examination of the servant Tranio in Shakespeare’s The Taming of the Shrew. It argues that Tranio’s informed and willing participation in this social performance embodies the anxieties about social mobility held by members of the Elizabethan elite. In contrast to other figures of social metamorphosis in the play, Tranio’s social transformation is temporary, even though, like Christopher Sly, he is transformed into a gentleman at the behest of his Lord. He must return to his servile status in the final act, however, not only because he can so successfully perform the role of master, but because he knowingly participates in his own social metamorphosis. The article suggests, in conclusion, that it is the servant’s knowledge of his own performative power that makes him a threat in Elizabethan society. 

  1. Influence of superplasticizer on microstructure of a 40 MPa strength concrete; Influencia do aditivo superplastificante na microestrutura de um concreto de resistencia mecanica de 40 MPa

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Sandra M.F.; Menezes, Raquel Maria R.O.; Figueiredo, Roberto B.; Aguilar, Maria Teresa P. [Universidade Federal de Minas Gerais (UFMG), MG (Brazil); Franca, Fabricio Carlos [LafargeHolcim, Rio de Janeiro, RJ (Brazil); Bezerra, Augusto Cesar da S. [Centro Federal de Educacao Tecnologica de Minas Gerais (CEFET-MG), MG (Brazil)

    2016-07-01

    The self compacting concrete has high fluidity and deformability. Studies analyze its performance through compressive strength, mortar content and / or water cement factor, which does not allow the evaluation of superplasticante influence the microstructure of these concretes. In this work, we evaluated the influence of superplasticizer comparing the phases present in a self-compacting concrete 40 MPa and at a same conventional compressive strength, same water / cement and mortar content. Therefore, scanning techniques were employed by electron microscope low vacuum using backscattered electrons and thermal analysis. The observed results show no significant differences in the microstructure of the two composites, ie the superplasticizer does not alter the microstructure of the self-compacting concrete. However, thermal analysis indicates that the present self-compacting concrete greater calcium hydroxide content which may suggest a lower content of such dry cement concrete. (author)

  2. Study of the Peripheral Nerve Fibers Myelin Structure Changes during Activation of Schwann Cell Acetylcholine Receptors.

    Directory of Open Access Journals (Sweden)

    Ekaterina E Verdiyan

    Full Text Available In the present paper we consider a new type of mechanism by which neurotransmitter acetylcholine (ACh regulates the properties of peripheral nerve fibers myelin. Our data show the importance of the relationship between the changes in the number of Schwann cell (SC acetylcholine receptors (AChRs and the axon excitation (different intervals between action potentials (APs. Using Raman spectroscopy, an effect of activation of SC AChRs on the myelin membrane fluidity was investigated. It was found, that ACh stimulates an increase in lipid ordering degree of the myelin lipids, thus providing evidence for specific role of the "axon-SC" interactions at the axon excitation. It was proposed, that during the axon excitation, the SC membrane K+- depolarization and the Ca2+-influx led to phospholipase activation or exocytosis of intracellular membrane vesicles and myelin structure reorganization.

  3. A spatial analysis of the expanding roles of nurses in general practice

    Directory of Open Access Journals (Sweden)

    Pearce Christopher

    2012-08-01

    Full Text Available Abstract Background Changes to the workforce and organisation of general practice are occurring rapidly in response to the Australian health care reform agenda, and the changing nature of the medical profession. In particular, the last five years has seen the rapid introduction and expansion of a nursing workforce in Australian general practices. This potentially creates pressures on current infrastructure in general practice. Method This study used a mixed methods, ‘rapid appraisal’ approach involving observation, photographs, and interviews. Results Nurses utilise space differently to GPs, and this is part of the diversity they bring to the general practice environment. At the same time their roles are partly shaped by the ways space is constructed in general practices. Conclusion The fluidity of nursing roles in general practice suggests that nurses require a versatile space in which to maximize their role and contribution to the general practice team.

  4. USO DO TERRITÓRIO E CONSOLIDAÇÃO DO AGRONEGÓCIO NA REGIÃO CENTRO-OESTE: UM ESTUDO SOBRE A INTEGRAÇÃO TERRITORIAL ATRAVÉS DO SISTEMA DE TRANSPORTE AÉREO

    Directory of Open Access Journals (Sweden)

    Fabrício Gallo

    2013-08-01

    Full Text Available The aim of this text is to make some reflections on the use of small aircrafts for the integration and modernization of the Brazilian territory. The system of air transport, in a country of large territorial extension, is very important to narrow the regional ties and it is an important  element of the productive space circuit of the modern agriculture developed in the Brazilian Center-West. The small aircrafts of not-regular routes, act as basic vector of the interactional fluidity, speeding the transport of people, in function of its flexibility of displacement and time, act as basic vector of the productivity integration of the Brazilian territory, a time that the production properly said and corporative command if had separated given to the possibilities techniques of the actual technician-scientific and informational period.

  5. Coming In: Queer Narratives of Sexual Self-Discovery.

    Science.gov (United States)

    Rosenberg, Shoshana

    2017-10-09

    Many models of queer sexuality continue to depict a linear narrative of sexual development, beginning in repression/concealment and eventuating in coming out. The present study sought to challenge this by engaging in a hermeneutically informed thematic analysis of interviews with eight queer people living in Western Australia. Four themes were identified: "searching for identity," "society, stigma, and self," "sexual self-discovery," and "coming in." Interviewees discussed internalized homophobia and its impact on their life; experiences and implications of finding a community and achieving a sense of belonging; the concept of sexual self-discovery being a lifelong process; and sexuality as fluid, dynamic, and situational rather than static. The article concludes by suggesting that the idea of "coming in"-arriving at a place of acceptance of one's sexuality, regardless of its fluidity or how it is viewed by society-offers considerable analytic leverage for understanding the journeys of sexual self-discovery of queer-identified people.

  6. Superior Performance Nanocomposites from Uniformly Dispersed Octadecylamine Functionalized Multi-Walled Carbon Nanotubes

    KAUST Repository

    Chen, Ye; Tao, Jing; Ezzeddine, Alaa; Mahfouz, Remi; Al-Shahrani, Abdullah; Alabedi, Gasan; Khashab, Niveen M.

    2015-01-01

    Polyetherimide (PEI) is a widely applied as engineering plastic in the electronics, aerospace, and automotive industries but the disadvantages of extremely low conductivity, atmospheric moisture absorption, and poor fluidity at high temperature limits its application. Herein, commercial multi-walled carbon nanotubes (MWCNTs) were modified with a long alkyl chain molecule, octadecylamine (ODA), to produce a uniform dispersion in commercial PEI matrices. Both covalent and noncovalent modification of MWCNTs with ODA, were prepared and compared. Modified MWCNTs were incorporated in PEI matrices to fabricate nanocomposite membranes by a simple casting method. Investigating mechanical properties, thermal stability, and conductivity of the polyetherimide (PEI)/MWCNT composites showed a unique combination of properties, such as high electrical conductivity, high mechanical properties, and high thermal stability at a low content of 1.0 wt % loading of ODA modified MWCNTs. Moreover, electrical resistivity decreased around 10 orders of magnitude with only 0.5 wt % of modified MWCNTs.

  7. Molecular Interactions at Membranes

    DEFF Research Database (Denmark)

    Jagalski, Vivien

    . Today, we know more than ever before about the properties of biological membranes. Advanced biophysical techniques and sophisticated membrane models allow us to answer specific questions about the structure of the components within membranes and their interactions. However, many detailed structural...... the surface-immobilization of LeuT by exchanging the detergent with natural phosphatidylcholine (PC) lipids. Various surface sensitive techniques, including neutron reflectometry (NR), are employed and finally enabled us to confirm the gross structure of LeuT in a lipid environment as predicted by molecular...... dynamic simulations. In a second study, the co-localization of three toxic plant-derived diterpene resin acids (RAs) within DPPC membranes was investigated. These compounds are reported to disrupt the membrane and increase its fluidity. The RAs used in this study vary in their toxicity while...

  8. Characterization of nanocomposites containing Ecoflex®, LDPE and organophilic bentonite

    International Nuclear Information System (INIS)

    Rios, A.R.; Rosa, D.S.; Poveda, P.N.S.; Viana, H.

    2011-01-01

    Considering the need for development of environmentally degradable polymers for high performance, this study aimed to develop and characterize compounds of LDPE containing different levels of Ecoflex® (biodegradable) and organophilic bentonite (environmentally correct, low cost and plentiful). The clay showed interlayer distance (d_0_0_1) of 17.59 Å, which confirms the organophilization organization and salts in monolayer lateral between the layers of bentonite. Through the test IF it can be verified that the fluidity of the compounds was reduced proportionately with the addition of nano clay, improving the dimensional stability of the material. The mechanical test showed that the addition of nano clay increased the maximum stress and elastic modulus of the composites. The FTIR assay corroborated the mechanical results, indicating the presence of interfacial interactions polymer/clay, through axial deformation bands OH related to hydroxyl groups of clay. (author)

  9. Development of cement material using inorganic additives

    International Nuclear Information System (INIS)

    Toyohara, Masumitsu; Satou, Tatsuaki; Wada, Mikio; Ishii, Tomoharu; Matsuo, Kazuaki.

    1997-01-01

    Inorganic admixtures to enhance the fluidity of cement material was developed. These admixtures turned into easy to immobilize the miscellaneous radioactive waste using cement material. It was found that the ζ potential of cement particles was directly proportional to the content of the inorganic admixtures in cement paste and the particles of cement were dispersed at the high ζ potential. The condensed sodium phosphate, which was the main component of the inorganic admixtures, retarded the dissolution of Ca 2+ ion from the cement, and generated the colloids by incorporating dissolved Ca 2+ ion. The cement material containing the inorganic admixtures was found to have the same mechanical strength and adsorption potential of radionuclides in comparison to normal cement materials. It was confirmed that the cement material containing the inorganic admixture was effectively filled gaps of miscellaneous radioactive waste. (author)

  10. Manganese oxide electrochemical capacitor with potassium poly(acrylate) hydrogel electrolyte

    Science.gov (United States)

    Lee, Kuang-Tsin; Wu, Nae-Lih

    An aqueous gel electrolyte has for the first time been successfully applied to the MnO 2· nH 2O-based pseudocapacitive electrochemical capacitors (ECs). The gel electrolyte is made of potassium poly(acrylate) (PAAK) polymer and aqueous solution of KCl. With the selected composition, PAAK:KCl:H 2O = 9.0%:6.7%:84.3% by weight, the gel shows no fluidity, possessing an ionic conductivity in the order of 10 -1 S cm -1. The gel electrolyte has been found to give substantially higher specific capacitances than those in the liquid electrolyte with the same salt (KCl) composition (1 M) and high power capability (>10 kW/kg).

  11. Manganese oxide electrochemical capacitor with potassium poly(acrylate) hydrogel electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Kuang-Tsin; Wu, Nae-Lih [Department of Chemical Engineering, National Taiwan University, Taipei 106 (China)

    2008-04-15

    An aqueous gel electrolyte has for the first time been successfully applied to the MnO{sub 2}.nH{sub 2}O-based pseudocapacitive electrochemical capacitors (ECs). The gel electrolyte is made of potassium poly(acrylate) (PAAK) polymer and aqueous solution of KCl. With the selected composition, PAAK:KCl:H{sub 2}O = 9.0%:6.7%:84.3% by weight, the gel shows no fluidity, possessing an ionic conductivity in the order of 10{sup -1} S cm{sup -1}. The gel electrolyte has been found to give substantially higher specific capacitances than those in the liquid electrolyte with the same salt (KCl) composition (1 M) and high power capability (>10 kW/kg). (author)

  12. Damage of DNA and plasma membranes in murine lymphoma cells irradiated under aerobic or hypoxic conditions

    International Nuclear Information System (INIS)

    Wlodek, D.

    1983-01-01

    A review of the knowledge of radiation effects on cell membranes and DNA and of repair mechanisms of radiation lesions is given. Investigations of properties of plasma membranes in L5178Y-S and L5178Y-R cells (surface charge, fluidity, transport of amino acids) indicate that there is no direct connection between membrane lesions and reproductive death. It was also found that in irradiated cells of both L5178Y-strains the rate of DNA chain elongation is the same, similarly as the amount of the initial DNA lesions and the rate of repair processes. Difference in the level of DNA synthesis inhibition is not proportional to the lethal effect. The results are also reported point to the difference between L5178Y-S and L5178Y-R cells in susceptibility of post-irradiation DNA synthesis to factors modifying chromatin conformation, such as inhibitors of (ADP-ribose) n polymerase. 221 refs. (author)

  13. Microfiltration conditions modify Lactobacillus bulgaricus cryotolerance in response to physiological changes.

    Science.gov (United States)

    Streit, Fernanda; Athès, Violaine; Bchir, Amine; Corrieu, Georges; Béal, Catherine

    2011-02-01

    This work aimed at analyzing the effect of microfiltration conditions (cross-flow velocity and transmembrane pressure) on the quality of frozen Lactobacillus bulgaricus CFL1 starters produced on pilot scale. Microfiltered cells were less resistant during the concentration process than centrifuged cells. In contrast, bacterial cryotolerance during freezing was improved after microfiltration, in a range of 28-88%, depending on the microfiltration conditions. During frozen storage, cell resistance was also affected by microfiltration conditions, either positively or negatively, compared to centrifugation. The best cryotolerance was obtained for cells microfiltered at a cross-flow velocity of 2 m/s and a transmembrane pressure of 0.15 MPa. This improvement was explained by considering membrane fatty acid composition of Lb. bulgaricus CFL1. This condition increased unsaturated to saturated and cyclic to saturated fatty acid ratios, which enhanced membrane fluidity, thus helping the cells to better resist freezing and frozen storage.

  14. Study on properties of mortar using silica fume and ground blast furnace slag. Silica fume oyobi koro slag funmatsu wo mochiita mortar no tokusei ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Shiiba, H; Honda, S; Araki, A [Fukuoka University, Fukuoka (Japan). Faculty of Engineering

    1992-09-01

    The effect of silica fume and ground blast furnace slag in concrete on the content of superplasticizer, and dynamic properties of hardened mortar with such admixtures were studied experimentally. Although the dependence of a flow value on the superplasticizer was dominated by kinds of superplasticizers, blast furnace slag enhanced the flow value resulting in a high fluidity. Adsorption of superplasticizers onto admixtures was dependent on kinds of superplasticizers, and adsorption onto blast furnace slag was 1.3-2 times that onto normal Portland cement (NPC). The compressive strength of mortar increased by mixing admixtures, while the bending strength was enhanced only by mixing silica fume. Mixing mortar was lower in dynamic elastic modulus than NPC mortar at the same compressive strength, and the velocity of supersonic wave in mortar was scarcely affected by mixing. 11 refs., 14 figs., 3 tabs.

  15. The baladi curative system of Cairo, Egypt.

    Science.gov (United States)

    Early, E A

    1988-03-01

    The article explores the symbolic structure of the baladi (traditional) cultural system as revealed in everyday narratives, with a focus on baladi curative action. The everyday illness narrative provides a cultural window to the principles of fluidity and restorative balance of baladi curative practices. The body is seen as a dynamic organism through which both foreign objects and physiological entities can move. The body should be in balance, as with any humorally-influenced system, and so baladi cures aim to restore normal balance and functioning of the body. The article examines in detail a narrative on treatment of a sick child, and another on treatment of fertility problems. It traces such cultural oppositions as insider: outsider; authentic:inauthentic; home remedy:cosmopolitan medicine. In the social as well as the medical arena these themes organize social/medical judgements about correct action and explanations of events.

  16. Team-based global organizations

    DEFF Research Database (Denmark)

    Zander, Lena; Butler, Christina; Mockaitis, Audra

    2015-01-01

    diversity in enhancing team creativity and performance, and 2) the sharing of knowledge in team-based organizations, while the other two themes address global team leadership: 3) the unprecedented significance of social capital for the success of global team leader roles; and 4) the link between shared......This chapter draws on a panel discussion of the future of global organizing as a team-based organization at EIBA 2014 in Uppsala, Sweden. We began by discussing contemporary developments of hybrid forms of hierarchy and teams-based organizing, but we venture to propose that as organizations become...... characterized by decreased importance of hierarchal structures, more fluidity across borders, even a possible dissolution of firm boundaries, we move towards team-based organizing as an alternative to more traditional forms of hierarchical-based organizing in global firms. To provide input for a discussion...

  17. Connecting the Production Multiple

    DEFF Research Database (Denmark)

    Lichen, Alex Yu; Mouritsen, Jan

    &OP process itself is a fluid object, but there is still possibility to organise the messy Production. There are connections between the Production multiple and the managerial technology fluid. The fluid enacted the multiplicity of Production thus making it more difficult to be organised because there were...... in opposite directions. They are all part of the fluid object. There is no single chain of circulating references that makes the object a matter of fact. Accounting fluidity means that references drift back and forth and enact new realities also connected to the chain. In this setting future research may......This paper is about objects. It follows post ANT trajectories and finds that objects are multiple and fluid. Extant classic ANT inspired accounting research largely sees accounting inscriptions as immutable mobiles. Although multiplicity of objects upon which accounting acts has been explored...

  18. Use of Gelidium amansii as a promising resource for bioethanol: a practical approach for continuous dilute-acid hydrolysis and fermentation.

    Science.gov (United States)

    Park, Jeong-Hoon; Hong, Ji-Yeon; Jang, Hyun Chul; Oh, Seung Geun; Kim, Sang-Hyoun; Yoon, Jeong-Jun; Kim, Yong Jin

    2012-03-01

    A facile continuous method for dilute-acid hydrolysis of the representative red seaweed species, Gelidium amansii was developed and its hydrolysate was subsequently evaluated for fermentability. In the hydrolysis step, the hydrolysates obtained from a batch reactor and a continuous reactor were systematically compared based on fermentable sugar yield and inhibitor formation. There are many advantages to the continuous hydrolysis process. For example, the low melting point of the agar component in G. amansii facilitates improved raw material fluidity in the continuous reactor. In addition, the hydrolysate obtained from the continuous process delivered a high sugar and low inhibitor concentration, thereby leading to both high yield and high final ethanol titer in the fermentation process. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Aspirin Increases the Solubility of Cholesterol in Lipid Membranes

    Science.gov (United States)

    Alsop, Richard; Barrett, Matthew; Zheng, Sonbo; Dies, Hannah; Rheinstadter, Maikel

    2014-03-01

    Aspirin (ASA) is often prescribed for patients with high levels of cholesterol for the secondary prevention of myocardial events, a regimen known as the Low-Dose Aspirin Therapy. We have recently shown that Aspirin partitions in lipid bilayers. However, a direct interplay between ASA and cholesterol has not been investigated. Cholesterol is known to insert itself into the membrane in a dispersed state at moderate concentrations (under ~37.5%) and decrease fluidity of membranes. We prepared model lipid membranes containing varying amounts of both ASA and cholesterol molecules. The structure of the bilayers as a function of ASA and cholesterol concentration was determined using high-resolution X-ray diffraction. At cholesterol levels of more than 40mol%, immiscible cholesterol plaques formed. Adding ASA to the membranes was found to dissolve the cholesterol plaques, leading to a fluid lipid bilayer structure. We present first direct evidence for an interaction between ASA and cholesterol on the level of the cell membrane.

  20. The effects of membrane cholesterol and simvastatin on red blood cell deformability and ATP release.

    Science.gov (United States)

    Forsyth, Alison M; Braunmüller, Susanne; Wan, Jiandi; Franke, Thomas; Stone, Howard A

    2012-05-01

    It is known that deformation of red blood cells (RBCs) is linked to ATP release from the cells. Further, membrane cholesterol has been shown to alter properties of the cell membrane such as fluidity and bending stiffness. Membrane cholesterol content is increased in some cardiovascular diseases, for example, in individuals with acute coronary syndromes and chronic stable angina, and therefore, because of the potential clinical relevance, we investigated the influence of altered RBC membrane cholesterol levels on ATP release. Because of the correlation between statins and reduced membrane cholesterol in vivo, we also investigated the effects of simvastatin on RBC deformation and ATP release. We found that reducing membrane cholesterol increases cell deformability and ATP release. We also found that simvastatin increases deformability by acting directly on the membrane in the absence of the liver, and that ATP release was increased for cells with enriched cholesterol after treatment with simvastatin. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Floating and flying ferrofluid bridges induced by external magnetic fields

    Science.gov (United States)

    Ma, Rongchao; Zhou, Yixin; Liu, Jing

    2015-04-01

    A ferrofluid is a mixture that exhibits both magnetism and fluidity. This merit enables the ferrofluid to be used in a wide variety of areas. Here we show that a floating ferrofluid bridge can be induced between two separated boards under a balanced external magnetic field generated by two magnets, while a flying ferrofluid bridge can be induced under an unbalanced external magnetic field generated by only one magnet. The mechanisms of the ferrofluid bridges were discussed and the corresponding mathematical equations were also established to describe the interacting magnetic force between the ferro particles inside the ferrofluid. This work answered a basic question that, except for the well-known floating water bridges that are related to electricity, one can also build up a liquid bridge that is related to magnetism.

  2. Slip casting of thoria-10 mole per cent yttria solid electrolyte

    International Nuclear Information System (INIS)

    Ramanathan, S.; Rao, S.V.K.

    1990-01-01

    One end closed thoria-yttria solid electrolyte have been fabricated by the slip casting technique. A systematic study of the influence of the process parameters on the characteristics of the final bodies has been carried out. Slips of ThO 2 -10 mole % Y 2 O 3 were prepared; their fluidity and castability were studied as a function of concentration, pH and particle size. The bodies were sintered at 2000degC and the physical properties like density and microstructure were evaluated. Slip cast bodies of bulk densities around 95% T.D. with relatively inhomogenous but predominantly fine grained structure could be obtained by optimizing the process variables. (author). 5 figs., 10 refs

  3. On the yield stress of complex materials

    Science.gov (United States)

    Calderas, F.; Herrera-Valencia, E. E.; Sanchez-Solis, A.; Manero, O.; Medina-Torres, L.; Renteria, A.; Sanchez-Olivares, G.

    2013-11-01

    In the present work, the yield stress of complex materials is analyzed and modeled using the Bautista-Manero-Puig (BMP) constitutive equation, consisting of the upper-convected Maxwell equation coupled to a kinetic equation to account for the breakdown and reformation of the fluid structure. BMP model predictions for a complex fluid in different flow situations are analyzed and compared with yield stress predictions of other rheological models, and with experiments on fluids that exhibit yield stresses. It is shown that one of the main features of the BMP model is that it predicts a real yield stress (elastic solid or Hookean behavior) as one of the material parameters, the zero shear-rate fluidity, is zero. In addition, the transition to fluid-like behavior is continuous, as opposed to predictions of more empirical models.

  4. Strange distance: towards an anthropology of interior dialogue.

    Science.gov (United States)

    Irving, Andrew

    2011-03-01

    The capacity for a complex inner life--encompassing inner speech, imaginative reverie, and unarticulated moods--is an essential feature of living with illness and a principal means through which people interpret, understand, and manage their condition. Nevertheless, anthropology lacks a generally accepted theory or methodological framework for understanding how interiority relates to people's public actions and expressions. Moreover, as conventional social-scientific methods are often too static to understand the fluidity of perception among people living with illness or bodily instability, I argue we need to develop new, practical approaches to knowing. By placing the problem of interiority directly into the field and turning it into an ethnographic, practice-based question to be addressed through fieldwork in collaboration with informants, this article works alongside women living with HIV/AIDS in Uganda with the aim of capturing the unvoiced but sometimes radical changes in being, belief, and perception that accompany terminal illness.

  5. Radiation shielding material

    International Nuclear Information System (INIS)

    Kawakubo, Takamasa; Yamada, Fumiyuki; Nakazato, Kenjiro.

    1976-01-01

    Purpose: To provide a material, which is used for printing a samples name and date on an X-ray photographic film at the same time an X-ray radiography. Constitution: A radiation shielding material of a large mass absorption coefficient such as lead oxide, barium oxide, barium sulfate, etc. is added to a solution of a radiation permeable substance capable of imparting cold plastic fluidity (such as microcrystalline wax, paraffin, low molecular polyethylene, polyvinyl chloride, etc.). The resultant system is agitated and then cooled, and thereafter it is press fitted to or bonded to a base in the form of a film of a predetermined thickness. This radiation shielding layer is scraped off by using a writing tool to enter information to be printed in a photographic film, and then it is laid over the film and exposed to X-radiation to thereby print the information on the film. (Seki, T.)

  6. Protic ionic liquids based on the dimeric and oligomeric anions: [(AcO)xH(x-1)]-.

    Science.gov (United States)

    Johansson, K M; Izgorodina, E I; Forsyth, M; MacFarlane, D R; Seddon, K R

    2008-05-28

    We describe a fluidity and conductivity study as a function of composition in N-methylpyrrolidine-acetic acid mixtures. The simple 1 : 1 acid-base mixture appears to form an ionic liquid, but its degree of ionicity is quite low and such liquids are better thought of as poorly dissociated mixtures of acid and base. The composition consisting of 3 moles acetic acid and 1 mole N-methylpyrrolidine is shown to form the highest ionicity mixture in this binary due to the presence of oligomeric anionic species [(AcO)(x)H(x-1)](-) stabilised by hydrogen bonds. These oligomeric species, being weaker bases than the acetate anion, shift the proton transfer equilibrium towards formation of ionic species, thus generating a higher degree of ionicity than is present at the 1 : 1 composition. A Walden plot analysis, thermogravimetric behaviour and proton NMR data, as well as ab initio calculations of the oligomeric species, all support this conclusion.

  7. Producing metallurgic coke

    Energy Technology Data Exchange (ETDEWEB)

    Abe, T.; Isida, K.; Vada, Y.

    1982-11-18

    A mixture of power producing coals with coal briquets of varying composition is proposed for coking in horizontal chamber furnaces. The briquets are produced from petroleum coke, coal fines or semicoke, which make up less than 27 percent of the mixture to be briquetted and coals with a standard coking output of volatile substances and coals with high maximal Gizeler fluidity. The ratio of these coals in the mixture is 0.6 to 2.1 or 18 to 32 percent, respectively. Noncaking or poorly caking coals are used as the power producing coals. The hardness of the obtained coke is DJ15-30 = 90.5 to 92.7 percent.

  8. Nitrided steel 38CrN3MAFA for supporting elements in nuclear power plants; Vysokoazotistaya stal` tipa 38HN3MAFA dlya krepezhnikh detajlej reaktorov AEhS

    Energy Technology Data Exchange (ETDEWEB)

    Rasheva, I; Argirov, Kh; Stojchev, T [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. po Metaloznanie i Tekhnologiya na Metalite

    1996-12-31

    Nitride doping of steel at different concentrations is achieved by counter-pressure casting in nitrogen ambience. A new type of steel is developed containing 0.05-0.2% N{sub 2}. It is compared to a standard 34NiCrMoV145 steel (DIN). The mechanical properties are improved significantly after a two-stage thermal treatment and are as follows: fluidity limit R{sub 0}.2>=1045 MPa, relative elongation A>=15%, relative shortening Z>=62%, impact viscosity KCU >= 1 MJ/m{sup 2}. The quench hardening consists of heating to 800-850{sup o} C in oil and cooling to 600{sup o} C in air. The steel is suitable for rotors, turbines, compressor shafts and reactor supporting elements in nuclear power plants. 3 refs., 6 figs., 6 tabs.

  9. Nitrided steel with increased reliability for steam turbine blades of low pressure cylinders; Vysokoazotistaya stal` s povishennoj nadezhdnostni dlya lopatok ha tsilindrov niskogo davleniya parnikh turbin

    Energy Technology Data Exchange (ETDEWEB)

    Andreev, Ch; Lengarski, P [Bylgarska Akademiya na Naukite, Sofia (Bulgaria). Inst. po Metaloznanie i Tekhnologiya na Metalite

    1996-12-31

    A new type of steel has been developed, containing 0.11-0.20% N and less than 0.05% C, the sum of both components being within the range 0.16-0.26%. The metal has an austenite-martensite structure with 10-30% austenite content. Samples obtained by counter-pressure casting have been investigated with respect to the influence of the thermal treatment on mechanical properties. The best properties are obtained when applying hardening by heating at 1050{sup o} C and cooling at 550{sup o} C: fluidity limit R{sub 0}.2>=850 MPa, relative elongation A>=15%, relative shortening Z>=50%, impact viscosity KCU >= 588 kJ/m{sup 2} at critical temperature of brittleness <-40{sup o} C. These properties are combined with high corrosion and wear resistance and make the steel suitable for steam turbine blades. 5 refs., 2 figs., 4 tabs.

  10. Leslie Marmon Silko and Simon J. Ortiz: Pathways to the Tradition

    Directory of Open Access Journals (Sweden)

    Dave Henderson

    2011-10-01

    Full Text Available Both Leslie Marmon Silko and Simon J. Ortiz have retold the story of a 1952 murder by two Pueblo brothers, a story that both writers first heard during their childhood years as it quickly became part of the local Native American traditional corpus. Both Silko and Ortiz are self-consciously indebted to the Native American storytelling tradition, particularly with respect to its malleability in the face of change, a fluidity that operates in tension with the preservation of certain fundamental religious and philosophical constants. Accordingly, Silko and Ortiz see their stories as providing pathways to the tradition, molding, reforming, and contributing to it without departing from it. Content, tone, style, and purpose are analyzed to reveal the variants in their redactions.

  11. Desulphurization of steel and pig iron

    Directory of Open Access Journals (Sweden)

    J. Kijac

    2008-10-01

    Full Text Available Metallurgical slag qualities must be defined by the whole complex of physico - chemical characteristics, such as an oxidative ability, optical basicity, sulphide capacity up to slag fluidity, its surface tension etc. The understanding of regulation of basic physico - chemical qualities of molten metals and slag depending on a chemical structure and a temperature has its importance at the level of the metallurgical process control. Presented paper deals with the possibilities how to exploit the sulphidic capacity for the desulphurisation evaluation in course of the metal reafining in the oxygen converter based on the set of the operational data. The integral part of the work is the process of the pig iron desulphurisation.

  12. THE APPLICATION OF Ni FOR IMPROVEMENT OF Al-Si-Fe ALLOYS

    Directory of Open Access Journals (Sweden)

    Jozef Petrík

    2009-09-01

    Full Text Available Iron, often present in secondary material (scrap forms brittle and hard needles in Al-Si alloys.These particles decrease the mechanical properties of castings. A reliable and economic method of iron elimination from aluminium alloys has not been well-known yet in metallurgical practice. The influence of nickel as an iron corrector (up to 0.7 % and iron (up to 2.5 % on the fluidity, microstructure and mechanical properties of the Al alloy with 9.75 % Si, 0.2 % Mg was evaluated. The presence of Ni results in shortening of the needles, but the segmentation of ß needles was not observed. Improvement of mechanical properties was observed despite of low affecting of microstructure.

  13. Metakaolin-Based Geopolymer with Added TiO2 Particles: Physicomechanical Characteristics

    Directory of Open Access Journals (Sweden)

    Luis A. Guzmán-Aponte

    2017-12-01

    Full Text Available The effect of the TiO2 addition on the physicomechanical properties of a geopolymer system based on metakaolin (MK and hydroxide and potassium silicate as activators is presented in this article. Three different liquid-solid systems (0.35, 0.40, and 0.45 and two titanium additions were investigated (5% and 10% of the cement content. The flowability, setting time, and mechanical strength of the geopolymer mixtures and their microstructural characteristics were evaluated using techniques such as X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, and scanning electron microscopy (SEM. It was concluded that a percentage of up to 10% TiO2 does not affect the mechanical properties of the geopolymer, although it does reduce the fluidity and setting times of the mixture.

  14. Effect of additives on the orientation of magnetic Sr-ferrite powders in powder injection molded compacts

    Energy Technology Data Exchange (ETDEWEB)

    Cho, T.S. [Sangju National Unviersity, Sangju (Korea); Jeung, W.Y. [Korea Institute of Science and Technology, Seoul (Korea)

    2001-03-01

    The effect of additives on the orientation of magnetic Sr-ferrite powders has been studied during powder injection molding under applied magnetic field for fabricating multi=pole anisotropic sintered Sr-ferrite magnets. The orientation of the Sr-ferrite powders depends sensitively on the fluidity of powder-binder mixture, related to the binder additives and the injection molding temperature, and the magnetic field intensity. The orientation of Sr-ferrite powders is good for the compacts with stearic acid added in the binder system of paraffin wax/ carnauba wax/HDPE, but it is poor of the compacts with silane coupling agent added. The orientation of sr-ferrites higher than 80% is achieved at the following useful conditions; apparent viscosity lower than 2500 poise in 1000 sec {sup -1} shear rate and applied magnetic field higher than 4 kOe. (author). 15 refs., 1 tab., 6 figs.

  15. Structural and physicochemical properties of polar lipids from thermophilic archaea.

    Science.gov (United States)

    Ulrih, Natasa Poklar; Gmajner, Dejan; Raspor, Peter

    2009-08-01

    The essential general features required for lipid membranes of extremophilic archaea to fulfill biological functions are that they are in the liquid crystalline phase and have extremely low permeability of solutes that is much less temperature sensitive due to a lack of lipid-phase transition and highly branched isoprenoid chains. Many accumulated data indicate that the organism's response to extremely low pH is the opposite of that to high temperature. The high temperature adaptation does not require the tetraether lipids, while the adaptation of thermophiles to acidic environment requires the tetraether polar lipids. The presence of cyclopentane rings and the role of polar heads are not so straightforward regarding the correlations between fluidity and permeability of the lipid membrane. Due to the unique lipid structures and properties of archaeal lipids, they are a valuable resource in the development of novel biotechnological processes. This microreview focuses primarily on structural and physicochemical properties of polar lipids of (hyper)thermophilic archaea.

  16. Islamic Credit Risk Analysis Case Of Sudanese Banking Sector 2006-2014

    Directory of Open Access Journals (Sweden)

    Mohammed A. SirElkhatim

    2017-06-01

    Full Text Available Islamic banking system has been expanding so quickly over the past few years. Moreover it has been developing significantly around the non-Muslim territories including Middle Eastern countries Southeast Asian countries and European countries and even in North American countries. The existing of Islamic banks is to attract the customers who seek to avoid interest. The prediction of corporate bankruptcies is an Important and widely studied topic since it can have significant impact on bank lending decisions and profitability the ultimate purpose of credit risk management is to ensure that credit fund is of safety profitability and fluidity. At present it is extremely important of commercial banks to set up an early bank risk warning system.

  17. Research and development of basic technologies for next generation industries, 'high crystalline polymeric material'. Evaluation on second term research and development; Jisedai sangyo kiban gijutsu kenkyu kaihatsu. Kokesshosei kobunshi zairyo (dainiki kenkyu kaihatsu kenkyu)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1988-03-01

    This research and development is intended to establish a basic technology related to high crystalline polymeric material that has dynamic properties comparable to metallic materials by single polymeric material as a structural material. Thick and large high-elasticity molded forms were obtained by searching poly-arylate material, and by developing such processing technologies as high-pressure injection molding, composite injection molding, and elongation fluidity molding. High-elasticity molded forms with uniform internal orientation were obtained by heating and molding liquid crystal polymers under high magnetic field. Solution molding was performed on a molecular composite consisting of rigid chains and soft chains, which was laminated and bonded to have obtained an isotropic form with as high elasticity as 54 GPa. In addition, high pressure powder formation of cross-linked polymers of di-acetylene system provided an isotropic form with sound wave elasticity of 23 GPa.

  18. Effect of phospholipid metabolites on model membrane fusion

    Energy Technology Data Exchange (ETDEWEB)

    Shragin, A.S.; Vasilenko, I.A.; Selishcheva, A.A.; Shvets, V.I.

    1985-01-01

    /sup 31/P-NMR spectroscopy and formation of fluorescent complexes between Tb/sup 3 +/ and dipicolinic acid were used to monitor liposome fusion and the effects of phospholipases C and D on the process. Phospholipase C was found highly efficient in initiating liposomal fusion, regardless of the phospholipid composition of the bilayer membranes. However, phospholipase D promoted liposomal fusion only in cases in which the membranes contained high concentrations of phospholipids incapable of forming bilayer membranes, such as phosphatidylethanolamine and cardiolipin. The mechanism of action of both enzymes in promoting liposomal fusion was ascribed to the generation of a metastable state in the membranes as a result of enzymatic formation of lipophilic metabolites 1,2-diacylglycerol and phosphatidic acid. The perturbation, or fluidity, of the liposomal membranes favored fusion on contact. 21 references, 4 figures.

  19. Science on a Sphere and Data in the Classroom: A Marriage Between Limitless Learning Experiences.

    Science.gov (United States)

    Zepecki, S., III; Dean, A. F.; Pisut, D.

    2017-12-01

    NOAA and other agencies have contributed significantly to the creation and distribution of educational materials to enhance the public understanding of the interconnectedness of the Earth processes and human activities. Intended for two different learning audiences, Science on a Sphere and Data in the Classroom are both educational tools used to enhance understanding of our world and how human activity influences change. Recently, NOAA has undertaken the task of marrying Data in the Classroom's NGSS aligned curriculum, which includes topics such as El Niño, sea level rise, and coral bleaching, with Science on a Sphere's Earth and space data visualization exhibits. This partnership allows for the fluidity of NOAA's data-driven learning materials, and fosters the homogeneity of formal and informal learning experiences for varied audiences.

  20. Physiological and molecular mechanisms associated with cross tolerance between hypoxia and low temperature in Thaumatotibia leucotreta

    DEFF Research Database (Denmark)

    Boardman, Leigh; Sørensen, Jesper Givskov; Terblanche, John S

    2015-01-01

    identified to date. Using larvae of false codling moth Thaumatotibia leucotreta, a pest of southern Africa, we investigated the physiological and molecular responses to hypoxia or temperature stress pre-treatments, followed by a standard low temperature exposure. Survival rates were significantly influenced...... by pretreatment conditions, although T. leucotreta shows relatively high basal resistance to various stressors (4% variation in larval survival across all pre-treatments). Results showed that mild pre-treatments with chilling and hypoxia increased resistance to low temperatures and that these responses were...... correlated with increased membrane fluidity (increased UFA:SFA) and/or alterations in heat shock protein 70 (HSP70); while general mechanical stress (shaking) and heat (2 h at 35 C) do not elicit cross tolerance (no change in survival or molecular responses). We therefore found support for some limited cold...

  1. Transmission-lattice based geometric phase analysis for evaluating the dynamic deformation of a liquid surface.

    Science.gov (United States)

    Shi, Wenxiong; Huang, Xianfu; Liu, Zhanwei

    2014-05-05

    Quantitatively measuring a dynamic liquid surface often presents a challenge due to high transparency, fluidity and specular reflection. Here, a novel Transmission-Lattice based Geometric Phase Analysis (TLGPA) method is introduced. In this method, a special lattice is placed underneath a liquid to be tested and, when viewed from above, the phase of the transmission-lattice image is modulated by the deformation of the liquid surface. Combining this with multi-directional Newton iteration algorithms, the dynamic deformation field of the liquid surface can be calculated from the phase variation of a series of transmission-lattice images captured at different moments. The developed method has the advantage of strong self-adaption ability to initial lattice rotational errors and this is discussed in detail. Dynamic 3D ripples formation and propagation was investigated and the results obtained demonstrated the feasibility of the method.

  2. Movers and stayers: Novel assemblages in changing environments

    Science.gov (United States)

    Hobbs, Richard L.; Valentine, Leonie E.; Standish, Rachel J.; Jackson, Stephen T.

    2018-01-01

    How species will respond to ongoing climate and other change is of increasing concern.Most attention is given to how species move or are moved, but many species stay.Understanding the dynamics of new species combinations is essential for successful conservation in a changing climate.Increased attention to species movement in response to environmental change highlights the need to consider changes in species distributions and altered biological assemblages. Such changes are well known from paleoecological studies, but have accelerated with ongoing pervasive human influence. In addition to species that move, some species will stay put, leading to an array of novel interactions. Species show a variety of responses that can allow movement or persistence. Conservation and restoration actions have traditionally focused on maintaining or returning species in particular places, but increasingly also include interventions that facilitate movement. Approaches are required that incorporate the fluidity of biotic assemblages into the goals set and interventions deployed.

  3. Understanding nomadic collaborative learning groups

    DEFF Research Database (Denmark)

    Ryberg, Thomas; Davidsen, Jacob; Hodgson, Vivien

    2018-01-01

    -term collaborations within the frame of Problem and Project Based Learning. By analysing the patterns of nomadic collaborative learning we identify and discuss how the two groups of students incorporate mobile and digital technologies as well as physical and/or non-digital technologies into their group work......The paper builds on the work of Rossitto et al. on collaborative nomadic work to develop three categories of practice of nomadic collaborative learning groups. Our study is based on interviews, workshops and observations of two undergraduate student's group practices engaged in self-organised, long....... Specifically, we identify the following categories of nomadic collaborative learning practices: “orchestration of work phases, spaces and activities,” “the orchestration of multiple technologies” and “orchestration of togetherness.” We found that for both groups of students there was a fluidity, situatedness...

  4. Possible mechanism of adhesion in a mica supported phospholipid bilayer

    International Nuclear Information System (INIS)

    Pertsin, Alexander; Grunze, Michael

    2014-01-01

    Phospholipid bilayers supported on hydrophilic solids like silica and mica play a substantial role in fundamental studies and technological applications of phospholipid membranes. In both cases the molecular mechanism of adhesion between the bilayer and the support is of primary interest. Since the possibilities of experimental methods in this specific area are rather limited, the methods of computer simulation acquire great importance. In this paper we use the grand canonical Monte Carlo technique and an atomistic force field to simulate the behavior of a mica supported phospholipid bilayer in pure water as a function of the distance between the bilayer and the support. The simulation reveals a possible adhesion mechanism, where the adhesion is due to individual lipid molecules that protrude from the bilayer and form widely spaced links with the support. Simultaneously, the bilayer remains separated from the bilayer by a thin water interlayer which maintains the bilayer fluidity

  5. Molecular basis for endotoxin neutralization by amphipathic peptides derived from the alpha-helical cationic core-region of NK-lysin.

    Science.gov (United States)

    Brandenburg, Klaus; Garidel, Patrick; Fukuoka, Satoshi; Howe, Jörg; Koch, Michel H J; Gutsmann, Thomas; Andrä, Jörg

    2010-08-01

    An analysis of the interaction of the NK-lysin derived peptide NK-2 and of analogs thereof with bacterial lipopolysaccharide (LPS, endotoxin) was performed to determine the most important biophysical parameters for an effective LPS neutralization. We used microcalorimetry, FTIR spectroscopy, Zeta potential measurements, and small-angle X-ray scattering to analyze the peptide:LPS binding enthalpy, the accessible LPS surface charge, the fluidity of the LPS hydrocarbon chains, their phase transition enthalpy change, the aggregate structure of LPS, and how these parameters are modulated by the peptides. We conclude that (i) a high peptide:LPS binding affinity, which is facilitated by electrostatic and hydrophobic interactions and which leads to a positive Zeta potential, (ii) the formation of peptide-enriched domains, which destabilize the lipid packing, demonstrated by a drastic decrease of phase transition enthalpy change of LPS, and (iii) the multilamellarization of the LPS aggregate structure are crucial for an effective endotoxin neutralization by cationic peptides.

  6. Effect of antihypertensive agents - captopril and nifedipine - on the functional properties of rat heart mitochondria

    Directory of Open Access Journals (Sweden)

    Ivana Kancirová

    2016-06-01

    Full Text Available Objective(s: Investigation of acute effect on cellular bioenergetics provides the opportunity to characterize the possible adverse effects of drugs more comprehensively. This study aimed to investigate the changes in biochemical and biophysical properties of heart mitochondria induced by captopril and nifedipine antihypertensive treatment. Materials and Methods: Male, 12-week-old Wistar rats in two experimental models (in vivo and in vitro were used. In four groups, the effects of escalating doses of captopril, nifedipine and combination of captopril + nifedipine added to the incubation medium (in vitro or administered per os to rat (in vivo on mitochondrial ATP synthase activity and membrane fluidity were monitored. Results: In the in vitro model we observed a significant inhibitory effect of treatment on the ATP synthase activity (P

  7. Microwave heating of electric cable insulated wires before their impregnation with a hydrophobic material

    Energy Technology Data Exchange (ETDEWEB)

    Niculae, D; Mihailescu, A [Romanian Electricity Authority (Romania); Indreias, I; Martin, D [Institute of Atomic Physics, Bucharest (Romania); Margaritescu, A [ICPE Electrostatica, Bucharest, (Romania); Zlatonovici, D

    1998-12-31

    Underground insulated telecommunication cables must be impregnated with a hydrophobic material in order to prevent water penetration damage. To do so, the cable wire bundle must be heated to a temperature of 60 to 90 degrees C to ensure proper fluidity of the hydrophobic material that must fill the free spaces between the copper wires of the telephone cable. This paper described the microwave heating method of the wires before their impregnation. A cylindrical applicator was designed to perform a telephone bundle heating test. 800 W of microwave power were used on a telephone cable made up of 800 wires of 0.4 mm in diameter. A uniform heating was obtained throughout the section. Microwave heating was also found to be 53 per cent more energy efficient than hot air heating. 4 refs., 4 figs.

  8. Discovery Mondays: Quantum physics - incredible but true

    CERN Multimedia

    2006-01-01

    Physicists use two main theories to describe the world around us - the general theory of relativity to describe the infinitely large and quantum theory to describe the infinitesimally small, at the scale of the atom and its constituent parts. Quantum physics is as fascinating as it is bewildering. And yet it's used in many practical applications - medical imaging, lasers and computers, to name but a few. Over the course of the evening, you'll become acquainted with strange phenomena such as super-fluidity, teleportation and quantum cryptography. And through some amazing sleights-of-hand and experiments, you'll be taken on a journey into the mysteries of the infinitesimally small... The event will be conducted in French. Come to Microcosm, (Reception Building 33, Meyrin site), on Monday 3 July from 7.30 p.m. to 9.00 p.m. Entrance is free http://www.cern.ch/LundisDecouverte/

  9. Social Influence on Observed Race

    Directory of Open Access Journals (Sweden)

    Zsófia Boda

    2018-01-01

    Full Text Available This article introduces a novel theoretical approach for understanding racial fluidity, emphasizing the social embeddedness of racial classifications. We propose that social ties affect racial perceptions through within-group micromechanisms, resulting in discrepancies between racial self-identifications and race as classified by others. We demonstrate this empirically on data from 12 Hungarian high school classes with one minority group (the Roma using stochastic actor-oriented models for the analysis of social network panel data. We find strong evidence for social influence: individuals tend to accept their peers' judgement about another student’s racial category; opinions of friends have a larger effect than those of nonfriends. Perceived social position also matters: those well-accepted among majority-race peers are likely to be classified as majority students themselves. We argue that similar analyses in other social contexts shall lead to a better understanding of race and interracial processes.

  10. The effects of Sepiolite-SPLF on heavy pigs fed liquid diets

    Directory of Open Access Journals (Sweden)

    P. Parisini

    2011-03-01

    Full Text Available Liquid feed delivery systems for pigs have tended to be more common in areas where liquid by-products (i.e. dairy whey are readily available and where the size of the production unit can justify the capital expenditure involved. The potential advantages of liquid feeding include: a reduction of feed loss during handling and feeding; b improvement in the pig's environment due to the reduction of dust in the atmosphere; c improved pig performance and feed conversion rate (Jensen and Mikkelsen, 1998; Dell’Orto et al., 1992; d flexibility in raw material use (opportunity to utilise more economic food source, i.e. silages; e improved dry matter intake in lactating sows. However, very few studies have been done concerning technical quality of the liquid feed with respect to homogeneity, fluidity and sedimentation (Hoppenbrock et al., 1998...

  11. Spacing Identity

    DEFF Research Database (Denmark)

    Stang Våland, Marianne; Georg, Susse

    2018-01-01

    In this paper, we analyze how architectural design, and the spatial and material changes this involves, contributes to the continuous shaping of identities in an organization. Based upon a case study of organizational and architectural change in a municipal administration at a time of major public...... sector reforms, we examine how design interventions were used to (re)form work and professional relationships. The paper examines how engagements with spatial arrangements and material artifacts affected people’s sense of both occupational and organizational identity. Taking a relational approach...... to sociomateriality, the paper contributes to the further theorizing of space in organization studies by proposing the concept of spacing identity to capture the fluidity of identity performance....

  12. Constructions of masculinity and femininity and sexual risk negotiation practices among women in urban Ghana.

    Science.gov (United States)

    Fiaveh, Daniel Y; Izugbara, Chimaraoke O; Okyerefo, Michael P K; Reysoo, Fenneke; Fayorsey, Clara K

    2015-01-01

    Using qualitative data gathered through in-depth interviews with women in Accra, Ghana, this paper explores narratives of masculinity and femininity and sexual risk negotiation practices among women. While women framed 'proper' masculinity in terms of stereotypical reproductive norms, they also acknowledged the fluidity and multiplicity of masculinities. Femininity was more uniformly characterised in terms of physical attractiveness and beauty, responsibility and reproduction. These features, especially those related to adherence to morally and socially appropriate sexual norms (e.g., menstrual and bodily hygiene, unplanned pregnancy etc.), influenced women's approach to sexual negotiation. Work aiming to support women to negotiate sex safely needs to pay attention to their notions of gender and practices of sexual negotiation.

  13. Understanding hospitality house guests' needs: a brief case report.

    Science.gov (United States)

    Duncan, Mary Katherine Waibel

    2011-08-01

    A.E. Kazak's (2006) call to develop theory-driven and empirically supported programs aimed at strengthening the competencies of families affected by pediatric illness applies to both medical and nonmedical facilities and institutions that care for pediatric patients and their loved ones. M.K.W. Duncan and A. Blugis (in press, this issue) note that despite the intuitive and practical nature of Maslow's Hierarchy of Needs, no theory translates into an infallible understanding of any individual guest's needs or a program of universally applied best practice standards for meeting those needs. Using Maslow's theory as a framework, this brief report describes the complexity and fluidity of one mother's needs during her stay at a hospitality house following the birth of her premature twin babies. Copyright © 2011 Elsevier Inc. All rights reserved.

  14. Between pink and blue: a multi-dimensional family approach to gender nonconforming children and their families.

    Science.gov (United States)

    Malpas, Jean

    2011-12-01

    Families of gender nonconforming children need to negotiate the interactions between two gender systems: a rigid gender binary imported from familial, social, and cultural experiences and a fluid gender spectrum articulated by their child. This article reviews parental reactions to nonconforming gender developments and poses that the parental mandates of protection and acceptance are problematized by the difference of gender norms between the child and the family, as well as the child and the environment. Through multiple therapeutic modalities-parental coaching and education, parent support group, and child and family therapy-the author illustrates interventions supporting both parents and prepubescent children in their negotiation of safety, connection, and fluidity. Case vignettes illustrate the method in action.

  15. Improved Mitochondrial Function in Brain Aging and Alzheimer Disease – the New Mechanism of Action of the Old Metabolic Enhancer Piracetam

    Science.gov (United States)

    Leuner, Kristina; Kurz, Christopher; Guidetti, Giorgio; Orgogozo, Jean-Marc; Müller, Walter E.

    2010-01-01

    Piracetam, the prototype of the so-called nootropic drugs’ is used since many years in different countries to treat cognitive impairment in aging and dementia. Findings that piracetam enhances fluidity of brain mitochondrial membranes led to the hypothesis that piracetam might improve mitochondrial function, e.g., might enhance ATP synthesis. This assumption has recently been supported by a number of observations showing enhanced mitochondrial membrane potential, enhanced ATP production, and reduced sensitivity for apoptosis in a variety of cell and animal models for aging and Alzheimer disease. As a specific consequence, substantial evidence for elevated neuronal plasticity as a specific effect of piracetam has emerged. Taken together, this new findings can explain many of the therapeutic effects of piracetam on cognition in aging and dementia as well as different situations of brain dysfunctions. PMID:20877425

  16. Improved mitochondrial function in brain aging and Alzheimer disease - the new mechanism of action of the old metabolic enhancer piracetam

    Directory of Open Access Journals (Sweden)

    Kristina Leuner

    2010-09-01

    Full Text Available Piracetam, the prototype of the so-called nootropic drugs’ is used since many years in different countries to treat cognitive impairment in aging and dementia. Findings that piracetam enhances fluidity of brain mitochondrial membranes led to the hypothesis that piracetam might improve mitochondrial function, e.g. might enhance ATP synthesis. This assumption has recently been supported by a number of observations showing enhanced mitochondrial membrane potential (MMP, enhanced ATP production, and reduced sensitivity for apoptosis in a variety of cell and animal models for aging and Alzheimer disease (AD. As a specific consequence, substantial evidence for elevated neuronal plasticity as a specific effect of piracetam has emerged. Taken together, these new findings can explain many of the therapeutic effects of piracetam on cognition in aging and dementia as well as different situations of brain dysfunctions.

  17. Sn and Ti influences on intermetallic phases damage in hot dip galvanizing

    Directory of Open Access Journals (Sweden)

    V. Di Cocco

    2012-10-01

    Full Text Available Protection against metallic materials corrosion is one of the most important means to reduce both maintenance costs and environmental impact. In the last years new studies on chemical baths compositions and fluxes have been performed in order to improve processes, corrosion resistance and mechanical behavior of Zn based coatings. Chemical bath composition is often improved by the Sn addition which increases the fluidity of the melt. Ti addition makes the coatings to change color under appropriate heat treatment. In this work a comparative microstructural analysis, in Zn-Sn and Zn-Ti coatings, is performed to evaluate intermetallic phases formation kinetics and the influence of intermetallic microstructure on coating damage under constant bending deformation.

  18. Role of Membrane Biophysics in Alzheimer's - related cell pathways

    Directory of Open Access Journals (Sweden)

    Donghui eZhu

    2015-05-01

    Full Text Available Cellular membrane alterations are commonly observed in many diseases, including Alzheimer’s disease (AD. Membrane biophysical properties, such as membrane molecular order, membrane fluidity, organization of lipid rafts, and adhesion between membrane and cytoskeleton, play an important role in various cellular activities and functions. While membrane biophysics impacts a broad range of cellular pathways, this review addresses the role of membrane biophysics in amyloid-β peptide aggregation, Aβ-induced oxidative pathways, amyloid precursor protein processing, and cerebral endothelial functions in AD. Understanding the mechanism(s underlying the effects of cell membrane properties on cellular processes should shed light on the development of new preventive and therapeutic strategies for this devastating disease.

  19. Fabrication of Spherical AlSi10Mg Powders by Radio Frequency Plasma Spheroidization

    Science.gov (United States)

    Wang, Linzhi; Liu, Ying; Chang, Sen

    2016-05-01

    Spherical AlSi10Mg powders were prepared by radio frequency plasma spheroidization from commercial AlSi10Mg powders. The fabrication process parameters and powder characteristics were investigated. Field emission scanning electron microscope, X-ray diffraction, laser particle size analyzer, powder rheometer, and UV/visible/infrared spectrophotometer were used for analyses and measurements of micrographs, phases, granulometric parameters, flowability, and laser absorption properties of the powders, respectively. The results show that the obtained spherical powders exhibit good sphericity, smooth surfaces, favorable dispersity, and excellent fluidity under appropriate feeding rate and flow rate of carrier gas. Further, acicular microstructures of the spherical AlSi10Mg powders are composed of α-Al, Si, and a small amount of Mg2Si phase. In addition, laser absorption values of the spherical AlSi10Mg powders increase obviously compared with raw material, and different spectra have obvious absorption peaks at a wavelength of about 826 nm.

  20. 80. special meeting on coke

    Energy Technology Data Exchange (ETDEWEB)

    1986-01-01

    There were 12 papers presented at the special meeting on coke. These have the following headings: relationship between coal properties and optical anisotropic textures of coke; development of optical texture of chemically modified low rank coal; relationship between fluid and swelling properties of Akabira coal; estimation of coal fluidity; present state and future of robotics; on the thermal stress during the carbonisation process of coals; development of estimation model for coke porosity distribution in the coke oven using X-ray CT; carbonization reaction of coke oven; relationship between qualities of coke and width of coke oven; development of carbonization model in coke ovens - estimation of growing clearance between heating wall and charge; development of automatic transparency analyzer for activated sludge process.

  1. Effect of Ground Waste Concrete Powder on Cement Properties

    Directory of Open Access Journals (Sweden)

    Xianwei Ma

    2013-01-01

    Full Text Available The paste/mortar attached to the recycled aggregate decreases the quality of the aggregate and needs to be stripped. The stripped paste/mortar is roughly 20% to 50% in waste concrete, but relevant research is very limited. In this paper, the effects of ground waste concrete (GWC powder, coming from the attached paste/mortar, on water demand for normal consistency, setting time, fluidity, and compressive strength of cement were analyzed. The results show that the 20% of GWC powder (by the mass of binder has little effect on the above properties and can prepare C20 concrete; when the sand made by waste red clay brick (WRB replaces 20% of river sand, the strength of the concrete is increased by 17% compared with that without WRB sand.

  2. Empirical models for end-use properties prediction of LDPE: application in the flexible plastic packaging industry

    Directory of Open Access Journals (Sweden)

    Maria Carolina Burgos Costa

    2008-03-01

    Full Text Available The objective of this work is to develop empirical models to predict end use properties of low density polyethylene (LDPE resins as functions of two intrinsic properties easily measured in the polymers industry. The most important properties for application in the flexible plastic packaging industry were evaluated experimentally for seven commercial polymer grades. Statistical correlation analysis was performed for all variables and used as the basis for proper choice of inputs to each model output. Intrinsic properties selected for resin characterization are fluidity index (FI, which is essentially an indirect measurement of viscosity and weight average molecular weight (MW, and density. In general, models developed are able to reproduce and predict experimental data within experimental accuracy and show that a significant number of end use properties improve as the MW and density increase. Optical properties are mainly determined by the polymer morphology.

  3. Gravitational waves from freely precessing neutron stars

    International Nuclear Information System (INIS)

    Jones, D.I.

    2001-01-01

    The purpose of this study is to assess the likely detectability of gravitational waves from freely precessing neutron stars. We begin by presenting a neutron star model of sufficient complexity to take into account both the elasticity and fluidity of a realistic neutron star. We then examine the effect of internal dissipation (i.e. heat generation within the star) and gravitational radiation reaction on the wobble. This is followed by an examination of various astrophysical scenarios where some mechanism might pump the precessional motion. We estimate the gravitational wave amplitude in these situations. Finally, we conclude that gravitational radiation from freely precessing neutron stars is almost certainly limited to a level undetectable by a LIGO II detector by internal dissipation. (author)

  4. Changes in the Fatty Acid Profile and Phospholipid Molecular Species Composition of Human Erythrocyte Membranes after Hybrid Palm and Extra Virgin Olive Oil Supplementation.

    Science.gov (United States)

    Pacetti, D; Gagliardi, R; Balzano, M; Frega, N G; Ojeda, M L; Borrero, M; Ruiz, A; Lucci, P

    2016-07-13

    This work aims to evaluate and compare, for the first time, the effects of extra virgin olive oil (EVOO) and hybrid palm oil (HPO) supplementation on the fatty acid profile and phospholipid (PL) molecular species composition of human erythrocyte membranes. Results supported the effectiveness of both HPO and EVOO supplementation (3 months, 25 mL/day) in decreasing the lipophilic index of erythrocytes with no significant differences between HPO and EVOO groups at month 3. On the other hand, the novel and rapid ultraperformance liquid chromatography-tandem mass spectrometry method used for PL analysis reveals an increase in the levels of phosphatidylcholine and phosphatidylethanolamine species esterified with polyunsaturated fatty acids. This work demonstrates the ability of both EVOO and HPO to increase the degree of unsaturation of erythrocyte membrane lipids with an improvement in membrane fluidity that could be associated with a lower risk of developing cardiovascular diseases.

  5. Men in transit: The spectrum of masculinity in Caio Fernando Abreu’s White Limit (1970

    Directory of Open Access Journals (Sweden)

    Juan Filipe Stacul

    2015-03-01

    Full Text Available In the present work, we aim at discussing the construction of subjectivity in relation to gender categories, especially in regards to male identity, in Caio Fernando Abreu’s first novel White Limit (Original title: Limite branco, 1970. We believe that the protagonist’s process of aging, alongside with his subject’s formation, in the narrative, takes us to face a fluidity, which puts at stake the notions of what is taken for granted as appropriate for the  individual.  Studies on the displacement of the contemporary subject, Gender Studies, and on men's studies in particular, will serve as the theoretical apparatus for the discussions raised here.

  6. Shifting Borderland of Technoscience

    DEFF Research Database (Denmark)

    Lindtner, Silvia; Cohn, Marisa; Leahu, Lucian

    2015-01-01

    other how to navigate changing terrains of technology research and design. To maximize in- depth collaboration between junior and senior scholars, we propose a format that includes in-depth mentoring sessions, panel presentations from junior and senior participants, group activities, and working......Since the publication of Phil Agre’s [1] seminal work on critical technical practice, the sites of intersection between computation and society have multiplied, and so too have the sociotechnical borderlands we inhabit. Critical methodologies such as “critical design” [8,6,5], “reflective design...... like big data and social computing pose new challenges. Given the fluidity of the landscape it is important for us to articulate the specificities of our scholarly borderlands. By bringing together junior and senior scholars we aim to provide a forum for researchers in this area to learn from each...

  7. The lipid content of cisplatin- and doxorubicin-resistant MCF-7 human breast cancer cells.

    Science.gov (United States)

    Todor, I N; Lukyanova, N Yu; Chekhun, V F

    2012-07-01

    To perform the comparative study both of qualitative and quantitative content of lipids in parental and drug resistant breast cancer cells. Parental (MCF-7/S) and resistant to cisplatin (MCF-7/CP) and doxorubicin (MCF-7/Dox) human breast cancer cells were used in the study. Cholesterol, total lipids and phospholipids content were determined by means of thin-layer chromatography. It was found that cholesterol as well as cholesterol ethers content are significantly higher but diacylglycerols, triacyl-glycerols content are significantly lower in resistant cell strains than in parental (sensitive) cells. Moreover the analysis of individual phospholipids showed the increase of sphingomyelin, phosphatidylserine, cardiolipin, phosphatidic acid and the decrease of phosphatidy-lethanolamine, phosphatidylcholine in MCF-7/CP and MCF-7/Dox cells. Obtained results allow to suggest that the lipid profile changes can mediate the modulation of membrane fluidity in drug resistant MCF-7 breast cancer cells.

  8. Microspectroscopic Study of Liposome-to-cell Interaction Revealed by Förster Resonance Energy Transfer.

    Science.gov (United States)

    Yefimova, Svetlana L; Kurilchenko, Irina Yu; Tkacheva, Tatyana N; Kavok, Nataliya S; Todor, Igor N; Lukianova, Nataliya Yu; Chekhun, Vasyl F; Malyukin, Yuriy V

    2014-03-01

    We report the Förster resonance energy transfer (FRET)-labeling of liposomal vesicles as an effective approach to study in dynamics the interaction of liposomes with living cells of different types (rat hepatocytes, rat bone marrow, mouse fibroblast-like cells and human breast cancer cells) and cell organelles (hepatocyte nuclei). The in vitro experiments were performed using fluorescent microspectroscopic technique. Two fluorescent dyes (DiO as the energy donor and DiI as an acceptor) were preloaded in lipid bilayers of phosphatidylcholine liposomes that ensures the necessary distance between the dyes for effective FRET. The change in time of the donor and acceptor relative fluorescence intensities was used to visualize and trace the liposome-to-cell interaction. We show that FRET-labeling of liposome vesicles allows one to reveal the differences in efficiency and dynamics of these interactions, which are associated with composition, fluidity, and metabolic activity of cell plasma membranes.

  9. Alteration in lipid composition of plasma membranes of sensitive and resistant Guerin carcinoma cells due to the action of free and liposomal form of cisplatin.

    Science.gov (United States)

    Naleskina, L A; Todor, I N; Nosko, M M; Lukianova, N Y; Pivnyuk, V M; Chekhun, V F

    2013-09-01

    To study in vivo changes of lipid composition of plasma membranes of sensitive and resistant to cisplatin Guerin carcinoma cells under influence of free and liposomal cisplatin forms. The isolation of plasma membranes from parental (sensitive) and resistant to cisplatin Guerin carcinoma cells was by differential ultracentrifugation in sucrose density gradient. Lipids were detected by method of thin-layer chromatography. It was determined that more effective action of cisplatin liposomal form on resistant cells is associated with essential abnormalities of conformation of plasma membrane due to change of lipid components and architectonics of rafts. It results in the increase of membrane fluidity. Reconstructions in lipid composition of plasma membranes of cisplatin-resistant Guerin carcinoma cells provide more intensive delivery of drug into the cells, increase of its concentration and more effective interaction with cellular structural elements.

  10. Growth Mechanism of Gold Nanorods in Binary Surfactant System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bo-Mi; Seo, Sun-Hwa; Joe, Ara; Shim, Kyu-Dong; Jang, Eue-Soon [Kumoh National Institute of Technology, Gumi (Korea, Republic of)

    2016-06-15

    In order to reveal the growth mechanism of gold nanorods (GNRs) in a binary surfactant system, we synthesized various GNRs by changing the concentration of the surfactants, AgNO{sub 3}, and HBr in the growth solution. We found that the benzyldime thylhexadecylammoniumchloride surfactant had weak interaction with the gold ions, but it could reduce the membrane fluidity. In addition, we could dramatically decrease the cetyltrimethylammonium bromide concentration required for GNR growth by adding an HBr solution. Notably, Ag{sup +} ions were necessary to break the symmetry of the seed crystals for GNR growth, but increasing the concentration of Ag{sup +} and Br{sup -} ions caused a decrease in the template size.

  11. Ni{sub 3}Al technology transfer

    Energy Technology Data Exchange (ETDEWEB)

    Sikka, V.K.; Viswanathan, S.; Santella, M.L. [Oak Ridge National Lab., TN (United States)] [and others

    1997-04-01

    Ductile Ni{sub 3}Al and Ni{sub 3}Al-based alloys have been identified for a range of applications. These applications require the use of material in a variety of product forms such as sheet, plate, bar, wire, tubing, piping, and castings. Although significant progress has been made in the melting, casting, and near-net-shape forming of nickel aluminides, some issues still remain. These include the need for: (1) high-strength castable composition for many applications that have been identified; (2) castability (mold type, fluidity, hot-shortness, porosity, etc.); (3) weld reparability of castings; and (4) workability of cast or powder metallurgy product to sheet, bar, and wire. The four issues listed above can be {open_quotes}show stoppers{close_quotes} for the commercial application of nickel aluminides. This report describes the work completed to address some of these issues during FY 1996.

  12. Thermogravimetric analysis in the characterization of colombian coals used in the production of coke

    International Nuclear Information System (INIS)

    Guerrero, Camilo; Salamanca, Monica E; Diaz, Jose de J

    2010-01-01

    Five types of coal from the states of Cundinamarca, Boyaca and Norte de Santander (Colombia) were characterized by proximate, ultimate, rheological, petrographic, calorific and thermogravimetric analysis. The parameters used, especially the ones which determine the rheological properties show that the studied coals and its blends could produce good quality coke. It was observed the inverse relationship between the volatile matter content and the mean vitrinite reflectance, relationship which is attributed to the increase of the aromaticity in the molecular structure of the coal as a consequence of the rank increase. The parameters derived from the thermogravimetric analysis, maximum velocity of de-volatilization and the temperature of maximum velocity of de-volatilization and the media reflectance of the vitrinite showed good correlations. Also was observed an interesting correlation between the velocity of de-volatilization and maximum fluidity. This shows that the thermogravimetric analysis can be a useful tool to characterize in a quick way coals used for metallurgical coke production.

  13. Grain Refinement of Permanent Mold Cast Copper Base Alloys

    Energy Technology Data Exchange (ETDEWEB)

    M.Sadayappan; J.P.Thomson; M.Elboujdaini; G.Ping Gu; M. Sahoo

    2005-04-01

    Grain refinement is a well established process for many cast and wrought alloys. The mechanical properties of various alloys could be enhanced by reducing the grain size. Refinement is also known to improve casting characteristics such as fluidity and hot tearing. Grain refinement of copper-base alloys is not widely used, especially in sand casting process. However, in permanent mold casting of copper alloys it is now common to use grain refinement to counteract the problem of severe hot tearing which also improves the pressure tightness of plumbing components. The mechanism of grain refinement in copper-base alloys is not well understood. The issues to be studied include the effect of minor alloy additions on the microstructure, their interaction with the grain refiner, effect of cooling rate, and loss of grain refinement (fading). In this investigation, efforts were made to explore and understand grain refinement of copper alloys, especially in permanent mold casting conditions.

  14. Emerging quasi-0D states at vanishing total entropy of the 1D hard sphere system: A coarse-grained similarity to the car parking problem

    Science.gov (United States)

    Frusawa, Hiroshi

    2014-05-01

    A coarse-grained system of one-dimensional (1D) hard spheres (HSs) is created using the Delaunay tessellation, which enables one to define the quasi-0D state. It is found from comparing the quasi-0D and 1D free energy densities that a frozen state due to the emergence of quasi-0D HSs is thermodynamically more favorable than fluidity with a large-scale heterogeneity above crossover volume fraction of ϕc=e/(1+e)=0.731⋯ , at which the total entropy of the 1D state vanishes. The Delaunay-based lattice mapping further provides a similarity between the dense HS system above ϕc and the jamming limit in the car parking problem.

  15. Emerging quasi-0D states at vanishing total entropy of the 1D hard sphere system: A coarse-grained similarity to the car parking problem

    International Nuclear Information System (INIS)

    Frusawa, Hiroshi

    2014-01-01

    A coarse-grained system of one-dimensional (1D) hard spheres (HSs) is created using the Delaunay tessellation, which enables one to define the quasi-0D state. It is found from comparing the quasi-0D and 1D free energy densities that a frozen state due to the emergence of quasi-0D HSs is thermodynamically more favorable than fluidity with a large-scale heterogeneity above crossover volume fraction of ϕ c =e/(1+e)=0.731⋯ , at which the total entropy of the 1D state vanishes. The Delaunay-based lattice mapping further provides a similarity between the dense HS system above ϕ c and the jamming limit in the car parking problem.

  16. Superoxide dismutase and catalase conjugated to polyethylene glycol increases endothelial enzyme activity and oxidant resistance

    International Nuclear Information System (INIS)

    Beckman, J.S.; Minor, R.L. Jr.; White, C.W.; Repine, J.E.; Rosen, G.M.; Freeman, B.A.

    1988-01-01

    Covalent conjugation of superoxide dismutase and catalase with polyethylene glycol (PEG) increases the circulatory half-lives of these enzymes from 125 I-PEG-catalase or 125 I-PEG-superoxide dismutase produced a linear, concentration-dependent increase in cellular enzyme activity and radioactivity. Fluorescently labeled PEG-superoxide dismutase incubated with endothelial cells showed a vesicular localization. Mechanical injury to cell monolayers, which is known to stimulate endocytosis, further increased the uptake of fluorescent PEG-superoxide dismutase. Addition of PEG and PEG-conjugated enzymes perturbed the spin-label binding environment, indicative of producing an increase in plasma membrane fluidity. Thus, PEG conjugation to superoxide dismutase and catalase enhances cell association of these enzymes in a manner which increases cellular enzyme activities and provides prolonged protection from partially reduced oxygen species

  17. Mass spectrometry profiling of oxysterols in human sperm identifies 25-hydroxycholesterol as a marker of sperm function

    Directory of Open Access Journals (Sweden)

    Chiara Zerbinati

    2017-04-01

    Full Text Available Cholesterol is a main lipid component of sperm cell that is essential for sperm membrane fluidity, capacitation, and acrosomal reaction. Recent data obtained in bovine sperm showed that sperm capacitation is associated to the formation of oxysterols, oxidized products of cholesterol. The aim of this study was to profile oxysterol content in human semen, and to investigate their potential role in sperm pathophysiology. Among the 12 oxysterols analyzed, 25-hydroxycholesterol (25-HC resulted the most represented in normozoospermic samples, and its concentration positively correlated with spermatozoa number. We detected Cholesterol 25-hydroxylase, the enzyme responsible for 25-HC production, in human spermatozoa at the level of the neck and the post acrosomal area. Upon incubation with spermatozoa, 25-HC induced calcium and cholesterol transients in connection with the acrosomal reaction. Our results support a role for 25-HC in sperm function.

  18. [Study on Xinyueshu spray drying assisted with copovidone and its effect on powder property].

    Science.gov (United States)

    Jiang, Yan-Rong; Zhang, Zhen-Hai; Ding, Dong-Mei; Yan, Hong-Mei; Hu, Shao-Ying; Jia, Xiao-Bin

    2013-12-01

    To study the application characteristics of copovidone (PVP-S630) in Xinyueshu extracts during the spray drying process, and its effect on such pharmaceutical properties as micromeritics and drug release behavior. PVP-S630 was added into Xinyueshu extracts to study on the spray drying, the effect of different dosages of PVP-S630 against the wall sticking effect of the spray drying, as well as the power property of Xinyueshu spray drying power and the dissolution in vitro behavior of the effective component of hyperoside. The results showed that PVP-S630 revealed a significant anti-wall sticking effect, with no notable change in the grain size of the spray drying power, increase in the fluidity, improvement in the moisture absorption and remarkable rise in the dissolution in vitro behavior of hyperoside. It was worth further studying the application of PVP-S630 in spray drying power of traditional Chinese medicine.

  19. Psychiatry in American Medical Education: The Case of Harvard's Medical School, 1900-1945.

    Science.gov (United States)

    Abraham, Tara H

    2018-01-01

    As American psychiatrists moved from the asylum to the private clinic during the early twentieth century, psychiatry acquired a growing presence within medical school curricula. This shift in disciplinary status took place at a time when medical education itself was experiencing a period of reform. By examining medical school registers at Harvard University, records from the Dean's office of Harvard's medical school, and oral histories, this paper examines the rise in prominence of psychiatry in medical education. Three builders of Harvard psychiatry - Elmer E. Southard, C. Macfie Campbell, and Harry C. Solomon - simultaneously sought to mark territory for psychiatry and its relevance. In doing so, they capitalized on three related elements: the fluidity that existed between psychiatry and neurology, the new venues whereby medical students gained training in psychiatry, and the broader role of patrons, professional associations, and certification boards, which sought to expand psychiatry's influence in the social and cultural life of twentieth-century America.

  20. Lab on a Biomembrane: Rapid prototyping and manipulation of 2D fluidic lipid bilayers circuits

    Science.gov (United States)

    Ainla, Alar; Gözen, Irep; Hakonen, Bodil; Jesorka, Aldo

    2013-01-01

    Lipid bilayer membranes are among the most ubiquitous structures in the living world, with intricate structural features and a multitude of biological functions. It is attractive to recreate these structures in the laboratory, as this allows mimicking and studying the properties of biomembranes and their constituents, and to specifically exploit the intrinsic two-dimensional fluidity. Even though diverse strategies for membrane fabrication have been reported, the development of related applications and technologies has been hindered by the unavailability of both versatile and simple methods. Here we report a rapid prototyping technology for two-dimensional fluidic devices, based on in-situ generated circuits of phospholipid films. In this “lab on a molecularly thin membrane”, various chemical and physical operations, such as writing, erasing, functionalization, and molecular transport, can be applied to user-defined regions of a membrane circuit. This concept is an enabling technology for research on molecular membranes and their technological use. PMID:24067786

  1. Numerical modelling of thermal and fluid flow phenomena in the mould channel

    Directory of Open Access Journals (Sweden)

    L. Sowa

    2007-12-01

    Full Text Available In the paper, a mathematical and a numerical model of the solidification of a cylindrical slender shaped casting, which take into account the process of filling the mould cavity with molten metal, has been proposed. Pressure and velocity fields were obtained by solving the momentum equations and the continuity equation, while the thermal fields were obtained by solving the heat conduction equation containing the convection term. Next, the numerical analysis of the solidification process of metals alloy in a cylindrical mould channel has been made. In the model one takes into account interdependence the heat transfer and fluid flow phenomena. Coupling of the thermal and fluid flow phenomena has been taken into consideration by the changes of the fluidity function and thermophysical parameters of alloy with respect to the temperature. The influence of the pressure and the temperature of metal pouring on the solid phase growth kinetics were estimated. The problem has been solved by the finite element method.

  2. Coder’s Manual: A Guide to TEPIAC Documentation.

    Science.gov (United States)

    1977-07-01

    Po Polonium Am Americium Hg Mercury Pr Praseodymium *Ar Argon (Hydrargyrum) Pt Platinum (also A) Ho Holmium Pu Plutonium *As Arsenic *1 Iodine Ra...Er 20 3 208 D ChD2 110 F F 2 Fe (FeF 21 209 E C 6H1 5ErO1 2S 3[Er(C 2 HSO 4)3] III G GaO4P [GaPO4] 210 F CH3 F 112 H 1iNO 212 G C8 H20Ge [Ge(C 2 H 5...Fluidity, 69 Heat conductance (contact), 62 Fluidized bed, 27 Heat conduction, 57 Fluorescence, 125 Heat conductivity, 57 Food products, 31 Heat content

  3. On the Unusual Homeoviscous Adaptation of the Membrane Fatty Acyl Components against the Thermal Stress in RhiΖobium meliloti

    International Nuclear Information System (INIS)

    Kang, Seb Yung; Jung, Seun Ho; Choi, Yong Hoon; Yang, Chul Hak; Kim, Hyun Won

    1999-01-01

    In order to maintain the optimal fluidity in membrane, microorganism genetically regulates the ratio of the unsaturated fatty acids (Ufos) to saturated ones of its biological membrane in response to external perturbing condition such as the change of temperature. The remodelling of fatty acyl chain composition is the most frequently observed response to altered growth temperature. It is reflected in the elevated proportions of unsaturated fatty acid (UFAs) at low temperature. Because cis double bonds, normally positioned at the middle of fatty acyl chains, introduce a kink of approximately 30 .deg. into acyl chain, UFAs pack less compactly and exhibit lower melting points than their saturated homologues. Thus, enrichment of membranes with UFAs offsets, to a significant degree, the increase in membrane order caused by a drop in temperature. This is so called homeoviscous adaptation of the membrane fatty acyl chains against thermal stress. Membrane maintains the optimal viscosity using homeoviscous adaptation.

  4. Involvement of NADH Oxidase in Biofilm Formation in Streptococcus sanguinis.

    Directory of Open Access Journals (Sweden)

    Xiuchun Ge

    Full Text Available Biofilms play important roles in microbial communities and are related to infectious diseases. Here, we report direct evidence that a bacterial nox gene encoding NADH oxidase is involved in biofilm formation. A dramatic reduction in biofilm formation was observed in a Streptococcus sanguinis nox mutant under anaerobic conditions without any decrease in growth. The membrane fluidity of the mutant bacterial cells was found to be decreased and the fatty acid composition altered, with increased palmitic acid and decreased stearic acid and vaccenic acid. Extracellular DNA of the mutant was reduced in abundance and bacterial competence was suppressed. Gene expression analysis in the mutant identified two genes with altered expression, gtfP and Idh, which were found to be related to biofilm formation through examination of their deletion mutants. NADH oxidase-related metabolic pathways were analyzed, further clarifying the function of this enzyme in biofilm formation.

  5. Characterization of LDPE/PBAT/PLA and organophilic bentonite nanocomposites

    International Nuclear Information System (INIS)

    Figueredo, Daniela Casimiro de; Viana, Hamilton; Rosa, Derval dos Santos; Poveda, Patricia Negrini Siqueira

    2011-01-01

    Due to the ascension of Green chemistry in the 90's, it has been a demand for the production of biodegradable materials which cause minimal impacts to environment. Some nanocomposites are in this material class. In this context, six formulations containing low density polyethylene (LDPE), a compatibilized commercial poly(butylene adipate-co-terephthalate) (PBAT) and poly(lactic acid) (PLA) blend under the trademark Ecovio and organophilic bentonite were processed by extrusion to make films which were characterized by X-ray diffraction, melt flow index (MFI) and mechanical tests. X- ray pattern revealed that the nano clay was composed predominantly of montmorillonite, quartz and kaolinite and it could promote formation of intercalated or exfoliated composites. Nano clay also affected the fluidity of composites with variations in module up to 4%, as evidenced by melt flow index. Mechanical tests demonstrated that there was no uniformity in mechanical behavior of the nanocomposites. (author)

  6. Celebrating Queer Lesbian Desires with Dorothy Allison: From moral monstrosity to the beautiful materiality of the body

    Directory of Open Access Journals (Sweden)

    Mélanie Grué

    2015-01-01

    Using social and queer theory on domination, sexuality and gender, this contribution explores how the queer American author Dorothy Allison celebrates the vilified transgressive lesbian body. As, in the 1970s, the mainstream american feminist movement crystallized around the definition of an acceptable sexuality in the name of femininity, female sexual practices were standardized according to strict identity frames, carnal desire was denied, and transgressive lesbians who play with gender roles were defined as abject. In response to this extreme taming of the body, Allison interrogates the notions of masculinity and femininity, domination and submission in her exploration of sexual pleasure and traumatized sexuality. She celebrates the aggressiveness and masculinity of queer lesbianism, promotes the fluidity of gender roles, and asserts the primacy of the flesh,sensuality, and materiality in sexuality.

  7. Time-dependent rheoforging of A6061 aluminum alloy on a mechanical servo press and the effects of forming conditions on homogeneity of rheoforged samples

    Directory of Open Access Journals (Sweden)

    Meng Yi

    2015-01-01

    Full Text Available The solid and liquid phases in semisolid metal slurry exhibited different forming behaviours during deformation result in products with inhomogeneous quality. A6061 aluminum alloy was forged in the semisolid state on a mechanical servo press with the capability of multistage compression. To improve the homogeneity of rheoforged samples a time-dependent rheoforging strategy was designed. The distributions of the microstructure and mechanical properties the samples manufactured under various experimental conditions were investigated. The A6061 samples forged in the temperature range from 625 to 628 ∘C with a short holding time of 4 s and the upper die preheated to 300 ∘C exhibited a homogeneous microstructure and mechanical properties. The homogeneity of rheoforged samples resulted from the controllable free motion capability of the mechanical servo press and the adjustable fluidity and viscosity of the semisolid slurry.

  8. Plant sterol metabolism. Δ7-Sterol-C5-Desaturase (STE1/DWARF7), Δ5,7-Sterol-Δ7-Reductase (DWARF5) and Δ24-Sterol-Δ24-Reductase (DIMINUTO/DWARF1) show multiple subcellular localizations in Arabidopsis thaliana (Heynh) L

    DEFF Research Database (Denmark)

    Silvestro, Daniele; Andersen, Tonni Grube; Schaller, Hubert

    2013-01-01

    in the corresponding enzymes. All fusion proteins were found to localize in the endoplasmic reticulum in functionally complemented plants. The results show that both ¿(5,7)-sterol-¿(7)-reductase and ¿(24)-sterol-¿(24)-reductase are in addition localized to the plasma membrane, whereas ¿(7)-sterol-C(5)-desaturase......Sterols are crucial lipid components that regulate membrane permeability and fluidity and are the precursors of bioactive steroids. The plant sterols exist as three major forms, free sterols, steryl glycosides and steryl esters. The storage of steryl esters in lipid droplets has been shown...... to contribute to cellular sterol homeostasis. To further document cellular aspects of sterol biosynthesis in plants, we addressed the question of the subcellular localization of the enzymes implicated in the final steps of the post-squalene biosynthetic pathway. In order to create a clear localization map...

  9. Effect of Duration on Ti Grain Refinement of A356 and Melt Quality

    Science.gov (United States)

    Gürsoy, Özen; Erzi, Eray; Yüksel, Çağlar; Dispinar, Derya

    Grain refinement of aluminium alloys increases fluidity and feedability; and thus higher mechanical properties and decreased porosity is achieved. Typically, various ratios of Ti-B is used as grain refiner. It is well known that due to the sedimentation, the effectiveness of the grain refinement decreases which is called the fading effect. In this work, this effect has been investigated by means of melt quality. Two different melting temperatures were selected (725 and 750C) and samples were cast into die and sand mould. After the addition of grain refiners, samples were collected at 10 minutes of interval. Metallographic examinations were carried out where microstructural change and porosity distribution were investigated. The results were correlated with bifilm index (i.e. melt quality).

  10. Sexual orientation and gender identity: review of concepts, controversies and their relation to psychopathology classification systems.

    Science.gov (United States)

    Moleiro, Carla; Pinto, Nuno

    2015-01-01

    Numerous controversies and debates have taken place throughout the history of psychopathology (and its main classification systems) with regards to sexual orientation and gender identity. These are still reflected on present reformulations of gender dysphoria in both the Diagnostic and Statistical Manual and the International Classification of Diseases, and in more or less subtle micro-aggressions experienced by lesbian, gay, bisexual and trans patients in mental health care. The present paper critically reviews this history and current controversies. It reveals that this deeply complex field contributes (i) to the reflection on the very concept of mental illness; (ii) to the focus on subjective distress and person-centered experience of psychopathology; and (iii) to the recognition of stigma and discrimination as significant intervening variables. Finally, it argues that sexual orientation and gender identity have been viewed, in the history of the field of psychopathology, between two poles: gender transgression and gender variance/fluidity.

  11. Sexual Orientation and Gender Identity: Review of concepts, controversies and their relation to psychopathology classification systems

    Directory of Open Access Journals (Sweden)

    Carla eMoleiro

    2015-10-01

    Full Text Available Numerous controversies and debates have taken place throughout the history of psychopathology (and its main classification systems with regards to sexual orientation and gender identity. These are still reflected on present reformulations of gender dysphoria in both DSM and ICD, and in more or less subtle micro-aggressions experienced by lesbian, gay, bisexual and trans patients in mental health care. The present paper critically reviews this history and current controversies. It reveals that this deeply complex field contributes (i to the reflection on the very concept of mental illness; (ii to the focus on subjective distress and person-centered experience of psychopathology; and (iii to the recognition of stigma and discrimination as significant intervening variables. Finally, it argues that sexual orientation and gender identity have been viewed, in the history of the field of psychopathology, between two poles: gender transgression and gender variance/fluidity.

  12. Nuclear fuel element

    International Nuclear Information System (INIS)

    Hirayama, Satoshi; Kawada, Toshiyuki; Matsuzaki, Masayoshi.

    1980-01-01

    Purpose: To provide a fuel element for reducing the mechanical interactions between a fuel-cladding tube and the fuel element and for alleviating the limits of the operating conditions of a reactor. Constitution: A fuel element having mainly uranium dioxide consists of a cylindrical outer pellet and cylindrical inner pellet inserted into the outer pellet. The outer pellet contains two or more additives selected from aluminium oxide, beryllium oxide, magnesium oxide, silicon oxide, sodium oxide, phosphorus oxide, calcium oxide and iron oxide, and the inner pellet contains nuclear fuel substance solely or one additive selected from calcium oxide, silicon oxide, aluminium oxide, magnesium oxide, zirconium oxide and iron oxide. The outer pellet of the fuel thus constituted is reduced in mechanical strength and also in the mechanical interactions with the cladding tube, and the plastic fluidity of the entire pellet is prevented by the inner pellet increased in the mechanical strength. (Kamimura, M.)

  13. Competências coletivas e formação em condução de veículos de socorro num contexto de especialização de bombeiros sapadores em França

    Directory of Open Access Journals (Sweden)

    Christine Vidal-Gomel

    2014-07-01

    Full Text Available This study was requested by a departmental firefighting and rescue school for firefighters in France. Based on ergonomics and professional didactics approaches, the aim is to analyze the activity of driving two emergency vehicles so to improve the training in the drivers’ specialization context. Based on interviews, observation recordings of emergency departures and self-confrontations, we showed that it is a collective, multidimensional activity and we identified different driving strategies, organized according to the pragmatic concept of “fluidity of traffic”. These strategies may then be used to serve the dual-purpose of a standby patrol service when called for an emergency: to arrive on site as fast as possible and to avoid every road incident. The findings highlight the limits of the current training program and the traps that come along the drivers’ specialization.

  14. A novel kind of concrete superplasticizer based on aryl isocyanate polycondensates

    Science.gov (United States)

    Ding, Bei; Qian, Shanshan; Qiu, Ying; Wang, Yi; Zheng, Chunyang; Wang, Gaoming

    2017-03-01

    A novel superplasticizer was synthesized by polycondensation of Alkyl phenol phosphate and toluene diisocyanate grafting with methoxy polyoxyethylene ether (MPEG). The chemical structure and molecular weight of polycondensates molecules were determined by 1H nuclear magnetic resonance (NMR) and gel permeation chromatography respectively. The experimental results indicated that the polycondensates of Alkyl phenol phosphate and toluene diisocyanate grafting with MPEG not only exhibited good water-reducing properties but also demonstrated effective anti-clay abilities alone. Furthermore, the polycondensates showed good fluidity maintaining abilities within 1-3 h and good workability of concrete. The results of T500 Time experiments show that lower plastic viscosity of the polycondensates leads to fresh concrete much “looser” than conventional PCEs in self-compacting concrete.

  15. Interaction of Impulsive Pressures of Cavitation Bubbles with Cell Membranes during Sonoporation

    Science.gov (United States)

    Kodama, Tetsuya; Koshiyama, Ken-ichiro; Tomita, Yukio; Suzuki, Maiko; Yano, Takeru; Fujikawa, Shigeo

    2006-05-01

    Ultrasound contrast agents (UCAs), are capable of enhancing non-invasive cytoplasmic molecular delivery in the presence of ultrasound. Collapse of UCAs may generate nano-scale cavitation bubbles, resulting in the transient permeabilization of the cell membrane. In the present study, we investigated the interaction of a cavitation bubble-induced shock wave with a cell membrane using acoustic theory and molecular dynamics (MD) simulation. From the theory, we obtained the shock wave propagation distance from the center of a cavitation bubble that would induce membrane damage. The MD simulation determined the relationship between the uptake of water molecules into the lipid bilayer and the shock wave. The interaction of the shock wave induced a structural change of the bilayer and subsequently increased the fluidity of each molecule. These changes in the bilayer due to shock waves may be an important factor in the use of UCAs to produce the transient membrane permeability during sonoporation.

  16. Multi-solid model modified to predict paraffin in petroleum fluids at high temperatures and pressures

    International Nuclear Information System (INIS)

    Escobar Remolina, Juan Carlos M; Barrios Ortiz, Wilson; Santoyo Ramirez Gildardo

    2009-01-01

    A thermodynamic structure has been modified in order to calculate cloud point, fluidity and amount of precipitated wax under a wide range of temperature conditions, composition, and high pressures. The model is based on a combination of ideal solution concepts, fluid characterization, and formation of multiple solid phases using Cubic State Equations. The experimental data utilized for testing the prediction capacity and potentiality of a model exhibit different characteristics: continuous series synthetic systems of heavy alkanes, discontinuous series, and dead or living petroleum fluids with indefinite fractions such as C7+, C10+, C20+, and C30+. The samples were taken from the literature, petroleum fluids from the main Colombian reservoirs, and some samples of Bolivian fluids. Results presented in this paper show the minimum standard deviations between experimental data and data calculated with a model. This allows a progress in decision-making processes for flow assurance in reservoirs, wells, and surface facilities in the petroleum industry.

  17. Slow creep in soft granular packings.

    Science.gov (United States)

    Srivastava, Ishan; Fisher, Timothy S

    2017-05-14

    Transient creep mechanisms in soft granular packings are studied numerically using a constant pressure and constant stress simulation method. Rapid compression followed by slow dilation is predicted on the basis of a logarithmic creep phenomenon. Characteristic scales of creep strain and time exhibit a power-law dependence on jamming pressure, and they diverge at the jamming point. Microscopic analysis indicates the existence of a correlation between rheology and nonaffine fluctuations. Localized regions of large strain appear during creep and grow in magnitude and size at short times. At long times, the spatial structure of highly correlated local deformation becomes time-invariant. Finally, a microscale connection between local rheology and local fluctuations is demonstrated in the form of a linear scaling between granular fluidity and nonaffine velocity.

  18. Fatty acid and sterol contents during tulip leaf senescence induced by methyl jasmonate

    Directory of Open Access Journals (Sweden)

    Marian Saniewski

    2013-12-01

    Full Text Available It has been shown previously that methyl jasmonate (JA-Me applied in lanolin paste on the bottom surface of intact tulip leaves causes a rapid and intense its senescence. The aim of this work was to study the effect of JA-Me on free and bound fatty acid and sterol contents during tulip leaf senescence. The main free and bound fatty acids of tulip leaf, in decreasing order of their abundance, were linolenic, linoleic, palmitic, oleic, stearic and myristic acids. Only the content of free linolenic acid decreased after treatment with JA-Me during visible stage of senescence. ß-Sitosterol (highest concentration, campesterol, stigmasterol and cholesterol were identified in tulip leaf. Methyl jasmonate evidently increased the level of ß-sitosterol, campesterol and stigmasterol during induced senescence. It is suggested that the increase in sterol concentrations under the influence of methyl jasmonate induced changes in membrane fluidity and permeability, which may be responsible for senescence.

  19. The influence of calcium lignosulphonate - sodium bicarbonate on the status of ettringite crystallization in fly ash cement paste

    Energy Technology Data Exchange (ETDEWEB)

    Yang, K.; Zhang, C.; Liu, Z. [Hebei Institute of Technology, Tang Shan (China)

    2002-01-01

    Calcium lignosulphonate (CL) - sodium bicarbonate (SB) (a total of 0.7% by weight of cement and CL to SB ratio of 1:1.8) will cause the fluidity of fly ash cement paste to decrease rapidly. It is the variation of the status of ettringite crystallization that causes this phenomenon. Experimental results show that CL-SB affects the liquid-phase composition of fly ash cement paste remarkably. As a result, ettringite crystallizes out in the shape of needles from the solution. These needle-like crystal particles are distributed in the solution at a certain distance from the surface of clinker particles. At the initial hydration stage, the crystallization of ettringite is stronger in fly ash cement with calcined gypsum than in fly ash cement with gypsum. 5 refs., 10 figs., 2 tabs.

  20. In vitro lipofection with novel asymmetric series of 1,2-dialkoylamidopropane-based cytofectins containing single symmetric bis-(2-dimethylaminoethane) polar headgroups.

    Science.gov (United States)

    Savva, Michalakis; Chen, Pensung; Aljaberi, Ahmad; Selvi, Bilge; Spelios, Michael

    2005-01-01

    Novel N,N'-diacyl-1,2-diaminopropyl-3-carbamoyl[bis-(2-dimethylaminoethane)] bivalent cationic lipids were synthesized and evaluated for in vitro transfection activity against a murine melanoma cell line. In the absence of the helper lipid DOPE (1,2-dioleoyl-sn-glycero-3-phosphoethanolamine), only the dioleoyl derivative 22 (1,2lb5) elicited transfection activity. The transfection activity of this lipid was reduced when formulated with DOPE. Contrary to that, the dimyristoyl derivative 19 (1,2lb2) mediated no activity when used alone but induced the highest levels of marker gene expression in the presence of DOPE. In an effort to correlate the transfection activity with cationic lipid structures, the physicochemical properties of cationic lipids in isolation and of lipoplexes were studied with surface tensiometry, photon correlation spectroscopy, gel electrophoresis mobility shift assay, and fluorescence techniques. In regard to the lipoplex properties, gel electrophoresis mobility shift assay and EtBr exclusion fluorescence assay revealed that the 1,2lb5 was the only lipid to associate and condense plasmid DNA, respectively. Photon correlation spectroscopy analysis found that 1,2lb5/DNA complexes were of relatively small size compared to all other lipoplexes. With respect to the properties of isolated lipids, Langmuir monolayer studies and fluorescence anisotropy on cationic lipid dispersions verified high two-plane elasticity and increased fluidity of the transfection competent dioleoyl derivative 1,2lb5, respectively. The results indicate that high transfection activity is mediated by cationic lipids characterized by an expanded mean molecular area, high molecular elasticity, and increased fluidity.