Position-specific isotope modeling of organic micropollutants transformation through different reaction pathways

International Nuclear Information System (INIS)

Jin, Biao; Rolle, Massimo

2016-01-01

The degradation of organic micropollutants occurs via different reaction pathways. Compound specific isotope analysis is a valuable tool to identify such degradation pathways in different environmental systems. We propose a mechanism-based modeling approach that provides a quantitative framework to simultaneously evaluate concentration as well as bulk and position-specific multi-element isotope evolution during the transformation of organic micropollutants. The model explicitly simulates position-specific isotopologues for those atoms that experience isotope effects and, thereby, provides a mechanistic description of isotope fractionation occurring at different molecular positions. To demonstrate specific features of the modeling approach, we simulated the degradation of three selected organic micropollutants: dichlorobenzamide (BAM), isoproturon (IPU) and diclofenac (DCF). The model accurately reproduces the multi-element isotope data observed in previous experimental studies. Furthermore, it precisely captures the dual element isotope trends characteristic of different reaction pathways as well as their range of variation consistent with observed bulk isotope fractionation. It was also possible to directly validate the model capability to predict the evolution of position-specific isotope ratios with available experimental data. Therefore, the approach is useful both for a mechanism-based evaluation of experimental results and as a tool to explore transformation pathways in scenarios for which position-specific isotope data are not yet available. - Highlights: • Mechanism-based, position-specific isotope modeling of micropollutants degradation. • Simultaneous description of concentration and primary and secondary isotope effects. • Key features of the model are demonstrated with three illustrative examples. • Model as a tool to explore reaction mechanisms and to design experiments. - We propose a modeling approach incorporating mechanistic information and

Position-Dependent Dynamics Explain Pore-Averaged Diffusion in Strongly Attractive Adsorptive Systems.

Science.gov (United States)

Krekelberg, William P; Siderius, Daniel W; Shen, Vincent K; Truskett, Thomas M; Errington, Jeffrey R

2017-12-12

Using molecular simulations, we investigate the relationship between the pore-averaged and position-dependent self-diffusivity of a fluid adsorbed in a strongly attractive pore as a function of loading. Previous work (Krekelberg, W. P.; Siderius, D. W.; Shen, V. K.; Truskett, T. M.; Errington, J. R. Connection between thermodynamics and dynamics of simple fluids in highly attractive pores. Langmuir 2013, 29, 14527-14535, doi: 10.1021/la4037327) established that pore-averaged self-diffusivity in the multilayer adsorption regime, where the fluid exhibits a dense film at the pore surface and a lower density interior pore region, is nearly constant as a function of loading. Here we show that this puzzling behavior can be understood in terms of how loading affects the fraction of particles that reside in the film and interior pore regions as well as their distinct dynamics. Specifically, the insensitivity of pore-averaged diffusivity to loading arises from the approximate cancellation of two factors: an increase in the fraction of particles in the higher diffusivity interior pore region with loading and a corresponding decrease in the particle diffusivity in that region. We also find that the position-dependent self-diffusivities scale with the position-dependent density. We present a model for predicting the pore-average self-diffusivity based on the position-dependent self-diffusivity, which captures the unusual characteristics of pore-averaged self-diffusivity in strongly attractive pores over several orders of magnitude.

Resonant nuclear reaction 23Mg (p,γ) 24Al in strongly screening magnetized neutron star crust

Science.gov (United States)

Liu, Jing-Jing; Liu, Dong-Mei

2017-12-01

Based on the relativistic theory of superstrong magnetic fields (SMF), by using three models those of Lai (LD), Fushiki (FGP), and our own (LJ), we investigate the influence of SMFs due to strong electron screening (SES) on the nuclear reaction 23Mg (p,γ) 24Al in magnetars. In a relatively low density environment (e.g., ρ 7102), our reaction rates can be 1.58 times and about three orders of magnitude larger than those of FGP and LD, respectively (B 12, ρ 7 are in units of 1012G, 107g cm-3). The significant increase of strong screening rate can imply that more 23Mg will escape from the Ne-Na cycle due to SES in a SMF. As a consequence, the next reaction, 24Al (β+, ν) 24Mg, will produce more 24Mg to participate in the Mg-Al cycle. Thus, it may lead to synthesis of a large amount of A>20 nuclides in magnetars. Supported by National Natural Science Foundation of China (11565020), the Counterpart Foundation of Sanya (2016PT43), the Special Foundation of Science and Technology Cooperation for Advanced Academy and Regional of Sanya (2016YD28), the Scientific Research Starting Foundation for 515 Talented Project of Hainan Tropical Ocean University (RHDRC201701) and the Natural Science Foundation of Hainan Province (114012)

Study on the plasma reaction process of hydroxyl generation by strong electric field ionization discharge

International Nuclear Information System (INIS)

Bai Mindi; Deng Shufang; Bai Xiyao; Zhang Zhitao

2004-01-01

Considering the change in the structure of reaction room, dielectric materials and process technology, authors have specifically studied the plasma reaction process of creating hydroxyl radical OH * and e aq - from ionization of O 2 and H 2 O through a strong electric field discharge. The production volume of hydroxyl radical OH * is up to the project application level, and process technology meets the 12 laws of green chemistry, free from environmental pollution from the source. The authors have emphatically researched on the green method of flue gas desulfurization, which will ionize SO 2 , H 2 O and O 2 in the flue gas to synthesis H 2 SO 4 in molecular level within 0.8 s without absorbent and catalyst. (author)

Pair production in a strong electric field with back-reaction

International Nuclear Information System (INIS)

Eisenberg, J.M.

1992-01-01

A summary is presented of the current status of efforts to solve the problem in which pairs are produced in a strong electric field, are accelerated by it, and then react back on it through the counter-field produced by their current. A review of recent developments in this back-reaction problem is given. A simple version of the theory of pair tunneling from a fixed electric field, is first presented and then a sketch is provided as to how this has been applied to the quark-gluon plasma. Then I turn to a field formulation of the problem for charged bosons, which leads to the need to carry out a renormalization program, outlined again in simple terms. Numerical results for this program are presented for one and for three spatial dimensions, and the corresponding physical behaviour of the system is discussed. I exhibit a phenomenological transport equation embodying physics that is essentially identical to that of the field formulation. Lastly, I present the extension to the fermion case and to the formulation in terms of boost-invariant variables (as required for the quark-gluon plasma). 6 figs., 17 refs. (author)

Community violence exposure and post-traumatic stress reactions among Gambian youth: the moderating role of positive school climate.

Science.gov (United States)

O'Donnell, Deborah A; Roberts, William C; Schwab-Stone, Mary E

2011-01-01

Community violence exposure among youth can lead to various negative outcomes, including post-traumatic stress symptoms. Research in the Western world indicates that a number of social support factors may moderate the relation between violence exposure and internalizing symptoms. Little research has been carried out in non-Western countries. This study aimed to fill this gap by exploring the relations among violence exposure, parental warmth, positive school climate, and post-traumatic stress reactions among youth in The Republic of The Gambia, Africa. A school-based survey of youth behaviors, feelings, attitudes, and perceptions was administered to 653 students at senior secondary schools in four Gambian communities. Students reported high levels of exposure to violence. Over half of students reported witnessing someone threatened with serious physical harm, beaten up or mugged, attacked or stabbed with a knife/piece of glass, or seriously wounded in an incident of violence. Nearly half of students reported being beaten up or mugged during the past year, and nearly a quarter reported being threatened with serious physical harm. There were no sex differences in levels of exposure. Traumatic stress symptoms were common, especially among females. Both violence witnessing and violent victimization significantly predicted post-traumatic stress symptoms, and positive school climate moderated the relationship. Among youth victimized by violence, positive school climate was most strongly correlated with lower levels of post-traumatic stress at low levels of exposure. Among youth who had witnessed violence, positive school climate was most strongly correlated with lower levels of post-traumatic stress at high levels of exposure. Community-based programs that bring together parents, schools, and youth may play an important role in combating the negative effects of some types of violence exposure among Gambian youth. Youth experiencing high levels of violent victimization

Visual evoked potentials show strong positive association with intracranial pressure in patients with cryptococcal meningitis

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Marcelo Adriano da Cunha Silva Vieira

2015-04-01

Full Text Available Objective : To verify the relationship between intracranial pressure and flash visual evoked potentials (F-VEP in patients with cryptococcal meningitis. Method The sample included adults diagnosed with cryptococcal meningitis admitted at a reference hospital for infectious diseases. The patients were subjected to F-VEP tests shortly before lumbar puncture. The Pearson’s linear correlation coefficient was calculated and the linear regression analysis was performed. Results : Eighteen individuals were subjected to a total of 69 lumbar punctures preceded by F-VEP tests. At the first lumbar puncture performed in each patient, N2 latency exhibited a strong positive correlation with intracranial pressure (r = 0.83; CI = 0.60 - 0.94; p < 0.0001. The direction of this relationship was maintained in subsequent punctures. Conclusion : The intracranial pressure measured by spinal tap manometry showed strong positive association with the N2 latency F-VEP in patients with cryptococcal meningitis.

Diverse Reactions of Thiophenes, Selenophenes, and Tellurophenes with Strongly Oxidizing I(III) PhI(L)2 Reagents.

Science.gov (United States)

Egalahewa, Sathsara; Albayer, Mohammad; Aprile, Antonino; Dutton, Jason L

2017-02-06

We report the outcomes of the reactions of aromatic group 16 thiophene, selenophene, and tellurophene rings with the I(III) oxidants PhI(OAc)(OTf) and [PhI(Pyr) 2 ][OTf] 2 (Pyr = pyridine). In all reactions, oxidative processes take place, with generation of PhI as the reduction product. However, with the exception of tellurophene with PhI(OAc)(OTf), +4 oxidation state complexes are not observed, but rather a variety of other processes occur. In general, where a C-H unit is available on the 5-membered ring, an electrophilic aromatic substitution reaction of either -IPh or pyridine onto the ring occurs. When all positions are blocked, reactions with PhI(OAc)(OTf) give acetic and triflic anhydride as the identifiable oxidative byproducts, while [PhI(Pyr) 2 ][OTf] 2 gives pyridine electrophilic aromatic substitution onto the peripheral rings. Qualitative mechanistic studies indicate that the presence of the oxidizable heteroatom is required for pyridine to act as an electrophile in a substantial manner.

Positional isotope exchange analysis of the uridine-diphosphoglucose pyrophosphorylase reaction

International Nuclear Information System (INIS)

Hester, L.; Hilscher, L.; Raushel, F.M.

1986-01-01

The enzyme uridine-diphosphoglucose pyrophosphorylase catalyzes the reversible formation of pyrophosphate and UDP-glucose from UTP and glc-1P. The positional isotope exchange reaction was measured using oxygen-18 labelled UTP. The synthesis of [β- 18 O 2 , βγ- 18 O, γ- 18 O 3 ]UTP was accomplished by the coupled activities of carbamate kinase, nucleoside diphosphate kinase, and nucleoside monophosphate kinase. The exchange of an oxygen-18 from a β-nonbridge position of the labelled UTP to the αβ-bridge position was measured with 31 P NMR. The ratio of the rate of net substrate turnover and the positional isotope exchange rate was measured as a function of the initial glc-1P concentration. This ratio was found to increase with an increasing concentration of glc-1P. The intercept at low glc-1P was found to be 1.2 and the slope was 4.5 mM -1 . These results have been interpreted to mean that this enzyme has an ordered addition of substrates. The lower limit for the release of pyrophosphate from E-UDPG-PP/sub i/ relative to V 2 is 1.2. The rate constant for the release of UTP from E-UTP relative to V 1 is 9

First positive reactions to cannabis constitute a priority risk factor for cannabis dependence.

Science.gov (United States)

Le Strat, Yann; Ramoz, Nicolas; Horwood, John; Falissard, Bruno; Hassler, Christine; Romo, Lucia; Choquet, Marie; Fergusson, David; Gorwood, Philip

2009-10-01

To assess the association between first reactions to cannabis and the risk of cannabis dependence. A cross-sectional population-based assessment in 2007. A campus in a French region (Champagne-Ardennes). A total of 1472 participants aged 18-21 years who reported at least one life-time cannabis consumption, of 3056 students who were screened initially [the Susceptibility Addiction Gene Environment (SAGE) study]. Positive and negative effects of first cannabis consumptions, present cannabis dependence and related risk factors were assessed through questionnaires.   The effects of first cannabis consumptions were associated dose-dependently with cannabis dependence at age 18-21 years, both according to the transversal approach of the SAGE study and to the prospective cohort of the Christchurch Health and Development Study (CHDS) assessed at the age of 25 years. Participants of the SAGE study who reported five positive effects of their first cannabis consumption had odds of life-time cannabis dependence that were 28.7 (95% confidence interval: 14.6-56.5) higher than those who reported no positive effects. This association remains significant after controlling for potentially confounding factors, including individual and familial variables. This study suggests an association between positive reactions to first cannabis uses and risk of life-time cannabis dependence, this variable having a central role among, and through, other risk factors. © 2009 The Authors. Journal compilation © 2009 Society for the Study of Addiction.

Reactions to merit pay increases: a longitudinal test of a signal sensitivity perspective.

Science.gov (United States)

Shaw, Jason D; Duffy, Michelle K; Mitra, Atul; Lockhart, Daniel E; Bowler, Matthew

2003-06-01

The relationships among merit pay raises, trait positive affectivity (PA), and reactions to merit pay increases (pay attitudes and behavioral intentions) were explored in a longitudinal study of hospital employees. Drawing on signal sensitivity theory, the authors expected that PA would moderate the relationship between merit pay raise size and reactions to the increase such that pay raise size would be more strongly related to pay attitudes and behavioral intentions among those low in PA. Results strongly supported the predictions in the case of reactions to the raise amount (happiness and effort intentions) but not for pay level satisfaction. Implications of the results and directions for future research are identified.

Pair production in a strong electric field with back-reaction

International Nuclear Information System (INIS)

Eisenberg, J.M.; Kluger, Y.; Svetitsky, B.

1992-01-01

We present a summary of the present status of efforts to solve the problem in which pairs are produced in a strong electric field, are accelerated by it, and then react back on it through the counter-field produced by their current. This picture has been used by Bialas and Czyz and others as a model for effects that may possibly arise in the study of the quark-gluon plasma. We here give a didactic review of recent developments in this back-reaction problem. We first present a simple version of the theory of pair tunneling from a fixed electric field, and then sketch how this has been applied to the quark-gluon plasma. Then we turn to a field formulation of the problem for charged bosons, which leads to the need to carry out a renormalization program, outlined again in simple terms. Numerical results for this program are presented for one spatial dimension, the corresponding physical behaviour of the system is discussed, and the implications for three spatial dimensions are considered. We exhibit a phenomenological transport equation embodying physics that is essentially identical to that of the field formulation, thus helping to tie the model of Bialas and Czyz for the quark-gluon plasma to a field-theory formulation. Last, we note the status of extensions to the problem with three space dimensions; the fermion case; the formulation in terms of boost-invariant variables (as desirable for the quark-gluon plasma); and transport equations derived in a fundamental and consistent fashion. 5 figs., 13 refs. (author)

Analysis of ping-pong reaction mechanisms by positional isotope exchange. Application to galactose-1-phosphate uridyltransferase

International Nuclear Information System (INIS)

Hester, L.S.; Raushel, F.M.

1987-01-01

A new positional isotope exchange method has been developed that can be used for the analysis of enzyme-catalyzed reactions which have ping-pong kinetic mechanisms. The technique can be used to measure the relative rates of ligand dissociation from enzyme-product complexes. Enzyme is incubated with the labeled substrate and an excess of the corresponding unlabeled product. The partitioning of the enzyme-product complex back toward free enzyme is determined from the rate of positional isotope exchange within the original labeled substrate. The partitioning of the enzyme-product complex forward toward free enzyme is determined from the rate of formation of totally unlabeled substrate. It has been shown that the ratio of the two rates provides a lower limit for the release of product from the enzyme-product complex. The technique has been applied to the reaction catalyzed by galactose-1-phosphate uridyltransferase. The lower limit for the release of glucose 1-phosphate from the uridyl-enzyme relative to the maximal velocity of the reverse reaction was determined to be 3.4 +/- 0.5

Position-specific isotope modeling of organic micropollutants transformations through different reaction pathways

Science.gov (United States)

Jin, Biao; Rolle, Massimo

2016-04-01

Organic compounds are produced in vast quantities for industrial and agricultural use, as well as for human and animal healthcare [1]. These chemicals and their metabolites are frequently detected at trace levels in fresh water environments where they undergo degradation via different reaction pathways. Compound specific stable isotope analysis (CSIA) is a valuable tool to identify such degradation pathways in different environmental systems. Recent advances in analytical techniques have promoted the fast development and implementation of multi-element CSIA. However, quantitative frameworks to evaluate multi-element stable isotope data and incorporating mechanistic information on the degradation processes [2,3] are still lacking. In this study we propose a mechanism-based modeling approach to simultaneously evaluate concentration as well as bulk and position-specific multi-element isotope evolution during the transformation of organic micropollutants. The model explicitly simulates position-specific isotopologues for those atoms that experience isotope effects and, thereby, provides a mechanistic description of isotope fractionation occurring at different molecular positions. We validate the proposed approach with the concentration and multi-element isotope data of three selected organic micropollutants: dichlorobenzamide (BAM), isoproturon (IPU) and diclofenac (DCF). The model precisely captures the dual element isotope trends characteristic of different reaction pathways and their range of variation consistent with observed multi-element (C, N) bulk isotope fractionation. The proposed approach can also be used as a tool to explore transformation pathways in scenarios for which position-specific isotope data are not yet available. [1] Schwarzenbach, R.P., Egli, T., Hofstetter, T.B., von Gunten, U., Wehrli, B., 2010. Global Water Pollution and Human Health. Annu. Rev. Environ. Resour. doi:10.1146/annurev-environ-100809-125342. [2] Jin, B., Haderlein, S.B., Rolle, M

Bifurcation of positive solutions to scalar reaction-diffusion equations with nonlinear boundary condition

Science.gov (United States)

Liu, Ping; Shi, Junping

2018-01-01

The bifurcation of non-trivial steady state solutions of a scalar reaction-diffusion equation with nonlinear boundary conditions is considered using several new abstract bifurcation theorems. The existence and stability of positive steady state solutions are proved using a unified approach. The general results are applied to a Laplace equation with nonlinear boundary condition and bistable nonlinearity, and an elliptic equation with superlinear nonlinearity and sublinear boundary conditions.

Two-step excitation structure changes of luminescence centers and strong tunable blue emission on surface of silica nanospheres

Energy Technology Data Exchange (ETDEWEB)

Yang, Lei, E-mail: nanoyang@qq.com; Jiang, Zhongcheng; Dong, Jiazhang; Zhang, Liuqian [Hunan University, College of Materials Science and Engineering (China); Pan, Anlian, E-mail: anlian.pan@gmail.com; Zhuang, Xiujuan [Hunan University, Key Laboratory for Micro-Nano Physics and Technology of Hunan Province (China)

2015-10-15

We report a scheme for investigating two-step stimulated structure change of luminescence centers. Amorphous silica nanospheres with uniform diameter of 9–15 nm have been synthesized by Stöber method. Strong hydroxyl-related infrared-absorption band is observed in infrared spectrum. The surface hydroxyl groups exert great influence on the luminescent behavior of silica. They provide stable and intermediate energy states to accommodate excitation electrons. The existence of these surface states reduces the energy barrier of photochemical reactions, creating conditions for two-step excitation process. By carefully examining excitation and emission process, the nearest excitation band is absent in both optical absorption spectrum and excitation spectrum. This later generated state confirms the generation of new luminescence centers as well as the existence of photochemical reactions. Stimulated by different energies, two-step excitation process impels different photochemical reactions, prompting generation of different lattice defects on surface area of silica. Thereby, tunable luminescence is achieved. After thermal treatment, strong gap excitation band appears with the disappearance of strong surface excitation band. Strong blue luminescence also disappears. The research is significance to precise introducing structural defects and controlling position of luminescence peaks.

The effect of catalyst support on the RWGS reaction

International Nuclear Information System (INIS)

Laosiripojana, N.; Sutthisripok, W.

2004-01-01

'Full text:' Methane steam reforming is generally applied in order to produce synthesis gas mainly consist of hydrogen and carbon monoxide for later utilization in SOFC. This reaction is always carried out with the water gas shift reaction over a catalyst at elevated temperatures resulting in some carbon dioxide production. The CO/CO2 production selectivity strongly depends on the influence of water gas shift reaction. It was observed that the reactivity of this reaction depended on the type of support material. Stabilities, activities, and kinetics of the reverse water gas shift reaction (RWGS) for commercial nickel on CeO2, ZrO2, CeO2-ZrO2, TiO2, MgO, and Al2O3 supports were studied in order to observe the influence of the support on this reaction. According to the experiment, the activities of Ni/CeO2 toward the reverse water gas shift reaction (RWGS) were very high, and reached equilibrium level at approximately 600 o C (where the conversion of CO2 was closed to 1). Other oxide supports provided lower activities toward this reaction. It was observed that the activity of Ni/Al2O3 toward this reaction was the lowest. The kinetics of this reaction was also studied. Carbon dioxide presented positive effect on the reverse water gas shift reaction. The reaction orders in carbon dioxide were observed to be positive partial value between 0-1. It slightly decreased with increasing temperature for Ni/ CeO2 and Ni/CeO2-ZrO2, whereas it seemed to be independent of the operating temperature for other materials in the range of conditions studied. Hydrogen also showed positive effect on the reverse water gas shift reaction for all materials. The reaction order in hydrogen for all materials was observed to be the positive value and less than one for the range of conditions studied. The approximate values for all catalysts were between 0.45-0.65, and seemed to be independent of the operating temperature. The estimated values of the apparent activation energy for RWGS reaction

Characterization of nonlymphoid cells in rat spleen, with special reference to strongly Ia-positive branched cells in T-cell areas

International Nuclear Information System (INIS)

Dijkstra, C.D.

1982-01-01

By use of a monoclonal antibody against Ia antigen in an immunoperoxidase method, strongly Ia-positive branched cells are found in the T-cell areas of the splenic white pulp of the rat. In order to further characterize these cells, enzyme histochemical characteristics, phagocytic capacity, and irradiation sensitivity have been studied. Evidence is presented that these strongly Ia-positive branched cells represent interdigitating cells. The influence of whole-body irradiation on interdigitating cells is discussed. Comparison with data from the literature on the in vitro dendritic cell isolated from spleen cell suspensions reveals many similarities between the described interdigitating cell in vivo and the dendritic cell in vitro

Strong coupling QCD and the (π+,π-) reaction

International Nuclear Information System (INIS)

Miller, G.A.; Washington Univ., Seattle, WA

1989-01-01

Previous six-quark bag model calculations are in disagreement with new (π + , π - ) data, but conventional nucleonic calculations are generally successful. Six-quark bag models are related to perturbative QCD. I argue that the strong coupling limit of QCD (SCQCD) is a more appropriate starting point for nuclear physics. 15 refs., 3 figs

Strong negative interference of ethamsylate (Dicynone®) in serum creatinine quantification via enzymatic assay using Trinder reaction.

Science.gov (United States)

Wiewiorka, Ondrej; Dastych, Milan; Čermáková, Zdenka

2013-08-01

With discrepancies encountered as early as the verification of enzymatic method for quantification of serum creatinine, our research pointed to a later confirmed interference caused by a compound called ethamsylate present in the commonly used antihemorrhagic drug Dicynone. We measured concentrations of creatinine of 10 patients with blood taken before and 15 minutes after the intravenous administration of a 500 mg dose of Dicynone. The creatinine concentration was determined using Jaffe method and enzymatic method that utilize Trinder reaction (Roche) in analyzer Cobas c 501 (Roche AG, Basel, Switzerland). We also monitored concentration of blood creatinine in three patients before and 15 minutes after application of Dicynone (500 mg i.v.) and in the following 6th, 12th, 18th, and 24th hours. We discovered a significant negative bias in creatinine results using enzymatic assay with Trinder reaction in blood taken 15 min after i.v. application of 500 mg Dicynone to patients compared to their pre-application values (average decrease of 47%). Unlike this, the results of compensated Jaffe method yielded steady results in all samples (average deviation 0.6% from original values). However, 12 h after the drug administration comparable results were seen as before the administration. Considering the strong negative interference of ethamsylate in enzymatic assay using Trinder reaction for creatinine quantification, blood from patients with prescribed Dicynone should be taken at least 12 h after the last application of the drug for obtaining the correct creatinine values.

Start Position Strongly Influences Fixation Patterns during Face Processing: Difficulties with Eye Movements as a Measure of Information Use

Science.gov (United States)

Arizpe, Joseph; Kravitz, Dwight J.; Yovel, Galit; Baker, Chris I.

2012-01-01

Fixation patterns are thought to reflect cognitive processing and, thus, index the most informative stimulus features for task performance. During face recognition, initial fixations to the center of the nose have been taken to indicate this location is optimal for information extraction. However, the use of fixations as a marker for information use rests on the assumption that fixation patterns are predominantly determined by stimulus and task, despite the fact that fixations are also influenced by visuo-motor factors. Here, we tested the effect of starting position on fixation patterns during a face recognition task with upright and inverted faces. While we observed differences in fixations between upright and inverted faces, likely reflecting differences in cognitive processing, there was also a strong effect of start position. Over the first five saccades, fixation patterns across start positions were only coarsely similar, with most fixations around the eyes. Importantly, however, the precise fixation pattern was highly dependent on start position with a strong tendency toward facial features furthest from the start position. For example, the often-reported tendency toward the left over right eye was reversed for the left starting position. Further, delayed initial saccades for central versus peripheral start positions suggest greater information processing prior to the initial saccade, highlighting the experimental bias introduced by the commonly used center start position. Finally, the precise effect of face inversion on fixation patterns was also dependent on start position. These results demonstrate the importance of a non-stimulus, non-task factor in determining fixation patterns. The patterns observed likely reflect a complex combination of visuo-motor effects and simple sampling strategies as well as cognitive factors. These different factors are very difficult to tease apart and therefore great caution must be applied when interpreting absolute

A large area position-sensitive ionization chamber for heavy-ion-induced reaction studies

CERN Document Server

Pant, L M; Dinesh, B V; Thomas, R G; Saxena, A; Sawant, Y S; Choudhury, R K

2002-01-01

A large area position-sensitive ionization chamber with a wide dynamic range has been developed to measure the mass, charge and energy of the heavy ions and the fission fragments produced in heavy-ion-induced reactions. The split anode geometry of the detector makes it suitable for both particle identification and energy measurements for heavy ions and fission fragments. The detector has been tested with alpha particles from sup 2 sup 4 sup 1 Am- sup 2 sup 3 sup 9 Pu source, fission fragments from sup 2 sup 5 sup 2 Cf and the heavy-ion beams from the 14UD Mumbai Pelletron accelerator facility. Using this detector, measurements on mass and total kinetic energy distributions in heavy-ion-induced fusion-fission reactions have been carried out for a wide range of excitation energies. Results on deep inelastic collisions and mass-energy correlations on different systems using this detector setup are discussed.

Reactions to the glass cliff - Gender differences in the explanations for the precariousness of women's leadership positions

NARCIS (Netherlands)

Ryan, M.K.; Haslam, S.A.; Postmes, T.

2007-01-01

Purpose - This paper aims to investigate the phenomenon of the glass cliff, whereby women are more likely than men to be placed in precarious leadership positions. Men's and women's reactions to this subtle form of gender discrimination are examined, the identity processes involved, and the

The effect of addition of primary positive salts, complex salt, on the ionic strength and rate constant at various temperatures by reaction kinetics

Science.gov (United States)

Kurade, S. S.; Ramteke, A. A.

2018-05-01

In this work, we have investigated the rate of reaction by using ionic strength at different temperatures. The main goal of this experiment is to determine the relation between ionic strength with reaction rate, reaction time and rate constant with temperature. It is observed that the addition of positive salt indicate the increasing ionic strength with increase in run time at various temperatures. Thus the temperature affects the speed of reaction and mechanism by which chemical reaction occurs and time variable plays vital role in the progress of reaction at different temperatures.

Determination of Double Bond Positions in Polyunsaturated Fatty Acids Using the Photochemical Paternò-Büchi Reaction with Acetone and Tandem Mass Spectrometry.

Science.gov (United States)

Murphy, Robert C; Okuno, Toshiaki; Johnson, Christopher A; Barkley, Robert M

2017-08-15

The positions of double bonds along the carbon chain of methylene interrupted polyunsaturated fatty acids are unique identifiers of specific fatty acids derived from biochemical reactions that occur in cells. It is possible to obtain direct structural information as to these double bond positions using tandem mass spectrometry after collisional activation of the carboxylate anions of an acetone adduct at each of the double bond positions formed by the photochemical Paternò-Büchi reaction with acetone. This reaction can be carried out by exposing a small portion of an inline fused silica capillary to UV photons from a mercury vapor lamp as the sample is infused into the electrospray ion source of a mass spectrometer. Collisional activation of [M - H] - yields a series of reverse Paternò-Büchi reaction product ions that essentially are derived from cleavage of the original carbon-carbon double bonds that yield an isopropenyl carboxylate anion corresponding to each double bond location. Aldehydic reverse Paternò-Büchi product ions are much less abundant as the carbon chain length and number of double bonds increase. The use of a mixture of D 0 /D 6 -acetone facilitates identification of these double bonds indicating product ions as shown for arachidonic acid. If oxygen is present in the solvent stream undergoing UV photoactivation, ozone cleavage ions are also observed without prior collisional activation. This reaction was used to determine the double bond positions in a 20:3 fatty acid that accumulated in phospholipids of RAW 264.7 cells cultured for 3 days.

Damping at positive frequencies in the limit J⊥-->0 in the strongly correlated Hubbard model

Science.gov (United States)

Mohan, Minette M.

1992-08-01

I show damping in the two-dimensional strongly correlated Hubbard model within the retraceable-path approximation, using an expansion around dominant poles for the self-energy. The damping half-width ~J2/3z occurs only at positive frequencies ω>5/2Jz, the excitation energy of a pure ``string'' state of length one, where Jz is the Ising part of the superexchange interaction, and occurs even in the absence of spin-flip terms ~J⊥ in contrast to other theoretical treatments. The dispersion relation for both damped and undamped peaks near the upper band edge is found and is shown to have lost the simple J2/3z dependence characteristic of the peaks near the lower band edge. The position of the first three peaks near the upper band edge agrees well with numerical simulations on the t-J model. The weight of the undamped peaks near the upper band edge is ~J4/3z, contrasting with Jz for the weight near the lower band edge.

Bombarding energy dependence of nucleon exchange and energy dissipation in the strongly damped reaction 209Bi + 136Xe

International Nuclear Information System (INIS)

Wilcke, W.W.; Schroeder, W.U.; Huizenga, J.R.; Birkelund, J.R.; Randrup, J.

1980-01-01

Although considerable progress has been achieved in the understanding of strongly damped reactions at energies several MeV/u above the Coulomb barrier, some important experimental results are not yet clearly understood. Among these is the degree of correlation between the nucleon exchange and the large energy losses observed. Experimental evidence suggesting nucleon exchange as described by a one-body model to be the major component of the dissipation mechanism is discussed. It is concluded that the previously unexplained bombarding energy dependence between energy loss and fragment charge dispersion can be understood on the basis of a nucleon exchange model, provided the Pauli exclusion principle is taken into account. No necessity is seen to invoke further energy dissipation mechanisms. 7 figures

Immune Recovery Syndrome in the HIV-positive patient: Radiological Findings of Paradoxical Reactions

International Nuclear Information System (INIS)

Martinez, E.; Sanchez, M. A.; Torres, M.; Benito, J.; Avila, A.

2004-01-01

To describe immune recovery syndrome (IRS) and related radiological findings in HIV-positive patients. To alert radiologists to the ever-increasingly frequent appearance of paradoxical reactions (PR) in granulomatous diseases under antiretroviral treatment. We present a retrospective study of 9 adult HIV-positive patients who showed IRS, 6 cases of tuberculosis (TBC), 2 cases of atypical mycobacterium and a case of sarcoidosis. At the time of IRS/PR diagnosis, any suspicion of infectious activity was excluded through the use of appropriate microbiological tests. clinical and radiological characteristics of the above mentioned cases are analyze here. All patients experienced a clinical and/or radiological worsening of condition following variable periods of antiretroviral and/or anti-tuberculosis treatment, and coinciding with viral load decrease and CD4-T-lymphocyte recovery. Diagnosis of IRS/PR was clinical in five cases and radiological in four. In all but one case, antiretroviral treatment had at some time been previously administered. IRS/PR is a diagnosis of exclusion which must be included in the differential diagnosis of newly appearing lesions or worsening of already existing ones in HIV-positive patients that have recently begun antiretroviral and/or anti-tuberculosis treatment. Such should be done after excluding drug resistance, treatment non-adherence and intercurrent disease. (Author) 8 refs

Community reaction to noise from power stations

International Nuclear Information System (INIS)

Job, R.F.S.; Hede, A.J.

1989-01-01

Community reaction is a major consideration in noise control. The relationship between noise exposure and community reaction has received considerable attention in relation to railway, traffic, aircraft and impulsive noise. The results have shown a number of features in common, including: similarly shaped noise/reaction functions; similar results across different measurement techniques and cultures, noise/reaction correlations based on individual respondent data are low (mean r = 0.42 ± 0.12: Job, 1988), although correlations of .58 and above have been reported correlations based on data grouped by noise exposure are generally high and relatively unaffected by the type of noise studied whereas correlations based on individual data tend to be lower for impulsive noise than for transportation noise attitude to the noise source and sensitivity to noise shows strong correlations with reaction. This paper reports that the present study was undertaken in order toe establish over a wider range of noise exposure whether community reaction to power station noise is similar to reaction to other types of non-impulsive noise. It is possible that reaction is different given important differences in the source of the noise which may affect attitude. Attitudes towards power stations may be more positive than attitudes to aircraft or rail noise for example, because almost all respondents use electricity regularly every day. Further, the power stations in the present study provided employment for the relatively small surrounding communities

Sensitivity analysis of uranium solubility under strongly oxidizing conditions

International Nuclear Information System (INIS)

Liu, L.; Neretnieks, I.

1999-01-01

To evaluate the effect of geochemical conditions in the repository on the solubility of uranium under strongly oxidizing conditions, a mathematical model has been developed to determine the solubility, by utilizing a set of nonlinear algebraic equations to describe the chemical equilibria in the groundwater environment. The model takes into account the predominant precipitation-dissolution reactions, hydrolysis reactions and complexation reactions that may occur under strongly oxidizing conditions. The model also includes the solubility-limiting solids induced by the presence of carbonate, phosphate, silicate, calcium, and sodium in the groundwater. The thermodynamic equilibrium constants used in the solubility calculations are essentially taken from the NEA Thermochemical Data Base of Uranium, with some modification and some uranium minerals added, such as soddyite, rutherfordite, uranophane, uranyl orthophosphate, and becquerelite. By applying this model, the sensitivities of uranium solubility to variations in the concentrations of various groundwater component species are systematically investigated. The results show that the total analytical concentrations of carbonate, phosphate, silicate, and calcium in deep groundwater play the most important role in determining the solubility of uranium under strongly oxidizing conditions

A field ion microscope study of the surface reaction of tungsten with n-octanol under an applied positive voltage: reaction conditions for the 'splitting' of (110) plane

International Nuclear Information System (INIS)

Terao, T.; Iwatsu, F.; Morikawa, H.

1993-01-01

Field ion microscopy is a powerful tool for the study of surface phenomena on an atomic scale, especially when they are crystal plane dependent, because the microscope shows many crystal planes of the sample tip simultaneously. Although a large number of FIM studies on vapor deposition, surface diffusion and surface reactions at a metal-gas interface have been reported, those on reactions at a metal-liquid interface are few. The authors have studied the corrosion or tungsten with aqueous solutions and found that water corroded the tungsten tips very severely to reduce the radius of curvature of the tip cap drastically. The reaction was so severe that it was not possible to trace it back to the very initial stages. They adopted, as a weaker reagent, one of the higher alcohols, n-octanol(C 8 H 17 OH), and found that it reacted with tungsten tips when an electrical pulse with a positive voltage between 5 and 10V was applied to the tip, giving very interesting field ion images in which the central (110) plane was divided into two parts located side by side across the [001] zone line. This means that some anisotropic surface reaction occurred which made a groove along the [001] zone line going through the (110) plane, usually the most stable plane chemically for bcc metals. They named this phenomenon 'splitting'. This reaction was less severe than that with water and some results on the morphology of the groove and on the reaction sequence have been reported. In the present paper more detailed reaction conditions which give rise to the splitting are described

Determining Role of the Chain Mechanism in the Temperature Dependence of the Gas-Phase Rate of Combustion Reactions

Science.gov (United States)

Azatyan, V. V.; Bolod'yan, I. A.; Kopylov, N. P.; Kopylov, S. N.; Prokopenko, V. M.; Shebeko, Yu. N.

2018-05-01

It is shown that the strong dependence of the rate of gas-phase combustion reactions on temperature is determined by the high values of the reaction rate constants of free atoms and radicals. It is established that with a branched chain mechanism, a special role in the reaction rate temperature dependence is played by positive feedback between the concentrations of active intermediate species and the rate of their change. The role of the chemical mechanism in the temperature dependence of the process rate with and without inhibitors is considered.

Small Winter Thunderstorm with Sprites and Strong Positive Discharge

Science.gov (United States)

Suzuki, Tomoyuki; Hayakawa, Masashi; Michimoto, Koichiro

A sprite campaign was conducted in the Hokuriku area of Japan during a winter of 2004/2005. On the basis of a combined analysis of the data from various instruments (CCD cameras, radar, VHF/LF∼MF lightning mapping system, field mill network, and ELF detector), we studied meteorological and electrical structures for winter thunderstorms and sprite-producing positive discharge. Typical winter sprite parent thunderstorms had a meso-scale cloud area with embedded small convective cells. Some small winter thunderstorms accompanied by the most frequent sprite events were found to cause 2∼3 sprite events during a short interval of about 3∼5 min. When the sprites were observed, the extent of the convective cells at 20 dBZ counter was atmost ∼20 × 20 km. The VHF sources associated with sprites were located near south of the convective cell and were mapped within very small areas of at most ∼10 × 10 km. This fact shows that some small winter thunderstorms can generate large positive charge associated with sprites. We will present the analysis of such a small thunderstorms with sprites and positive lightning discharges.

Chemical reactions induced and probed by positive muons

International Nuclear Information System (INIS)

Ito, Yasuo

1990-01-01

The application of μ + science, collectively called μSR, but encompassing a variety of methods including muon spin rotation, muon spin relaxation, muon spin repolarization, muon spin resonance and level-crossing resonance, to chemistry is introduced emphasizing the special aspects of processes which are 'induced and probed' by the μ + itself. After giving a general introduction to the nature and methods of muon science and a short history of muon chemistry, selected topics are given. One concerns the usefulness of muonium as hydrogen-like probes of chemical reactions taking polymerization of vinyl monomers and reaction with thiosulphate as examples. Probing solitons in polyacetylene induced and probed by μ + is also an important example which shows the unique nature of muonium. Another important topic is 'lost polarization'. Although this term is particular to muonium. Another important topic is 'lost polarization'. Although this term is particular to muon chemistry, the chemistry underlining the phenomenon of lost polarization has an importance to both radiation and hot atom chemistries. (orig.)

Desensitization in delayed drug hypersensitivity reactions -- an EAACI position paper of the Drug Allergy Interest Group.

Science.gov (United States)

Scherer, K; Brockow, K; Aberer, W; Gooi, J H C; Demoly, P; Romano, A; Schnyder, B; Whitaker, P; Cernadas, J S R; Bircher, A J

2013-07-01

Drug hypersensitivity may deprive patients of drug therapy, and occasionally no effective alternative treatment is available. Successful desensitization has been well documented in delayed drug hypersensitivity reactions. In certain situations, such as sulfonamide hypersensitivity in HIV-positive patients or hypersensitivity to antibiotics in patients with cystic fibrosis, published success rates reach 80%, and this procedure appears helpful for the patient management. A state of clinical tolerance may be achieved by the administration of increasing doses of the previously offending drug. However, in most cases, a pre-existent sensitization has not been proven by positive skin tests. Successful re-administration may have occurred in nonsensitized patients. A better understanding of the underlying mechanisms of desensitization is needed. Currently, desensitization in delayed hypersensitivity reactions is restricted to mild, uncomplicated exanthems and fixed drug eruptions. The published success rates vary depending on clinical manifestations, drugs, and applied protocols. Slower protocols tend to be more effective than rush protocols; however, underreporting of unsuccessful procedures is very probable. The decision to desensitize a patient must always be made on an individual basis, balancing risks and benefits. This paper reviews the literature and presents the expert experience of the Drug Hypersensitivity Interest Group of the European Academy of Allergy and Clinical Immunology. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Coupled-reaction-channel analysis of the (d,6Li) reaction on 24Mg and 26Mg to low-lying states

International Nuclear Information System (INIS)

Oelert, W.

1986-01-01

Experimental spectroscopic factors of the alpha-transfer reaction on nuclei of the sd-shell show rather strong inconsistencies and scatter much more strongly than explainable by the quoted errors. The poorer the quality of agreement between experimental and theoretical angular distribution shapes, the more inconsistent the comparison of spectroscopic factors either between different experiments or between theory and experiment. In view of the strong deformation of nuclei in the lower part of the sd-shell, higher-order reaction mechanisms are expected. A coupled-reaction-channel analysis for the transitions to the 0 + , 2 + , and 4 + states of the ground-state bands in 20 Ne and 22 Ne excited via the (d, 6 Li) reaction yields good agreement between experimental and theoretical angular distribution shapes as well as spectroscopic information. (orig.)

Investigating Initial Disclosures and Reactions to Unexpected, Positive HPV Diagnosis.

Science.gov (United States)

Smith, Rachel A; Hernandez, Rachael; Catona, Danielle

2014-07-01

Initial disclosures of health conditions are critical communication moments. Existing research focuses on disclosers; integrating confidants into studies of initial disclosures is needed. Guided by the disclosure decision-making model (DD-MM; Greene, 2009), this study examined what diagnosed persons and confidants may say when faced with unexpected test results and unexpected disclosures, respectively. Participants ( N = 151) recorded an audio-visual message for another person, after imagining that they or the other person had just received unexpected, positive HPV test results. The qualitative analysis revealed four themes: (1) impression management and social distance, (2) invisible symptoms and advice regarding future disclosures, (3) expressing and acknowledging emotional reactions, and (4) misunderstandings and lacking knowledge about HPV. These findings suggested that DD-MM may be a relevant framework for understanding not only when disclosers share, but what disclosers and confidants say in early conversations about new diagnoses. While disclosers' and confidants' messages showed marked similarities, important differences appeared. For example, confidants focused on assuaging disclosers' fear about the consequences, whereas disclosers expressed distress related to their uncertainty about the prognosis of an HPV infection and how to prepare for next steps. The discussion highlighted implications for the DD-MM, HPV disclosures, and future interventions.

Studies in the reaction dynamics of beam-gas chemiluminescent reactions

International Nuclear Information System (INIS)

Prisant, M.G.

1984-01-01

This thesis develops techniques for the analysis and interpretation of data obtained from beam-gas chemiluminescence experiments. These techniques are applied to experimental studies of atom transfer reactions of the type A + BC → AB + C. A procedure is developed for determining the product rotational alignment in the center-of-mass frame from polarization measurements of chemiluminescent atom-diatom exchange reactions under beam-gas conditions. Knowledge of a vector property of a reaction, such as product alignment, provides information on the disposition of angular momentum by a chemical reaction. Fluorescence polarization and hence product alignment are measured for two prototype reactions. The reaction of metastable calcium atoms with hydrogen-chloride gas yields highly aligned calcium-chloride product which exhibits little variation of alignment with vibrational state. The reaction of ground-state calcium with fluorine gas yields moderately aligned product which shows strong variation of alignment with vibration. A multi-surface direct-interaction model is developed to interpret product alignment and population data. The predictions of this model for the reaction of calcium with fluorine show reasonable agreement with experiment

Dose-response testing with nickel sulphate using the TRUE test in nickel-sensitive individuals. Multiple nickel sulphate patch-test reactions do not cause an 'angry back'

DEFF Research Database (Denmark)

Andersen, Klaus Ejner; Lidén, C; Hansen, J

1993-01-01

The aim of this study was to employ the TRUE test assay to confirm the presence or absence of the 'angry back' phenomenon, i.e. that a strong positive patch-test reaction heightens adjacent patch-test response. In addition, we wished to establish the dose-response relationship for nickel sulphate...... back' phenomenon was not apparent in this study, as the spill-over effect was not statistically significant. Strong reactions to high concentrations of nickel sulphate did not enhance the response to adjacent lower concentrations of nickel sulphate....

Fermionic reaction coordinates and their application to an autonomous Maxwell demon in the strong-coupling regime

Science.gov (United States)

Strasberg, Philipp; Schaller, Gernot; Schmidt, Thomas L.; Esposito, Massimiliano

2018-05-01

We establish a theoretical method which goes beyond the weak-coupling and Markovian approximations while remaining intuitive, using a quantum master equation in a larger Hilbert space. The method is applicable to all impurity Hamiltonians tunnel coupled to one (or multiple) baths of free fermions. The accuracy of the method is in principle not limited by the system-bath coupling strength, but rather by the shape of the spectral density and it is especially suited to study situations far away from the wide-band limit. In analogy to the bosonic case, we call it the fermionic reaction coordinate mapping. As an application, we consider a thermoelectric device made of two Coulomb-coupled quantum dots. We pay particular attention to the regime where this device operates as an autonomous Maxwell demon shoveling electrons against the voltage bias thanks to information. Contrary to previous studies, we do not rely on a Markovian weak-coupling description. Our numerical findings reveal that in the regime of strong coupling and non-Markovianity, the Maxwell demon is often doomed to disappear except in a narrow parameter regime of small power output.

The prevalence of positive reactions in the atopy patch test with aeroallergens and food allergens in subjects with atopic eczema: a European multicenter study.

Science.gov (United States)

Darsow, U; Laifaoui, J; Kerschenlohr, K; Wollenberg, A; Przybilla, B; Wüthrich, B; Borelli, S; Giusti, F; Seidenari, S; Drzimalla, K; Simon, D; Disch, R; Borelli, S; Devillers, A C A; Oranje, A P; De Raeve, L; Hachem, J-P; Dangoisse, C; Blondeel, A; Song, M; Breuer, K; Wulf, A; Werfel, T; Roul, S; Taieb, A; Bolhaar, S; Bruijnzeel-Koomen, C; Brönnimann, M; Braathen, L R; Didierlaurent, A; André, C; Ring, J

2004-12-01

The atopy patch test (APT) was proposed to evaluate IgE-mediated sensitizations in patients with atopic eczema (AE). The prevalence and agreement with clinical history and specific IgE (sIgE) of positive APT reactions was investigated in six European countries using a standardized method. A total of 314 patients with AE in remission were tested in 12 study centers on clinically uninvolved, non-abraded back skin with 200 index of reactivity (IR)/g of house dust mite Dermatophagoides pteronyssinus, cat dander, grass, and birch pollen allergen extracts with defined major allergen contents in petrolatum. Extracts of egg white, celery and wheat flour with defined protein content were also patch tested. APT values were evaluated at 24, 48, and 72 h according to the European Task Force on Atopic Dermatitis (ETFAD) guidelines. In addition, skin-prick test (SPT) and sIgE and a detailed history on allergen-induced eczema flares were obtained. Previous eczema flares, after contact with specific allergens, were reported in 1% (celery) to 34% (D. pteronyssinus) of patients. The frequency of clear-cut positive APT reactions ranged from 39% with D. pteronyssinus to 9% with celery. All ETFAD intensities occured after 48 and 72 h. Positive SPT (16-57%) and elevated sIgE (19-59%) results were more frequent. Clear-cut positive APT with all SPT and sIgE testing negative was seen in 7% of the patients, whereas a positive APT without SPT or sIgE for the respective allergen was seen in 17% of the patients. APT, SPT and sIgE results showed significant agreement with history for grass pollen and egg white (two-sided Pr > /Z/ atopic controls, no positive APT reaction was seen. Aeroallergens and food allergens are able to elicit eczematous skin reactions after epicutaneous application. As no gold standard for aeroallergen provocation in AE exists, the relevance of aeroallergens for AE flares may be evaluated by APT in addition to SPT and sIgE. The data may contribute to the international

Japanese position paper on sodium-water reaction testing and design

International Nuclear Information System (INIS)

Sato, M.; Hiroi, H.; Tanabe, H.; Miyake, O.; Kuroha, M.; Hoshi, Y.

1984-01-01

PNC has been developing the steam generator with helically coiled heat transfer tube bundle and downcommer tubes for the prototype fast reactor Monju since 1968. To establish the safety design against the sodium-water reaction accident was one of the most important R and D items at the start of the development. PNC started the experimental study initially in the large leak region in 1970. Until now, during twelve years, the experimental studies have been performed, which covers the phenomena from a micro leak to a large one, with the use of the SWAT-1 rig, SWAT-2 loop, SWAT-3 loop, and SWAT-4 rigs. The reliable leak detection system is necessary to minimize the damage by the sodium-water reaction. Two groups of efforts have been paid for developing the detection system. One is to develop the leak detector itself, and another is to grasp the hydrogen transport behavior in the sodium in the steam generator and the secondary piping system. Four sodium loops have been used for the development. The development of computer codes has also progressed in parallel with the sodium-water reaction experiments. Three codes have been accomplished for the design tools against the sodium-water reaction. Through the efforts mentioned above, sufficient experiences were obtained for designing and operating the Monju steam generator system

Determination of nuclear friction in strongly damped reactions from prescission neutron multiplicities

NARCIS (Netherlands)

Wilczynski, J; SiwekWilczynska, K; Wilschut, HW

Nonfusion, fissionlike reactions in collisions of four heavy systems (well below the fusion extra-push energy threshold), Mr which Hinde and co-workers had measured the prescission neutron multiplicities, have been analyzed in terms of the deterministic dynamic model of Feldmeier coupled to a

Polymer reaction engineering, an integrated approach

NARCIS (Netherlands)

Meyer, T.; Keurentjes, J.T.F.; Meyer, T.; Keurentjes, J.T.F.

2005-01-01

Summary This chapter contains sections titled: Polymer Materials A Short History of Polymer Reaction Engineering The Position of Polymer Reaction Engineering Toward Integrated Polymer Reaction Engineering The Disciplines in Polymer Reaction Engineering The Future: Product-inspired Polymer Reaction

Positive patch test reactions to oxidized limonene: exposure and relevance.

Science.gov (United States)

Bråred Christensson, Johanna; Andersen, Klaus E; Bruze, Magnus; Johansen, Jeanne D; Garcia-Bravo, Begoña; Gimenez Arnau, Ana; Goh, Chee-Leok; Nixon, Rosemary; White, Ian R

2014-11-01

R-Limonene is a common fragrance terpene found in domestic and industrial products. R-Limonene autoxidizes on air exposure, and the oxidation products can cause contact allergy. In a recent multicentre study, 5.2% (range 2.3-12.1%) of 2900 patients showed a positive patch test reaction to oxidized R-limonene. To study the exposure to limonene among consecutive dermatitis patients reacting to oxidized R-limonene in an international setting, and to assess the relevance of the exposure for the patients' dermatitis. Oxidized R-limonene 3.0% (containing limonene hydroperoxides at 0.33%) in petrolatum was tested in 2900 consecutive dermatitis patients in Australia, Denmark, the United Kingdom, Singapore, Spain, and Sweden. A questionnaire assessing exposure to limonene-containing products was completed. Overall, exposure to products containing limonene was found and assessed as being probably relevant for the patients' dermatitis in 36% of the limonene-allergic patients. In Barcelona and Copenhagen, > 70% of the patients were judged to have had an exposure to limonene assessed as relevant. Oxidized R-limonene is a common fragrance allergen, and limonene was frequently found in the labelling on the patients' products, and assessed as relevant for the patients' dermatitis. A large number of domestic and occupational sources for contact with R-limonene were identified. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Strongly coupled Coulomb systems with positive dust grains: thermal and UV-induced plasmas

International Nuclear Information System (INIS)

Samarian, A.A.

2000-01-01

Full text: A plasma containing macroscopic dust particles or grains (often referred to as a dusty or colloidal or complex plasma) has the feature that grains may be charged by electron or ion flux or by photo- or thermoelectron emission. Electron emission from a grain surface produces a positive charge; capture of electrons produces the reverse effect making the dust grains negatively charged. Most dusty plasma research is concerned with the ordered dust structures (so-called 'plasma crystal') in glow discharges. The dust grains in these experiments were found to carry a negative charge due to the higher mobility of electrons as compared to ions in the discharge plasma. In recent years, in parallel with the study of the properties of plasma crystals under discharge conditions, attempts to obtain a structure from positively charged dust grains have been made, and structure formation processes for various charging mechanisms, particularly thermoelectron emission and photoemission, have been investigated. In this paper we review the essential features of strongly coupled plasmas with positive dust grains. An ordered structure of CeO 2 grains has been experimentally observed in a combustion products jet. The grains were charged positively and suspended in the plasma flow. Their charge is about 10 3 a and the calculated value of a Coulomb coupling parameter Γ is >10, corresponding to a plasma liquid. The ordered structures of Al 2 O 3 dust grains in propellant combustion products plasma have been observed for the first time. These structures were found in the sheath boundary of condensation region. The obtained data let us estimate the value of parameter Γ =3-40, corresponding to the plasma liquid state. The possibility is studied of the formation of ordered dust grain structures in thermal plasma. The range of the required values of the coupling parameter Γ is calculated using the results of diagnostic measurements carried out in thermal plasma with grains of

Mitsuda's reactions: induced by BCG in the normal Rhesus ("Macacca mulatta"

Directory of Open Access Journals (Sweden)

M. J. Pereira Filho

1955-12-01

Full Text Available The reversals of Mitsuda's reactions induced by BCG have been objected to based on the possiblem interference of other determination causes of the phenomenon: tuberculous primo-infections, communicants of unsuspected leprosy, revearsals due to other causes, such as anti-diphteric and anti-tetanic vaccination, etc. In order to study the problem, we have used Rhesus monkeys (Macaca mulatta, which were reared in isolation, in an attempt to avoid the referred to interferences. Prior to the experiments, all animals were tested and found negative to radiograph, tuberculin and lepromin tests and were then submitted to the application of BCG vaccine (from 1 to 3 days old, in different doses and by different via. At different times, after the application of BCG, they were again submitted to the radiographic, tuberculin and lepromin tests. In the tables I to IV the experiences were summarised. From the experiments, the following conclusions were reached: 1 - From 12 Rhesus that received BCG 11 showed reversals of the Mitsuda reaction (91.7%. 2 - These reverseals took place both in tests effected shortly after BCG (from 6 days to 2 months, and tests effected much later (from 7 to 12 months after BCG. 3 - Some differences were found in the results, according to the dosis and the application via of the BCG. a - The testicular and peritonela via (0,02g were the only that determined strong positive Mitsuda's reactions (+++. b - By oral via, animals that received high dosis (0.6g and 1.2 g, there resulted uniform and regular reversals, even though of low intensity (+; but from those who got small doses (0.2 g. one showed no reversals in all tests, and the other presented reversals in the 2nd and 3rd tests only, also with low positivity (+. 4 In the 2nd and 3rd Mitsuda's reactions in the same animals, positivity was always precocious (generally within 48 hours, one getting the impression that there occurs a sensibilization of the animal body by the antigen with

Excitation functions for quasielastic transfer reactions induced with heavy ions in bismuth

International Nuclear Information System (INIS)

Gardes, D.; Bimbot, R.; Maison, J.; de Reilhac, L.; Rivet, M.F.; Fleury, A.; Hubert, F.; Llabador, Y.

1978-01-01

The excitation functions for the production of 210 Bi, 210 Po, /sup 207-211/At, and 211 Rn through quasielastic transfer reactions induced with heavy ions in 209 Bi have been measured. The corresponding reactions involved the transfer of one neutron, one proton, two charges, and three charges from projectile to target. The projectiles used were 12 C, 14 N, 16 O, 19 F, 20 Ne, 40 Ar, 40 Ca, 56 Fe, and 63 Cu. The experimental techniques involved target irradiations and off-line α and γ activity measurements. Chemical separations were used to solve specific problems. Careful measuremnts of incident energies and cross sections were performed close to the reaction thresholds. All excitation functions exhibit the typical features of quasielastic transfer reactions: a sharp increase at low energy, and a constant value at high incident energy. The position of the thresholds are strongly influenced by the energetics of the reaction: High cross sections are observed under the strong interaction barrier if the energy balance at the minimum distance of approach is positive. This balance is equal to the difference between the interaction potentials in the entrance and exit channels, corrected for the mass balance. The constant cross sections observed for the high energy part of a given excitation function are consistent with the assumption that the curve P (R) which represents the transfer probability versus the distance between the nucleus centers does not vary with incident energy. This assumption implies the constancy of the optimum distance of approach R/sub opt/, of the R window ΔR for which P (R) is significant, and of the magnitude of P (R). Moreover the data show that the high energy cross sections for one-proton transfer are independent of the projectile, while odd-even effects of the projectile atomic number Z on the two-charge transfer cross sections are observed for the lightest incident ions 14 N to 20 Ne

Concerted effects in the reaction of ·OH radicals with aromatics: radiolytic oxidation of salicylic acid

International Nuclear Information System (INIS)

Albarran, G.; Schuler, R.H.

2003-01-01

Liquid chromatographic and capillary electrophoretic studies have been used to resolve the products produced in the radiolytic oxidation of salicylic acid in aqueous solution. These studies have shown that, as in the case of phenol, · OH radicals preferentially add to the positions ortho and para to the OH substituent. However, in contrast to its reaction with phenol, addition at the ortho position is favored over addition at the para position. Because · OH radical is a strong electrophile this difference suggests that the electron population at the ortho position in the salicylate anion is enhanced as a result of the hydrogen bonding in salicylic acid

Resonant elastic scattering, inelastic scattering and astrophysical reactions; Diffusion elastique resonante, diffusion inelastique et reactions astrophysiques

Energy Technology Data Exchange (ETDEWEB)

De Oliveira Santos, F. [Grand Accelerateur National d' Ions Lourds, UMR 6415, 14 - Caen (France)

2007-07-01

Nuclear reactions can occur at low kinetic energy. Low-energy reactions are characterized by a strong dependence on the structure of the compound nucleus. It turns out that it is possible to study the nuclear structure by measuring these reactions. In this course, three types of reactions are treated: Resonant Elastic Scattering (such as N{sup 14}(p,p)N{sup 14}), Inelastic Scattering (such as N{sup 14}(p,p')N{sup 14*}) and Astrophysical reactions (such as N{sup 14}(p,{gamma})O{sup 15}). (author)

Survey of the (3He,t) reaction: Excitation of the isobaric analog of the giant dipole resonance

International Nuclear Information System (INIS)

Tabor, S.L.; Chang, C.C.; Collins, M.T.; Wagner, G.J.; Wu, J.R.; Halderson, D.W.; Petrovich, F.

1982-01-01

The ( 3 He,t) reaction at 130 and 170 MeV has been investigated on targets of 12 C, 16 O, 27 Al, 28 Si, 40 Ca, 46 Ti, and 90 Zr. Data for the ( 3 He, 3 He') reaction were measured simultaneously for reference purposes. Structure is observed in the spectra from the ( 3 He, 3 He') and ( 3 He,t) reaction at the expected positions of the giant quadrupole resonance and the isobaric analog of the giant dipole resonance, respectively. An angular distribution was measured for the suspected giant dipole resonance structure in the 40 Ca( 3 He,t) 40 Sc reaction at 130 MeV. The data are reasonably described by a collective model calculation based on the Goldhaber-Teller model for the giant dipole resonance. Several other strong peaks at excitation energies below the giant dipole resonance are observed in the ( 3 He,t) spectra. Most notable of these are the ones at the expected positions for analogs of well known 1 + states and 1hω stretched states in the targets

Substrate-Directed Catalytic Selective Chemical Reactions.

Science.gov (United States)

Sawano, Takahiro; Yamamoto, Hisashi

2018-05-04

The development of highly efficient reactions at only the desired position is one of the most important subjects in organic chemistry. Most of the reactions in current organic chemistry are reagent- or catalyst-controlled reactions, and the regio- and stereoselectivity of the reactions are determined by the inherent nature of the reagent or catalyst. In sharp contrast, substrate-directed reaction determines the selectivity of the reactions by the functional group on the substrate and can strictly distinguish sterically and electronically similar multiple reaction sites in the substrate. In this Perspective, three topics of substrate-directed reaction are mainly reviewed: (1) directing group-assisted epoxidation of alkenes, (2) ring-opening reactions of epoxides by various nucleophiles, and (3) catalytic peptide synthesis. Our newly developed synthetic methods with new ligands including hydroxamic acid derived ligands realized not only highly efficient reactions but also pinpointed reactions at the expected position, demonstrating the substrate-directed reaction as a powerful method to achieve the desired regio- and stereoselective functionalization of molecules from different viewpoints of reagent- or catalyst-controlled reactions.

Reactions to abortion and subsequent mental health.

Science.gov (United States)

Fergusson, David M; Horwood, L John; Boden, Joseph M

2009-11-01

There has been continued interest in the extent to which women have positive and negative reactions to abortion. To document emotional reactions to abortion, and to examine the links between reactions to abortion and subsequent mental health outcomes. Data were gathered on the pregnancy and mental health history of a birth cohort of over 500 women studied to the age of 30. Abortion was associated with high rates of both positive and negative emotional reactions; however, nearly 90% of respondents believed that the abortion was the right decision. Analyses showed that the number of negative responses to the abortion was associated with increased levels of subsequent mental health disorders (Pabortion and reporting negative reactions had rates of mental health disorders that were approximately 1.4-1.8 times higher than those not having an abortion. Abortion was associated with both positive and negative emotional reactions. The extent of negative emotional reactions appeared to modify the links between abortion and subsequent mental health problems.

Prism plot analysis of the reaction positive Pi+ P → P Pi+ Pi0 at 4.1 GeV/C

International Nuclear Information System (INIS)

Heller, M.E.

1980-01-01

A sample of events fit to the reaction pi + p → p pi + pi 0 and extracted from exposures of a hydrogen bubble chamber to 4.09 GeV/c positive pions, has been separated into its channels by the method of prism plot tagging. Background affecting the reaction has been removed by the same method. The separated channels have been studied, and the dominant resonances fit with the Dual Absorptive Model. The delta+ + is found to be consistent with that extracted from higher-momentum data by conventional means, and is well fit by the model, using rho exchange. The rho + is well fit by an extended parameterization of the model at all but the lowest momentum transfers. Omega-meson exchange is indicated as the dominant mechanism for the reaction pi + p → rho + for momentum transfers greater than 0.02 GeV 2 /c 2 ; pion exchange is suggested as the probable mechanism at lower momentum transfers

Experimental and numerical reaction analysis on sodium-water chemical reaction field

International Nuclear Information System (INIS)

Deguchi, Yoshihiro; Takata, Takashi; Yamaguchi, Akira; Kikuchi, Shin; Ohshima, Hiroyuki

2015-01-01

In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using an elementary reaction analysis. A quasi one-dimensional flame model is applied to a sodium-water counter-flow reaction field. The analysis contains 25 elementary reactions, which consist of 17 H_2-O_2 and 8 Na-H_2O reactions. Temperature and species concentrations in the counter-flow reaction field were measured using laser diagnostics such as LIF and CARS. The main reaction in the experimental conditions is Na+H_2O → NaOH+H and OH is produced by H_2O+H → H_2+OH. It is demonstrated that the reaction model in this study well explains the structure of the sodium-water counter-flow diffusion flame. (author)

A sol-gel method for preparing ZnO quantum dots with strong blue emission

International Nuclear Information System (INIS)

Chen Zhong; Li Xiaoxia; Du Guoping; Chen Nan; Suen, Andy Y.M.

2011-01-01

ZnO quantum dots (QDs) with strong blue emission have been successfully synthesized by sol-gel method, and their crystal structures, sizes, and photoluminescence properties were characterized by X-ray diffractometer, scanning electron microscope, and ultraviolet-visible spectroscopy. It has been found that ZnO QDs had a hexagonal wurtzite crystal structure, and their average diameter was about 16.0-32.2 nm. Both the reaction time and temperature were found to have a strong influence on the average size and photoluminescence properties of ZnO QDs. Longer reaction time and higher reaction temperature resulted in larger average size for ZnO QDs. It has been shown that at reaction temperature 60 deg. C the emission intensity for ZnO QDs increased first with reaction time before 7 h and then decreased after 7 h. For the same reaction time 7 h, ZnO QDs synthesized at 60 deg. C showed the strongest emission intensity. It was found that annealing in nitrogen, vacuum, and air all resulted in an increase of the size of ZnO QDs and a reduction in their photoluminescence. The dependence of the size and properties of ZnO QDs on the reaction parameters as well as the annealing conditions has been discussed. - Highlights: → ZnO quantum dots (QDs) with strong blue emission were prepared by sol-gel method. → ZnO QDs had a pure spectral blue with the chromaticity coordinates (0.166, 0.215). → Optimal reaction time and temperature were 7 h and 60 deg. C, respectively.

Coming Out and the Potential for Growth in Sexual Minorities: The Role of Social Reactions and Internalized Homonegativity.

Science.gov (United States)

Solomon, David; McAbee, James; Åsberg, Kia; McGee, Ashley

2015-01-01

Coming out is a significant and sometimes difficult process in the lives of sexual minorities, but disclosure can also affect wellbeing in positive ways, including reduced distress and greater relationship satisfaction. This study investigates the possibility of stress-related growth and depreciation following coming out. To obtain a diverse sample with varying coming-out experiences, data were collected from undergraduate students as well as from online sources, including lesbian, gay, and bisexual support groups and Pride groups. Regression analyses indicated that negative social reactions to coming out predicted both growth and depreciation, although they more strongly predicted depreciation. Positive social reactions were positively related to stress-related growth, while internalized homonegativity was inversely associated with growth. Although the two sample sources (online and campus) differed in some ways, sample source was not a significant predictor in the regressions, nor was it indicated as a moderator in exploratory ANOVA analyses.

Lipid-rich carcinoma of the breast that is strongly positive for estrogen receptor: a case report and literature review

Directory of Open Access Journals (Sweden)

Oba T

2016-03-01

Full Text Available Takaaki Oba,1 Mayu Ono,1 Asumi Iesato,1 Toru Hanamura,1 Takayuki Watanabe,1 Tokiko Ito,1 Toshiharu Kanai,1 Kazuma Maeno,1 Ken-ichi Ito,1 Ayako Tateishi,2 Akihiko Yoshizawa,2 Fumiyoshi Takayama31Division of Breast, Endocrine and Respiratory Surgery, Department of Surgery, Shinshu University School of Medicine, Matsumoto, Nagano, 2Department of Laboratory Medicine, Shinshu University Hospital, 3Imaging Center, Ichinose Neurosurgical Hospital, Matsumoto, JapanAbstract: Lipid-rich carcinoma (LRC of the breast is a rare breast cancer variant that accounts for <1% of all breast malignancies. It has been reported that LRCs are negative for estrogen receptor. Here, we report a case of LRC of the breast that was strongly positive for estrogen receptor and treated with endocrine adjuvant therapy. A 52-year-old postmenopausal female noticed a lump in her right breast by self-examination and presented to our hospital. Physical examination revealed an elastic 30 mm ×20 mm hard mass in the upper medial part of her right breast. The findings obtained using ultrasonography, mammography, and contrast-enhanced magnetic resonance imaging suggested breast cancer. Core needle biopsy resulted in the diagnosis of invasive carcinoma. The patient underwent mastectomy and sentinel lymph node biopsy. Histopathologically, the tumor cells were abundant in foamy cytoplasm. Because the presence of marked cytoplasmic lipid droplets was confirmed by Sudan IV staining and electron microscopic examination of the tumor and the lipid droplets were negative for periodic acid–Schiff staining, the tumor was diagnosed as an LRC. Immunohistochemically, estrogen and progesterone receptors of the tumor were strongly positive, human epidermal growth factor receptor type 2 was negative, and the ratio of Ki-67-positive cells was ~30%. After surgery, the patient underwent combination chemotherapy with anthracycline, cyclophosphamide, and 5-fluorouracil, followed by docetaxel. Thereafter

Real-time polymerase chain reaction with melting analysis of positive blood culture specimens in bloodstream infections: diagnostic value and turnaround time.

Science.gov (United States)

Angeletti, Silvia; Gherardi, Giovanni; De Florio, Lucia; Avola, Alessandra; Crea, Francesca; Riva, Elisabetta; Vitali, Massimiliano Andrea; Galluzzo, Sara; Dicuonzo, Giordano

2013-01-01

A Real-time polymerase chain reaction (PCR) with melting analysis was devised to target bacterial and fungal genes together with the most prevalent antimicrobial resistance genes in 250 positive blood culture broths. This method allowed the blood culture cultivated pathogens to be classified into clinically relevant groups such as Enterobacteriaceae, oxidase-positive bacilli, oxidase-positive coccobacilli, S. aureus and yeast. Enterococci and streptococci could be distinguished from CoNS only by the Gram stain. Gram-positive bacilli were discriminated from Gram-positive cocci by Gram stain. Furthermore, the most important antimicrobial resistant genes such as mecA, vanA, bla TEM , bla SHV and bla CTX-M could be identified. All results were obtained with a turnaround time of three hours from the moment of blood culture positivity compared to 24-72 hours for phenotypic methods. In conclusion, the proposed approach can allow the clinician to implement proper early management of sepsis patients.

Hybrid capacitors utilizing halogen-based redox reactions at interface between carbon positive electrode and aqueous electrolytes

Science.gov (United States)

Yamazaki, Shigeaki; Ito, Tatsuya; Murakumo, Yuka; Naitou, Masashi; Shimooka, Toshiharu; Yamagata, Masaki; Ishikawa, Masashi

2016-09-01

We propose novel hybrid capacitors (HCs) with electrolyte-involved redox reactions of bromide or iodide species by pretreatment of an activated carbon positive electrode. The treatment is simple; impregnation of pores at an activated carbon fiber cloth (ACFC) as a positive electrode with bromine- or iodine-containing water before cell assembly. The treated positive electrode is applied to a HC cell with a non-treated negative electrode of ACFC and its electrochemical performance is investigated by galvanostatic cycling and leakage current tests. Few studies on such "electrolytic" charge storage systems have provided acceptable capacitor performance because of inevitable self-discharge caused by diffusion of charged species form an electrode to the other one through an electrolyte. Nevertheless, our electrolyte-redox-based HCs show excellent performance without undesirable diffusion of charged species. Moreover, the present HC utilizing a bromide redox system fulfills a practical cell voltage of 1.8 V in spite of an aqueous electrolyte system. This high voltage provides excellent energy density, which is 5 times higher than that in a conventional aqueous electric double-layer capacitor (EDLC), and 1.2 times higher even than that in a 2.7 V-class non-aqueous EDLC, while keeping high charge-discharge rate capability.

Developmental Aspects of Reaction to Positive Inducements

Science.gov (United States)

Lindskold, Svenn; And Others

1970-01-01

Probes children's behavioral sensitivity to variation in reward probability and magnitude (bribes) and suggests that preadolescent children do respond to promises of positive inducements for cooperation in a mixed-motive situation. (WY)

Prevailence of Patch Test Positivity with Some Bases

Directory of Open Access Journals (Sweden)

J S Pasricha

1987-01-01

Full Text Available To evaluate the suitability of some chemicals to act as bases for antigens for patch tests, patch tests were performed with these agents in patients having contact dermatitis. Propylene glycol′used as such produced positive reactions in 25 (50% patients of which 12 were 2 + or more, polyethylene glycol 200 produced positive reactions in 9 (18% cases of which 4 cases were 2 + or more, a mixture of liquid paraffin and hard paraffin gave rise to positive reactions in 10 (10% cases 3 of these being 2 +, a mixture of liquid paraffin and bees wax was positive in 14 (14,Yo cases 3 of these being 2 +, yellow petrolatum was positive in 4 (8% cases, one of which was 2 +, white petrolatum was positive in S (6% cases all of these being + reactions only, and glycerol gave rise to a I + reaction in only one (2% caw. In tropical countries, water should be as base for as many antigens as possible for others, a control test with the b must be included.

The effect of mass transport on the graphite/CO2 reaction

International Nuclear Information System (INIS)

Stephen, W.J.

1984-11-01

The Graphite/CO 2 reaction is strongly inhibited by the reaction product CO and therefore any model for the influence of mass transport on reaction rate should consider this. The problem of internal mass transport alone has been considered in previous notes. This note extends the models to include external mass transport. Results are compared with simple first order reaction with no volume change. The calculations demonstrate that, for strong CO inhibition, external mass transport limits reaction at a much lower rate than for first order kinetics and that the usual concept of three reaction zones corresponding to chemical control, in-pore diffusion control and boundary layer control can be unrealistically idealised. (U.K.)

The unusually strong hydrogen bond between the carbonyl of Q(A) and His M219 in the Rhodobacter sphaeroides reaction center is not essential for efficient electron transfer from Q(A)(-) to Q(B).

Science.gov (United States)

Breton, Jacques; Lavergne, Jérôme; Wakeham, Marion C; Nabedryk, Eliane; Jones, Michael R

2007-06-05

In native reaction centers (RCs) from photosynthetic purple bacteria the primary quinone (QA) and the secondary quinone (QB) are interconnected via a specific His-Fe-His bridge. In Rhodobacter sphaeroides RCs the C4=O carbonyl of QA forms a very strong hydrogen bond with the protonated Npi of His M219, and the Ntau of this residue is in turn coordinated to the non-heme iron atom. The second carbonyl of QA is engaged in a much weaker hydrogen bond with the backbone N-H of Ala M260. In previous work, a Trp side chain was introduced by site-directed mutagenesis at the M260 position in the RC of Rb. sphaeroides, resulting in a complex that is completely devoid of QA and therefore nonfunctional. A photochemically competent derivative of the AM260W mutant was isolated that contains a Cys side chain at the M260 position (denoted AM260(W-->C)). In the present work, the interactions between the carbonyl groups of QA and the protein in the AM260(W-->C) suppressor mutant have been characterized by light-induced FTIR difference spectroscopy of the photoreduction of QA. The QA-/QA difference spectrum demonstrates that the strong interaction between the C4=O carbonyl of QA and His M219 is lost in the mutant, and the coupled CO and CC modes of the QA- semiquinone are also strongly perturbed. In parallel, a band assigned to the perturbation of the C5-Ntau mode of His M219 upon QA- formation in the native RC is lacking in the spectrum of the mutant. Furthermore, a positive band between 2900 and 2400 cm-1 that is related to protons fluctuating within a network of highly polarizable hydrogen bonds in the native RC is reduced in amplitude in the mutant. On the other hand, the QB-/QB FTIR difference spectrum is essentially the same as for the native RC. The kinetics of electron transfer from QA- to QB were measured by the flash-induced absorption changes at 780 nm. Compared to native RCs the absorption transients are slowed by a factor of about 2 for both the slow phase (in the

Incidents of chemical reactions in cell equipment

Energy Technology Data Exchange (ETDEWEB)

Baldwin, N.M.; Barlow, C.R. [Uranium Enrichment Organization, Oak Ridge, TN (United States)

1991-12-31

Strongly exothermic reactions can occur between equipment structural components and process gases under certain accident conditions in the diffusion enrichment cascades. This paper describes the conditions required for initiation of these reactions, and describes the range of such reactions experienced over nearly 50 years of equipment operation in the US uranium enrichment program. Factors are cited which can promote or limit the destructive extent of these reactions, and process operations are described which are designed to control the reactions to minimize equipment damage, downtime, and the possibility of material releases.

12C(d,p) 13C reaction at Esub(d) = 30 MeV to the positive-parity states in 13C

International Nuclear Information System (INIS)

Ohnuma, H.; Hoshino, N.; Mikoshiba, O.

1985-07-01

The 12 C(d, p) 13 C reaction has been studied at Esub(d) = 30 MeV. All the known positive-parity states of 13 C below 10 MeV in excitation energy, including the 7/2 + and 9/2 + states, are observed in this reaction. The angular distributions for these positive-parity bound and unbound states are analyzed in CCBA frame work. The 13 C wave functions, which reproduce the resonant and non-resonant scattering of neutrons from 12 C, also give good accounts of the experimentally observed angular distributions and energy spectra of outgoing protons in the 12 C(d, p) 13 C reaction. In most cases the cross section magnitude and the angular distribution shape are primarily determined by the 0 + x j component, even if it is only a small fraction of the total wave function. An exception is the 7/2 + state, where the main contribution comes from the 2 + x dsub(5/2) component. The inclusion of the 4 + state in 12 C and the gsub(9/2) and gsub(7/2) neutron components in the n + 12 C system has very small effects on the low-spin states, but is indispensable for a good fit to the 7/2 + and 9/2 + angular distributions. The transitions to the negative-parity states, 1/2 1 - , 3/2 1 - , 5/2 - , 7/2 - and 1/2 3 - , are also observed experimentally, and analyzed by DWBA. (author)

Selective scanning tunnelling microscope electron-induced reactions of single biphenyl molecules on a Si(100) surface.

Science.gov (United States)

Riedel, Damien; Bocquet, Marie-Laure; Lesnard, Hervé; Lastapis, Mathieu; Lorente, Nicolas; Sonnet, Philippe; Dujardin, Gérald

2009-06-03

Selective electron-induced reactions of individual biphenyl molecules adsorbed in their weakly chemisorbed configuration on a Si(100) surface are investigated by using the tip of a low-temperature (5 K) scanning tunnelling microscope (STM) as an atomic size source of electrons. Selected types of molecular reactions are produced, depending on the polarity of the surface voltage during STM excitation. At negative surface voltages, the biphenyl molecule diffuses across the surface in its weakly chemisorbed configuration. At positive surface voltages, different types of molecular reactions are activated, which involve the change of adsorption configuration from the weakly chemisorbed to the strongly chemisorbed bistable and quadristable configurations. Calculated reaction pathways of the molecular reactions on the silicon surface, using the nudge elastic band method, provide evidence that the observed selectivity as a function of the surface voltage polarity cannot be ascribed to different activation energies. These results, together with the measured threshold surface voltages and the calculated molecular electronic structures via density functional theory, suggest that the electron-induced molecular reactions are driven by selective electron detachment (oxidation) or attachment (reduction) processes.

Exact solutions of strong gravity in generalized metrics

International Nuclear Information System (INIS)

Hojman, R.; Smailagic, A.

1981-05-01

We consider classical solutions for the strong gravity theory of Salam and Strathdee in a wider class of metrics with positive, zero and negative curvature. It turns out that such solutions exist and their relevance for quark confinement is explored. Only metrics with positive curvature (spherical symmetry) give a confining potential in a simple picture of the scalar hadron. This supports the idea of describing the hadron as a closed microuniverse of the strong metric. (author)

Nuclear structure effects in multi-nucleon transfer and sequential fission reactions

International Nuclear Information System (INIS)

Biswas, D.C.

2001-01-01

The role of the nuclear structure in multi-nucleon transfer and sequential fission reactions has been discussed. The recent results on multi-nucleon transfer and transfer induced fission reaction, have brought out many interesting features in understanding the reaction mechanism and collective dynamics of heavy ion reactions. The structure of the projectile nucleus has strong influence on the transfer of multi-nucleons and/or clusters from the projectile to the target. The mechanism of multi-nucleon transfer between two heavy nuclei is a complex process which has a strong dependence on the ground state Q-value of the reaction as well as on the number of transferred nucleons

Weakly and strongly coupled Belousov-Zhabotinsky patterns

Science.gov (United States)

Weiss, Stephan; Deegan, Robert D.

2017-02-01

We investigate experimentally and numerically the synchronization of two-dimensional spiral wave patterns in the Belousov-Zhabotinsky reaction due to point-to-point coupling of two separate domains. Different synchronization modalities appear depending on the coupling strength and the initial patterns in each domain. The behavior as a function of the coupling strength falls into two qualitatively different regimes. The weakly coupled regime is characterized by inter-domain interactions that distorted but do not break wave fronts. Under weak coupling, spiral cores are pushed around by wave fronts in the other domain, resulting in an effective interaction between cores in opposite domains. In the case where each domain initially contains a single spiral, the cores form a bound pair and orbit each other at quantized distances. When the starting patterns consist of multiple randomly positioned spiral cores, the number of cores decreases with time until all that remains are a few cores that are synchronized with a partner in the other domain. The strongly coupled regime is characterized by interdomain interactions that break wave fronts. As a result, the wave patterns in both domains become identical.

Reaction of Titanocene Alkyls with Pyridines; A Novel Type of Cyclometallation Reaction

NARCIS (Netherlands)

Klei, E.; Teuben, J.H.

1981-01-01

Reaction of Cp2TiR (R = alkyl) with 2-substituted-pyridines and with quinolines leads to α-metallation of these ligands with formation of triangular titanocycles containing TiIII. Proof of the metallation at the α-position comes from reactions of the complexes formed with I2 and D2O/DCl which yield

Growing Platinum-Ruthenium-Tin ternary alloy nanoparticles on reduced graphene oxide for strong ligand effect toward enhanced ethanol oxidation reaction.

Science.gov (United States)

Xia, Qing Qing; Zhang, Lian Ying; Zhao, Zhi Liang; Li, Chang Ming

2017-11-15

Uniform Pt 1 Ru 0.5 Sn 0.5 ternary alloy nanoparticles are in situ deposited on reduced graphene oxide (Pt 1 Ru 0.5 Sn 0.5 -RGO) through its functional groups and defects as nucleation sites to greatly electrocatalyze ethanol oxidation reaction for much higher mass current densities, larger apparent specific current densities and better stability than commercial Pt-C catalyst (Pt-C(commer)). Mechanistic studies indicate that the excellent electrocatalytic activity and anti-poisoning are resulted from a strong ligand effect of the ternary alloy components, in which the charge transfer is boosted while decreasing the density of states close to the Fermi level of Pt to reduce bond energy between Pt and CO-like adsorbates for greatly improved anti-poisoning ability. This work holds a great promise to fabricate a high performance anode catalyst with a low Pt loading for direct ethanol fuel cells. Copyright © 2017. Published by Elsevier Inc.

Reaction of Aldehydes/Ketones with Electron-Deficient 1,3,5-Triazines Leading to Functionalized Pyrimidines as Diels-Alder/Retro-Diels-Alder Reaction Products: Reaction Development and Mechanistic Studies.

Science.gov (United States)

Yang, Kai; Dang, Qun; Cai, Pei-Jun; Gao, Yang; Yu, Zhi-Xiang; Bai, Xu

2017-03-03

Catalytic inverse electron demand Diels-Alder (IEDDA) reactions of heterocyclic aza-dienes are rarely reported since highly reactive and electron-rich dienophiles are often found not compatible with strong acids such as Lewis acids. Herein, we disclose that TFA-catalyzed reactions of electron-deficient 1,3,5-triazines and electron-deficient aldehydes/ketones can take place. These reactions led to highly functionalized pyrimidines as products in fair to good yields. The reaction mechanism was carefully studied by the combination of experimental and computational studies. The reactions involve a cascade of stepwise inverse electron demand hetero-Diels-Alder (ihDA) reactions, followed by retro-Diels-Alder (rDA) reactions and elimination of water. An acid was required for both ihDA and rDA reactions. This mechanism was further verified by comparing the relative reactivity of aldehydes/ketones and their corresponding vinyl ethers in the current reaction system.

Low energy nuclear reactions: 2007 update

International Nuclear Information System (INIS)

Krivit, S. B.

2007-01-01

Introduction: This paper presents an overview of the field of low energy nuclear reactions (LENR), a branch of condensed matter nuclear science. It explains some of the various terminologies that have been used to describe this field since it debuted as 'cold fusion' in 1989. The paper also reviews some of the most interesting news and developments regarding low energy nuclear reaction experiments and theory, and some of the sociological and political trends that have affected the field over the last 18 years. It concludes with a list of resources and information for scientists, journalists and decision makers. Understanding the Nature of the Reactions The worldwide LENR research effort includes 200 researchers in 13 nations. Over the last 18 years, 12 international conferences have been held, as well as 7 regional conferences in Italy, 14 in Russia and 7 in Japan. The significant questions that face this field of research are: a) Are LENRs a genuine nuclear reaction? b) If so, is there a release of excess energy? and c) Are transmutations possible? If the answers to these questions turn out to be positive, the next questions will be: d) Is the energy release cost-effective? and e) Are the transmutations useful? Despite the fact that repeatability and reproducibility are challenging, the required parameters for achieving the excess heat effect are well understood. First, a high atomic loading ratio of D into Pd is required. In most conditions, 0.90 is the minimum threshold required to produce an excess heat effect. Second, a high electrical current density in the cathode is needed, 250 mA/cm 2 under most conditions. The third requirement is for some kind of dynamic trigger to impose a deuterium flux in, on or around the cathode. The challenge that researchers face is how to achieve these conditions. Some of the Most Interesting Research Developments Work by Stanislaw Szpak, Pamela Boss and Frank Gordon at the U.S. Navy's SPAWAR Systems Center in San Diego has

Strong monotonicity in mixed-state entanglement manipulation

International Nuclear Information System (INIS)

Ishizaka, Satoshi

2006-01-01

A strong entanglement monotone, which never increases under local operations and classical communications (LOCC), restricts quantum entanglement manipulation more strongly than the usual monotone since the usual one does not increase on average under LOCC. We propose strong monotones in mixed-state entanglement manipulation under LOCC. These are related to the decomposability and one-positivity of an operator constructed from a quantum state, and reveal geometrical characteristics of entangled states. These are lower bounded by the negativity or generalized robustness of entanglement

Defensive marketing: how a strong incumbent can protect its position.

Science.gov (United States)

Roberts, John H

2005-11-01

There has been a lot of research on marketing as an offensive tactic-how it can help companies successfully launch new products, enter new markets, or gain share with existing products in their current markets. But for nearly every new product launch, market entrant, or industry upstart grabbing market share, there is an incumbent that must defend its position. And there has been little research on how these defenders can use marketing to preemptively respond to new or anticipated threats. John H. Roberts outlines four basic types of defensive marketing strategies: positive, inertial, parity, and retarding. With the first two, you establish and communicate your points of superiority relative to the new entrant; with the second two, you establish and communicate strategic points of comparability with your rival. Before choosing a strategy, you need to assess the weapons you have available to protect your market position-your brand identity, the products and services that support that identity, and your means of communicating it. Then assess your customers' value to you and their vulnerability to being poached by rivals. The author explains how Australian telecommunications company Telstra, facing deregulation, used a combination of the four strategies (plus the author's customer response model) to fend off market newcomer Optus. Telstra was prepared, for instance, to reach deep into its pockets and engage in a price war. But the customer response model indicated that a parity strategy-in which Telstra would offer lower rates on some routes and at certain times of day, even though its prices, on average, were higher than its rival's-was more likely to prevent consumers from switching. Ultimately, Telstra was able to retain several points of market share it otherwise would have lost. The strategies described here, though specific to Telstra's situation, offer lessons for any company facing new and potentially damaging competition.

Reaction Equilibrium of the ω-Transamination of (S)-Phenylethylamine

DEFF Research Database (Denmark)

Voges, Matthias; Abu, Rohana; Deslauriers, Maria Gundersen

2017-01-01

This work focuses on the thermodynamic equilibrium of the ω-transaminase-catalyzed reaction of (S)-phenylethylamine with cyclohexanone to acetophenone and cyclohexylamine in aqueous solution. For this purpose, the equilibrium concentrations of the reaction were experimentally investigated under...... varying reaction conditions. It was observed that the temperature (30 and 37 °C), the pH (between pH 7 and pH 9), as well as the initial reactant concentrations (between 5 and 50 mmol·kg-1) influenced the equilibrium position of the reaction. The position of the reaction equilibrium was moderately shifted...... position to the reactant side. In order to explain these effects, the activity coefficients of the reacting agents were calculated and the activity-based thermodynamic equilibrium constant Kth of the reaction was determined. For this purpose, the activity coefficients of the reacting agents were modeled...

Liquid-Crystalline Ionic Liquids as Ordered Reaction Media for the Diels-Alder Reaction.

Science.gov (United States)

Bruce, Duncan W; Gao, Yanan; Canongia Lopes, José Nuno; Shimizu, Karina; Slattery, John M

2016-11-02

Liquid-crystalline ionic liquids (LCILs) are ordered materials that have untapped potential to be used as reaction media for synthetic chemistry. This paper investigates the potential for the ordered structures of LCILs to influence the stereochemical outcome of the Diels-Alder reaction between cyclopentadiene and methyl acrylate. The ratio of endo- to exo-product from this reaction was monitored for a range of ionic liquids (ILs) and LCILs. Comparison of the endo:exo ratios in these reactions as a function of cation, anion and liquid crystallinity of the reaction media, allowed for the effects of liquid crystallinity to be distinguished from anion effects or cation alkyl chain length effects. These data strongly suggest that the proportion of exo-product increases as the reaction media is changed from an isotropic IL to a LCIL. A detailed molecular dynamics (MD) study suggests that this effect is related to different hydrogen bonding interactions between the reaction media and the exo- and endo-transition states in solvents with layered, smectic ordering compared to those that are isotropic. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Confining Domains Lead to Reaction Bursts: Reaction Kinetics in the Plasma Membrane

Science.gov (United States)

Kalay, Ziya; Fujiwara, Takahiro K.; Kusumi, Akihiro

2012-01-01

Confinement of molecules in specific small volumes and areas within a cell is likely to be a general strategy that is developed during evolution for regulating the interactions and functions of biomolecules. The cellular plasma membrane, which is the outermost membrane that surrounds the entire cell, was considered to be a continuous two-dimensional liquid, but it is becoming clear that it consists of numerous nano-meso-scale domains with various lifetimes, such as raft domains and cytoskeleton-induced compartments, and membrane molecules are dynamically trapped in these domains. In this article, we give a theoretical account on the effects of molecular confinement on reversible bimolecular reactions in a partitioned surface such as the plasma membrane. By performing simulations based on a lattice-based model of diffusion and reaction, we found that in the presence of membrane partitioning, bimolecular reactions that occur in each compartment proceed in bursts during which the reaction rate is sharply and briefly increased even though the asymptotic reaction rate remains the same. We characterized the time between reaction bursts and the burst amplitude as a function of the model parameters, and discussed the biological significance of the reaction bursts in the presence of strong inhibitor activity. PMID:22479350

Confining domains lead to reaction bursts: reaction kinetics in the plasma membrane.

Directory of Open Access Journals (Sweden)

Ziya Kalay

Full Text Available Confinement of molecules in specific small volumes and areas within a cell is likely to be a general strategy that is developed during evolution for regulating the interactions and functions of biomolecules. The cellular plasma membrane, which is the outermost membrane that surrounds the entire cell, was considered to be a continuous two-dimensional liquid, but it is becoming clear that it consists of numerous nano-meso-scale domains with various lifetimes, such as raft domains and cytoskeleton-induced compartments, and membrane molecules are dynamically trapped in these domains. In this article, we give a theoretical account on the effects of molecular confinement on reversible bimolecular reactions in a partitioned surface such as the plasma membrane. By performing simulations based on a lattice-based model of diffusion and reaction, we found that in the presence of membrane partitioning, bimolecular reactions that occur in each compartment proceed in bursts during which the reaction rate is sharply and briefly increased even though the asymptotic reaction rate remains the same. We characterized the time between reaction bursts and the burst amplitude as a function of the model parameters, and discussed the biological significance of the reaction bursts in the presence of strong inhibitor activity.

Diazotisation of Weakly Basic Aromatic and Heterocyclic Amines in Strongly Acid Media

Science.gov (United States)

Godovikova, Tamara I.; Rakitin, Oleg A.; Khmel'nitskii, Lenor I.

1983-05-01

The review is devoted to the diazotisation of weakly basic aromatic amines. The methods of synthesis of diazonium salts based on these amines by non-traditional methods are examined. Data on the mechanism of the diazotisation reaction in strongly acid media are surveyed. Reactions of diazonium salts leading to the synthesis of new compounds are presented. The bibliography includes 75 references.

Comparative study on bromide and iodide ion-isotopic exchange reactions using strongly basic anion exchange resin Duolite A-113

International Nuclear Information System (INIS)

Lokhande, R.S.; Dole, M.H.; Singare, P.U.

2006-01-01

Kinetics of ion-isotopic exchange reaction was studied using industrial grade ion exchange resin Duolite A-113. The radioactive isotopes 131 I and 82 Br were used to trace the ion-isotopic exchange reaction. The experiments were performed in the temperature range of 26.0degC to 43.0degC and the concentration of external ionic solution varying from 0.005 M to 0.100 M. For bromide ion-isotopic exchange reaction, the calculated values of specific reaction rate, initial rate of bromide ion exchange, and amount of bromide ions exchanged were obtained higher than that for iodide ion-isotopic exchange reaction under identical experimental conditions. The observed variation in the results for two ion-isotopic exchange reactions was due to the difference in the ionic size of bromide and iodide ions. (author)

Serologic reactions against Salmonella in samples from broiler parent stock with and without preceding colibacillosis: A case-control study

DEFF Research Database (Denmark)

Gradel, K.O.; Feld, Niels Christian; Andersen, J. S.

2001-01-01

In the Danish Salmonella Control Program, eggs from broiler parent flocks are surveyed by serologic analysis every 4 wk for antibodies against Salmonella lipopolysaccharide O-antigens 1, 4, 5, 9, and 12 (Mix-enzyme-linked immunosorbent assay [ELISA]) and 6 and 7 (Infantis-ELISA). The antibody...... response is measured in percentage optical density (OD%) of a strong positive reaction, and the cutoff value has been determined to be 40 OD%. Two or more reactors above 40 OD% will place the parent flock under suspicion. There has been concern about possible cross-reactions between Salmonella spp....... and other Enterobacteriaceae, e.g., Escherichia coli, because a high specificity of a Salmonella antibody test is desirable. Moreover, false-positive Salmonella results have economic consequences and impede planning the production. A case-control study based on cases of clinical E. coli infections...

Elimination Reactions of (E)-2,4,6-Trinitrobenzaldehyde O-benzoyloximes Promoted by R2NH in MeCN. Change of Reaction Mechanism

International Nuclear Information System (INIS)

Cho, Bong Rae; Pyun, Sang Yong

2010-01-01

We have studied the nitrile-forming elimination reactions from 1 promoted by R 2 NH in MeCN. The reaction proceeded by (E1cb) irr mechanism. Change of the β-aryl group from 2,4-dinitrophenyl to a more strongly electron-withdrawing 2,4,6-trinitrophenyl increased the reaction rate by 470-fold, shifted the transition state toward more reactant-like, and changed the reaction mechanism from E2 to (E1cb) irr . To the best of our knowledge, this is the first example of nitrile-forming elimination reaction that proceeds by the (E1cb) irr mechanism in MeCN. Noteworthy is the carbanion stabilizing ability of the 2,4,6-trinitrophenyl group in aprotic solvent. Nitrile-forming elimination reactions of (E)-benzaldoxime derivatives have been extensively investigated under various conditions. The reactions proceeded by the E2 mechanism in MeCN despite the fact that the reactants have syn stereochemistry, poor leaving, and sp 2 hybridized β-carbon atom, all of which favor E1cb- or E1cb-like transition state. Moreover, the transition state structures were relatively insensitive to the variation of the reactant structures. The results have been attributed to the poor anion solvating ability of MeCN, which favors E2 transition state with maximum charge dispersal. For eliminations from strongly activated (E)-2,4-(NO 2 ) 2 C 6 H 3 CH=NOC(O)C 6 H 4 X, a change in the reaction mechanism from E2 to (E1cb) irr was observed as the base-solvent was changed from R 2 NH in MeCN to R 2 NH/R 2 NH 2 + in 70 mol % MeCN(aq). A combination of a strong electron-withdrawing β-aryl group and anion-solvating protic solvent was required for the mechanistic change

Reaction Qualifications Revisited

DEFF Research Database (Denmark)

Lippert-Rasmussen, Kasper

2009-01-01

  When, in a competitive sphere, people are selected on the basis of qualifications only, their chances of acquiring positions of advantage may seem to depend entirely upon their abilities, not discriminatory bias. However, if reaction qualifications - i.e. characteristics which contribute...... to a person's effectiveness by causing a favourable reaction in customers, co-workers etc. (for short: recipients) - are involved, this assumption is false. Building on work by Wertheimer, Mason, and Miller, this paper proposes an account of the reaction qualifications that count, from the point of view...... of merit. Specifically, it preserves symmetry between negative evaluations of antimeritocratic bases of selection and negative evaluations of qualifications rooted in comparable antimeritocratic reactions. So if employers should not select among applicants on the basis of their (the employers') racial...

Cystic neutrophilic granulomatous mastitis: an underappreciated pattern strongly associated with gram-positive bacilli.

Science.gov (United States)

Renshaw, Andrew A; Derhagopian, Robert P; Gould, Edwin W

2011-09-01

Although granulomatous lobular mastitis is associated with gram-positive bacilli such as Corynebacterium, this association is not well known. We report 3 cases of mastitis caused by gram-positive bacilli. All 3 abscesses were suppurative with distinct enlarged cystic spaces in which rare gram-positive bacilli were identified. Two cases were also granulomatous. Cultures in all 3 cases were negative. All 3 patients recovered after biopsy and tetracycline-based therapy. Infection in the breast by gram-positive bacilli is associated with a distinct histologic pattern, including cystic spaces in the setting of neutrophilic/granulomatous inflammation that can be recognized and should prompt careful search for the organism within enlarged vacuoles.

Dispersion Theory of Direct Nuclear Reactions

Energy Technology Data Exchange (ETDEWEB)

Shapiro, I. S. [Institute Of Theoretical And Experimental Physics, Moscow, USSR (Russian Federation)

1963-01-15

The main difficulty of nuclear theory is that nuclei contain many (i. e. more than two) but not too many particles. Therefore, the precise equations of motion (Schrodinger equation) become practically useless, and at the same time it is impossible to apply statistical methods with confidence. The latter circumstance is graphically expressed in direct nuclear reactions. The essence of these phenomena consists in that a particle hitting the target nucleus transfers its energy and momentum either to one nuclear nucleon or to a comparatively small group of nucleons. This fact would not by itself be surprising if at the same time we did not observe a directly opposite picture corresponding to the production of a compound nucleus, i. e. the statistical distribution among all degrees of freedom of the energy transferred to the nucleus. In macroscopic physics the co-existence of. such processes is impossible since they would contradict the second law of thermodynamics. Such processes occur quite often in nuclear physics because of the inapplic- ability of the asymptotic laws of the theory of probabilities. Since statistical methods were obviously unsuited for the direct process theory, this led to the conviction that it was necessary to return to the Schrodinger equation for a system of many interacting particles. But the technique of solving such equations is still confined to perturbation theory and therefore it was the latter that was used to describe direct nuclear reactions despite the fact that the interaction between nucleons is strong and the application of perturb- ation theory to the interaction of free nucleons (to n-p or p-p scattering, for example) leads to results which strongly contradict experimental data. The results of the application of perturbation theory to direct nuclear reactions sometimes agree with experimental data and sometimes cqntradict them, but in either case they can hardly satisfy the investigator because it seems impossible to give the

Dispersion Theory of Direct Nuclear Reactions

International Nuclear Information System (INIS)

Shapiro, I.S.

1963-01-01

The main difficulty of nuclear theory is that nuclei contain many (i. e. more than two) but not too many particles. Therefore, the precise equations of motion (Schrodinger equation) become practically useless, and at the same time it is impossible to apply statistical methods with confidence. The latter circumstance is graphically expressed in direct nuclear reactions. The essence of these phenomena consists in that a particle hitting the target nucleus transfers its energy and momentum either to one nuclear nucleon or to a comparatively small group of nucleons. This fact would not by itself be surprising if at the same time we did not observe a directly opposite picture corresponding to the production of a compound nucleus, i. e. the statistical distribution among all degrees of freedom of the energy transferred to the nucleus. In macroscopic physics the co-existence of. such processes is impossible since they would contradict the second law of thermodynamics. Such processes occur quite often in nuclear physics because of the inapplic- ability of the asymptotic laws of the theory of probabilities. Since statistical methods were obviously unsuited for the direct process theory, this led to the conviction that it was necessary to return to the Schrodinger equation for a system of many interacting particles. But the technique of solving such equations is still confined to perturbation theory and therefore it was the latter that was used to describe direct nuclear reactions despite the fact that the interaction between nucleons is strong and the application of perturb- ation theory to the interaction of free nucleons (to n-p or p-p scattering, for example) leads to results which strongly contradict experimental data. The results of the application of perturbation theory to direct nuclear reactions sometimes agree with experimental data and sometimes cqntradict them, but in either case they can hardly satisfy the investigator because it seems impossible to give the

Starting off on the right foot: strong right-footers respond faster with the right foot to positive words and with the left foot to negative words.

Science.gov (United States)

de la Vega, Irmgard; Graebe, Julia; Härtner, Leonie; Dudschig, Carolin; Kaup, Barbara

2015-01-01

Recent studies have provided evidence for an association between valence and left/right modulated by handedness, which is predicted by the body-specificity hypothesis (Casasanto, 2009) and also reflected in response times. We investigated whether such a response facilitation can also be observed with foot responses. Right-footed participants classified positive and negative words according to their valence by pressing a key with their left or right foot. A significant interaction between valence and foot only emerged in the by-items analysis. However, when dividing participants into two groups depending on the strength of their footedness, an interaction between valence and left/right was observed for strong right-footers, who responded faster with the right foot to positive words, and with the left foot to negative words. No interaction emerged for weak right-footers. The results strongly support the assumption that fluency lies at the core of the association between valence and left/right.

Computational and experimental studies on stabilities, reactions and reaction rates of cations and ion-dipole complexes

NARCIS (Netherlands)

Ervasti, H.K.

2008-01-01

In this thesis, ion stability, ion-molecule reactions and reaction rates are studied using mass spectrometry and molecular modelling. In Chapter 2 the effect of functional group substitution on neutral and ionised ketene are studied. Electron-donating substituents show a stabilising positive

Systematic uncertainties in direct reaction theories

International Nuclear Information System (INIS)

Lovell, A E; Nunes, F M

2015-01-01

Nuclear reactions are common probes to study nuclei and in particular, nuclei at the limits of stability. The data from reaction measurements depend strongly on theory for a reliable interpretation. Even when using state-of-the-art reaction theories, there are a number of sources of systematic uncertainties. These uncertainties are often unquantified or estimated in a very crude manner. It is clear that for theory to be useful, a quantitative understanding of the uncertainties is critical. Here, we discuss major sources of uncertainties in a variety of reaction theories used to analyze (d,p) nuclear reactions in the energy range E d = 10–20 MeV, and we provide a critical view on how these have been handled in the past and how estimates can be improved. (paper)

Transport processes in exothermic gas-solid reactions

International Nuclear Information System (INIS)

Vijay, P.L.; Sathiyamoorthy, D.

1997-01-01

The variation of the concentration of gaseous reactant, temperature distribution for an exothermic reaction, the diffusivity factor and the reaction ratio profiles with various radial positions of a solid reactant have been computed and illustrated for a specific case of reduction reaction of UO 3 by hydrogen

Cholangiocarcinoma with respect to IgG4 Reaction

Directory of Open Access Journals (Sweden)

Kenichi Harada

2014-01-01

Full Text Available IgG4 reactions marked by infiltration of IgG4-positive plasma cells in affected organs occur in cancer patients and in patients with IgG4-related diseases. Extrahepatic cholangiocarcinomas including gall bladder cancer are often accompanied by significant IgG4 reactions; these reactions show a negative correlation with CD8-positive cytotoxic T cells, suggesting that the evasion of immune surveillance is associated with cytotoxic T cells. The regulatory cytokine IL-10 may induce IgG4-positive plasma cell differentiation or promote B cell switching to IgG4 in the presence of IL-4. Cholangiocarcinoma cells may function as nonprofessional antigen presenting cells that indirectly induce IgG4 reactions via the IL-10-producing cells and/or these may act as Foxp3-positive and IL-10-producing cells that directly induce IgG4 reactions. Moreover, IgG4-related disease is a high-risk factor for cancer development; IgG4-related sclerosing cholangitis (IgG4-SC cases associated with cholangiocarcinoma or its precursor lesion biliary intraepithelial neoplasia (BilIN have been reported. IgG4-positive cell infiltration is an important finding of IgG4-SC but is not a histological hallmark of IgG4-SC. For the diagnosis of IgG4-SC, its differentiation from cholangiocarcinoma remains important.

The path to improved reaction rates for astrophysics

International Nuclear Information System (INIS)

Rauscher, T.

2011-01-01

This review focuses on nuclear reactions in astrophysics and, more specifically, on reactions with light ions (nucleons and α particles) proceeding via the strong interaction. It is intended to present the basic definitions essential for studies in nuclear astrophysics, to point out the differences between nuclear reactions taking place in stars and in a terrestrial laboratory, and to illustrate some of the challenges to be faced in theoretical and experimental studies of those reactions. The discussion revolves around the relevant quantities for astrophysics, which are the astrophysical reaction rates. The sensitivity of the reaction rates to the uncertainties in the prediction of various nuclear properties is explored and some guidelines for experimentalists are also provided. (author)

Heavy-ion induced multinucleon transfer reactions in the 2s--1d shell

International Nuclear Information System (INIS)

Olmer, C.

1975-01-01

In order to investigate whether new nuclear structure information can be obtained from studying the direct transfer of more than two nucleons using heavy-ion projectiles, we have investigated the 28 Si( 16 O, 12 C) 32 S and 12 C( 14 N,d) 24 Mg reactions as candidates for the direct transfer of four- and twelve-nucleons, respectively. The counter telescope-position sensitive detector kinematic coincidence method--both angular distributions (22 0 less than theta/sub L/ less than 95 0 , E/sub L/ = 55.54 MeV) and excitation functions (theta/sub L/ = 26 0 , 50 less than E/sub L/ less than 63 MeV) were obtained for strongly excited states below 10 MeV in excitation in the first reaction. For the 12 C + 14 N interaction, a measurement of the angular distributions (25 0 less than theta/sub L/ less than 140 0 , E/sub L/ = 20,25 MeV) for proton, deuteron and alpha-particle emission to many low-lying states sufficed for the present purposes. Comparison of Hauser-Feshbach statistical model calculations with these data indicated that the light-particle production from the 12 C + 14 N interaction as investigated here is predominantly compound nuclear in nature. The selectively strong population of a few states in 32 S by the 28 Si-( 16 O, 12 C) 32 S reaction is primarily direct. The structure of these states was deduced from available light-ion-induced transfer reaction studies and shell model calculations; the importance of shell model configurations is indicated, and an alpha-particle transfer model can not account for the observed selectivity. Calculations of the 28 Si( 16 O, 12 C) 32 S reaction with a microscopic multinucleon transfer code indicate selectivities consistent with the present results. Moreover, the calculations suggest the presence of other, unexpected selectivities, all of which may be understood on a physical basis, and some of which appear as an extension of a similar effect seen in two-nucleon transfer reactions

Interaction of a neutral composite particle with a strong Coulomb field

International Nuclear Information System (INIS)

Wong, Cheuk-Yin.

1988-01-01

The author discusses the interaction of the quasi-composite (e/sup /plus//e/sup /minus//) system with an external electromagnetic field. This problem addresses the question of the origin of strong positron lines in quasi-elastic heavy-ion reactions. 3 refs

Time behaviour of the reaction front in the catalytic A + B → B + C reaction-diffusion processes

International Nuclear Information System (INIS)

Nicolini, F.G.; Rodriguez, M.A.; Wio, H.S.

1994-07-01

The problem of the time evolution of the position and width of a reaction front between initially separated reactants for the catalytic reaction A + B → B + C (C inert) is treated within a recently introduced Galanin-like scheme. (author). 6 refs

Energy, Electron Transfer and Photocatalytic Reactions of Visible Light Absorbing Transition Metal Complexes

Energy Technology Data Exchange (ETDEWEB)

Schmehl, Russell H. [Tulane Univ., New Orleans, LA (United States)

2016-03-02

This is the final technical report for a project carried out at Tulane University of New Orleans that describes the development of light induced (solar) reactions geared toward decomposing water into its component elements : hydrogen and oxygen. Much of the work involved optimizing systems for absorbing visible light and undergoing light promoted reactions to generate very strong reducing agents that are capable of reacting with water to produce hydrogen. Additional portions of the research were collaborative efforts to put the strong reducing agents to work in reaction with hydrogen generation catalysts prepared elsewhere. Time resolved laser spectroscopic methods were used to evaluate the light induced reactions and characterize very reactive intermediate substances formed during the reactions.

Including lateral interactions into microkinetic models of catalytic reactions

DEFF Research Database (Denmark)

Hellman, Anders; Honkala, Johanna Karoliina

2007-01-01

In many catalytic reactions lateral interactions between adsorbates are believed to have a strong influence on the reaction rates. We apply a microkinetic model to explore the effect of lateral interactions and how to efficiently take them into account in a simple catalytic reaction. Three differ...... different approximations are investigated: site, mean-field, and quasichemical approximations. The obtained results are compared to accurate Monte Carlo numbers. In the end, we apply the approximations to a real catalytic reaction, namely, ammonia synthesis....

Micellar Catalysis of Diels-Alder Reactions : Substrate Positioning in the Micelle

NARCIS (Netherlands)

Rispens, Theo; Engberts, Jan B.F.N.

2002-01-01

We have studied the kinetics of the Diels-Alder reactions of cyclopentadiene, sorbyl alcohol, and sorbyltrimethylammonium bromide with a series of N-substituted maleimides in micellar media. Micellar rate constants have been determined and were found to be 20-40 times lower than the respective

Electromagnetic radiation from positive-energy bound electrons in the Coulomb field of a nucleus at rest in a strong uniform magnetic field

Energy Technology Data Exchange (ETDEWEB)

Arsenyev, S. A.; Koryagin, S. A., E-mail: koryagin@appl.sci-nnov.ru [Russian Academy of Sciences, Institute of Applied Physics (Russian Federation)

2012-06-15

A classical analysis is presented of the electromagnetic radiation emitted by positive-energy electrons performing bound motion in the Coulomb field of a nucleus at rest in a strong uniform magnetic field. Bounded trajectories exist and span a wide range of velocity directions near the nucleus (compared to free trajectories with similar energies) when the electron Larmor radius is smaller than the distance at which the electron-nucleus Coulomb interaction energy is equal to the mechanical energy of an electron. The required conditions occur in magnetic white dwarf photospheres and have been achieved in experiments on production of antihydrogen. Under these conditions, the radiant power per unit volume emitted by positive-energy bound electrons is much higher than the analogous characteristic of bremsstrahlung (in particular, in thermal equilibrium) at frequencies that are below the electron cyclotron frequency but higher than the inverse transit time through the interaction region in a close collision in the absence of a magnetic field. The quantum energy discreteness of positive-energy bound states restricts the radiation from an ensemble of bound electrons (e.g., in thermal equilibrium) to nonoverlapping spectral lines, while continuum radiative transfer is dominated by linearly polarized bremsstrahlung.

Age differences in emotional reactions: arousal and age-relevance count.

Science.gov (United States)

Streubel, Berit; Kunzmann, Ute

2011-12-01

Recent findings suggest positivity effects in older adults' attention and memory, but few studies have examined such effects on the level of emotional reactivity. In this study, 52 young and 52 older adults rated 172 pictures of the International Affective Picture System, differing in arousal and age-relevance, in terms of valence and discrete emotions. Age differences in the ratio of pleasantness reactions to pleasant pictures vs. unpleasantness reactions to unpleasant pictures as well as age differences in absolute levels of unpleasantness and pleasantness reactions suggest that positivity effects in older adults' subjective emotional reactions are reduced under high arousal. There is also evidence that positivity effects may be restricted to stimuli with low relevance in old age.

Distortion effects in pion-induced knock-out reactions

International Nuclear Information System (INIS)

Jain, B.K.

The cross-section for (π + ,π + p) reaction on 12 C is calculated in DWIA at 100 and 180 MeV incident energy. The effect of pion distortion is found to be strong. Around 180 MeV the effect is strongly absorptive while around 10O MeV it is mainly dispersive. (auth.)

Maximum Principles for Discrete and Semidiscrete Reaction-Diffusion Equation

Directory of Open Access Journals (Sweden)

Petr Stehlík

2015-01-01

Full Text Available We study reaction-diffusion equations with a general reaction function f on one-dimensional lattices with continuous or discrete time ux′  (or  Δtux=k(ux-1-2ux+ux+1+f(ux, x∈Z. We prove weak and strong maximum and minimum principles for corresponding initial-boundary value problems. Whereas the maximum principles in the semidiscrete case (continuous time exhibit similar features to those of fully continuous reaction-diffusion model, in the discrete case the weak maximum principle holds for a smaller class of functions and the strong maximum principle is valid in a weaker sense. We describe in detail how the validity of maximum principles depends on the nonlinearity and the time step. We illustrate our results on the Nagumo equation with the bistable nonlinearity.

Modeling chemical reactions for drug design.

Science.gov (United States)

Gasteiger, Johann

2007-01-01

Chemical reactions are involved at many stages of the drug design process. This starts with the analysis of biochemical pathways that are controlled by enzymes that might be downregulated in certain diseases. In the lead discovery and lead optimization process compounds have to be synthesized in order to test them for their biological activity. And finally, the metabolism of a drug has to be established. A better understanding of chemical reactions could strongly help in making the drug design process more efficient. We have developed methods for quantifying the concepts an organic chemist is using in rationalizing reaction mechanisms. These methods allow a comprehensive modeling of chemical reactivity and thus are applicable to a wide variety of chemical reactions, from gas phase reactions to biochemical pathways. They are empirical in nature and therefore allow the rapid processing of large sets of structures and reactions. We will show here how methods have been developed for the prediction of acidity values and of the regioselectivity in organic reactions, for designing the synthesis of organic molecules and of combinatorial libraries, and for furthering our understanding of enzyme-catalyzed reactions and of the metabolism of drugs.

Pharmacogenetics and Predictive Testing of Drug Hypersensitivity Reactions.

Science.gov (United States)

Böhm, Ruwen; Cascorbi, Ingolf

2016-01-01

Adverse drug reactions adverse drug reaction (ADR) occur in approximately 17% of patients. Avoiding ADR is thus mandatory from both an ethical and an economic point of view. Whereas, pharmacogenetics changes of the pharmacokinetics may contribute to the explanation of some type A reactions, strong relationships of genetic markers has also been shown for drug hypersensitivity belonging to type B reactions. We present the classifications of ADR, discuss genetic influences and focus on delayed-onset hypersensitivity reactions, i.e., drug-induced liver injury, drug-induced agranulocytosis, and severe cutaneous ADR. A guidance how to read and interpret the contingency table is provided as well as an algorithm whether and how a test for a pharmacogenetic biomarker should be conducted.

Kiss-induced severe anaphylactic reactions

Directory of Open Access Journals (Sweden)

Atanasković-Marković Marina

2010-01-01

Full Text Available Introduction. Ingestion is the principal route for food allergens to trigger allergic reaction in atopic persons. However, in some highly sensitive patients severe symptoms may develop upon skin contact and by inhalation. The clinical spectrum ranges from mild facial urticaria and angioedema to life-threatening anaphylactic reactions. Outline of Cases. We describe cases of severe anaphylactic reactions by skin contact, induced by kissing in five children with prior history of severe anaphylaxis caused by food ingestion. These cases were found to have the medical history of IgE mediated food allergy, a very high total and specific serum IgE level and very strong family history of allergy. Conclusion. The presence of tiny particles of food on the kisser's lips was sufficient to trigger an anaphylactic reaction in sensitized children with prior history of severe allergic reaction caused by ingestion of food. Allergic reaction provoked with food allergens by skin contact can be a risk factor for generalized reactions. Therefore, extreme care has to be taken in avoiding kissing allergic children after eating foods to which they are highly allergic. Considering that kissing can be a cause of severe danger for the food allergic patient, such persons should inform their partners about the risk factor for causing their food hypersensitivity.

Permanganate oxidation of α-amino acids: kinetic correlations for the nonautocatalytic and autocatalytic reaction pathways.

Science.gov (United States)

Perez-Benito, Joaquin F

2011-09-08

The reactions of permanganate ion with seven α-amino acids in aqueous KH(2)PO(4)/K(2)HPO(4) buffers have been followed spectrophotometrically at two different wavelengths: 526 nm (decay of MnO(4)(-)) and 418 nm (formation of colloidal MnO(2)). All of the reactions studied were autocatalyzed by colloidal MnO(2), with the contribution of the autocatalytic reaction pathway decreasing in the order glycine > l-threonine > l-alanine > l-glutamic acid > l-leucine > l-isoleucine > l-valine. The rate constants corresponding to the nonautocatalytic and autocatalytic pathways were obtained by means of either a differential rate law or an integrated one, the latter requiring the use of an iterative method for its implementation. The activation parameters for the two pathways were determined and analyzed to obtain statistically significant correlations for the series of reactions studied. The activation enthalpy of the nonautocatalytic pathway showed a strong, positive dependence on the standard Gibbs energy for the dissociation of the protonated amino group of the α-amino acid. Linear enthalpy-entropy correlations were found for both pathways, leading to isokinetic temperatures of 370 ± 21 K (nonautocatalytic) and 364 ± 28 K (autocatalytic). Mechanisms in agreement with the experimental data are proposed for the two reaction pathways.

Youth Reactions to Participation in Psychological Assessment Procedures

Science.gov (United States)

Saldana, Lisa; DuBois, David L.

2006-01-01

This study investigates self-reported positive and negative reactions of youth to psychological assessment procedures. A community sample (COM) reported reactions to completing a self-report questionnaire of negative emotional states. A clinical sample (CL) reported reactions both to completion of the questionnaire and to a clinical intake.…

Synthesis and stability of strongly acidic benzamide derivatives

DEFF Research Database (Denmark)

Diness, Frederik; Bjerrum, Niels J.; Begtrup, Mikael

2018-01-01

Reactivity studies of strong organic acids based on the replacement of one or both of the oxygens in benzoic acids with the trifluoromethanesulfonamide group are reported. Novel derivatives of these types of acids were synthesized in good yields. The generated N-triflylbenzamides were further...... functionalized through cross-coupling and nucleophilic aromatic substitution reactions. All compounds were stable in dilute aqueous solutions. Studies of stability under acidic and basic conditions are also reported....

Diagnostic impact of thallium scintigraphy and cardiac fluoroscopy when the exercise ECG is strongly positive

International Nuclear Information System (INIS)

Chaitman, B.R.; Brevers, G.; Dupras, G.; Lesperance, J.; Bourassa, M.G.

1984-01-01

We studied 83 men, who had a chest pain syndrome, no prior history of myocardial infarction, and exercise-induced horizontal or downsloping ST segment depression greater than or equal to 0.2 mV. The 38 patients unable to complete Bruce stage II had a significant increased risk of coronary (0.97 vs 0.71) and multivessel (0.88 vs 0.61) disease (p less than 0.01) compared to the pretest risk; data obtained from exercise-reperfusion thallium scintigraphy and cardiac fluoroscopy did not alter the risk of coronary or multivessel disease. The 45 patients who had ST depression greater than or equal to 0.2 mV and a peak work capacity greater than or equal to Bruce stage III did not have a significant increased risk of coronary (0.76) or multivessel disease (0.44). When both exercise-reperfusion thallium scintigraphy and cardiac fluoroscopy were abnormal in this latter patient subgroup, the post-test risk of multivessel disease was increased from 0.44 to 0.82 (p less than 0.03); when both tests were normal, none of the patients had multivessel disease (p less than 0.03) and only 0.18 had coronary artery disease. Thus, cardiac fluoroscopy and exercise thallium scintigraphy increase the diagnostic content of the strongly positive exercise ECG, particularly in men who have a peak work capacity greater than or equal to Bruce stage III

Imaging the electron transfer reaction of Ne2+ with Ar using position-sensitive coincidence spectroscopy

International Nuclear Information System (INIS)

Harper, Sarah M; Hu Wanping; Price, Stephen D

2002-01-01

A new experiment, employing position-sensitive detection coupled with time-of-flight mass spectrometry, has been used to investigate the single-electron transfer reaction between Ne 2+ and Ar by detecting the resulting pairs of singly charged ions in coincidence. The experimental technique allows the determination of the individual velocity vectors of the ionic products, in the centre-of-mass frame, for each reactive event detected. The experiments show that forward scattering dominates the reactivity, although a bimodal angular distribution is apparent. In addition, the spectra show that at laboratory frame collision energies from 4-14 eV the reactivity is dominated by Ne 2+ (2p 4 , 3 P) accepting an electron from an argon atom to form the ground state of Ne + together with an Ar + ion in an excited electronic level, predominantly arising from the Ar + (3s 2 3p 4 3d) configuration. The form of this reactivity, and the differences between the reactivity observed in these experiments and those performed at higher collision energies, are well reproduced by Landau-Zener theory

Imaging the reactions of molecular dications: a new probe of dicationic reaction dynamics and energetics

International Nuclear Information System (INIS)

Wan-Ping Hu, S.; Harper, S.M.; Price, S.D.

2002-01-01

Experiments which generated angularly resolved data to prove the dynamics of dication chemical reactions were performed using a position sensitive coincidence (PSCO) apparatus, to detect in coincidence both of the charged products from such reaction. It consists of a ion source, a hemispherical energy analyser, and a time-of-flight mass spectrometer. Initial experiments to test the apparatus performance were runned on the atomic electron transfer reaction: Ne 2+ + Ar → Ne + + Ar + . Angular distributions, translational and internal energies of the product ions were extracted, as well as the scattering diagram among other data. (nevyjel)

Genetic signature of strong recent positive selection at interleukin-32 gene in goat

Directory of Open Access Journals (Sweden)

Akhtar Rasool Asif

2017-07-01

Full Text Available Objective Identification of the candidate genes that play key roles in phenotypic variations can provide new information about evolution and positive selection. Interleukin (IL-32 is involved in many biological processes, however, its role for the immune response against various diseases in mammals is poorly understood. Therefore, the current investigation was performed for the better understanding of the molecular evolution and the positive selection of single nucleotide polymorphisms in IL-32 gene. Methods By using fixation index (FST based method, IL-32 (9375 gene was found to be outlier and under significant positive selection with the provisional combined allocation of mean heterozygosity and FST. Using nucleotide sequences of 11 mammalian species from National Center for Biotechnology Information database, the evolutionary selection of IL-32 gene was determined using Maximum likelihood model method, through four models (M1a, M2a, M7, and M8 in Codeml program of phylogenetic analysis by maximum liklihood. Results IL-32 is detected under positive selection using the FST simulations method. The phylogenetic tree revealed that goat IL-32 was in close resemblance with sheep IL-32. The coding nucleotide sequences were compared among 11 species and it was found that the goat IL-32 gene shared identity with sheep (96.54%, bison (91.97%, camel (58.39%, cat (56.59%, buffalo (56.50%, human (56.13%, dog (50.97%, horse (54.04%, and rabbit (53.41% respectively. Conclusion This study provides evidence for IL-32 gene as under significant positive selection in goat.

Diels-Alder reactions in confined spaces: the influence of catalyst structure and the nature of active sites for the retro-Diels-Alder reaction.

Science.gov (United States)

Cantín, Ángel; Gomez, M Victoria; de la Hoz, Antonio

2016-01-01

Diels-Alder cycloaddition between cyclopentadiene and p -benzoquinone has been studied in the confined space of a pure silica zeolite Beta and the impact on reaction rate due to the concentration effect within the pore and diffusion limitations are discussed. Introduction of Lewis or Brønsted acid sites on the walls of the zeolite strongly increases the reaction rate. However, contrary to what occurs with mesoporous molecular sieves (MCM-41), Beta zeolite does not catalyse the retro-Diels-Alder reaction, resulting in a highly selective catalyst for the cycloaddition reaction.

Entropy Generation in a Chemical Reaction

Science.gov (United States)

Miranda, E. N.

2010-01-01

Entropy generation in a chemical reaction is analysed without using the general formalism of non-equilibrium thermodynamics at a level adequate for advanced undergraduates. In a first approach to the problem, the phenomenological kinetic equation of an elementary first-order reaction is used to show that entropy production is always positive. A…

Dynamics of anion-molecule reactions at low energy

International Nuclear Information System (INIS)

Mikosch, J.

2007-11-01

Anion-molecule reactions must find their way through deeply bound entrance and exit channel complexes separated by a central barrier. This results in low reaction rates and rich dynamics since direct pathways compete with the formation of transient intermediates. In this thesis we examine the probability of proton transfer to a small anion and transient lifetimes of a thermoneutral bimolecular nucleophilic substitution (S N 2) reaction at well defined variable temperature down to 8 Kelvin in a multipole trap. The observed strong inverse temperature dependence is attributed to the deficit of available quantum states in the entrance channel at decreasing temperature. Furthermore we investigate scattering dynamics of S N 2 reactions at defined relative energy between 0.4 and 10 eV by crossed beam slice imaging. A weakly exothermic reaction with high central barrier proceeds via an indirect, complex-mediated mechanism at low relative energies featuring high internal product excitation in excellent quantitative agreement with a statistical model. In contrast, direct backward scattering prevails for higher energies with product velocities close to the kinematical cutoff. For a strongly exothermic reaction, competing S N 2-, dihalide- and proton transfer-channels are explored which proceed by complex mediation for low energy and various rebound-, grazing- and collision induced bond rupture-mechanisms at higher energy. From our data and a collaboration with theory we identify a new indirect roundabout S N 2 mechanism involving CH 3 -rotation. (orig.)

Dynamics of anion-molecule reactions at low energy

Energy Technology Data Exchange (ETDEWEB)

Mikosch, J.

2007-11-15

Anion-molecule reactions must find their way through deeply bound entrance and exit channel complexes separated by a central barrier. This results in low reaction rates and rich dynamics since direct pathways compete with the formation of transient intermediates. In this thesis we examine the probability of proton transfer to a small anion and transient lifetimes of a thermoneutral bimolecular nucleophilic substitution (S{sub N}2) reaction at well defined variable temperature down to 8 Kelvin in a multipole trap. The observed strong inverse temperature dependence is attributed to the deficit of available quantum states in the entrance channel at decreasing temperature. Furthermore we investigate scattering dynamics of S{sub N}2 reactions at defined relative energy between 0.4 and 10 eV by crossed beam slice imaging. A weakly exothermic reaction with high central barrier proceeds via an indirect, complex-mediated mechanism at low relative energies featuring high internal product excitation in excellent quantitative agreement with a statistical model. In contrast, direct backward scattering prevails for higher energies with product velocities close to the kinematical cutoff. For a strongly exothermic reaction, competing S{sub N}2-, dihalide- and proton transfer-channels are explored which proceed by complex mediation for low energy and various rebound-, grazing- and collision induced bond rupture-mechanisms at higher energy. From our data and a collaboration with theory we identify a new indirect roundabout S{sub N}2 mechanism involving CH{sub 3}-rotation. (orig.)

Quasielastic reactions

International Nuclear Information System (INIS)

Hansen, O.

1983-01-01

A brief review is presented of the experimental and theoretical situation regarding transfer reactions and inelastic scattering. In the first category there is little (very little) precision data for heavy projectiles and consequently almost no experience with quantitative theoretical analysis. For the inelastic scattering the rather extensive data strongly supports the coupled channels models with collective formfactors. At the most back angles, at intensities about 10 -5 of Rutherford scattering, a second, compound-like mechanism becomes dominant. The description of the interplay of these two opposite mechanisms provides a new challenge for our understanding

Limonene hydroperoxide analogues show specific patch test reactions.

Science.gov (United States)

Christensson, Johanna Bråred; Hellsén, Staffan; Börje, Anna; Karlberg, Ann-Therese

2014-05-01

The fragrance terpene R-limonene is a very weak sensitizer, but forms allergenic oxidation products upon contact with air. The primary oxidation products of oxidized limonene, the hydroperoxides, have an important impact on the sensitizing potency of the oxidation mixture. One analogue, limonene-1-hydroperoxide, was experimentally shown to be a significantly more potent sensitizer than limonene-2-hydroperoxide in the local lymph node assay with non-pooled lymph nodes. To investigate the pattern of reactivity among consecutive dermatitis patients to two structurally closely related limonene hydroperoxides, limonene-1-hydroperoxide and limonene-2-hydroperoxide. Limonene-1-hydroperoxide, limonene-2-hydroperoxide, at 0.5% in petrolatum, and oxidized limonene 3.0% pet. were tested in 763 consecutive dermatitis patients. Of the tested materials, limonene-1-hydroperoxide gave most reactions, with 2.4% of the patients showing positive patch test reactions. Limonene-2-hydroperoxide and oxidized R-limonene gave 1.7% and 1.2% positive patch test reactions, respectively. Concomitant positive patch test reactions to other fragrance markers in the baseline series were frequently noted. The results are in accordance with the experimental studies, as limonene-1-hydroperoxide gave more positive patch test reactions in the tested patients than limonene-2-hydroperoxide. Furthermore, the results support the specificity of the allergenic activity of the limonene hydroperoxide analogues and the importance of oxidized limonene as a cause of contact allergy. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Strongly coupled inorganic/nanocarbon hybrid materials for advanced electrocatalysis.

Science.gov (United States)

Liang, Yongye; Li, Yanguang; Wang, Hailiang; Dai, Hongjie

2013-02-13

Electrochemical systems, such as fuel cell and water splitting devices, represent some of the most efficient and environmentally friendly technologies for energy conversion and storage. Electrocatalysts play key roles in the chemical processes but often limit the performance of the entire systems due to insufficient activity, lifetime, or high cost. It has been a long-standing challenge to develop efficient and durable electrocatalysts at low cost. In this Perspective, we present our recent efforts in developing strongly coupled inorganic/nanocarbon hybrid materials to improve the electrocatalytic activities and stability of inorganic metal oxides, hydroxides, sulfides, and metal-nitrogen complexes. The hybrid materials are synthesized by direct nucleation, growth, and anchoring of inorganic nanomaterials on the functional groups of oxidized nanocarbon substrates including graphene and carbon nanotubes. This approach affords strong chemical attachment and electrical coupling between the electrocatalytic nanoparticles and nanocarbon, leading to nonprecious metal-based electrocatalysts with improved activity and durability for the oxygen reduction reaction for fuel cells and chlor-alkali catalysis, oxygen evolution reaction, and hydrogen evolution reaction. X-ray absorption near-edge structure and scanning transmission electron microscopy are employed to characterize the hybrids materials and reveal the coupling effects between inorganic nanomaterials and nanocarbon substrates. Z-contrast imaging and electron energy loss spectroscopy at single atom level are performed to investigate the nature of catalytic sites on ultrathin graphene sheets. Nanocarbon-based hybrid materials may present new opportunities for the development of electrocatalysts meeting the requirements of activity, durability, and cost for large-scale electrochemical applications.

Nestin- and doublecortin-positive cells reside in adult spinal cord meninges and participate in injury-induced parenchymal reaction.

Science.gov (United States)

Decimo, Ilaria; Bifari, Francesco; Rodriguez, Francisco Javier; Malpeli, Giorgio; Dolci, Sissi; Lavarini, Valentina; Pretto, Silvia; Vasquez, Sandra; Sciancalepore, Marina; Montalbano, Alberto; Berton, Valeria; Krampera, Mauro; Fumagalli, Guido

2011-12-01

Adult spinal cord has little regenerative potential, thus limiting patient recovery following injury. In this study, we describe a new population of cells resident in the adult rat spinal cord meninges that express the neural stem/precursor markers nestin and doublecortin. Furthermore, from dissociated meningeal tissue a neural stem cell population was cultured in vitro and subsequently shown to differentiate into functional neurons or mature oligodendrocytes. Proliferation rate and number of nestin- and doublecortin-positive cells increased in vivo in meninges following spinal cord injury. By using a lentivirus-labeling approach, we show that meningeal cells, including nestin- and doublecortin-positive cells, migrate in the spinal cord parenchyma and contribute to the glial scar formation. Our data emphasize the multiple roles of meninges in the reaction of the parenchyma to trauma and indicate for the first time that spinal cord meninges are potential niches harboring stem/precursor cells that can be activated by injury. Meninges may be considered as a new source of adult stem/precursor cells to be further tested for use in regenerative medicine applied to neurological disorders, including repair from spinal cord injury. Copyright © 2011 AlphaMed Press.

Statics and thermodynamics of strongly coupled multicomponent plasmas

International Nuclear Information System (INIS)

Rosenfeld, Y.

1980-01-01

A description of strongly coupled plasmas, in which the direct correlation functions, c/sub i/j(r), are obtained by simple scaling from a universal function, is derived and found to be in full agreement with available computer simulation data, which it thus extends for arbitrary mixtures. It is thermodynamically consistent with the ''ion-sphere'' charge-averaging prediction for the enhancement factors for nuclear reaction rates, the results for which confirm the universality of the bridge functions for mixtures

Temperature dependence on sodium-water chemical reaction

International Nuclear Information System (INIS)

Tamura, Kenta; Deguchi, Yoshihiro; Suzuki, Koichi; Takata, Takashi; Yamaguchi, Akira; Kikuchi, Shin; Ohshima, Hiroyuki

2012-01-01

In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes. This process ends up damages on the heat transport equipment in the SFR. Therefore, the study on sodium-water chemical reactions is of paramount importance for security reasons. This study aims to clarify the sodium-water reaction mechanisms using laser diagnostics. A quasi one-dimensional flame model is also applied to a sodium-water counter-flow reaction field. Temperature, H 2 , H 2 O, OH, Na and Particulate matter were measured using laser induced fluorescence and CARS in the counter-flow reaction field. The temperature of the reaction field was also modified to reduce the condensation of Na in the reaction zone. (author)

Gram-negative, but not Gram-positive, bacteria elicit strong PGE2 production in human monocytes.

Science.gov (United States)

Hessle, Christina C; Andersson, Bengt; Wold, Agnes E

2003-12-01

Gram-positive and Gram-negative bacteria induce different cytokine patterns in human mononuclear cells. We have seen that Gram-positives preferentially induce IL-12 and TNF-alpha, whereas Gram-negatives induce more IL-10, IL-6, and IL-8. In this study, we compared the capacity of these two groups of bacteria to induce PGE2. Monocytes stimulated with Gram-negative bacterial species induced much more PGE2 than did Gram-positive bacteria (5600 +/- 330 vs. 1700 +/- 670 pg/mL, p Gram-positive and Gram-negative bacteria. We suggest that Gram-positive and Gram-negative bacteria may stimulate different innate effector functions; Gram-positive bacteria promoting cell-mediated effector functions whereas Gram-negative bacteria inducing mediators inhibiting the same.

Epicardial adipose tissue volume and adipocytokine imbalance are strongly linked to human coronary atherosclerosis.

Science.gov (United States)

Shimabukuro, Michio; Hirata, Yoichiro; Tabata, Minoru; Dagvasumberel, Munkhbaatar; Sato, Hiromi; Kurobe, Hirotsugu; Fukuda, Daiju; Soeki, Takeshi; Kitagawa, Tetsuya; Takanashi, Shuichiro; Sata, Masataka

2013-05-01

The impact of epicardial adipose tissue (EAT) over abdominal or overall adiposity on coronary artery disease (CAD) is currently unknown. We compared the association among EAT volume (EATV), cytokine/adipocytokine profiles in EAT and subcutaneous fat, and atherogenic CAD. Paired samples were obtained from EAT and subcutaneous adipose tissue during elective cardiac surgery for CAD (n=50) or non-CAD (n=50). EATV was the sum of cross-sectional EAT areas, and visceral and subcutaneous fat areas were determined at the umbilicus level on computed tomography scans. CD68(+), CD11c(+), and CD206(+) cells were counted using immunohistochemical staining. Cytokine/adipocytokine expression was evaluated using quantitative real-time polymerase chain reaction. Multivariate analysis indicated that male sex, age, diabetes mellitus, high triglycerides, and low high-density lipoprotein cholesterol, and EATV index (EATV/body surface area, cm(3)/m(2)) were significant CAD predictors (corrected R(2)=0.401; PEATV index positively correlated with the CD68(+) and CD11c(+) cell numbers and nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3 (NLRP3), interleukin-1β, and interleukin-1R expression; and negatively correlated with adiponectin expression in EAT. A multivariate analysis model, including CD68(+) cells and interleukin-1β, and adiponectin expression in EAT strongly predicted CAD (corrected R(2)=0.756; PEATV and macrophage and cytokine/adipocytokine signals in EAT strongly correlated with CAD. Our findings suggest that EATV and adipocytokine imbalance are strongly linked to human coronary atherosclerosis.

Strongly not relatives Kähler manifolds

Directory of Open Access Journals (Sweden)

Zedda Michela

2017-02-01

Full Text Available In this paper we study Kähler manifolds that are strongly not relative to any projective Kähler manifold, i.e. those Kähler manifolds that do not share a Kähler submanifold with any projective Kähler manifold even when their metric is rescaled by the multiplication by a positive constant. We prove two results which highlight some relations between this property and the existence of a full Kähler immersion into the infinite dimensional complex projective space. As application we get that the 1-parameter families of Bergman-Hartogs and Fock-Bargmann-Hartogs domains are strongly not relative to projective Kähler manifolds.

The positions effect of biarticular muscles on the walking fatigue of bipedal robots

Directory of Open Access Journals (Sweden)

Brahim FERNINI

2016-12-01

Full Text Available The objective of this paper is to model a bipedal robot with springs like biarticular muscles and to study the positions effect of biarticular muscles on the walking fatigue of bipedal robots through the analysis of the works of the ground reaction force (GRF accumulated at joints and the analysis of the works done by biarticular muscles. We can define the walking fatigue in this paper by the fatigue of joints and muscles caused by the increment of the works accumulated at joints and the increment of the works done by biarticular muscles during the walk period of bipedal robots. It’s found from this study that the position of the muscle biceps femoris (BF has a strong impact on the fatigue of leg joints and the fatigue of the muscle itself during the walk period of bipedal robots.

Unimolecular and collisionally induced ion reactions

International Nuclear Information System (INIS)

Beynon, J.H.; Boyd, R.K.

1978-01-01

The subject is reviewed under the following headings: introduction (mass spectroscopy and the study of fragmentation reactions of gaseous positive ions); techniques and methods (ion sources, detection systems, analysis of ions, data reduction); collision-induced reactions of ions and unimolecular fragmentations of metastable ions; applications (ion structure, energetic measurements, analytical applications, other applications). 305 references. (U.K.)

A strongly nonlinear reaction-diffusion model for a deterministic diffusive epidemic

International Nuclear Information System (INIS)

Kirane, M.; Kouachi, S.

1992-10-01

In the present paper the mathematical validity of a model on the spread of an infectious disease is proved. This model was proposed by Bailey. The mathematical validity is proved by means of a positivity, uniqueness and existence theorem. In spite of the apparent simplicity of the problem, the solution requires a delicate set of techniques. It seems very difficult to extend these techniques to a model in more than one dimension without imposing conditions on the diffusivities. (author). 7 refs

Position-specific isotope modeling of organic micropollutants transformation through different reaction pathways

DEFF Research Database (Denmark)

Jin, Biao; Rolle, Massimo

2016-01-01

The degradation of organic micropollutants occurs via different reaction pathways. Compound specific isotope analysis is a valuable tool to identify such degradation pathways in different environmental systems. We propose a mechanism-based modeling approach that provides a quantitative framework ...

Adverse reactions and other factors that impact subsequent blood donation visits.

Science.gov (United States)

Custer, Brian; Rios, Jorge A; Schlumpf, Karen; Kakaiya, Ram M; Gottschall, Jerome L; Wright, David J

2012-01-01

The importance of adverse reactions in terms of donor safety recently has received significant attention, but their role in subsequent donation behavior has not been thoroughly investigated. Six REDS-II blood centers provided data for this analysis. Summary minor and major adverse reaction categories were created. The influence of adverse reactions on donation was examined in two ways: Kaplan-Meier curves were generated to determine the cumulative pattern of first return, and adjusted odds ratios (AORs) for demographic and other factors positively and negatively associated with return were estimated using multivariable logistic regression. Donors who had major reactions had longer times to return than donors with minor or no reactions. The AOR of returning for donors with major reactions was 0.32 (95% confidence interval [CI], 0.28-0.37) and with minor reactions 0.59 (95% CI, 0.56-0.62) when compared to donors who did not have reactions. Conversely, the most important factors positively associated with return were the number of donations in the previous year and increasing age. Subsequent return, whether a major, minor, or no reaction occurred, varied by blood center. Factors that are associated with the risk of having adverse reactions were not substantial influences on the return after adverse reactions. Having an adverse reaction leads to significantly lower odds of subsequent donation irrespective of previous donation history. Factors that have been associated with a greater risk of adverse reactions were not important positive or negative predictors of return after a reaction. © 2011 American Association of Blood Banks.

Spontaneous Hedonic Reactions to Social Media Cues.

Science.gov (United States)

van Koningsbruggen, Guido M; Hartmann, Tilo; Eden, Allison; Veling, Harm

2017-05-01

Why is it so difficult to resist the desire to use social media? One possibility is that frequent social media users possess strong and spontaneous hedonic reactions to social media cues, which, in turn, makes it difficult to resist social media temptations. In two studies (total N = 200), we investigated less-frequent and frequent social media users' spontaneous hedonic reactions to social media cues using the Affect Misattribution Procedure-an implicit measure of affective reactions. Results demonstrated that frequent social media users showed more favorable affective reactions in response to social media (vs. control) cues, whereas less-frequent social media users' affective reactions did not differ between social media and control cues (Studies 1 and 2). Moreover, the spontaneous hedonic reactions to social media (vs. control) cues were related to self-reported cravings to use social media and partially accounted for the link between social media use and social media cravings (Study 2). These findings suggest that frequent social media users' spontaneous hedonic reactions in response to social media cues might contribute to their difficulties in resisting desires to use social media.

The Dutch Brucella abortus monitoring programme for cattle: the impact of false-positive serological reactions and comparison of serological tests.

Science.gov (United States)

Emmerzaal, A; de Wit, J J; Dijkstra, Th; Bakker, D; van Zijderveld, F G

2002-02-01

The Dutch national Brucella abortus eradication programme for cattle started in 1959. Sporadic cases occurred yearly until 1995; the last infected herd was culled in 1996. In August 1999 the Netherlands was declared officially free of bovine brucellosis by the European Union. Before 1999, the programme to monitor the official Brucella-free status of bovine herds was primarily based on periodical testing of dairy herds with the milk ring test (MRT) and serological testing of all animals older than 1 year of age from non-dairy herds, using the micro-agglutination test (MAT) as screening test. In addition, serum samples of cattle that aborted were tested with the MAT. The high number of false positive reactions in both tests and the serum agglutination test (SAT) and complement fixation test (CFT) used for confirmation seemed to result in unnecessary blockade of herds, subsequent testing and slaughter of animals. For this reason, a validation study was performed in which three indirect enzyme-linked immunosorbent assays (ELISAs), the CFT and the SAT were compared using a panel of sera from brucellosis-free cattle, sera from experimentally infected cattle, and sera from cattle experimentally infected with bacteria which are known to induce cross-reactive antibodies (Pasteurella, Salmonella, Yersinia, and Escherichia). Moreover, four ELISAs and the MRT were compared using a panel of 1000 bulk milk samples from Brucella-free herds and 12 milk samples from Brucella abortus- infected cattle. It is concluded that the ELISA obtained from ID-Lelystad is the most suitable test to monitor the brucelosis free status of herds because it gives rise to fewer false-positive reactions than the SAT.

A connection between the strong and weak interactions

International Nuclear Information System (INIS)

Treiman, S.B.

1989-01-01

By studying weak scattering reactions (such as pion-nucleon scattering), the author and his colleague Marvin L Goldberger became renowned in the 1950s for work on dispersion relations. As a result of their collaboration a remarkable and unexpected connection was found between strong and weak interaction quantities. Agreement with experiment was good. Work by others found the same result, but via the partially conserved axial reactor current relation between the axial current divergence and the canonical pion field. (UK)

Attributions of responsibility and affective reactions to decision outcomes.

Science.gov (United States)

Zeelenberg, M; van der Pligt, J; de Vries, N K

2000-06-01

Immediate affective reactions to outcomes are more intense following decisions to act than following decisions not to act. This finding holds for both positive and negative outcomes. We relate this "actor-effect" to attribution theory and argue that decision makers are seen as more responsible for outcomes when these are the result of a decision to act as compared to a decision not to act. Experiment 1 (N = 80) tests the main assumption underlying our reasoning and shows that affective reactions to decision outcomes are indeed more intense when the decision maker is seen as more responsible. Experiment 2 (N = 40) tests whether the actor effect can be predicted on the basis of differential attributions following action and inaction. Participants read vignettes in which active and passive actors obtained a positive or negative outcome. Action resulted in more intense affect than inaction, and positive outcomes resulted in more intense affect than negative outcomes. Experiment 2 further shows that responsibility attributions and affective reactions to outcomes are highly correlated; that is, more extreme affective reactions are associated with more internal attributions. We discuss the implications for research on post-decisional reactions.

A strongly nonlinear reaction diffusion model for a deterministic diffusive epidemic

International Nuclear Information System (INIS)

Kirane, M.; Kouachi, S.

1993-04-01

In the present paper the mathematical validity of a model on the spread of an infectious disease is proved. This model was proposed by Bailey. The mathematical validity is proved by means of a positivity, uniqueness and existence theorem. Moreover the large time behaviour of the global solutions is analyzed. In spite of the apparent simplicity of the problem, the solution requires a delicate set of techniques. It seems very difficult to extend these techniques to a model in more than one dimension without imposing conditions on the data. (author). 9 refs

Tandem Reaction of Cationic Copolymerization and Concertedly Induced Hetero-Diels-Alder Reaction Preparing Sequence-Regulated Polymers.

Science.gov (United States)

Matsumoto, Suzuka; Kanazawa, Arihiro; Kanaoka, Shokyoku; Aoshima, Sadahito

2017-06-14

A unique tandem reaction of sequence-controlled cationic copolymerization and site-specific hetero-Diels-Alder (DA) reaction is demonstrated. In the controlled cationic copolymerization of furfural and 2-acetoxyethyl vinyl ether (AcOVE), only the furan ring adjacent to the propagating carbocation underwent the hetero-DA reaction with the aldehyde moiety of another furfural molecule. A further and equally important feature of the copolymerization is that the obtained copolymers had unprecedented 2:(1 + 1)-type alternating structures of repeating sequences of two VE and one furfural units in the main chain and one furfural unit in the side chain. The specific DA reaction is attributed to the delocalization of the positive charge to the side furan ring.

HLA-A*3101 and carbamazepine-induced hypersensitivity reactions in Europeans.

LENUS (Irish Health Repository)

McCormack, Mark

2011-03-24

Carbamazepine causes various forms of hypersensitivity reactions, ranging from maculopapular exanthema to severe blistering reactions. The HLA-B*1502 allele has been shown to be strongly correlated with carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis (SJS-TEN) in the Han Chinese and other Asian populations but not in European populations.

Challenge for real-time and real-space resolved spectroscopy of surface chemical reactions. Aiming at trace of irreversible and inhomogeneous reactions

International Nuclear Information System (INIS)

Amemiya, Kenta

2015-01-01

A novel experimental technique, time-resolved wavelength-dispersive soft X-ray imaging spectroscopy, is proposed in order to achieve real-time and real-space resolved spectroscopy for the observation of irreversible and inhomogeneous surface chemical reactions. By combining the wavelength-dispersed soft X rays, in which the X-ray wavelength (photon energy) changes as a function of position on the sample, with the photoelectron emission microscope, the soft X-ray absorption spectra are separately obtained at different positions on the sample without scanning the X-ray monochromator. Therefore, the real-time resolved measurement of site-selective soft X-ray absorption spectroscopy is realized in one event without repeating the chemical reaction. It is expected that the spatial distribution of different chemical species is traced during the surface chemical reaction, which is essential to understand the reaction mechanism. (author)

Outline of cold nuclear fusion reaction

International Nuclear Information System (INIS)

Tachikawa, Enzo

1991-01-01

In 2010, as the total supply capacity of primary energy, 666 million liter is anticipated under the measures of thorough energy conservation. The development of energy sources along the energy policy based on environment preservation, safety, the quantity of resources and economy is strongly demanded. The nuclear power generation utilizing nuclear fission has been successfully carried out. As the third means of energy production, the basic research and technical development have been actively advanced on the energy production utilizing nuclear fusion reaction. The main object of the nuclear fusion research being advanced now is D-D reaction and D-T reaction. In order to realize low temperature nuclear fusion reaction, muon nuclear fusion has been studied so far. The cold nuclear fusion reaction by the electrolysis of heavy water has been reported in 1989, and its outline is ixplained in this report. The trend of the research on cold nuclear fusion is described. But the possibility of cold nuclear fusion as an energy source is almost denied. (K.I.)

Flame Structure and Emissions of Strongly-Pulsed Turbulent Diffusion Flames with Swirl

Science.gov (United States)

Liao, Ying-Hao

This work studies the turbulent flame structure, the reaction-zone structure and the exhaust emissions of strongly-pulsed, non-premixed flames with co-flow swirl. The fuel injection is controlled by strongly-pulsing the fuel flow by a fast-response solenoid valve such that the fuel flow is completely shut off between pulses. This control strategy allows the fuel injection to be controlled over a wide range of operating conditions, allowing the flame structure to range from isolated fully-modulated puffs to interacting puffs to steady flames. The swirl level is controlled by varying the ratio of the volumetric flow rate of the tangential air to that of the axial air. For strongly-pulsed flames, both with and without swirl, the flame geometry is strongly impacted by the injection time. Flames appear to exhibit compact, puff-like structures for short injection times, while elongated flames, similar in behaviors to steady flames, occur for long injection times. The flames with swirl are found to be shorter for the same fuel injection conditions. The separation/interaction level between flame puffs in these flames is essentially governed by the jet-off time. The separation between flame puffs decreases as swirl is imposed, consistent with the decrease in flame puff celerity due to swirl. The decreased flame length and flame puff celerity are consistent with an increased rate of air entrainment due to swirl. The highest levels of CO emissions are generally found for compact, isolated flame puffs, consistent with the rapid quenching due to rapid dilution with excess air. The imposition of swirl generally results in a decrease in CO levels, suggesting more rapid and complete fuel/air mixing by imposing swirl in the co-flow stream. The levels of NO emissions for most cases are generally below the steady-flame value. The NO levels become comparable to the steady-flame value for sufficiently short jet-off time. The swirled co-flow air can, in some cases, increase the NO

First Measurement of Reaction-in-Flight Neutrons at the National Ignition Facility

Science.gov (United States)

Tonchev, A.; Becker, J.; Bleuel, D.; Bionta, R.; Fortner, D.; Henry, E.; Khater, H.; Shaughnessy, D.; Schnider, D.; Stoeffl, W.; Yeamans, C.; Boswell, M.; Bredeweg, T.; Grim, G.; Jungman, G.; Fowler, M.; Hayes, A.; Obst, A.; Rundberg, R.; Schulz, A.; Wilhelmy, J.; Tornow, W.; Bhike, M.; Howell, C.; Gooden, M.; LLNL/LANL/TUNL Collaboration

2013-10-01

The first measurement of reaction-in-flight (RIF) neutrons, also known as tertiary neutrons, has been performed at the National Ignition Facility (NIF) using an activation technique. Thulium foils positioned at 50 cm from the burning deuterium-tritium (DT) capsule have been exposed to the characteristic DT neutron spectrum. The high-energy part of these neutrons with energies above 15.0 MeV can produce 167Tm via the 169Tm(n,3n) reaction. The 208-keV γ-ray, emitted from the decay of 167Tm with a half-life of 9.2 days, has been measured using two clover detectors. The first preliminary result implies that the ratio of RIF neutrons (En > 15.0 MeV) versus the total neutrons is 1 × 10 -4 +/- 3 × 10 -5. The important implication of these measurements on our knowledge of the charged-particle stopping power in strongly coupled quantum-degenerate plasma will be presented. This work was performed under the auspices of the Lawrence Livermore National Security, LLC, (LLNS) under Contract No. DE-AC52-07NA27344.

The design of a position-sensitive thermal-neutron detector

International Nuclear Information System (INIS)

Zhang Yi; Chen Ziyu; Shen Ji

2007-01-01

We design a type of position-sensitive thermal-neutron detector. The design is based on the nuclear reaction 10 B(n, α) 7 Li, and solid boron-10 is used as the target material while the alpha and lithium-7 particles from the reaction are caught as the source of position information of the original neutrons. With the help of MCNP software, we simulate the distribution of alpha particles in the boron target, which leads to the optimal thickness of target, physical efficiency and position resolution. (authors)

Enhanced pycnonuclear reactions in ultrahigh-pressure metals

International Nuclear Information System (INIS)

Ichimaru, Setsuo; Kitamura, Hikaru

1995-01-01

By combining the concepts of pycnonuclear reactions at low temperatures and their enhancement due to strong internuclear Coulomb correlations, we predict the possibilities of a novel scheme for fusion in ultrahigh-pressure liquid-metallic hydrogen near the freezing conditions, for the reactions 2 H(p,γ) 3 He, 3 H(d,n) 4 He, and 7 Li(p,α) 4 He. Time evolution is followed for p-d reaction after a pulsed compression with 1 kJ input and the initial conditions of mass density ≅ 20 g/cm 3 , temperature ≅ 1400 K, pressure ≅ 490 Mbar, and radius ≅ 0.017 cm; an energy yield of 33 kJ in 0.03 fs is thus predicted. (author)

Role of hexadecapole deformation of projectile 28Si in heavy-ion fusion reactions near the Coulomb barrier

Science.gov (United States)

Kaur, Gurpreet; Hagino, K.; Rowley, N.

2018-06-01

The vast knowledge regarding the strong influence of quadrupole deformation β2 of colliding nuclei in heavy-ion sub-barrier fusion reactions inspires a desire to quest the sensitivity of fusion dynamics to higher order deformations, such as β4 and β6 deformations. However, such studies have rarely been carried out, especially for deformation of projectile nuclei. In this article, we investigated the role of β4 of the projectile nucleus in the fusion of the 28Si+92Zr system. We demonstrated that the fusion barrier distribution is sensitive to the sign and value of the β4 parameter of the projectile, 28Si, and confirmed that the 28Si nucleus has a large positive β4. This study opens an indirect way to estimate deformation parameters of radioactive nuclei using fusion reactions, which is otherwise difficult because of experimental constraints.

Inclusive two-photon reactions at TRISTAN

International Nuclear Information System (INIS)

Drees, M.

1995-01-01

After briefly reviewing past accomplishments of TRISTAN experiments in the field of inclusive two-photon reactions, I discuss open problems in the Monte Carlo simulation of such reactions. The main emphasis is on multiple scattering, i.e. events where at least two pairs of partons scatter within the same γγ collision to form at least four (mini)jets. The cross section for such events might just be observable at TRISTAN. While theoretical arguments for the existence of such events are strong, they have not yet been directly observed experimentally, thereby potentially opening a new opportunity for TRISTAN experiments. (author)

Tuberculin reaction and BCG scar

DEFF Research Database (Denmark)

Timmermann, Clara Amalie Gade; Biering-Sørensen, Sofie; Aaby, Peter

2015-01-01

rate ratio (MRR) comparing children with a BCG scar with those without was 0.42 (95% CI = 0.19; 0.93). There was a similar tendency for TST positivity: MRR = 0.47 (95% CI = 0.14; 1.54). For LBW children who had both a positive TST reaction and a scar, the MRR was 0.22 (95% CI = 0.05; 0.87). For NBW...

Impact of self-esteem and sex on stress reactions.

Science.gov (United States)

Kogler, Lydia; Seidel, Eva-Maria; Metzler, Hannah; Thaler, Hanna; Boubela, Roland N; Pruessner, Jens C; Kryspin-Exner, Ilse; Gur, Ruben C; Windischberger, Christian; Moser, Ewald; Habel, Ute; Derntl, Birgit

2017-12-08

Positive self-evaluation is a major psychological resource modulating stress coping behavior. Sex differences have been reported in self-esteem as well as stress reactions, but so far their interactions have not been investigated. Therefore, we investigated sex-specific associations of self-esteem and stress reaction on behavioral, hormonal and neural levels. We applied a commonly used fMRI-stress task in 80 healthy participants. Men compared to women showed higher activation during stress in hippocampus, precuneus, superior temporal gyrus (STG) and insula. Furthermore, men outperformed women in the stress task and had higher cortisol and testosterone levels than women after stress. Self-esteem had an impact on precuneus, insula and STG activation during stress across the whole group. During stress, men recruit regions associated with emotion and stress regulation, self-referential processing and cognitive control more strongly than women. Self-esteem affects stress processing, however in a sex-independent fashion: participants with lower self-esteem show higher activation of regions involved in emotion and stress regulation, self-referential processing and cognitive control. Taken together, our data suggest that men are more engaged during the applied stress task. Across women and men, lower self-esteem increases the effort in emotion and stress processing and cognitive control, possibly leading to self-related thoughts in stressful situations.

STRONG SOLAR WIND DYNAMIC PRESSURE PULSES: INTERPLANETARY SOURCES AND THEIR IMPACTS ON GEOSYNCHRONOUS MAGNETIC FIELDS

International Nuclear Information System (INIS)

Zuo, Pingbing; Feng, Xueshang; Wang, Yi; Xie, Yanqiong; Xu, Xiaojun

2015-01-01

In this investigation, we first present a statistical result of the interplanetary sources of very strong solar wind dynamic pressure pulses (DPPs) detected by WIND during solar cycle 23. It is found that the vast majority of strong DPPs reside within solar wind disturbances. Although the variabilities of geosynchronous magnetic fields (GMFs) due to the impact of positive DPPs have been well established, there appears to be no systematic investigations on the response of GMFs to negative DPPs. Here, we study both the decompression effects of very strong negative DPPs and the compression from strong positive DPPs on GMFs at different magnetic local time sectors. In response to the decompression of strong negative DPPs, GMFs on the dayside near dawn and near dusk on the nightside, are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of the events when GOES is located at the midnight sector, the GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that under certain conditions magnetic depression of nightside GMFs can be caused by the impact of positive DPPs. Here, we find that a stronger pressure enhancement may have a higher probability of producing the exceptional depression of GMF at the midnight region. Statistically, both the decompression effect of strong negative DPPs and the compression effect of strong positive DPPs depend on the magnetic local time, which are stronger at the noon sector

STRONG SOLAR WIND DYNAMIC PRESSURE PULSES: INTERPLANETARY SOURCES AND THEIR IMPACTS ON GEOSYNCHRONOUS MAGNETIC FIELDS

Energy Technology Data Exchange (ETDEWEB)

Zuo, Pingbing; Feng, Xueshang; Wang, Yi [SIGMA Weather Group, State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing (China); Xie, Yanqiong [College of Meteorology and Oceanography, PLA University of Science and Technology, Nanjing (China); Xu, Xiaojun, E-mail: pbzuo@spaceweather.ac.cn, E-mail: fengx@spaceweather.ac.cn [Space Science Institute, Macau University of Science and Technology, Macao (China)

2015-10-20

In this investigation, we first present a statistical result of the interplanetary sources of very strong solar wind dynamic pressure pulses (DPPs) detected by WIND during solar cycle 23. It is found that the vast majority of strong DPPs reside within solar wind disturbances. Although the variabilities of geosynchronous magnetic fields (GMFs) due to the impact of positive DPPs have been well established, there appears to be no systematic investigations on the response of GMFs to negative DPPs. Here, we study both the decompression effects of very strong negative DPPs and the compression from strong positive DPPs on GMFs at different magnetic local time sectors. In response to the decompression of strong negative DPPs, GMFs on the dayside near dawn and near dusk on the nightside, are generally depressed. But near the midnight region, the responses of GMF are very diverse, being either positive or negative. For part of the events when GOES is located at the midnight sector, the GMF is found to abnormally increase as the result of magnetospheric decompression caused by negative DPPs. It is known that under certain conditions magnetic depression of nightside GMFs can be caused by the impact of positive DPPs. Here, we find that a stronger pressure enhancement may have a higher probability of producing the exceptional depression of GMF at the midnight region. Statistically, both the decompression effect of strong negative DPPs and the compression effect of strong positive DPPs depend on the magnetic local time, which are stronger at the noon sector.

Assessment of preschoolers’ positive empathy: concurrent and longitudinal relations with positive emotion, social competence, and sympathy

OpenAIRE

Sallquist, Julie; Eisenberg, Nancy; Spinrad, Tracy L.; Eggum, Natalie D.; Gaertner, Bridget M.

2009-01-01

The purpose of this study was to examine a new measure of children’s dispositional positive empathy (i.e., reactions to others’ positive emotions) and its concurrent and longitudinal relations with positive emotion, social competence, and empathy/sympathy with negative emotions. At Time 1, 192 3.5-year-olds (88 girls) participated; at Time 2, 1 year later, 168 4.5-year-olds (79 girls) participated. Children’s positive empathy was reported by mothers and observed in the laboratory at Time 2. A...

Polymerase chain reaction system using magnetic beads for analyzing a sample that includes nucleic acid

Science.gov (United States)

Nasarabadi, Shanavaz [Livermore, CA

2011-01-11

A polymerase chain reaction system for analyzing a sample containing nucleic acid includes providing magnetic beads; providing a flow channel having a polymerase chain reaction chamber, a pre polymerase chain reaction magnet position adjacent the polymerase chain reaction chamber, and a post pre polymerase magnet position adjacent the polymerase chain reaction chamber. The nucleic acid is bound to the magnetic beads. The magnetic beads with the nucleic acid flow to the pre polymerase chain reaction magnet position in the flow channel. The magnetic beads and the nucleic acid are washed with ethanol. The nucleic acid in the polymerase chain reaction chamber is amplified. The magnetic beads and the nucleic acid are separated into a waste stream containing the magnetic beads and a post polymerase chain reaction mix containing the nucleic acid. The reaction mix containing the nucleic acid flows to an analysis unit in the channel for analysis.

Strong coupling of collection of emitters on hyperbolic meta-material

Science.gov (United States)

Biehs, Svend-Age; Xu, Chenran; Agarwal, Girish S.

2018-04-01

Recently, considerable effort has been devoted to the realization of a strong coupling regime of the radiation matter interaction in the context of an emitter at a meta surface. The strong interaction is well realized in cavity quantum electrodynamics, which also show that strong coupling is much easier to realize using a collection of emitters. Keeping this in mind, we study if emitters on a hyperbolic meta materials can yield a strong coupling regime. We show that strong coupling can be realized for densities of emitters exceeding a critical value. A way to detect strong coupling between emitters and hyperbolic metamaterials is to use the Kretschman-Raether configuration. The strong coupling appears as the splitting of the reflectivity dip. In the weak coupling regime, the dip position shifts. The shift and splitting can be used to sense active molecules at surfaces.

Amplitude equations for a sub-diffusive reaction-diffusion system

International Nuclear Information System (INIS)

Nec, Y; Nepomnyashchy, A A

2008-01-01

A sub-diffusive reaction-diffusion system with a positive definite memory operator and a nonlinear reaction term is analysed. Amplitude equations (Ginzburg-Landau type) are derived for short wave (Turing) and long wave (Hopf) bifurcation points

Impression management during evaluation and psychological reactions post-donation of living kidney donors.

Science.gov (United States)

Hildebrand, Lee; Melchert, Timothy P; Anderson, Rebecca C

2014-08-01

Many healthcare providers have been concerned about the extent to which potential kidney donors use impression management or concealment of important information regarding their medical history, current functioning, or other circumstances that could affect whether they are accepted as donors. To date, however, there has been very little empirical examination of these questions. It is also not known whether donors' use of impression management pre-donation is related to their reactions and adjustment post-donation. This study surveyed 76 individuals who had donated a kidney one to six yr previously regarding their use of impression management and their concealing of information during their psychological evaluations. They were also asked about their reactions to the donation and whether they would make the same decision again. In addition, 21 of these donors participated in focus groups that explored these questions in depth. Many of the kidney donors reported that they possessed very strong motivation to donate and consequently used impression management in their interactions with medical professionals pre-donation. Very few donors, however, indicated that they concealed information during their pre-donation evaluations. The donors' psychological reactions post-donation were generally positive, and nearly all indicated that they would make the same decision again. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Sonogashira–Hagihara reactions of halogenated glycals

Directory of Open Access Journals (Sweden)

Dennis C. Koester

2012-05-01

Full Text Available Herein, we report on our findings of the Sonogashira–Hagihara reaction with 1-iodinated and 2-brominated glycals using several aromatic and aliphatic alkynes. This Pd-catalyzed cross-coupling reaction presents a facile access to alkynyl C-glycosides and sets the stage for a reductive/oxidative refunctionalization of the enyne moiety to regenerate either C-glycosidic structures or pyran derivatives with a substituent in position 2.

Probability distribution of wave packet delay time for strong overlapping of resonance levels

International Nuclear Information System (INIS)

Lyuboshits, V.L.

1983-01-01

Time behaviour of nuclear reactions in the case of high level densities is investigated basing on the theory of overlapping resonances. In the framework of a model of n equivalent channels an analytical expression is obtained for the probability distribution function for wave packet delay time at the compound nucleus production. It is shown that at strong overlapping of the resonance levels the relative fluctuation of the delay time is small at the stage of compound nucleus production. A possible increase in the duration of nuclear reactions with the excitation energy rise is discussed

High prevalence of human anti-bovine IgG antibodies as the major cause of false positive reactions in two-site immunoassays based on monoclonal antibodies

DEFF Research Database (Denmark)

Andersen, Ditte C; Koch, Claus; Jensen, Charlotte H

2004-01-01

were purified by protein G affinity chromatography from culture supernatant containing 10% (v/v) fetal calf serum (FCS). Human anti-animal IgG (bovine, mouse, horse, and swine) antibodies and human anti-bovine serum albumin antibodies were measured using an ELISA design, with direct bridging...... of the solid phase and biotinylated antigens. The false positive reactions were abolished by addition of 1% (v/v) bovine serum to the dilution buffer (DB). Human anti-bovine IgG antibodies (HABIA) were detected in 99 out of 104 sera from blood donors (50 females; 54 males). HABIA levels in male sera (n = 54......) were positively correlated to the false positive signals in the PP14 ELISA (r = 0.923; p detected in the donor sera, but levels and frequencies were lower compared to that of HABIA. Furthermore, HABIA were...

Urinary oxytocin positively correlates with performance in facial visual search in unmarried males, without specific reaction to infant face.

Science.gov (United States)

Saito, Atsuko; Hamada, Hiroki; Kikusui, Takefumi; Mogi, Kazutaka; Nagasawa, Miho; Mitsui, Shohei; Higuchi, Takashi; Hasegawa, Toshikazu; Hiraki, Kazuo

2014-01-01

The neuropeptide oxytocin plays a central role in prosocial and parental behavior in non-human mammals as well as humans. It has been suggested that oxytocin may affect visual processing of infant faces and emotional reaction to infants. Healthy male volunteers (N = 13) were tested for their ability to detect infant or adult faces among adult or infant faces (facial visual search task). Urine samples were collected from all participants before the study to measure the concentration of oxytocin. Urinary oxytocin positively correlated with performance in the facial visual search task. However, task performance and its correlation with oxytocin concentration did not differ between infant faces and adult faces. Our data suggests that endogenous oxytocin is related to facial visual cognition, but does not promote infant-specific responses in unmarried men who are not fathers.

Erythema-index of clinical patch test reactions

DEFF Research Database (Denmark)

Jemec, G B; Johansen, J D

1995-01-01

that the method could be used for the grading of eczematous reactions in a clinical setting as well. OBJECTIVE: To assess the usefulness of the erythema index for the quantification of eczematous reactions using the Derma-Spectrometer (Cortex technology, Hadsund, Denmark) in a clinical setting. METHOD......: The erythema index of 56 patch test reactions ranging from +? to +++, was compared to regional controls and negative patch tests (189). The effects of intrumental application pressure was studied in 5 volunteers. Statistical analysis was carried out using Mann-Whitney and Jonckheere-Terpstra tests. RESULTS......: The erythema-index was significantly higher in all degrees of patch test reactions than in uninvolved regional skin or negative patch tests. It also showed a significant positive trend for higher values in +, ++ and +++ reactions (P

Reactions of stabilized Criegee Intermediates

Science.gov (United States)

Vereecken, Luc; Harder, Hartwig; Novelli, Anna

2014-05-01

Carbonyl oxides (Criegee intermediates) were proposed as key intermediates in the gas phase ozonolysis of alkenes in 1975 by Rudolf Criegee. Despite the importance of ozonolysis in atmospheric chemistry, direct observation of these intermediates remained elusive, with only indirect experimental evidence for their role in the oxidation of hydrocarbons, e.g. through scavenging experiments. Direct experimental observation of stabilized CI has only been achieved since 2008. Since then, a concerted effort using experimental and theoretical means is in motion to characterize the chemistry and kinetics of these reactive intermediates. We present the results of theoretical investigations of the chemistry of Criegee intermediates with a series of coreactants which may be of importance in the atmosphere, in experimental setups, or both. This includes the CI+CI cross-reaction, which proceeds with a rate coefficient near the collision limit and can be important in experimental conditions. The CI + alkene reactions show strong dependence of the rate coefficient depending on the coreactants, but is generally found to be rather slow. The CI + ozone reaction is sufficiently fast to occur both in experiment and the free troposphere, and acts as a sink for CI. The reaction of CI with hydroperoxides, ROOH, is complex, and leads both to the formation of oligomers, as to the formation of reactive etheroxides, with a moderately fast rate coefficient. The importance of these reactions is placed in the context of the reaction conditions in different atmospheric environments ranging from unpolluted to highly polluted.

Strong ion difference in urine: new perspectives in acid-base assessment.

OpenAIRE

Gattinoni, L.; Carlesso, E.; Cadringher, P.; Caironi, P.

2006-01-01

The plasmatic strong ion difference (SID) is the difference between positively and negatively charged strong ions. At pH 7.4, temperature 37°C and partial carbon dioxide tension 40 mmHg, the ideal value of SID is 42 mEq/l. The buffer base is the sum of negatively charged weak acids ([HCO3 -], [A-], [H2PO4 -]) and its normal value is 42 mEq/l. According to the law of electroneutrality, the amount of positive and negative charges must be equal, and therefore the SID value is equal to the buffer...

Rational Design in Catalysis: A Mechanistic Study of β-Hydride Eliminations in Gold(I) and Gold(III) Complexes Based on Features of the Reaction Valley.

Science.gov (United States)

Castiñeira Reis, Marta; López, Carlos Silva; Kraka, Elfi; Cremer, Dieter; Faza, Olalla Nieto

2016-09-06

β-Hydride eliminations for ethylgold(III) dichloride complexes are identified as reactions with an unusually long prechemical stage corresponding to the conformational preparation of the reaction complex and spanning six phases. The prechemical process is characterized by a geared rotation of the L-Au-L group (L = Cl) driving methyl group rotation and causing a repositioning of the ligands. This requires more than 28 kcal/mol of the total barrier of 34.0 kcal/mol, according to the unified reaction valley approach, which also determines that the energy requirements of the actual chemical process leading to the β-elimination product are only about 5.5 kcal/mol. A detailed mechanistic analysis was used as a basis for a rational design of substrates (via substituents on the ethyl group) and/or ligands, which can significantly reduce the reaction barrier. This strategy takes advantage of either a higher trans activity of the ligands or a tuned electronic demand of the ethyl group. The β-hydride elimination of gold(I) was found to suffer from strong Coulomb and exchange repulsion when a positively charged hydrogen atom enforces a coordination position in a d(10)-configured gold atom, thus triggering an unassisted σ-π Au(I)-C conversion.

Ramifications of ostracism as a consequence of revelation of HIV positive status: its effect o individuals and families in Botswana

Directory of Open Access Journals (Sweden)

Tabitha T. Langeni

2003-12-01

the structure and composition of the family in Botswana. The study showed that the highest proportion of respondents who would abandon an HIV positive partner (58.4% occurs among young people aged 15 to 19 years; and that the propensity to abandon an HIV positive partner diminishes with advancement in age. In-depth inquiries on why HIV positive partners would be abandoned produced responses that revolved around fear of exposure, vulnerability and association with an HIV positive individual. The study showed that the highest proportion of respondents who would not reveal their HIV positive status occurs among those who have lost a relative or a friend to AIDS. Fear of being isolated, rejected, stigmatized and unwanted featured among the top reasons why respondents would not reveal their HIV positive status. Society’s reaction towards HIV positive individuals and families with HIV/AIDS patients appeared strong enough to drive individuals to hide their positive status and to go ahead and take the risk of onward transmission of the virus.

Running on a lower-body positive pressure treadmill

DEFF Research Database (Denmark)

Raffalt, Peter C; Hovgaard-Hansen, Line; Jensen, Bente Rona

2013-01-01

This study investigated maximal oxygen consumption (VO2max) and time to exhaustion while running on a lower-body positive pressure treadmill (LBPPT) at normal body weight (BW) as well as how BW support affects respiratory responses, ground reaction forces, and stride characteristics.......This study investigated maximal oxygen consumption (VO2max) and time to exhaustion while running on a lower-body positive pressure treadmill (LBPPT) at normal body weight (BW) as well as how BW support affects respiratory responses, ground reaction forces, and stride characteristics....

Convection and reaction in a diffusive boundary layer in a porous medium: nonlinear dynamics.

Science.gov (United States)

Andres, Jeanne Therese H; Cardoso, Silvana S S

2012-09-01

We study numerically the nonlinear interactions between chemical reaction and convective fingering in a diffusive boundary layer in a porous medium. The reaction enhances stability by consuming a solute that is unstably distributed in a gravitational field. We show that chemical reaction profoundly changes the dynamics of the system, by introducing a steady state, shortening the evolution time, and altering the spatial patterns of velocity and concentration of solute. In the presence of weak reaction, finger growth and merger occur effectively, driving strong convective currents in a thick layer of solute. However, as the reaction becomes stronger, finger growth is inhibited, tip-splitting is enhanced and the layer of solute becomes much thinner. Convection enhances the mass flux of solute consumed by reaction in the boundary layer but has a diminishing effect as reaction strength increases. This nonlinear behavior has striking differences to the density fingering of traveling reaction fronts, for which stronger chemical kinetics result in more effective finger merger owing to an increase in the speed of the front. In a boundary layer, a strong stabilizing effect of reaction can maintain a long-term state of convection in isolated fingers of wavelength comparable to that at onset of instability.

K X-rays and nuclear reaction times in the deep inelastic reactions U+U and U+Pb at 7.5 MeV/amu

International Nuclear Information System (INIS)

Stoller, C.

1985-01-01

The K-shell ionisation probability of the heavy reaction products emerging from binary deep inelastic collisions of U + U and U + Pb at 7.5 MeV/amu has been measured as a function of the total kinetic energy loss - Q. After subtraction of the ionisation probability due to internal conversion of γ-rays, a strongly Q-dependent Psub(K) is found, in agreement with theoretical predictions relating the change in ionisation probability to the nuclear sticking time. The deduced nuclear reaction times are in qualitative agreement with predictions from nuclear models of deep inelastic reactions. (orig.)

Spontaneous hedonic reactions to social media cues

NARCIS (Netherlands)

Koningsbruggen, G.M. van; Hartmann, T.; Eden, A.; Veling, H.P.

2017-01-01

Why is it so difficult to resist the desire to use social media? One possibility is that frequent social media users possess strong and spontaneous hedonic reactions to social media cues, which, in turn, makes it difficult to resist social media temptations. In two studies (total N = 200), we

Pion-induced knock-out reactions

International Nuclear Information System (INIS)

Jain, B.K.; Phatak, S.C.

1977-01-01

A strong absorption model for pion-induced Knock-out reactions is proposed. The distortion of the in-coming and out-going pions has been included by (1) computing pion wave number in nuclear medium (dispersive effect) and (2) excluding the central region of the nucleus where the real pion-absorption is dominant (absorption effect). In order to study the dependence of the (π + π + p) reaction on the off-shell pion-nucleon t-matrix, different off-shell extrapolations are used. The magnitude of the cross-sections seems to be sensitive to the type of off-shell extrapolation; their shapes, however, are similar. The theoretical results are compared with experimental data. The agreement between the theoretical results for separable off-shell extrapolation and the data is good. (author)

Deuteron stripping reactions with Tabakin potential

International Nuclear Information System (INIS)

Osman, A.

1976-05-01

Deuteron stripping reactions are considered. Due to the strong repulsion between nucleons at very short distances, we have investigated the nuclear short-range correlations. The neutron proton nuclear potential in the deuteron is taken as a short-range repulsive core surrounded by a long-range attractive potential. The neutron-proton potential is taken as the Tabakin separable potential to take into account the short-range correlations. The differential cross-sections for deuteron stripping reactions have been calculated in two different cases by taking Yamaguchi or Breit et al type parameters for the Tabakin potential used. The angular distributions for different (d,p) stripping reactions on the different target nuclei 28 Si, 32 , 34 S, 36 Ar, 40 , 48 Ca, 50 , 52 , 54 Cr have been calculated using the DWBA calculations. Our present theoretical calculations for the angular distributions of the different reactions cosidered have been fitted to the experimental data, where good agreement is obtained. The extracted spectroscopic factors from the present work are found to be more reliable

Modeling of fluctuating reaction networks

International Nuclear Information System (INIS)

Lipshtat, A.; Biham, O.

2004-01-01

Full Text:Various dynamical systems are organized as reaction networks, where the population size of one component affects the populations of all its neighbors. Such networks can be found in interstellar surface chemistry, cell biology, thin film growth and other systems. I cases where the populations of reactive species are large, the network can be modeled by rate equations which provide all reaction rates within mean field approximation. However, in small systems that are partitioned into sub-micron size, these populations strongly fluctuate. Under these conditions rate equations fail and the master equation is needed for modeling these reactions. However, the number of equations in the master equation grows exponentially with the number of reactive species, severely limiting its feasibility for complex networks. Here we present a method which dramatically reduces the number of equations, thus enabling the incorporation of the master equation in complex reaction networks. The method is examplified in the context of reaction network on dust grains. Its applicability for genetic networks will be discussed. 1. Efficient simulations of gas-grain chemistry in interstellar clouds. Azi Lipshtat and Ofer Biham, Phys. Rev. Lett. 93 (2004), 170601. 2. Modeling of negative autoregulated genetic networks in single cells. Azi Lipshtat, Hagai B. Perets, Nathalie Q. Balaban and Ofer Biham, Gene: evolutionary genomics (2004), In press

Reaction Dynamics of CH{sub 3} + HBr → CH{sub 4} + Br at 150-1000 K

Energy Technology Data Exchange (ETDEWEB)

Ree, Jongbaik [Chonnam National Univ., Gwangju (Korea, Republic of); Kim, Yoo Hang [Inha Univ., Incheon (Korea, Republic of); Shin, Hyung Kyu [Univ. of Nevado, Nevado (United States)

2013-08-15

The kinetics of the radical-polar molecule reaction CH{sub 3} + HBr → CH{sub 4} + Br has been studied at temperatures between 150 and 1000 K using classical dynamics procedures. Potential energy surfaces constructed using analytical forms of inter- and intramolecular interaction energies show a shallow well and barrier in the entrance channel, which affect the collision dynamics at low temperatures. Different collision models are used to distinguish the reaction occurring at low- and high-temperature regions. The reaction proceeds rapidly via a complex-mode mechanism below room temperature showing strong negative temperature dependence, where the effects of molecular attraction, H-atom tunneling and recrossing of collision complexes are found to be important. The temperature dependence of the rate constant between 400 and 1000 K is positive, the values increasing in accordance with the increase of the mean speed of collision. The rate constant varies from 7.6 Χ 10{sup -12} at 150 K to 3.7 Χ 10{sup -12} at 1000 K via a minimum value of 2.5 Χ 10{sup -12} cm{sup 3} molecule{sup -1} s{sup -1} at 400 K.

Close encounters: Analyzing how social similarity and propinquity contribute to strong network connections.

OpenAIRE

Reagans, Ray Eugene

2010-01-01

Models of network formation emphasize the importance of social similarity and propinquity in producing strong interpersonal connections. The positive effect each factor can have on tie strength has been documented across a number of studies, and yet we know surprisingly very little about how the two factors combine to produce strong ties. Being in close proximity could either amplify or dampen the positive effect that social similarity can have on tie strength. Data on tie strength among teac...

Potential surfaces in symmetric heavy-ion reactions

International Nuclear Information System (INIS)

Royer, G.; Piller, C.; Mignen, J.; Raffray, Y.

1989-01-01

The entrance channel in symmetric heavy-ion reactions is studied in the liquid-drop model approach including the nuclear proximity energy and allowing ellipsoidal deformations of the colliding nuclei. In the whole mass range a sudden transition occurs from oblate to prolate shapes when the proximity forces become important. This strongly affects the effective moment of inertia. The ellipsoidal deformations reduce the fusion barrier width for light systems and lower the potential barrier height for medium and heavy nuclei. The results are in agreement with the empirical effective barrier shift determined by Aguiar et al for the 58 Ni + 58 Ni, 74 Ge + 74 Ge and 80 Se + 80 Se systems. The sub-barrier fusion enhancement in heavy-ion reactions might be explained by the slowness of the process. Below the static fusion barrier, the reaction time is long; allowing some adiabaticity and deformations of the colliding ions. Above the barrier, the reaction is more sudden and the deformation degree of freedom is frozen

Reaction of tin(iv) phthalocyanine dichloride with decamethylmetallocenes (M = CrII and CoII). Strong magnetic coupling of spins in (Cp*2Co+){SnIVCl2(Pc˙3-)}˙-·2C6H4Cl2.

Science.gov (United States)

Konarev, Dmitri V; Troyanov, Sergey I; Shestakov, Alexander F; Yudanova, Evgeniya I; Otsuka, Akihiro; Yamochi, Hideki; Kitagawa, Hiroshi; Lyubovskaya, Rimma N

2018-01-23

The reaction of tin(iv) phthalocyanine dichloride {Sn IV Cl 2 (Pc 2- )} with decamethylmetallocenes (Cp* 2 M, M = Co, Cr) has been studied. Decamethylcobaltocene reduces Sn IV Cl 2 (Pc 2- ) to form the (Cp* 2 Co + ){Sn IV Cl 2 (Pc˙ 3- )}˙ - ·2C 6 H 4 Cl 2 (1) complex. The negative charge of {Sn IV Cl 2 (Pc˙ 3- )}˙ - is delocalized over the Pc macrocycle providing the alternation of the C-N(imine) bonds, the appearance of new bands in the NIR range and a strong blue shift of both the Soret and Q-bands in the spectrum of 1. The magnetic moment of 1 is equal to 1.68μ B at 300 K, indicating the contribution of one S = 1/2 spin of the Pc˙ 3- macrocycles. These macrocycles form closely packed double stacks in 1 with effective π-π interactions providing strong antiferromagnetic coupling of spins at a Weiss temperature of -80 K. Decamethylchromocene initially also reduces Sn IV Cl 2 (Pc 2- ) to form the [(Cp* 2 Cr + ){Sn VI Cl 2 (Pc˙ 3- )}˙ - complex but further reaction between the ions is observed. This reaction is accompanied by the substitution of one Cp* ligand of Cp* 2 Cr by chloride anions originating from {Sn IV Cl 2 (Pc˙ 3- )}˙ - to form the complex {(Cp*CrCl 2 )(Sn IV (μ-Cl)(Pc 2- ))}·C 6 H 4 Cl 2 (2) in which the (Cp*CrCl 2 ) and {Sn IV (Pc 2- )} species are bonded through the μ-bridged Cl - anion. According to the DFT calculations, this reaction proceeds via an intermediate [(Cp* 2 CrCl)(SnClPc)] complex.

Near-field strong coupling of single quantum dots.

Science.gov (United States)

Groß, Heiko; Hamm, Joachim M; Tufarelli, Tommaso; Hess, Ortwin; Hecht, Bert

2018-03-01

Strong coupling and the resultant mixing of light and matter states is an important asset for future quantum technologies. We demonstrate deterministic room temperature strong coupling of a mesoscopic colloidal quantum dot to a plasmonic nanoresonator at the apex of a scanning probe. Enormous Rabi splittings of up to 110 meV are accomplished by nanometer-precise positioning of the quantum dot with respect to the nanoresonator probe. We find that, in addition to a small mode volume of the nanoresonator, collective coherent coupling of quantum dot band-edge states and near-field proximity interaction are vital ingredients for the realization of near-field strong coupling of mesoscopic quantum dots. The broadband nature of the interaction paves the road toward ultrafast coherent manipulation of the coupled quantum dot-plasmon system under ambient conditions.

Urinary oxytocin positively correlates with performance in facial visual search in unmarried males, without specific reaction to infant face

Directory of Open Access Journals (Sweden)

Atsuko eSaito

2014-07-01

Full Text Available The neuropeptide oxytocin plays a central role in prosocial and parental behavior in non-human mammals as well as humans. It has been suggested that oxytocin may affect visual processing of infant faces and emotional reaction to infants. Healthy male volunteers (N = 13 were tested for their ability to detect infant or adult faces among adult or infant faces (facial visual search task. Urine samples were collected from all participants before the study to measure the concentration of oxytocin. Urinary oxytocin positively correlated with performance in the facial visual search task. However, task performance and its correlation with oxytocin concentration did not differ between infant faces and adult faces. Our data suggests that endogenous oxytocin is related to facial visual cognition, but does not promote infant-specific responses in unmarried men who are not fathers.

Evaluation of Chemical Kinetic for Mathematics Model Reduction of Cadmium Reaction Rate, Constant and Reaction Orde in to Electrochemical Process

International Nuclear Information System (INIS)

Prayitno

2007-01-01

The experiment was reduction of cadmium rate with electrochemical influenced by time process, concentration, current strength and type of electrode plate. The aim of the experiment was to know the influence, mathematic model reduction of cadmium the reaction rate, reaction rate constant and reaction orde influenced by time process, concentration, current strength and type of electrode plate. Result of research indicate the time processing if using plate of copper electrode is during 30 minutes and using plate of aluminium electrode is during 20 minutes. Condition of strong current that used in process of electrochemical is only 0.8 ampere and concentration effective is 5.23 mg/l. The most effective type Al of electrode plate for reduction from waste and the efficiency of reduction is 98 %. (author)

Knowledge, perception, practices and barriers of healthcare professionals in Bosnia and Herzegovina towards adverse drug reaction reporting and pharmacovigilance

Directory of Open Access Journals (Sweden)

Maša Amrain

2014-09-01

Full Text Available Introduction: Pharmacovigilance is an arm of patient care. No one wants to harm patients, but unfortunately any medicine will sometimes do just this. Underreporting of adverse drug reactions by healthcare professionals is a major problem in many countries. In order to determine whether our pharmacovigilance system could be improved, and identify reasons for under-reporting, a study to investigate the role of health care professionals in adverse drug reaction (ADR reporting was performed.Methods: A pretested questionnaire comprising of 20 questions was designed for assessment of knowledge, perceptions, practice and barriers toward ADR reporting on a random sample of 1000 healthcare professionals in Bosnia and Herzegovina.Results: Of the 1000 respondents, 870 (87% completed the questionnaire. The survey showed that 62.9% health care professionals would report ADR to the Agency for Medicinal Products and Medical Device of Bosnia and Herzegovina (ALMBIH. Most of surveyed respondents has a positive perception towards ADR reporting, and believes that this is part of their professional and legal obligation, and they also recognize the importance of reporting adverse drug reactions. Only small percent (15.4% of surveyed health care professionals reported adverse drug reaction.Conclusions: The knowledge of ADRs and how to report them is inadequate among health care professionals. Perception toward ADR reporting was positive, but it is not reflected in the actual practice of ADRs, probably because of little experience and knowledge regarding pharmacovigilance. Interventions such as education and training, focusing on the aims of pharmacovigilance, completing the ADR form and clarifying the reporting criteria are strongly recommended.

Photochemical reaction products in air pollution

Energy Technology Data Exchange (ETDEWEB)

Stephens, E R; Darley, E F; Taylor, O C; Scott, W E

1961-01-01

Isolation and purification of peroxyacetyl nitrate (PAN) from artificial photochemical reaction of olefins and NO/sub x/ in air are analyzed. Olefin splits at the double bond, one end forming carbonyl compound and the other yielding PAN, among others. At concentrations below 1 ppM, PAN causes plant damage. At a concentration of about 1 ppM, PAN is a strong eye irritant.

Effect of Floodplain Inundation on River Pollution in Taiwan's Strong Monsoonal Climate

Science.gov (United States)

Hester, E. T.; Lin, A. Y. C.

2017-12-01

River-floodplain interaction provides important benefits such as flood mitigation, provision of ecological habitat, and improved water quality. Human actions have historically reduced such interaction and associated benefits by diking, floodplain fill, and river regulation. In response, floodplain restoration has become popular in North America and Europe, but is less practiced in Asia. In Taiwan, unusually strong monsoons and steep terrain alter floodplain dynamics relative to elsewhere around the world, and provide a unique environment for floodplain management. We used numerical models of flow, transport, and reaction in river channels and floodplains to quantify the effect of river-floodplain interaction on water quality in Taiwan's strong monsoon and high topographic relief. We conducted sensitivity analyses of parameters such as river slope, monsoon severity, reservoir operation mode, degree of floodplain reconnection, contaminant reaction rate, and contaminant reaction type on floodplain connectivity and contaminant mitigation. We found significant differences in floodplain hydraulics and residence times in Taiwan's steep monsoonal environment relative to the shallower non-monsoonal environment typical of the eastern USA, with significant implications for water quality. For example, greater flashiness of floodplain inundation in Taiwan provides greater challenges for reconnecting sufficient floodplain volume to handle monsoonal runoff. Yet longer periods when floodplains are reliably dry means that such lands may have greater value for seasonal use such as parks or agriculture. The potential for floodplain restoration in Taiwan is thus significant, but qualitatively different than in the eastern USA.

Uranium/water vapor reactions in gaseous atmospheres

International Nuclear Information System (INIS)

Jackson, R.L.; Condon, J.B.; Steckel, L.M.

1977-07-01

Experiments have been performed to determine the effect of varying humidities, gaseous atmospheres, and temperatures on the uranium/water vapor reaction. A balance, which allowed continuous in-system weighings, was used to determine the rates of the uranium/water vapor reactions at water vapor pressures of 383, 1586, and 2853 Pa and at temperatures of 80, 100, and 150 0 C in atmospheres of hydrogen, argon, or argon/oxygen mixtures. Based on rate data, the reactions were characterized as hydriding or nonhydriding. Hydriding reactions were found to be preferred in moist hydrogen systems at the higher temperatures and the lower humidities. The presence of hydrogen in hydriding systems was found to initially inhibit the reaction, but causes an acceleration of the rate in the final stages. In general, reaction rates of hydriding systems approached the hydriding rates calculated and observed in dry hydrogen. Hydriding and nonhydriding reaction rates showed a positive correlation to temperature and water vapor pressure. Final reaction rates in moist argon/oxygen mixtures of 1.93, 4.57, and 9.08 mole percent oxygen were greater than the rates observed in moist hydrogen or argon. Final reaction rates were negatively correlated to the oxygen concentration

Nuclear halo and its related reactions

International Nuclear Information System (INIS)

Zhang Huanqiao

2005-01-01

nuclear halo in terms of the analytical expressions of the expectation value for the operator r 2 in a finite square-well potential. Nuclear reactions induced by halo and weekly bound nuclei are a topic of current interest. We have measured the complete fusion cross sections of 6 Li+ 208 Pb and found the fusion cross sections above the Coulomb barrier are suppressed due to the breakup effects of weekly bound projectile 6 Li. We have also measured the elastic and quasi-elastic excitation functions of 6,7 Li, 9 Be+ 208 Pb, 209 Ri. From these excitation functions, barrier distributions are extracted and compared with the predictions of the coupled-channels model. It is found that the barrier distributions are somehow broaden and shift to lower energies which may be a signature of the breakup effects of the weekly bound projectiles. Gomes et al. study the behavior of the fusion, breakup, reaction, and elastic scattering of different projectiles on 64 Zn at near and above barrier energies. They found that the elastic (noncapture) breakup cross section is important at energies close to and above the Coulomb barrier and increases the reaction cross sections. In addition, they show that the breakup process at near and below barrier energies is responsible for the vanishing of the usual threshold anomaly of the optical and gives rise to a new type of anomaly. Recently, Newton et al. systematically analyzed the high precision fusion cross sections for Z p Z t p Z t 48 Ca+ 90,96 Zr at the XTU Tandem accelerator facility of the Laboratori Nazionali di Legnaro, Italy. The comparison of experimental 40,48 Ca+ 90,96 Zr fusion data shows that fusion of 40 Ca+ 96 Zr is much enhanced due to the positive Q-values of the transfer channels. The much larger enhancement for the 40 Ca+ 96 Zr as compared to other three systems clearly indicates that neutron transfer with the positive Q-value should play a significant role in sub-barrier fusion. In order to extract the information on the complex

Temperature dependence of electrocatalytic and photocatalytic oxygen evolution reaction rates using NiFe oxide

KAUST Repository

Nurlaela, Ela

2016-01-25

The present work compares oxygen evolution reaction (OER) in electrocatalysis and photocatalysis in aqueous solutions using nanostructured NiFeOx as catalysts. The impacts of pH and reaction temperature on the electrocatalytic and photocatalytic OER kinetics were investigated. For electrocatalysis, a NiFeOx catalyst was hydrothermally decorated on Ni foam. In 1 M KOH solution, the NiFeOx electrocatalyst achieved 10 mA cm-2 at an overpotential of 260 mV. The same catalyst was decorated on the surface of Ta3N5 photocatalyst powder. The reaction was conducted in the presence of 0.1 M Na2S2O8 as a strong electron scavenger, thus likely leading to the OER being kinetically relevant. When compared with the bare Ta3N5, NiFeOx/Ta3N5 demonstrated a 5-fold improvement in photocatalytic activity in the OER under visible light irradiation, achieving a quantum efficiency of 24 % at 480 nm. Under the conditions investigated, a strong correlation between the electrocatalytic and photocatalytic performances was identified: an improvement in electrocatalysis corresponded with an improvement in photocatalysis without altering the identity of the materials. The rate change at different pH was likely associated with electrocatalytic kinetics that accordingly influenced the photocatalytic rates. The sensitivity of the reaction rates with respective to the reaction temperature resulted in an apparent activation energy of 25 kJ mol-1 in electrocatalysis, whereas that in photocatalysis was 16 kJ mol-1. The origin of the difference in these activation energy values is likely attributed to the possible effects of temperature on the individual thermodynamic and kinetic parameters of the reaction process. The work described herein demonstrates a method of “transferring the knowledge of electrocatalysis to photocatalysis” as a strong tool to rationally and quantitatively understand the complex reaction schemes involved in photocatalytic reactions.

Strong disorder RG approach of random systems

International Nuclear Information System (INIS)

Igloi, Ferenc; Monthus, Cecile

2005-01-01

There is a large variety of quantum and classical systems in which the quenched disorder plays a dominant ro-circumflex le over quantum, thermal, or stochastic fluctuations: these systems display strong spatial heterogeneities, and many averaged observables are actually governed by rare regions. A unifying approach to treat the dynamical and/or static singularities of these systems has emerged recently, following the pioneering RG idea by Ma and Dasgupta and the detailed analysis by Fisher who showed that the Ma-Dasgupta RG rules yield asymptotic exact results if the broadness of the disorder grows indefinitely at large scales. Here we report these new developments by starting with an introduction of the main ingredients of the strong disorder RG method. We describe the basic properties of infinite disorder fixed points, which are realized at critical points, and of strong disorder fixed points, which control the singular behaviors in the Griffiths-phases. We then review in detail applications of the RG method to various disordered models, either (i) quantum models, such as random spin chains, ladders and higher dimensional spin systems, or (ii) classical models, such as diffusion in a random potential, equilibrium at low temperature and coarsening dynamics of classical random spin chains, trap models, delocalization transition of a random polymer from an interface, driven lattice gases and reaction diffusion models in the presence of quenched disorder. For several one-dimensional systems, the Ma-Dasgupta RG rules yields very detailed analytical results, whereas for other, mainly higher dimensional problems, the RG rules have to be implemented numerically. If available, the strong disorder RG results are compared with another, exact or numerical calculations

Nuclear effects in protonium formation low-energy three-body reaction: p̄ + (pμ1s → (p̄pα + μ−: Strong p̄–p interaction in p̄ + (pμ1s

Directory of Open Access Journals (Sweden)

Sultanov Renat A.

2016-01-01

Full Text Available A three-charge-particle system (p̄, μ−, p+ with an additional matter-antimatter, i.e. p̄–p+, nuclear interaction is the subject of this work. Specifically, we carry out a few-body computation of the following protonium formation reaction: p̄ + (p+μ−1s → (p̄p+1s + μ−, where p+ is a proton, p̄ is an antiproton, μ− is a muon, and a bound state of p+ and its counterpart p̄ is a protonium atom: Pn = (p̄p+. The low-energy cross sections and rates of the Pn formation reaction are computed in the framework of a Faddeev-like equation formalism. The strong p̄–p+ interaction is approximately included in this calculation.

Temperature dependence of muonium reaction rates in the gas phase

International Nuclear Information System (INIS)

Fleming, D.G.; Garner, D.M.; Mikula, R.J.; British Columbia Univ., Vancouver

1981-01-01

A study of the temperature dependence of reaction rates has long been an important tool in establishing reaction pathways in chemical reactions. This is particularly true for the reactions of muonium (in comparison with those of hydrogen) since a measurement of the activation energy for chemical reaction is sensitive to both the height and the position of the potential barrier in the reaction plane. For collision controlled reactions, on the other hand, the reaction rate is expected to exhibit a weak T 1 sup(/) 2 dependence characteristic of the mean collision velocity. These concepts are discussed and their effects illustrated in a comparison of the chemical and spin exchange reaction rates of muonium and hydrogen in the temperature range approx.300-approx.500 K. (orig.)

Further study of the reactions of fishes to toxic solutions

Energy Technology Data Exchange (ETDEWEB)

Jones, J R.E.

1948-01-01

This paper records some further observations on the reactions of fish to toxic solutions. The method of experimentation resembles that described in a previous paper by the writer (Jones, 1947b). In every case the solution is presented as an alternative to the Aberystwyth tap water, which is well aerated, very soft, of pH 6.8. In experiments with sodium sulphide a supply system is arranged in which dilute sodium sulphide solution, brought to pH 6.8 by the addition of sulphuric acid, is automatically made up as it runs into the observation vessel. Gasterosteus aculeatus l. reacts negatively to a 0.001N solution almost immediately; at greater dilution the reaction time lengthens, at 0.00008N is about 47 min. Over the concentration range tested the reaction time is always shorter than the survival time. Gasterosteus is positive to 0.04N lead nitrate. As a positive reaction is also displayed to equivalent concentrations of calcium nitrate, sodium nitrate and sodium chloride it is possible that the osmotic pressure of the solution is its attractive feature. At 0.01N the positive response to lead nitrate disappears and at 0.004N is replaced by a very definite negative reaction which is maintained down to 0.00002N. The minnow (Phoxinus phoxinus l.) is also negative to dilute lead nitrate and will detect and avoid a 0.000004N solution. Gasterosteus will avoid water more acid than pH 5.6 or more alkaline than pH 11.4. Over the range 5.8-11.2 the fish are indifferent or very vaguely positive. Gasterosteus is negative to 0.04 and 0.01N ammonia solution, positive to 0.001 and 0.0001N. The general result with ammonia is thus the converse of that observed with lead nitrate.

Position paper of the EAACI: food allergy due to immunological cross-reactions with common inhalant allergens.

Science.gov (United States)

Werfel, T; Asero, R; Ballmer-Weber, B K; Beyer, K; Enrique, E; Knulst, A C; Mari, A; Muraro, A; Ollert, M; Poulsen, L K; Vieths, S; Worm, M; Hoffmann-Sommergruber, K

2015-09-01

In older children, adolescents, and adults, a substantial part of all IgE-mediated food allergies is caused by cross-reacting allergenic structures shared by inhalants and foods. IgE stimulated by a cross-reactive inhalant allergen can result in diverse patterns of allergic reactions to various foods. Local, mild, or severe systemic reactions may occur already after the first consumption of a food containing a cross-reactive allergen. In clinical practice, clinically relevant sensitizations are elucidated by skin prick testing or by the determination of specific IgE in vitro. Component-resolved diagnosis may help to reach a diagnosis and may predict the risk of a systemic reaction. Allergy needs to be confirmed in cases of unclear history by oral challenge tests. The therapeutic potential of allergen immunotherapy with inhalant allergens in pollen-related food allergy is not clear, and more placebo-controlled studies are needed. As we are facing an increasing incidence of pollen allergies, a shift in sensitization patterns and changes in nutritional habits, and the occurrence of new, so far unknown allergies due to cross-reactions are expected. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Solid strong base K-Pt/NaY zeolite nano-catalytic system for completed elimination of formaldehyde at room temperature

Science.gov (United States)

Song, Shaoqing; Wu, Xi; Lu, Changhai; Wen, Meicheng; Le, Zhanggao; Jiang, Shujuan

2018-06-01

Solid strong base nano-catalytic system of K-modification NaY zeolite supported 0.08% Pt (K-Pt/NaY) were constructed for eliminating HCHO at room temperature. In the catalytic process, activation energy over K-Pt/NaY nano-catalytic system was greatly decreased along with the enhanced reaction rate. Characterization and catalytic tests revealed the surface electron structure of K-Pt/NaY was improved, as reflected by the enhanced HCHO adsorption capability, high sbnd OH concentration, and low-temperature reducibility. Therefore, the optimal K-Pt/NaY showed high catalytic efficiency and strong H2O tolerance for HCHO elimination by directly promoting the reaction between active sbnd OH and formate species. These results may suggest a new way for probing the advanced solid strong base nano-catalytic system for the catalytic elimination of indoor HCHO.

Papulo-Nodular Reactions in Black Tattoos as Markers of Sarcoidosis: Study of 92 Tattoo Reactions from a Hospital Material.

Science.gov (United States)

Sepehri, Mitra; Hutton Carlsen, Katrina; Serup, Jørgen

2016-01-01

Sarcoidosis is, from historical data, suggested to be more prevalent among patients with tattoo reactions. We aimed to evaluate this association in a systematic study. This is a consecutive study of patients with tattoo complications, diagnosed in the "Tattoo Clinic" at Bispebjerg University Hospital in Copenhagen, Denmark, from 2008 to 2015, based on clinical assessment and histology. From the overall group of 494 tattoo complications in 406 patients, 92 reactions in 72 patients showed a papulo-nodular pattern studied for local and systemic sarcoidosis, since sarcoidosis is expected to be nodular. Of the 92 reactions with a papulo-nodular pattern, 27 (29%) reactions in 19 patients were diagnosed as cutaneous or systemic sarcoidosis, supported by histology; 65 (71%) were diagnosed as non-sarcoidosis due to histology and no clinical sarcoid manifestations. "Rush phenomenon" with concomitant reaction in many other black tattoos, triggered by a recent tattoo with a papulo-nodular reaction, was observed in 70% in the sarcoidosis group and 28% in the non-sarcoidosis group, indicating a predisposing factor which may be autoimmune and linked with sarcoidosis. Agglomerates of black pigment forming foreign bodies may in the predisposed individual trigger widespread reaction in the skin and internal organs. Black tattoos with papulo-nodular reactions should be seen as markers of sarcoidosis. Papulo-nodular reactions may, as triggers, induce widespread reactions in other black tattoos - a "rush phenomenon" - depending on individual predisposition. Sarcoidosis is estimated to be 500-fold increased in papulo-nodular reactions compared to the prevalence in the general population, and the association with black tattoos is strong. © 2017 S. Karger AG, Basel.

Single-step electron transfer on the nanometer scale: ultra-fast charge shift in strongly coupled zinc porphyrin-gold porphyrin dyads.

Science.gov (United States)

Fortage, Jérôme; Boixel, Julien; Blart, Errol; Hammarström, Leif; Becker, Hans Christian; Odobel, Fabrice

2008-01-01

The synthesis, electrochemical properties, and photoinduced electron transfer processes of a series of three novel zinc(II)-gold(III) bisporphyrin dyads (ZnP--S--AuP(+)) are described. The systems studied consist of two trisaryl porphyrins connected directly in the meso position via an alkyne unit to tert-(phenylenethynylene) or penta(phenylenethynylene) spacers. In these dyads, the estimated center to center interporphyrin separation distance varies from 32 to 45 A. The absorption, emission, and electrochemical data indicate that there are strong electronic interactions between the linked elements, thanks to the direct attachment of the spacer on the porphyrin ring through the alkyne unit. At room temperature in toluene, light excitation of the zinc porphyrin results in almost quantitative formation of the charge shifted state (.+)ZnP--S--AuP(.), whose lifetime is in the order of hundreds of picoseconds. In this solvent, the charge-separated state decays to the ground state through the intermediate population of the zinc porphyrin triplet excited state. Excitation of the gold porphyrin leads instead to rapid energy transfer to the triplet ZnP. In dichloromethane the charge shift reactions are even faster, with time constants down to 2 ps, and may be induced also by excitation of the gold porphyrin. In this latter solvent, the longest charge-shifted lifetime (tau=2.3 ns) was obtained with the penta-(phenylenethynylene) spacer. The charge shift reactions are discussed in terms of bridge-mediated super-exchange mechanisms as electron or hole transfer. These new bis-porphyrin arrays, with strong electronic coupling, represent interesting molecular systems in which extremely fast and efficient long-range photoinduced charge shift occurs over a long distance. The rate constants are two to three orders of magnitude larger than for corresponding ZnP--AuP(+) dyads linked via meso-phenyl groups to oligo-phenyleneethynylene spacers. This study demonstrates the critical

Probing cluster structures through sub-barrier transfer reactions

Directory of Open Access Journals (Sweden)

Rafferty D. C.

2016-01-01

Full Text Available Multinucleon transfer probabilities and excitation energy distributions have been measured in 16,18O, 19F + 208Pb at energies between 90% - 100% of the Coulomb barrier. A strong 2p2n enhancement is observed for all reactions, though most spectacularly in the 18O induced reaction. Results are interpreted in terms of the Semiclassical model, which seems to suggest α-cluster transfer in all studied systems. The relation to cluster-states in the projectile is discussed, with the experimental results consistent with previous structure studies. Dissipation of energy in the collisions of 18O is compared between different reaction modes, with cluster transfer associated with dissipation over a large number of internal states. Cluster transfer is shown to be a long range dissipation mechanism, which will inform the development of future models to treat these dynamic processes in reactions.

Combustion Synthesis Reaction Behavior of Cold-Rolled Ni/Al and Ti/Al Multilayers

Science.gov (United States)

2011-04-01

reaction modes of the films. Anselmi-Tamburini and Munir (21) studied the 2 SHS reaction in laminated Ni/Al foils and established a sequence of... convolution of three peaks. The very large broad peak, centered on position C, contains a superimposed peak appearing as a shoulder (position A) and a

Diversity-Oriented Syntheses by Combining CuAAC and Stereoselective INCIC Reactions with Peptides

DEFF Research Database (Denmark)

Wang, Yuanyuan; Madsen, Anders; Diness, Frederik

2017-01-01

Cascade reactions proceeding through peptide-derived N-carbamoyl iminium ions are reported. Two new reactions of N-carbamoyl iminium ions are described, including a stereoselective double cyclization generating N,N′-aminals and an acid-promoted auto-oxidation. Mechanistic investigations revealed...... that the N,N′-aminal formation is reversible under strongly acidic conditions. Both of these new reactions proved to be completely orthogonal to subsequent CuAAC chemistry. The reactions were performed in solution and on solid support. The robustness and high stereoselectivity of the methodology holds great...

On the Differential Market Reaction to Dividend Announcement: Evidence from an Emerging Equity Market

Directory of Open Access Journals (Sweden)

Muntazir Hussain

2013-09-01

Full Text Available The corporate finance literature for market reaction to dividend announcements reports mixed results: some of studies support a positive response of markets as a result of dividend announcement whereas some report negative. This study is an attempt to investigate the heterogeneous market reaction to dividend announcement for 73 firms listed in the Karachi Stock Exchange. We investigated this phenomenon with a novel methodology using both the event study and multivariate regression for the possible effects of firm-specific factors associated with dividend announcements. We report that the market reaction is one-sided as the majority of companies in the sample are with positive CAR for the given period. We cannot ignore the importance of firm-specific factors that have an effect on the dividends but we conclude that the majority of companies in the sample period portray a positive CAR and the market reaction is positive.

Non-Specific Reactions during Immunomagnetic Separation of Listeria

Directory of Open Access Journals (Sweden)

Iveta Zachová

2005-01-01

Full Text Available Problems occurring during the immunomagnetic separation (IMS of Listeria using immunomagnetic particles Dynabeads® anti-Listeria (Dynal Biotech, Norway were specified. Characteristics of these particles were compared with anti-Listeria spp. magnetite particles (Quantum Magnetics, USA. Pure cultures of Listeria innocua, Arthrobacter spp., Bacillus subtilis, Citrobacter braakii, Escherichia coli, Enterobacter aerogenes, Enterobacter cloacae and Staphylococcus aureus were used to evaluate non-specific reactions during IMS. Gram-positive microorganisms, especially Staphylococcus aureus and Arthrobacter spp., were found to be responsible for non-specific reactions in most cases. The capacity of Dynabeads® anti-Listeria particles was determined to be about 10 % of the initial pure cultures of Listeria spp., after 10 min of incubation. Non-specific reactions during IMS of Listeria were examined on the artificially inoculated food samples in which Gram-positive bacteria showed the highest percentage of capture. Influence of washing in two buffers was also studied.

Application of laser diagnostics to sodium-water chemical reaction field

International Nuclear Information System (INIS)

Deguchi, Yoshihiro; Tamura, Kenta; Muranaka, Ryota; Kusano, Koji; Kikuchi, Shin; Kurihara, Akikazu

2013-01-01

In a sodium-cooled fast reactor (SFR), liquid sodium is used as a heat transfer fluid because of its excellent heat transport capability. On the other hand, it has strong chemical reactivity with water vapor. One of the design basis accidents of the SFR is the water leakage into the liquid sodium flow by a breach of heat transfer tubes in a steam generator. Therefore the study on sodium-water chemical reactions is of paramount importance for safety reasons. This study aims to clarify the sodium-water reaction mechanisms using laser diagnostics. The sodium-water counter-flow reactions were measured using laser diagnostics such as laser induced fluorescence, CARS, Raman scattering and photo-fragmentation. The measurement results show that the sodium-water reaction proceeds mainly by the reaction Na + H 2 O → NaOH + H and the main product is NaOH in this reaction. Its forward and backward reaction rates tend to balance with each other and the whole reaction rate reduces as temperature increases. (author)

Resonances in the nuclear reactions 15N + 12C and 15N + 16O

International Nuclear Information System (INIS)

Monnehan, G.A.

1987-06-01

The reaction 12 C + 15 N have been studied at 15 N beam energies between 30 and 70 MeV. For each reaction, about twelve residual nuclei have been identified through the γ-ray detection method. Excitation functions were obtained for the fusion and peripheral channels. Resonances are seen in the channels containing at least one α particle at energies below 50 MeV. At higher energies, strong structures are observed in the direct reaction channels. The evolution of the fusion cross section is well reproduced by a model based on the statistical desexcitation of the compound nucleus if the discrete states of the residual nuclei are taken into account. The favourable observation of resonant phenomena in 15 N induced reactions can be understood in terms of a small number of channels open to the grazing wave. In the range 50 to 60 MeV, there is a strong coupling between the fusion and the direct reaction channels. The occurrence of resonances above E lab = 50 MeV in the peripheral channels is explained with the band crossing and effective barrier models. In the 15 N induced reactions, the absorption of the surface waves is weak [fr

Synthesis of N,N-Bis(nonaflyl) Squaric Acid Diamide and its Application to Organic Reactions

International Nuclear Information System (INIS)

Cheon, Cheol Hong; Yamamoto, Hisashi

2010-01-01

We have developed a new strong Brφnsted acid bearing two nonaflyl groups based on the squaric acid scaffold. The Brφnsted acid 2 showed the almost same reactivity as bistriflyl squaramide 1 in Mukaiyama aldol and Michael reactions of benzaldehyde with silyl enol ether. Moreover, the utility of Brφnsted acid 2 could be expanded to carbonyl ene reaction of rac-citronellal. Further application of this new Brφnsted acid to organic reactions and to flow system reactors is currently underway in our laboratory. Brφnsted acid catalysis is one of the growing fields in modern organic synthesis.1 Although several Brφnsted acids, such as urea/thiourea, TADDOL, and phosphoric acid, have been applied to a variety of organic reactions, other Brφnsted acid scaffolds have been much less explored. Recently, Rawal et al have developed a Brφnsted acid catalyst based on squaric acid moiety and successfully applied it as a catalyst for conjugate addition of 1,3-dicarbonyl compounds to nitroolefins. More recently, we have developed a strong Brφnsted acid derived from squaric acid by introducing a strong electron withdrawing trifluoromethanesulfonyl (Tf) group and applied it to Mukaiyama aldol and Michael reaction of a variety of aldehydes, ketones, and α,β-unsaturated ketones. As a continuing effort to develop strong Brφnsted acids based on the squaric acid scaffold, it was expected that replacement of Tf group with a longer perfluoro-alkanesulfonyl group would be able to tune the physical properties, such as solubilities in organic solvents and fluoro-philicity, without loss of reactivity. Herein, we report the development of a new Brφnsted acid based on the squaric acid scaffold carrying two nonafluorobutanesulfonyl (Nf) groups and the preliminary results of its reactivity to various organic reactions

False positive reaction due to endogenous biotin activity in glandular epithelium of decidua Reação falso positiva em epitélio glandular da decídua devido a atividade endógena de biotina

Directory of Open Access Journals (Sweden)

Liliana Cruz Spano

2005-06-01

Full Text Available Biotin-labeled probe was used in an in situ hybridisation assay to localize virus infection in formalin-fixed, paraffin embedded tissues taken from eleven abortion cases. Probes for human cytomegalovirus (HCMV, human Parvovirus B19 (B19 and human adenovirus type 2 (HAd2, were labeled with biotin-11-dUTP by nick-translation reaction. Streptavidin-alkaline-phosphatase (SAP was used to detect biotin, followed by 4-nitroblue tetrazolium/5-bromo-4-chloro-3-indolyl phosphate (NBT/BCIP solution. Positive reaction was observed in nucleus of glandular ephitelium cells of decidua either in positive or in negative control at first and second gestational trimester. The reaction was not inhibited with blocking solution for alkaline phosphatase endogenous activity and it persisted even with probes omission. The use of adequate negative control permitted to reveal the presence of nuclear biotin in glandular epithelium of decidua, responsible for false positivity in detection systems involving streptavidin biotin system (StrepABC. The stained cells resembled to cytophatic effect due to herpesvirus, which could induce further misinterpretation. The results obtained in this study strongly recommend that DNA detection by in situ hybridisation reaction in gestational endometrium should be done without using StrepABC system.Sondas marcadas com biotina foram utilizadas neste trabalho para detecção de infecção viral por hibridização in situ em tecidos fixados com formalina e embebidos em parafina de 11 casos obtidos de abortamento. Sondas para citomegalovírus humano (HCMV, parvovírus B19 humano (B19 e adenovírus humano tipo 2 (HAd2, foram marcadas com biotina-11-dUTP através da reação de nick-translation. Estreptavidina conjugada com fosfatase alcalina (SAP seguida por solução de 4-nitro-azul de tetrazolio/5-bromo-4-cloro-3-indolil fosfato (NBT/BCIP foram utilizadas para detecção da biotina após a reação de hibridização. Reação positiva foi

On the adsorption/reaction of acetone on pure and sulfate-modified zirconias.

Science.gov (United States)

Crocellà, Valentina; Cerrato, Giuseppina; Morterra, Claudio

2013-08-28

In situ FTIR spectroscopy was employed to investigate some aspects of the ambient temperature (actually, IR-beam temperature) adsorption of acetone on various pure and sulfate-doped zirconia specimens. Acetone uptake yields, on all examined systems and to a variable extent, different types of specific molecular adsorption, depending on the kind/population of available surface sites: relatively weak H-bonding interaction(s) with surface hydroxyls, medium-strong coordinative interaction with Lewis acidic sites, and strong H-bonding interaction with Brønsted acidic centres. Moreover acetone, readily and abundantly adsorbed in molecular form, is able to undergo the aldol condensation reaction (yielding, as the main reaction product, adsorbed mesityl oxide) only if the adsorbing material possesses some specific surface features. The occurrence/non-occurrence of the acetone self-condensation reaction is discussed, and leads to conclusions concerning the sites that catalyze the condensation reaction that do not agree with either of two conflicting interpretations present in the literature of acetone uptake/reaction on, mainly, zeolitic systems. In particular, what turns out to be actually necessary for the acetone aldol condensation reaction to occur on the examined zirconia systems is the presence of coordinatively unsaturated O(2-) surface sites of basicity sufficient to lead to the extraction of a proton from one of the CH3 groups of adsorbed acetone.

HIV Status Disclosure in the Workplace: Positive and Stigmatizing Experiences of Health Care Workers Living with HIV.

Science.gov (United States)

Stutterheim, Sarah E; Brands, Ronald; Baas, Ineke; Lechner, Lilian; Kok, Gerjo; Bos, Arjan E R

We explored workplace experiences of 10 health care providers with HIV in the Netherlands. We used semi-structured interviews to discuss motivations for disclosure and concealment, reactions to disclosures, the impact of reactions, and coping with negative reactions. Reasons for disclosure were wanting to share the secret, expecting positive responses, observing positive reactions to others, wanting to prevent negative reactions, and being advised to disclose. Reasons for concealment included fearing negative reactions, observing negative reactions, previous negative experiences, having been advised to conceal, and considering disclosure unnecessary. Positive reactions included seeing HIV as a nonissue; showing interest, support, and empathy; and maintaining confidentiality. Negative reactions included management wanting to inform employees, work restrictions, hiring difficulties, gossip, and hurtful comments, resulting in participants being upset, taken aback, angry, depressed, or feeling resignation. Participants coped by providing information, standing above the experience, attributing reactions to ignorance, seeking social support, or leaving their jobs. Copyright © 2017 Association of Nurses in AIDS Care. Published by Elsevier Inc. All rights reserved.

Angular-momentum-assisted dissociation of CO in strong optical fields

Science.gov (United States)

Mullin, Amy; Ogden, Hannah; Murray, Matthew; Liu, Qingnan; Toro, Carlos

2017-04-01

Filaments are produced in CO gas by intense, chirped laser pulses. Visible emission from C2 is observed as a result of chemical reactions of highly excited CO. At laser intensities greater than 1014 W cm-2, the C2 emission shows a strong dependence on laser polarization. Oppositely chirped pulses of light with ω0 = 800 nm are recombined spatially and temporally to generate angularly accelerating electric fields (up to 30 THz) that either have an instantaneous linear polarization or act as a dynamic polarization grating that oscillates among linear and circular polarizations. The angularly accelerating linear polarization corresponds to an optical centrifuge that concurrently drives molecules into high rotational states (with J 50) and induces strong-field dissociation. Higher order excitation is observed for the time-varying laser polarization configuration that does not induce rotational excitation. The results indicate that the presence of rotational angular momentum lowers the threshold for CO dissociation in strong optical fields by coupling nuclear and electronic degrees of freedom. Support from NSF CHE-1058721 and the University of Maryland.

Co-solvent effects on reaction rate and reaction equilibrium of an enzymatic peptide hydrolysis.

Science.gov (United States)

Wangler, A; Canales, R; Held, C; Luong, T Q; Winter, R; Zaitsau, D H; Verevkin, S P; Sadowski, G

2018-04-25

This work presents an approach that expresses the Michaelis constant KaM and the equilibrium constant Kth of an enzymatic peptide hydrolysis based on thermodynamic activities instead of concentrations. This provides KaM and Kth values that are independent of any co-solvent. To this end, the hydrolysis reaction of N-succinyl-l-phenylalanine-p-nitroanilide catalysed by the enzyme α-chymotrypsin was studied in pure buffer and in the presence of the co-solvents dimethyl sulfoxide, trimethylamine-N-oxide, urea, and two salts. A strong influence of the co-solvents on the measured Michaelis constant (KM) and equilibrium constant (Kx) was observed, which was found to be caused by molecular interactions expressed as activity coefficients. Substrate and product activity coefficients were used to calculate the activity-based values KaM and Kth for the co-solvent free reaction. Based on these constants, the co-solvent effect on KM and Kx was predicted in almost quantitative agreement with the experimental data. The approach presented here does not only reveal the importance of understanding the thermodynamic non-ideality of reactions taking place in biological solutions and in many technological applications, it also provides a framework for interpreting and quantifying the multifaceted co-solvent effects on enzyme-catalysed reactions that are known and have been observed experimentally for a long time.

Explicit strong stability preserving multistep Runge–Kutta methods

KAUST Repository

Bresten, Christopher; Gottlieb, Sigal; Grant, Zachary; Higgs, Daniel; Ketcheson, David I.; Né meth, Adrian

2015-01-01

High-order spatial discretizations of hyperbolic PDEs are often designed to have strong stability properties, such as monotonicity. We study explicit multistep Runge-Kutta strong stability preserving (SSP) time integration methods for use with such discretizations. We prove an upper bound on the SSP coefficient of explicit multistep Runge-Kutta methods of order two and above. Numerical optimization is used to find optimized explicit methods of up to five steps, eight stages, and tenth order. These methods are tested on the linear advection and nonlinear Buckley-Leverett equations, and the results for the observed total variation diminishing and/or positivity preserving time-step are presented.

Explicit strong stability preserving multistep Runge–Kutta methods

KAUST Repository

Bresten, Christopher

2015-10-15

High-order spatial discretizations of hyperbolic PDEs are often designed to have strong stability properties, such as monotonicity. We study explicit multistep Runge-Kutta strong stability preserving (SSP) time integration methods for use with such discretizations. We prove an upper bound on the SSP coefficient of explicit multistep Runge-Kutta methods of order two and above. Numerical optimization is used to find optimized explicit methods of up to five steps, eight stages, and tenth order. These methods are tested on the linear advection and nonlinear Buckley-Leverett equations, and the results for the observed total variation diminishing and/or positivity preserving time-step are presented.

Measurement of total reaction cross sections of exotic neutron rich nuclei

International Nuclear Information System (INIS)

Mittig, W.; Chouvel, J.M.; Wen Long, Z.

1987-01-01

Total reaction cross-sections of neutron rich nuclei from C to Mg in a thick Si-target have been measured using the detection of the associated γ-rays in a 4Π-geometry. This cross-section strongly increases with neutron excess, indicating an increase of as much as 15% of the reduced strong absorption radius with respect to stable nuclei

Insights into the mechanisms on chemical reactions: reaction paths for chemical reactions

International Nuclear Information System (INIS)

Dunning, T.H. Jr.; Rosen, E.; Eades, R.A.

1987-01-01

We report reaction paths for two prototypical chemical reactions: Li + HF, an electron transfer reaction, and OH + H 2 , an abstraction reaction. In the first reaction we consider the connection between the energetic terms in the reaction path Hamiltonian and the electronic changes which occur upon reaction. In the second reaction we consider the treatment of vibrational effects in chemical reactions in the reaction path formalism. 30 refs., 9 figs

Reactions of laser ablated uranium with nitrogen studied using matrix isolation spectroscopy

International Nuclear Information System (INIS)

Sankaran, K.; Sundararajan, K.; Viswanathan, K.S.

1999-01-01

Unusual reactions were found to occur when uranium was laser ablated in the presence of nitrogen. The reaction products were trapped in a rigid inert gas matrix and studied using infrared spectroscopy. The species formed were strongly dependent on the partial pressure of nitrogen in the matrix gas used during the ablation process; at low nitrogen partial pressures uranium dinitride (NUN) was the major reaction product, while at high partial pressures of nitrogen the mononitride, UN, was the predominant product. (author)

The 'compensation effect' in the graphite/CO2 reaction

International Nuclear Information System (INIS)

Stephen, W.J.

1983-08-01

The compensation effect is the often observed linear relationship between the activation energy and pre-exponential factor in the Arrhenius equations of a series of related reactions. Previously reported studies of the graphite/CO 2 reaction at different total pressures and CO 2 /CO ratios are used as an example of the compensation effect. The effect is shown in general to be an artefact produced by a strong correlation between the parameter estimates in the conventional Arrhenius plot. A transformation of the Arrhenius plot to minimise the overall correlation between estimates and thus enable detection of a true compensation effect is presented. The results of this transformation on the kinetic data for the graphite/CO 2 reaction are consistent with previous analyses of the reaction system. They show that there is only a limited compensation effect within this study and demonstrate the influence of the approach to equilibrium of the graphite/CO 2 reaction. (author)

On the effect of tether composition on cis/trans selectivity in intramolecular Diels-Alder reactions.

Science.gov (United States)

Paddon-Row, Michael N; Longshaw, Alistair I; Willis, Anthony C; Sherburn, Michael S

2009-01-05

Intramolecular Diels-Alder (IMDA) transition structures (TSs) and energies have been computed at the B3LYP/6-31+G(d) and CBS-QB3 levels of theory for a series of 1,3,8-nonatrienes, H(2)C=CH-CH=CH-CH(2)-X-Z-CH=CH(2) [-X-Z- = -CH(2)-CH(2)- (1); -O-C(=O)- (2); -CH(2)-C(=O)- (3); -O-CH(2)- (4); -NH-C(=O)- (5); -S-C(=O)- (6); -O-C(=S)- (7); -NH-C(=S)- (8); -S-C(=S)- (9)]. For each system studied (1-9), cis- and trans-TS isomers, corresponding, respectively, to endo- and exo-positioning of the -C-X-Z- tether with respect to the diene, have been located and their relative energies (E(rel) (TS)) employed to predict the cis/trans IMDA product ratio. Although the E(rel) (TS) values are modest (typically NH or S), the IMDA cis stereoselectivity diminishes. The predicted stereochemical reaction preferences are explained in terms of two opposing effects operating in the cis-TS, namely (1) unfavorable torsional (eclipsing) strain about the C4-C5 bond, that is caused by the -C-X-C(=Y)- group's strong tendency to maintain local planarity; and (2) attractive electrostatic and secondary orbital interactions between the endo-(thio)carbonyl group, C=Y, and the diene. The former interaction predominates when X is weakly electronegative (X=N, S), while the latter is dominant when X is more strongly electronegative (X=O), or a methylene group (X=CH(2)) which increases tether flexibility. These predictions hold up to experimental scrutiny, with synthetic IMDA reactions of 1, 2, 3, and 4 (published work) and 5, 6, and 8 (this work) delivering ratios close to those calculated. The reactions of thiolacrylate 5 and thioamide 8 represent the first examples of IMDA reactions with tethers of these types. Our results point to strategies for designing tethers, which lead to improved cis/trans-selectivities in IMDAs that are normally only weakly selective. Experimental verification of the validity of this claim comes in the form of fumaramide 14, which undergoes a more trans-selective IMDA reaction

Method of improving heterogeneous oil reservoir polymer flooding effect by positively-charged gel profile control

Science.gov (United States)

Zhao, Ling; Xia, Huifen

2018-01-01

The project of polymer flooding has achieved great success in Daqing oilfield, and the main oil reservoir recovery can be improved by more than 15%. But, for some strong oil reservoir heterogeneity carrying out polymer flooding, polymer solution will be inefficient and invalid loop problem in the high permeability layer, then cause the larger polymer volume, and a significant reduction in the polymer flooding efficiency. Aiming at this problem, it is studied the method that improves heterogeneous oil reservoir polymer flooding effect by positively-charged gel profile control. The research results show that the polymer physical and chemical reaction of positively-charged gel with the residual polymer in high permeability layer can generate three-dimensional network of polymer, plugging high permeable layer, and increase injection pressure gradient, then improve the effect of polymer flooding development. Under the condition of the same dosage, positively-charged gel profile control can improve the polymer flooding recovery factor by 2.3∼3.8 percentage points. Under the condition of the same polymer flooding recovery factor increase value, after positively-charged gel profile control, it can reduce the polymer volume by 50 %. Applying mechanism of positively-charged gel profile control technology is feasible, cost savings, simple construction, and no environmental pollution, therefore has good application prospect.

[Consensus position document on the child with an allergic reaction after vaccination or an allergy to vaccine components].

Science.gov (United States)

Echeverría Zudaire, L; Ortigosa Del Castillo, L; Alonso Lebrero, E; Álvarez García, F J; Cortés Álvarez, N; García Sánchez, N; Martorell Aragonés, A

2015-07-01

Vaccinations are one of the main public health tools for the control of vaccine-preventable diseases. If a child is labeled to have had an allergic reaction to a vaccine, the next immunizations will probably be suspended in that child, with the risks involved in this decision. The rate of severe allergic reactions is very low, ranging between 0.5-1/100,000 doses. The causes of allergic reactions to vaccines, more than the vaccine itself, are often due to residual protein components in the manufacturing process, such as gelatin or egg, and rarely to yeast or latex. Most of vaccine reactions are mild, localized at the site of injection, but in some circumstances, severe anaphylactic reactions can occur. If an immediate-type allergic reaction is suspected when vaccinating, or a child allergic to some of the vaccine components has to be vaccinated, a correct diagnosis of the possible allergy has to be made. The usual components of each vaccine should be known, in order to determine if vaccination can be performed safely on the child. Copyright © 2014 Asociación Española de Pediatría. Published by Elsevier España, S.L.U. All rights reserved.

Experimental study of the $^{66}$Ni$(d,p)^{67}$Ni one-neutron transfer reaction

CERN Document Server

Diriken, J.; Andreyev, A.N.; Antalic, S.; Bildstein, V.; Blazhev, A.; Darby, I.G.; De Witte, H.; Eberth, J.; Elseviers, J.; Fedosseev, V.N.; Flavigny, F.; Fransen, Ch.; Georgiev, G.; Gernhauser, R.; Hess, H.; Huyse, M.; Jolie, J.; Kröll, Th.; Krücken, R.; Lutter, R.; Marsh, B.A.; Mertzimekis, T.; Muecher, D.; Orlandi, R.; Pakou, A.; Raabe, R.; Randisi, G.; Reiter, P.; Roger, T.; Seidlitz, M.; Seliverstov, M.; Sotty, C.; Tornqvist, H.; Van De Walle, J.; Van Duppen, P.; Voulot, D.; Warr, N.; Wenander, F.; Wimmer, K.

2015-01-01

The quasi-SU(3) sequence of the positive parity $νg_{9/2}, d_{5/2}, s_{1/2}$ orbitals above the N=40 shell gap are assumed to induce strong quadrupole collectivity in the neutron-rich Fe (Z=26) and Cr (Z=24) isotopes below the nickel region. In this paper the position and strength of these single-particle orbitals are characterized in the neighborhood of $^{68}$Ni (Z=28,N=40) through the $^{66}$Ni($d,p$)$^{67}$Ni one-neutron transfer reaction at 2.95 MeV/nucleon in inverse kinematics, performed at the REX-ISOLDE facility in CERN. A combination of the Miniball $\\gamma$-array and T-REX particle-detection setup was used and a delayed coincidence technique was employed to investigate the 13.3-$\\mu$s isomer at 1007 keV in $^{67}$Ni. Excited states up to an excitation energy of 5.8 MeV have been populated. Feeding of the $νg_{9/2}$ (1007 keV) and $νd_{5/2}$ (2207 keV and 3277 keV) positive-parity neutron states and negative parity ($νpf$) states have been observed at low excitation energy. The extracted relativ...

Tritium production in neutron induced reactions

International Nuclear Information System (INIS)

Krasa, A.; Andreotti, E.; Hult, M.; Marissens, G.; Plompen, A.; Angelone, M.; Pillon, M.

2011-01-01

We present an overview of the present knowledge of (n,t) reaction excitation functions in the 14-21 MeV energy range for Cd, Cr, Fe, Mg, Mo, Ni, Pb, Pd, Ru, Sn, Ti, Zr. Experimental data are compared with evaluated data libraries, cross-section systematics, and TALYS calculations. The new values for the "5"0Cr(n,t)"4"8V cross-section measured using γ-spectrometry at 15, 16, 17.3 MeV are presented. The trend of the results confirms that while early experimental data at 14.6 MeV are strongly overestimated, the calculations performed with the default version of TALYS strongly underestimate the excitation curve in the measured energy region

Feelings of Women With Strong Family Histories Who Subsequent to Their Breast Cancer Diagnosis Tested BRCA Positive.

Science.gov (United States)

Joseph, Meera; Rab, Faiza; Panabaker, Karen; Nisker, Jeff

2015-05-01

Family physicians in Canada as reported in several studies do not recognize the importance of family history in relation to breast/ovarian cancer and thus Canadian women with strong family histories continue to develop early-onset breast cancer without the knowledge of or ability to make choices regarding increased surveillance or preventative strategies. This study explored the feelings of women who learned about their hereditary risk only after their diagnosis younger than 52 years and who eventually tested positive for a BRCA gene mutation. Thirty-four such women were mailed an invitation to participate in this research including a letter of information, consent form, and discussion prompts for their written narrative response. Rigorous mixed method analyses were performed using Charmaz-based qualitative analyses as well as quantitative analyses. Thirteen women (38.2%) responded with narratives for qualitative analysis from which 4 themes were coconstructed as follows: I, types of emotions; II, emotional response; III, coping with emotions; and IV, advice to women at similar risk. Women felt they should have learned about their hereditary risk from their family physician and through public education before their diagnosis. Although not experienced at the time of diagnosis, anger, frustration, and regret were experienced after receiving their BRCA results. These emotions arose from our research participants' lack of opportunity for prior genetic counseling and testing opportunity for genetic counseling and testing. With increased public and physician education, it is hoped that women with significant family histories of breast/ovarian cancer will be identified before diagnosis and given options regarding cancer surveillance and risk reduction strategies.

Astrophysical Nuclear Reaction Rates in the Dense Metallic Environments

Science.gov (United States)

Kilic, Ali Ihsan

2017-09-01

Nuclear reaction rates can be enhanced by many orders of magnitude in dense and relatively cold astrophysical plasmas such as in white dwarfs, brown dwarfs, and giant planets. Similar conditions are also present in supernova explosions where the ignition conditions are vital for cosmological models. White dwarfs are compact objects that have both extremely high interior densities and very strong local magnetic fields. For the first time, a new formula has been developed to explain cross section and reaction rate quantities for light elements that includes not only the nuclear component but also the material dependence, magnetic field, and crystal structure dependency in dense metallic environments. I will present the impact of the developed formula on the cross section and reaction rates for light elements. This could have possible technological applications in energy production using nuclear fusion reactions.

Parenting style and adolescent's reaction to conflict: is there a relationship?

Science.gov (United States)

Miller, Jessica M; DiIorio, Colleen; Dudley, William

2002-12-01

To determine if the reactions of adolescents toward hypothetical situations that can lead to conflict and violence varied by parenting style of their mothers. This study was part of a larger research project involving adolescents and their mothers participating in a longitudinal HIV-prevention program. Mothers and their adolescents were recruited from a community-based organization (CBO) and interviewed separately. Data were analyzed using the responses of 439 African-American adolescents ranging from ages 11 to 14 years. The responses of adolescents to questions about parenting were used to classify mothers into one of three parenting styles: authoritative, authoritarian, or permissive. The "anticipated reactions to hypothetical situations" scale consists of 11 items with 6 response categories. The six responses were reclassified into three categories ranging from "not at all violent" to "extremely violent." Higher scores indicate more violent reactions to the hypothetical situations. The parenting scale consists of two subscales: a 13-item parental involvement scale and a 13-item parental control scale. Items were rated on a 5-point Likert scale from "strongly disagree" to "strongly agree." Analysis of variance was used to determine if the anticipated reactions of adolescents toward hypothetical situations varied by parenting style of their mothers. Adolescent participants who reported a more permissive parenting style expressed more intense negative reactions toward the hypothetical situations that can provoke conflict. Male adolescents also expressed more intense reactions than females to the situations. There was no difference in intensity of reaction by age after controlling for gender and parenting style. Parenting style is associated with adolescents' reactions to hypothetical situations that can provoke conflict. This finding highlights the importance of considering parents and their approach to child-rearing as a factor in the adolescent's ability to

Collective plasma corrections to thermonuclear reactions rates in dense plasmas

International Nuclear Information System (INIS)

Tsytovich, V.N.

2002-01-01

General kinetic equations for nuclear reaction in dense plasmas are obtained. They take into account the first order collective plasma effects. Together with previously known corrections proportional to Z i Z j , the product of the charges Z i and Z j of two interacting nuclei, it is shown that there exist corrections proportional to the squares Z i 2 and Z j 2 of the charges. It is shown that the Salpeter's [1] correction due to the plasma screening of the interaction potential is at least r/d smaller (r is the nuclei size and d is Debye screening length) than previously thought and is zero in the approximation when the terms of the order r/d are neglected. But the correlation effects in the first approximation in the parameter 1/N d (where N d is the number of particle in the Debye sphere) give corrections which often coincide with the first order Salpeter's corrections (found by expansion in another small parameter, the ratio of thermal energy to Gamov's energy). The correlation corrections are ∝ Z i Z j , have a different physical meaning than the corrections [1], can have a different sign and are present for reactions where the Salpeter's corrections are zero. Previously in astrophysical applications it was widely used the interpolation formulas between weak and strong Salpeter's screening corrections. Since the correlation correction take place the previously known Salpeter's corrections and the strong correlation corrections is difficult to describe analytically, the interpolation formulas between the weak and strong correlations cannot be yet found. A new type of corrections are found here which are proportional to the square of the charges. They are due to collective change in electrostatic self-energy of the plasma system during the nuclear reactions. The latter corrections are found by taking into account the changes of plasma particle fluctuations by the nuclear reactions. Numerical evaluation of the plasma corrections for the nuclear reactions of the

Comparison of polymerase chain reaction (PCR) and loop-mediated ...

African Journals Online (AJOL)

Comparison of polymerase chain reaction (PCR) and loop-mediated isothermal amplification (LAMP) for diagnosis of Fusarium solani in human immunodeficiency virus (HIV) positive patients. ... The test was carried out in 1 h reaction at 65°C in a heater block. The specificity of the test was 100% and its sensitivity was a ...

The chloroindole auxins of pea, strong plant growth hormones or endogenous herbicides

International Nuclear Information System (INIS)

Engvild, K.C.

1994-02-01

In this work the three theses below are discussed: 1) Identification and quantitative determination of the very strong plant hormone, the auxin 4-chloroindole-3-acetic acid methyl ester, in immature seeds of Pisum, Vicia, Lathyrus, and Lens spp. by incorporation of radioactive 36 Cl, thin layer chromatography, autoradiography, colour reactions, and gas chromatography/mass spectrometry. 2) The strong biological activity of 4-chloroindole-3-acetic acid and its analogues and its ability to induce strong, almost irreversible, ethylene evolution. 3) The possible role of chloroindole auxin in plants, particularly if it might be the hypothetical death hormone, secreted from developing seeds, which induces senescence and kills the mother plant at maturity; if plants generally have several auxin types, growth promoters and endogenous herbicides; and if other chlorine-containing plant hormones occur in developing seeds of other crop species. (au) (7 tabs., 8 ills., 144 refs.)

Enhancing the efficiency of polymerase chain reaction using graphene nanoflakes.

Science.gov (United States)

Abdul Khaliq, R; Kafafy, Raed; Salleh, Hamzah Mohd; Faris, Waleed Fekry

2012-11-16

The effect of the recently developed graphene nanoflakes (GNFs) on the polymerase chain reaction (PCR) has been investigated in this paper. The rationale behind the use of GNFs is their unique physical and thermal properties. Experiments show that GNFs can enhance the thermal conductivity of base fluids and results also revealed that GNFs are a potential enhancer of PCR efficiency; moreover, the PCR enhancements are strongly dependent on GNF concentration. It was found that GNFs yield DNA product equivalent to positive control with up to 65% reduction in the PCR cycles. It was also observed that the PCR yield is dependent on the GNF size, wherein the surface area increases and augments thermal conductivity. Computational fluid dynamics (CFD) simulations were performed to analyze the heat transfer through the PCR tube model in the presence and absence of GNFs. The results suggest that the superior thermal conductivity effect of GNFs may be the main cause of the PCR enhancement.

Methyl salicylate: a reactive chemical warfare agent surrogate to detect reaction with hypochlorite.

Science.gov (United States)

Salter, W Bruce; Owens, Jeffery R; Wander, Joseph D

2011-11-01

Methyl salicylate (MeS) has a rich history as an inert physical simulant for the chemical warfare agents sulfur mustard and soman, where it is used extensively for liquid- and vapor-permeation testing. Here we demonstrate possible utility of MeS as a reactivity simulant for chlorine-based decontaminants. In these experiments MeS was reacted with sodium hypochlorite varying stoichiometry, temperature, reaction time, and pH. No colored oxidation products were observed; however, chlorination of the aromatic ring occurred ortho (methyl 3-chlorosalicylate) and para (methyl 5-chlorosalicylate) to the position bearing the -OH group in both the mono- and disubstituted forms. The monosubstituted para product accumulated initially, and the ortho and 3,5-dichloro products formed over the next several hours. Yields from reactions conducted below pH 11 declined rapidly with decreasing pH. Reactions run at 40 °C produced predominantly para substitution, while those run at 0 °C produced lower yields of ortho- and para-substituted products. Reactions were also carried out on textile substrates of cotton, 50/50 nylon-cotton, and a meta aramid. The textile data broadly reproduced reaction times and stoichiometry observed in the liquid phase, but are complicated by physical and possibly chemical interactions with the fabric. These data indicate that, for hypochlorite-containing neutralizing agents operating at strongly alkaline pH, one can expect MeS to react stoichiometrically with the hypochlorite it encounters. This suggests utility of MeS in lieu of such highly hazardous surrogates as monochloroalkyl sulfides as a simulant for threat scenarios involving the stoichiometric decomposition of sulfur mustard. Specifically, the extent of coverage of the simulant on a fabric by the neutralizing agent can be directly measured. Similar reactivity toward other halogen oxidizing agents is likely but remains to be demonstrated.

Fusion dynamics in 40Ca induced reactions

International Nuclear Information System (INIS)

Prasad, E.; Hinde, D.J.; Williams, E.

2017-01-01

Synthesis of superheavy elements (SHEs) and investigation of their properties are among the most challenging research topics in modern science. A non-compound nuclear process called quasi fission is partly responsible for the very low production cross sections of SHEs. The formation and survival probabilities of the compound nucleus (CN) strongly depend on the competition between fusion and quasi fission. A clear understanding of these processes and their dynamics is required to make reliable predictions of the best reactions to synthesise new SHEs. All elements beyond Nh are produced using hot fusion reactions and beams of 48 Ca were used in most of these experiments. In this context a series of fission measurements have been carried out at the Australian National University (ANU) using 40;48 Ca beams on various targets ranging from 142 Nd to 249 Cf. Some of the 40 Ca reactions will be discussed in this symposium

Variation in reaction norms: Statistical considerations and biological interpretation.

Science.gov (United States)

Morrissey, Michael B; Liefting, Maartje

2016-09-01

Analysis of reaction norms, the functions by which the phenotype produced by a given genotype depends on the environment, is critical to studying many aspects of phenotypic evolution. Different techniques are available for quantifying different aspects of reaction norm variation. We examine what biological inferences can be drawn from some of the more readily applicable analyses for studying reaction norms. We adopt a strongly biologically motivated view, but draw on statistical theory to highlight strengths and drawbacks of different techniques. In particular, consideration of some formal statistical theory leads to revision of some recently, and forcefully, advocated opinions on reaction norm analysis. We clarify what simple analysis of the slope between mean phenotype in two environments can tell us about reaction norms, explore the conditions under which polynomial regression can provide robust inferences about reaction norm shape, and explore how different existing approaches may be used to draw inferences about variation in reaction norm shape. We show how mixed model-based approaches can provide more robust inferences than more commonly used multistep statistical approaches, and derive new metrics of the relative importance of variation in reaction norm intercepts, slopes, and curvatures. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Low-temperature fabrication of mesoporous solid strong bases by using multifunction of a carbon interlayer.

Science.gov (United States)

Liu, Xiao-Yan; Sun, Lin-Bing; Liu, Xiao-Dan; Li, Ai-Guo; Lu, Feng; Liu, Xiao-Qin

2013-10-09

Mesoporous solid strong bases are highly promising for applications as environmentally benign catalysts in various reactions. Their preparation attracts increasing attention for the demand of sustainable chemistry. In the present study, a new strategy was designed to fabricate strong basicity on mesoporous silica by using multifunction of a carbon interlayer. A typical mesoporous silica, SBA-15, was precoated with a layer of carbon prior to the introduction of base precursor LiNO3. The carbon interlayer performs two functions by promoting the conversion of LiNO3 at low temperatures and by improving the alkali-resistant ability of siliceous host. Only a tiny amount of LiNO3 was decomposed on pristine SBA-15 at 400 °C; for the samples containing >8 wt % of carbon, however, LiNO3 can be entirely converted to strongly basic sites Li2O under the same conditions. The guest-host redox reaction was proven to be the answer for the conversion of LiNO3, which breaks the tradition of thermally induced decomposition. More importantly, the residual carbon layer can prevent the siliceous frameworks from corroding by the newly formed strongly basic species, which is different from the complete destruction of mesostructure in the absence of carbon. Therefore, materials possessing both ordered mesostructure and strong basicity were successfully fabricated, which is extremely desirable for catalysis and impossible to realize by conventional methods. We also demonstrated that the resultant mesoporous basic materials are active in heterogeneous synthesis of dimethyl carbonate (DMC) and the yield of DMC can reach 32.4%, which is apparently higher than that over the catalysts without a carbon interlayer (<12.9%) despite the same lithium content. The strong basicity, in combination with the uniform mesopores, is believed to be responsible for such a high activity.

Fulminant leukemoid reaction due to postpartum Clostridium sordellii infection

Directory of Open Access Journals (Sweden)

Prabhat Agrawal

2012-01-01

Full Text Available Clostridium sordellii is gram positive anaerobic spore forming rod and it has been demonstrated to cause gas gangrene, refractory shock, leukemoid reaction, and pleuroperitoneal effusion due to capillary leak. We report here a case of postpartum female who presented with leukemoid reaction, ascites, pleural effusion, and shock without fever 7 days after normal vaginal home delivery.

Transmission of the allergy reaction of a delayed type against Salmonella abortus ovis through blood plasma of gamma-irradiated guinea pigs

International Nuclear Information System (INIS)

Kostov, G.

1977-01-01

Use is made of blood plasma taken from guinea pigs (sensibilized with a live culture of Salmonella abortus ovis and then irradiated with 800 rad gamma-rays) to transmit the skin allergy reaction to normal, nonsensibilized guinea pigs. The allergy reaction has been demonstrated in the recipients of plasma as early as the 3-4th hour following the injection of the allergen into the skin. It reaches its peak at the 12-24th hour and later on strongly diminishes, remaining in few of the animals only up to the 48th hour. The infiltrate at the site of injection in the skin of positively reacting animals contains at the 24th hour cells of the polymorphonuclear type, which predominate, while the cells of the mononuclear type are few in number. There are no precipitins in the plasma of the donors, and the titer of the agglutinins and the cytophile antibodies is very low. Regardless of these findings it is concluded that the transmitted allergy reaction is of the fast type (after Arthuss), and not of the delayed one. (author)

Positive implicit attitudes toward odor words.

Science.gov (United States)

Bulsing, Patricia J; Smeets, Monique A M; van den Hout, Marcel A

2007-07-01

Associations between certain odors and for instance health effects may lead to positive or negative attitudes toward these odors. However, in experiments we conducted using the Implicit Association Test (IAT), we encountered attitudes even to odor "words." The IAT is based on the principle that reaction times measuring the association between words from a target dimension (in this case, odor vs. a neutral reference category) and an attribute dimension (i.e., positive or negative words) reflect the attitude to the target, where attitude-congruent associations between target and attribute are reflected by shorter reaction times. In a first experiment, we found distinctly positive attitudes to the concept odor in a student sample, which was replicated in a second experiment. In the main experiment, subjects in the aromatherapy group, who prefer using scented consumer products for relaxation purposes, showed a significantly more positive attitude toward odor words in the IAT than a control group, who did not have such a preference. The fact that results from the implicit test were not always associated with explicitly stated attitudes toward the odor words attests to the fact that the IAT measures the attitude of interest in a different way. As such, the IAT has added value in circumstances where explicit tests can be biased.

Proton exchange in acid–base complexes induced by reaction coordinates with heavy atom motions

International Nuclear Information System (INIS)

Alavi, Saman; Taghikhani, Mahdi

2012-01-01

Highlights: ► Proton exchange in acid–base complexes is studied. ► The structures, binding energies, and normal mode vibrations are calculated. ► Transition state structures of proton exchange mechanism are determined. ► In the complexes studied, the reaction coordinate involves heavy atom rocking. ► The reaction coordinate is not simply localized in the proton movements. - Abstract: We extend previous work on nitric acid–ammonia and nitric acid–alkylamine complexes to illustrate that proton exchange reaction coordinates involve the rocking motion of the base moiety in many double hydrogen-bonded gas phase strong acid–strong base complexes. The complexes studied involve the biologically and atmospherically relevant glycine, formic, acetic, propionic, and sulfuric acids with ammonia/alkylamine bases. In these complexes, the magnitude of the imaginary frequencies associated with the proton exchange transition states are −1 . This contrasts with widely studied proton exchange reactions between symmetric carboxylic acid dimers or asymmetric DNA base pair and their analogs where the reaction coordinate is localized in proton motions and the magnitude of the imaginary frequencies for the transition states are >1100 cm −1 . Calculations on complexes of these acids with water are performed for comparison. Variations of normal vibration modes along the reaction coordinate in the complexes are described.

Prospective assessment of the false positive rate of the Australian snake venom detection kit in healthy human samples.

Science.gov (United States)

Nimorakiotakis, Vasilios Bill; Winkel, Kenneth D

2016-03-01

The Snake Venom Detection Kit (SVDK; bioCSL Pty Ltd, Australia) distinguishes venom from the five most medically significant snake immunotypes found in Australia. This study assesses the rate of false positives that, by definition, refers to a positive assay finding in a sample from someone who has not been bitten by a venomous snake. Control unbroken skin swabs, simulated bite swabs and urine specimens were collected from 61 healthy adult volunteers [33 males and 28 females] for assessment. In all controls, simulated bite site and urine samples [a total of 183 tests], the positive control well reacted strongly within one minute and no test wells reacted during the ten minute incubation period. However, in two urine tests, the negative control well gave a positive reaction (indicating an uninterpretable test). A 95% confidence interval for the false positive rate, on a per-patient rate, derived from the findings of this study, would extend from 0% to 6% and, on a per-test basis, it would be 0-2%. It appears to be a very low incidence (0-6%) of intrinsic true false positives for the SVDK. The clinical impresssion of a high SVDK false positive rate may be mostly related to operator error. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Modification of the performance of WO3-ZrO2 catalysts by metal addition in hydrocarbon reactions

Directory of Open Access Journals (Sweden)

Gerardo Carlos Torres

2012-01-01

Full Text Available A study of the different hydrocarbon reactions over Ni doped WO3-ZrO2 catalysts was performed. Ni was found as NiO at low Ni concentration while at high Ni concentrations a small fraction was present as a metal. For both cases, Ni strongly modified total acidity and concentration of strong acid sites. In the cyclohexane dehydrogenation reaction, Ni addition promotes both benzene and methyl cyclopentane production. The hydroconversion activity (n-butane and n-octane increases with the augment of total acidity produced by Ni. The selectivity to reaction products is modified according to the acid strength distribution changes produced by Ni addition.

Pattern and predictors of partner disclosure of HIV status among HIV positive pregnant women in Nnewi Nigeria.

Science.gov (United States)

Udigwe, G O; Mbachu, I I; Oguaka, V; Onyegbule, O A; Udegbunam, O; Umeononihu, O S

2013-01-01

Sub-Saharan Africa has continued to bear the greatest burden of HIV/AIDS epidemic in the world. Partner disclosure of status may create opportunities for support or rejection. This study evaluated the pattern of partner disclosure of HIV positive women, their partners' reaction and factors that affect disclosure of HIV status to partners. This was a descriptive cross-sectional study conducted among pregnant women in Nnamdi Azikiwe University Teaching Hospital Nnewi An interviewer-administered questionnaire was used to obtain relevant information from the subjects. Data was analysed using SPSS version 20 software. One hundred and twenty six women participated in this study. The mean age of the women was 30.4 years +/- 5 while the mean parity was 2.6 +/- 1. All the patients had at least primary education with 63.5% having secondary education as the highest educational attainment. One hundred and sixteen (92.1%) were in monogamous marriage. One hundred and fourteen 90.5%) had disclosed their HIV status to their partners. Eighty-three (66.7%) of the women did this by self. Partners initial reaction was supportive in 84 (66.7%) of the women. Partner's subsequent reaction showed that 103 (81.2%) were supportive, 7 (5.6%) were indifferent while 4 (3.2%) were abusive and violent. The partner's HIV status showed that 54 (42.9) tested positive to HIV antibodies while 52 (41.3%) tested negative to HIV antibodies and 20 (15.9%) do not know partner's HIV status. There was strong correlation between disclosure of HIV status with monogamous marriage and duration of illness. The partners' reaction to HIV status of their female partners was largely supportive. Disclosure of HIV status should be encouraged in view of the needed support of the partner in management of these women.

Correlating intravenous radiographic contrast media reactions with the allergic profile

International Nuclear Information System (INIS)

Chua-Lim, A.; Enright, T.; Duda, E.; Lim, D.T.

1987-01-01

To determine the relevance of allergy as a predisposing factor in reactions to radiographic contrast media, the authors investigated the incidence of allergy among 100 randomly selected patients undergoing intravenous excretory urography and CT. The study population consisted of 50 reactors and 50 nonreactos to radiographic contrast media. All 100 subjects completed an allergy history, percutaneous allergy tests, and an in vitro specific IgE assay to common allergens. Thirty-four of 50 reactors had a positive allergy history, in contrast to 15 of 50 nonreactors (P < .001). Twenty-seven reactors had positive skin tests, in contrast to 12 of 50 nonreactors (P < .005). In vitro IgE assay results are pending. The results indicate that patients with positive histories or positive skin tests or both are at an increased risk for reactions to radiographic contrast media

Studies of heavy-ion reactions and transuranic nuclei

International Nuclear Information System (INIS)

Schroeder, W.U.; Huizenga, J.R.

1991-08-01

The development of the ''cold-fusion'' episode is reviewed. Ongoing studies of compound-nucleus formation and decay via the neutron multiplicity distribution confirm the validity of conventional statistical theory. The excitation energy partition in near-barrier damped 58 Ni + 208 Pb collisions is found to be largely independent of the direction of net mass transfer, supporting a diffusion-like nucleon-exchange mechanism. Exclusive experiments on the heavy reaction systems 197 Au + 208 Pb and 209 Bi + 136 Xe in the Fermi-energy domain have revealed important new insights into the reaction mechanism, which is found to be dominated by damped, binary processes. The effectiveness of the neutron multiplicity as an impact-parameter filter is demonstrated. It is shown that very-heavy-ion reactions lead to transient nuclear systems with temperatures in excess of τ = 6 MeV and transfer of large, aligned spins to reaction fragments. The first measurements of neutrons in coincidence with kinematically identified reaction fragments provide evidence for the binary, sequential character of dissipative collisions in the Fermi-energy domain. Also for the first time, a full event characterization was achieved for nuclear reactions in terms of neutrons and charged particles. Technical information on this experiment is provided. First results yield strong evidence for dominantly binary primary reaction dynamics of even highly dissipative 209 Bi + (28MeV/u) 136 Xe collisions, associated with several intermediate-mass fragments

Uniform silver/polypyrrole core-shell nanoparticles synthesized by hydrothermal reaction

Energy Technology Data Exchange (ETDEWEB)

Wang Shibin [Department of Chemistry, Tsinghua University, Beijing 100084 (China); Shi Gaoquan [Department of Chemistry, Tsinghua University, Beijing 100084 (China)]. E-mail: gshi@tsinghua.edu.cn

2007-04-15

Uniformly sized silver/polypyrrole (Ag/PPy) core-shell nanoparticles were synthesized by one-step hydrothermal reaction of pyrrole and silver nitrate in the presence of polyvinyl pyrrolidone (PVP) as protection agent. The morphology and structures of the nanoparticles have been studied by scanning and transmission electronic microscopes, X-ray diffractometer and Raman spectroscopy. The experimental results indicated that the particles had 120 nm silver cores with 20 nm polypyrrole (PPy) coatings. The reaction conditions have strong effects on the morphology of the nanoparticles.

Uniform silver/polypyrrole core-shell nanoparticles synthesized by hydrothermal reaction

International Nuclear Information System (INIS)

Wang Shibin; Shi Gaoquan

2007-01-01

Uniformly sized silver/polypyrrole (Ag/PPy) core-shell nanoparticles were synthesized by one-step hydrothermal reaction of pyrrole and silver nitrate in the presence of polyvinyl pyrrolidone (PVP) as protection agent. The morphology and structures of the nanoparticles have been studied by scanning and transmission electronic microscopes, X-ray diffractometer and Raman spectroscopy. The experimental results indicated that the particles had 120 nm silver cores with 20 nm polypyrrole (PPy) coatings. The reaction conditions have strong effects on the morphology of the nanoparticles

Reaction parameters for controlled sonosynthesis of gold nanoparticles

Energy Technology Data Exchange (ETDEWEB)

Gonzalez M, A. L. [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Paseo Colon esq. Paseo Tollocan s/n, 50120 Toluca, Estado de Mexico (Mexico); Cabrera L, L. I. [UNAM-UAEM, Centro Conjunto de Investigacion en Quimica Sustentable, Km 14.5 Carretera Toluca-Atlacomulco, 50200 San Cayetano-Toluca, Estado de Mexico (Mexico)

2015-07-01

The synthesis of gold nanoparticles by sonochemical technique has been previously performed with excellent results. The synthesis has been carried out in the presence of citric acid, a strong reducing agent, which allows the nucleation and growth of gold nanoparticles, at the same time that controls particle size. In this work we report the use of sodium tartrate as a mild reducing agent that allows a better understanding of the effect of the reaction parameters during gold nanoparticle synthesis. A conventional sonication bath (37 k Hz) was used for the sonochemical synthesis. This work focuses on the reaction temperature effect and the effect of sodium tartrate concentration. It was confirmed that particle size, and particle morphology is dependent of these two reaction parameters. Equally, colloidal stabilization was related to reaction temperature and sodium tartrate concentration. It was also determined that Ostwald ripening takes place during sonochemical reaction under our conditions, allowing to understand the mechanism that takes place during synthesis. Gold nanoparticles with main particle size of 17 nm were achieved by this method. Characterization techniques used: Fourier transform infrared spectra (Ftir), X-ray diffraction and Atomic Force Microscope was used in order to determine particle size of the synthetic product of reaction M10c by tapping mode. (Author)

Reaction parameters for controlled sonosynthesis of gold nanoparticles

International Nuclear Information System (INIS)

Gonzalez M, A. L.; Cabrera L, L. I.

2015-01-01

The synthesis of gold nanoparticles by sonochemical technique has been previously performed with excellent results. The synthesis has been carried out in the presence of citric acid, a strong reducing agent, which allows the nucleation and growth of gold nanoparticles, at the same time that controls particle size. In this work we report the use of sodium tartrate as a mild reducing agent that allows a better understanding of the effect of the reaction parameters during gold nanoparticle synthesis. A conventional sonication bath (37 k Hz) was used for the sonochemical synthesis. This work focuses on the reaction temperature effect and the effect of sodium tartrate concentration. It was confirmed that particle size, and particle morphology is dependent of these two reaction parameters. Equally, colloidal stabilization was related to reaction temperature and sodium tartrate concentration. It was also determined that Ostwald ripening takes place during sonochemical reaction under our conditions, allowing to understand the mechanism that takes place during synthesis. Gold nanoparticles with main particle size of 17 nm were achieved by this method. Characterization techniques used: Fourier transform infrared spectra (Ftir), X-ray diffraction and Atomic Force Microscope was used in order to determine particle size of the synthetic product of reaction M10c by tapping mode. (Author)

Positional games

CERN Document Server

Hefetz, Dan; Stojaković, Miloš; Szabó, Tibor

2014-01-01

This text serves as a thorough introduction to the rapidly developing field of positional games. This area constitutes an important branch of combinatorics, whose aim it is to systematically develop an extensive mathematical basis for a variety of two-player perfect information games. These range from such popular games as Tic-Tac-Toe and Hex to purely abstract games played on graphs and hypergraphs. The subject of positional games is strongly related to several other branches of combinatorics such as Ramsey theory, extremal graph and set theory, and the probabilistic method. These notes cover a variety of topics in positional games, including both classical results and recent important developments. They are presented in an accessible way and are accompanied by exercises of varying difficulty, helping the reader to better understand the theory. The text will benefit both researchers and graduate students in combinatorics and adjacent fields.

197Au(d,3He)196Pt reaction and the supersymmetry scheme

International Nuclear Information System (INIS)

Vergnes, M.; Berrier-Ronsin, G.; Rotbard, G.; Vernotte, J.; Langevin- Joliot, H.; Gerlic, E.; Wiele, J. van de; Guillot, J.

1981-01-01

The 197 Au(d, 3 He) 196 Pt reaction has been studied at Esub(d) = 108 MeV. An important breakdown of the selection rules of the supersymmetry scheme is observed for the 2 2 + level. The generally strong excitation of the 2 2 + level by transfer reactions in the Pt region leads to question the validity of the supersymmetry scheme at least for this level

Ion exchange equilibrium for some uni-univalent and uni-divalent reaction systems using strongly basic anion exchange resin Duolite A-102 D

Directory of Open Access Journals (Sweden)

R.S. Lokhande

2008-04-01

Full Text Available The study on thermodynamics of ion exchange equilibrium for uni-univalent Cl-/I-, Cl-/Br-, and uni-divalent Cl-/SO42-, Cl-/C2O42- reaction systems was carried out using ion exchange resin Duolite A-102 D. The equilibrium constant K was calculated by taking into account the activity coefficient of ions both in solution as well as in the resin phase. The K values calculated for uni-univalent and uni-divalent anion exchange reaction systems was observed to increase with rise in temperature, indicating the endothermic exchange reactions having enthalpy values of 13.7, 38.0, 23.9, 22.9 kJ/mol, respectively.

Method and apparatus for obtaining enhanced production rate of thermal chemical reactions

Science.gov (United States)

Tonkovich, Anna Lee Y [Pasco, WA; Wang, Yong [Richland, WA; Wegeng, Robert S [Richland, WA; Gao, Yufei [Kennewick, WA

2003-04-01

The present invention is a method and apparatus (vessel) for providing a heat transfer rate from a reaction chamber through a wall to a heat transfer chamber substantially matching a local heat transfer rate of a catalytic thermal chemical reaction. The key to the invention is a thermal distance defined on a cross sectional plane through the vessel inclusive of a heat transfer chamber, reaction chamber and a wall between the chambers. The cross sectional plane is perpendicular to a bulk flow direction of the reactant stream, and the thermal distance is a distance between a coolest position and a hottest position on the cross sectional plane. The thermal distance is of a length wherein the heat transfer rate from the reaction chamber to the heat transfer chamber substantially matches the local heat transfer rate.

Cry babies and pollyannas: Infants can detect unjustified emotional reactions.

Science.gov (United States)

Chiarella, Sabrina S; Poulin-Dubois, Diane

2013-08-01

Infants are attuned to emotional facial and vocal expressions, reacting most prominently when they are exposed to negative expressions. However, it remains unknown if infants can detect whether a person's emotions are justifiable given a particular context. The focus of the current paper was to examine whether infants react the same way to unjustified (e.g., distress following a positive experience) and justified (e.g., distress following a negative experience) emotional reactions. Infants aged 15 and 18 months were shown an actor experiencing negative and positive experiences, with one group exposed to an actor whose emotional reactions were consistently unjustified (i.e., did not match the event), while the other saw an actor whose emotional reactions were justified (i.e., always matched the event). Infants' looking times and empathic reactions were examined. Only 18-month-olds detected the mismatching facial expressions: those in the unjustified group showed more hypothesis testing (i.e., checking) across events than the justified group. Older infants in the justified group also showed more concerned reactions to negative expressions than those in the unjustified group. The present findings indicate that infants implicitly understand how the emotional valence of experiences is linked to subsequent emotional expressions.

Age and the experience of strong self-conscious emotion.

Science.gov (United States)

Henry, Julie D; von Hippel, William; Nangle, Matthew R; Waters, Michele

2018-04-01

It remains unclear whether there are age-related changes in the experience of strong self-conscious emotion, such as shame, guilt, pride and embarrassment. Because shame and guilt figure prominently in the aetiology of depressive symptoms and other mental health problems, a better understanding of how age affects the strong experience of these two negative self-conscious emotions is of particular importance. Thirty younger, 30 middle-aged and 30 older adults were compared on standardised cognitive assessments, in addition to an interview-based measure that assessed whether there are age differences in the likelihood of strongly experiencing four different types of self-conscious emotion within the past five years (shame, guilt, embarrassment and pride). The three groups did not differ in their likelihood of reporting an event that strongly elicited the positive self-conscious emotion of pride. However, older adults were more likely to report sources of pride that were other (as opposed to self) focused. Older adults were also less likely to report experiencing events that elicited all three negative self-conscious emotions, in particular, shame. Strong negative self-conscious emotion, and in particular shame, appears to be experienced less by older than younger adults.

Reaction diffusion equations with boundary degeneracy

Directory of Open Access Journals (Sweden)

Huashui Zhan

2016-03-01

Full Text Available In this article, we consider the reaction diffusion equation $$ \\frac{\\partial u}{\\partial t} = \\Delta A(u,\\quad (x,t\\in \\Omega \\times (0,T, $$ with the homogeneous boundary condition. Inspired by the Fichera-Oleinik theory, if the equation is not only strongly degenerate in the interior of $\\Omega$, but also degenerate on the boundary, we show that the solution of the equation is free from any limitation of the boundary condition.

Hydroxychloroquine-induced acute generalized exanthematous pustulosis with positive patch-testing.

Science.gov (United States)

Charfi, Ons; Kastalli, Sarrah; Sahnoun, Rym; Lakhoua, Ghozlane

2015-01-01

Acute generalized exanthematous pustulosis (AGEP) is a severe cutaneous adverse reaction, mostly induced by drugs. Hydroxychloroquine have been rarely reported in literature as a causative drug of this reaction. We report a case of AGEP induced by hydroxychloroquine with systemic involvement and confirmed by positive patch testing.

<strong>Mini-project>

DEFF Research Database (Denmark)

Katajainen, Jyrki

2008-01-01

In this project the goal is to develop the safe * family of containers for the CPH STL. The containers to be developed should be safer and more reliable than any of the existing implementations. A special focus should be put on strong exception safety since none of the existing prototypes available...

η production in proton-nucleus reactions

International Nuclear Information System (INIS)

Cassing, W.; Batko, G.; Vetter, T.; Wolf, G.

1991-01-01

The production of η-mesons in proton-nucleus reactions is analysed with respect to primary nucleon-nucleon (NN→NN η ) and secondary pion-nucleon (πN→ηN) production processes on the basis of Hartree-Fock groundstate momentum distributions and free on-shell production processes. The folding model adopted compares well for meson production with more involved simulations based on VUU transport equations. Similar to K + production in proton-nucleus reactions the η-mesons are primarily produced by the πN→ηN channel. However, η-mesons are absorbed in nuclei via excitation of the N * (1535) resonance which leads to strong distortions of the primordial spectra. On the other hand, the experimental mass dependence of the differential cross sections might yield information about the in-medium properties of this resonance. (orig.)

Development of tipping-over analysis of cask subjected to earthquake strong motion

International Nuclear Information System (INIS)

Shirai, Koji; Ito, Chihiro; Ryu, Hiroshi

1993-01-01

Since a cask is vertically oriented during loading in cask-storage, it is necessary to investigate the integrity of the cask against tipping-over during strong earthquakes. The rocking and sliding behavior of the cask during strong earthquakes can be analyzed as a dynamic vibration problem for a rigid cylinder. In this paper, in order to clarify the tipping-over characteristics of a cask during strong earthquakes, the authors applied the Distinct Element Method (DEM) to the seismic response analysis of the cask. DEM was introduced by Cundall P.A. in 1971. It is based on the use of an explicit numerical scheme. The cask was considered to be a rigid polygonal element, which satisfied the equation of motion and the law of action and reaction. They examined the applicability of this code by comparison with experimental results obtained from shaking table tests using scale model casks considering the dimension of a 100 ton class full-scale cask

Rejection Positivity Predicts Trial-to-Trial Reaction Times in an Auditory Selective Attention Task: A Computational Analysis of Inhibitory Control

Directory of Open Access Journals (Sweden)

Sufen eChen

2014-08-01

Full Text Available A series of computer simulations using variants of a formal model of attention (Melara & Algom, 2003 probed the role of rejection positivity (RP, a slow-wave electroencephalographic (EEG component, in the inhibitory control of distraction. Behavioral and EEG data were recorded as participants performed auditory selective attention tasks. Simulations that modulated processes of distractor inhibition accounted well for reaction-time (RT performance, whereas those that modulated target excitation did not. A model that incorporated RP from actual EEG recordings in estimating distractor inhibition was superior in predicting changes in RT as a function of distractor salience across conditions. A model that additionally incorporated momentary fluctuations in EEG as the source of trial-to-trial variation in performance precisely predicted individual RTs within each condition. The results lend support to the linking proposition that RP controls the speed of responding to targets through the inhibitory control of distractors.

Investigations on an environment friendly chemical reaction process (eco-chemistry). 2; Kankyo ni yasashii kagaku hanno process (eko chemistry) ni kansuru chosa. 2

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

In order to structure a chemical reaction process that does not discharge a large amount of waste by-products or harmful chemical substances, or so-called environment friendly process, investigations and discussions were given based on the results derived in the previous fiscal year. A proposal was made to reduce environmental load on development of oxidized and dehydrogenated catalysts that can produce selectively ethylene, propylene and isobutylene in an oxidation process. In liquid phase oxidation, redox-based oxidation and solid catalyzation of automatic oxidation reaction were enumerated. In acid base catalyst reaction, development of ultra strong solid acid was described to structure no pollution discharging process. In the fine chemical and pharmaceutical fields, the optical active substance method and the position-selective aromatics displacement reaction were evaluated to reduce environmental load. A questionnaire survey performed on major chemical corporations inside and outside the country revealed the following processes as the ones that can cause hidden environmental problems: processes discharging large amount of wastes, processes treating dangerous materials, and processes consuming large amount of energy. Development of catalysts is important that can realize high yield, high selectivity and reactions under mild conditions as a future environment harmonizing chemical process. 117 refs., 23 figs., 22 tabs.

Performance monitoring and response conflict resolution associated with choice stepping reaction tasks.

Science.gov (United States)

Watanabe, Tatsunori; Tsutou, Kotaro; Saito, Kotaro; Ishida, Kazuto; Tanabe, Shigeo; Nojima, Ippei

2016-11-01

Choice reaction requires response conflict resolution, and the resolution processes that occur during a choice stepping reaction task undertaken in a standing position, which requires maintenance of balance, may be different to those processes occurring during a choice reaction task performed in a seated position. The study purpose was to investigate the resolution processes during a choice stepping reaction task at the cortical level using electroencephalography and compare the results with a control task involving ankle dorsiflexion responses. Twelve young adults either stepped forward or dorsiflexed the ankle in response to a visual imperative stimulus presented on a computer screen. We used the Simon task and examined the error-related negativity (ERN) that follows an incorrect response and the correct-response negativity (CRN) that follows a correct response. Error was defined as an incorrect initial weight transfer for the stepping task and as an incorrect initial tibialis anterior activation for the control task. Results revealed that ERN and CRN amplitudes were similar in size for the stepping task, whereas the amplitude of ERN was larger than that of CRN for the control task. The ERN amplitude was also larger in the stepping task than the control task. These observations suggest that a choice stepping reaction task involves a strategy emphasizing post-response conflict and general performance monitoring of actual and required responses and also requires greater cognitive load than a choice dorsiflexion reaction. The response conflict resolution processes appear to be different for stepping tasks and reaction tasks performed in a seated position.

Marital Expectations in Strong African American Marriages.

Science.gov (United States)

Vaterlaus, J Mitchell; Skogrand, Linda; Chaney, Cassandra; Gahagan, Kassandra

2017-12-01

The current exploratory study utilized a family strengths framework to identify marital expectations in 39 strong African American heterosexual marriages. Couples reflected on their marital expectations over their 10 or more years of marriage. Three themes emerged through qualitative analysis and the participants' own words were used in the presentation of the themes. African Americans indicated that there was growth in marital expectations over time, with marital expectations often beginning with unrealistic expectations that grew into more realistic expectations as their marriages progressed. Participants also indicated that core expectations in strong African American marriages included open communication, congruent values, and positive treatment of spouse. Finally, participants explained there is an "I" in marriage as they discussed the importance of autonomy within their marital relationships. Results are discussed in association with existing research and theory. © 2016 Family Process Institute.

Community College Faculty Recruitment: Predictors of Applicant Attraction to Faculty Positions.

Science.gov (United States)

Winter, Paul A.; Kjorlien, Chad L.

2000-01-01

Utilizes MBA students' biographical data and reactions to simulated position ads for community college business faculty positions to identify predictors of applicant decisions. Reveals four significant predictors of participants' ratings of simulated positions: applicant's current job satisfaction, spouse's contribution to household income,…

Strong copper(II) species in estuarine and sea waters investigated by a method with high detection window.

Science.gov (United States)

Alberti, Giancarla; Biesuz, Raffaela; D'Agostino, Girolamo; Scarponi, Giuseppe; Pesavento, Maria

2007-02-15

The distribution of copper(II) in species of different stability in some estuarine and sea water samples (Adriatic Sea) was investigated by a method based on the sorption of the metal ion on a strongly sorbing resin, Chelex 100, whose sorbing properties have been previously characterized. From them, it is possible to predict very high values of detection windows at the considered conditions, for example side reaction coefficient as high as 10(10) at pH 7.5. Strong copper(II) species in equilibrium with Chelex 100 were detected, at concentration 2-20nM, with a reaction coefficient approximately 10(10.6) at pH 7.45 in sea water, strictly depending on the acidity. They represent 50-70% of the total metal ion and are the strongest copper(II) complexes found in sea water. Weak complexes too were detected in all the samples, with reaction coefficient lower than ca. 10(9) at the same pH. The method applied, named resin titration (RT), was described in a previous investigation, and is here modified in order to be carried out on oceanographic boat during a cruise in the Adriatic Sea.

Evaluation of Nickel Allergic Reactions to the Essure Micro Insert: Theoretical Risk or Daily Practice?

Science.gov (United States)

Siemons, Sara; Vleugels, Michel; van Eijndhoven, Hugo

2017-01-01

To evaluate whether de novo development of nickel sensitization is related to placement of the Essure device, and to evaluate whether the grade of reaction to nickel increased after device placement in patients with a confirmed nickel allergy. Prospective cohort study (Canadian Task Force classification II-2). Two nonacademic training hospitals in The Netherlands. Healthy women of childbearing age desiring permanent sterilization. At least 72 hours before Essure sterilization, each patient received 2 patches, 1 patch with a nickel solution in 5% petrolatum and 1 control patch. In addition, the patient was asked to complete a questionnaire on allergy-related symptoms. The patch test was scored according to the criteria for contact dermatitis of Devos and Van Der Valk. At 3 months after Essure sterilization, the patch test and the questionnaire were repeated. All 169 patients underwent Essure sterilization and completed the patch test cycle. There were no statistically significant changes in patch test results and allergy-related symptoms after sterilization. Before sterilization, 29% of the patients had a positive patch test and 1.8% also showed a positive reaction to the control patch. Only 20.7% of the patients had a history of allergic reactions to nickel. After sterilization, 29% had a positive patch test and 0.6% also showed a positive reaction to the control patch. Among the patients with a positive patch test before sterilization, the grade of reaction did not increase after sterilization. Moreover, these patients did not exhibit any increase in allergy-related symptoms. Among 4 patients with a previous negative patch test, 2 developed a grade 1 reaction and 2 developed a grade 2 reaction after sterilization. Two of these 4 patients had a history of allergic reactions to nickel before sterilization despite a negative patch test. After sterilization, these 4 patients exhibited no increase in allergy-related symptoms. There were no statistically significant

Safe venting of ''red oil'' runaway reactions

International Nuclear Information System (INIS)

Paddleford, D.F.; Fauske, H.K.

1994-01-01

Calorimetry testing of Tri-n-butyl phosphate (TBP) saturated with strong nitric acid was performed to determine the relationship between vent size and pressure buildup in the event of a runaway reaction. These experiments show that runaway can occur in an open system, but that even when runaway is induced in the TBP/HN0 3 system, dangerous pressure buildup will be prevented with practical vent size

Positional Concerns and Institutions

DEFF Research Database (Denmark)

Landes, Xavier

2013-01-01

that invoking envy or subjective well-being is not fully satisfying for regulating positional concerns. More compelling reasons seem, in complement with efficiency, to be related to considerations for equality. In other words, if institutions could have strong reasons to pay attention to and regulate positional...... their implications for economics, positional concerns imply important normative dimensions. There have been presumed to be a symptom of envy, reduce people’s happiness, and create problems of social interaction or economic inefficiencies. Individuals are, for instance, prone to pick states of the world that improve...... concerns, it would be in virtue of their impact on the social product and individuals’ conditions of living....

Dynamical barrier and isotope effects in the simplest substitution reaction via Walden inversion mechanism

Science.gov (United States)

Zhao, Zhiqiang; Zhang, Zhaojun; Liu, Shu; Zhang, Dong H.

2017-02-01

Reactions occurring at a carbon atom through the Walden inversion mechanism are one of the most important and useful classes of reactions in chemistry. Here we report an accurate theoretical study of the simplest reaction of that type: the H+CH4 substitution reaction and its isotope analogues. It is found that the reaction threshold versus collision energy is considerably higher than the barrier height. The reaction exhibits a strong normal secondary isotope effect on the cross-sections measured above the reaction threshold, and a small but reverse secondary kinetic isotope effect at room temperature. Detailed analysis reveals that the reaction proceeds along a path with a higher barrier height instead of the minimum-energy path because the umbrella angle of the non-reacting methyl group cannot change synchronously with the other reaction coordinates during the reaction due to insufficient energy transfer from the translational motion to the umbrella mode.

From the Ground Up: Establishing Strong Core Policies for Infants, Toddlers, and Families

Science.gov (United States)

Ullrich, Rebecca; Cole, Patricia; Gebhard, Barbara; Matthews, Hannah; Schmit, Stephanie

2017-01-01

Because the earliest years of life are a period of incredible growth, they present an opportunity to shape strong and positive development. Good health, secure and stable families, and positive early learning environments are necessary to foster children's physical, intellectual, and social-emotional development during this significant period. Yet…

[Electromagnetic studies of nuclear structure and reactions

International Nuclear Information System (INIS)

1992-01-01

The experimental goals are focused on developing an understanding of strong interactions and the structure of hadronic systems by determination of the electromagnetic response; these goals will be accomplished through coincidence detection of final states. Nuclear modeling objectives are to organize and interpret the data through a consistent description of a broad spectrum of reaction observables; calculations are performed in a nonrelativistic diagrammatic framework as well as a relativistic QHD approach. Work is described according to the following arrangement: direct knockout reactions (completion of 16 O(e,e'p), 12 C(e,e'pp) progress, large acceptance detector physics simulations), giant resonance studies (intermediate-energy experiments with solid-state detectors, the third response function in 12 C(e,e'p 0 ) and 16 O(e,e'p 0 ), comparison of the 12 C(e, e'p 0 ) and 16 O(e,e'p 3 ) reactions, quadrupole strength in the 16 O(e,e'α 0 ) reaction, quadrupole strength in the 12 C(e,e'α) reaction, analysis of the 12 C(e,e'p 1 ) and 16 O(e,e'p 3 ) angular distributions, analysis of the 40 Ca(e,e'x) reaction at low q, analysis of the higher-q 12 C(e,e'x) data from Bates), models of nuclear structure (experimental work, Hartree-Fock calculations, phonon excitations in spherical nuclei, shell model calculations, variational methods for relativistic fields), and instrumentation development efforts (developments at CEBAF, CLAS contracts, BLAST developments)

Effects on nuclear fusion reaction on diffusion and thermal conduction in a magnetoplasma

International Nuclear Information System (INIS)

Sakai, Kazuo; Aono, Osamu.

1976-12-01

In spite of the well spread belief in the field of irreversible thermodynamics, vectorial phenomena couple thermodynamically with the scalar phenomena. Transport coefficients concerning the diffusion and the thermal conduction across a strong magnetic field are calculated in the presence of the deuteron-triton fusion reaction on the basis of the gas kinetic theory. When the reaction takes place, the diffusion increases and the thermal conduction decreases. Effects of the reaction exceed those of the Coulomb collision as the temperature is high enough. (auth.)

Evidence for a glassy state in strongly driven carbon

International Nuclear Information System (INIS)

Brown, C.R.D.; Gericke, D.O.; Wunsch, K.; Cammarata, M.; Fritz, D.; Glenzer, S.H.; Heimann, P.; Lee, H.J.; Lemke, H.; Nagler, B.; Zhu, D.; Galtier, E.; Moinard, A.; Rosmej, F.B.

2014-01-01

Here, we report results of an experiment creating a transient, highly correlated carbon state using a combination of optical and x-ray lasers. Scattered x-rays reveal a highly ordered state with an electrostatic energy significantly exceeding the thermal energy of the ions. Strong Coulomb forces are predicted to induce nucleation into a crystalline ion structure within a few picoseconds. However, we observe no evidence of such phase transition after several tens of picoseconds but strong indications for an over-correlated fluid state. The experiment suggests a much slower nucleation and points to an intermediate glassy state where the ions are frozen close to their original positions in the fluid. (authors)

Anaphylactic reaction to iodinated contrast media. Review the relevant loterature

International Nuclear Information System (INIS)

Kuwashima, Shigeko; Kitajima, Kazuhiro; Kohno, Tatsuo; Kaji, Yasushi; Takahashi, Tetuya; Seki, Masaya; Sakamoto, Tomoyuki

2007-01-01

Recently, iodinated contrast media are necessary for CT examinations and they occupy an important position in the radiological diagnosis. Nonionic contrast media significantly reduce the prevalence of all degree of adverse reaction to contrast media rather than ionic contrast media. So, generally, iodinated contrast media are safe and widely used, but adverse reaction after intravenous iodinated contrast media are not uncommon. Severe and potentially life-threatening reaction occur by using the iodinated contrast media practically. Patients at risk must be identified before the contrast media study, and all possible measures must be taken to deal effectively with spontaneous anaphylactic reactions. We report three cases of anaphylactic reactions by iodinated contrast media on CT. (author)

Isospin aspects in nuclear reactions involving Ca beams at 25 MeV/nucleon

Energy Technology Data Exchange (ETDEWEB)

Lombardo, I., E-mail: ilombardo@lns.infn.it; Agodi, C.; Alba, R.; Amorini, F.; Anzalone, A. [INFN Laboratori Nazionali del Sud (Italy); Auditore, L. [Universita di Messina, and INFN-Gr. Coll. Messina, Dipartimento di Fisica (Italy); Berceanu, I. [Institute for Physics and Nuclear Engineering (Romania); Cardella, G. [INFN, Sezione di Catania (Italy); Cavallaro, S. [INFN Laboratori Nazionali del Sud (Italy); Chatterjee, M. B. [Saha Institute of Nuclear Physics (India); Filippo, E. De [INFN, Sezione di Catania (Italy); Di Pietro, A.; Figuera, P. [INFN Laboratori Nazionali del Sud (Italy); Giuliani, G.; Geraci, E.; Grassi, L. [Dipartimento di Fisica e Astronomia Universita di Catania (Italy); Grzeszczuk, A. [University of Silesia, Institute of Physics (Poland); Han, J. [INFN Laboratori Nazionali del Sud (Italy); La Guidara, E. [INFN, Sezione di Catania (Italy); Lanzalone, G. [INFN Laboratori Nazionali del Sud (Italy); and others

2011-11-15

Isospin dependence of dynamical and thermodynamical properties observed in reactions {sup 40}Ca+ {sup 40,48}Ca and {sup 40}Ca + {sup 46}Ti at 25 MeV/nucleon has been studied. We used the CHIMERA multi-detector array. Strong isospin effects are seen in the isotopic distributions of light nuclei and in the competition between different reaction mechanisms in semi-central collisions. We will show also preliminary results obtained in nuclear collision {sup 48}Ca + {sup 48}Ca at 25MeV/nucleon, having very high N/Z value in the entrance channel (N/Z = 1.4). The enhancement of evaporation residue production confirms the strong role played by the N/Z degree of freedom in nuclear dynamics.

High vacuum general purpose scattering chamber for nuclear reaction study

International Nuclear Information System (INIS)

Suresh Kumar; Ojha, S.C.

2003-01-01

To study the nuclear reactions induced by beam from medium energy accelerators, one of the most common facility required is a scattering chamber. In the scattering chamber, projectile collides with the target nucleus and the scattered reaction products are detected with various type of nuclear detector at different angles with respect to the beam. The experiments are performed under high vacuum to minimize the background reaction and the energy losses of the charged particles. To make the chamber general purpose various requirement of the experiments are incorporated into it. Changing of targets, changing angle of various detectors while in vacuum are the most desired features. The other features like ascertaining the beam spot size and position on the target, minimizing the background counts by proper beam dump, accurate positioning of the detector as per plan etc. are some of the important requirements

Your position in society matters for how happy you are

DEFF Research Database (Denmark)

Ejrnæs, Anders; Greve, Bent

2017-01-01

in society (subjective position). The study drew on data from the European Social Survey. Two important findings emerged from the analysis. First, an individual's subjective position in society is a more important predictor of happiness than objective measures such as income, education and labour market......This article shows that people's perception of their position in society is strongly correlated with their level of happiness, and thus that differences in happiness levels among countries in different welfare state clusters are influenced by people's perceptions of their relative position...... position. Second, the link between individuals’ perceived position in society and their level of happiness is moderated by the welfare state. In the Nordic countries, people's perceptions of their position in society have less influence on happiness whereas in Eastern European countries we found a strong...

Switching dynamics in reaction networks induced by molecular discreteness

International Nuclear Information System (INIS)

Togashi, Yuichi; Kaneko, Kunihiko

2007-01-01

To study the fluctuations and dynamics in chemical reaction processes, stochastic differential equations based on the rate equation involving chemical concentrations are often adopted. When the number of molecules is very small, however, the discreteness in the number of molecules cannot be neglected since the number of molecules must be an integer. This discreteness can be important in biochemical reactions, where the total number of molecules is not significantly larger than the number of chemical species. To elucidate the effects of such discreteness, we study autocatalytic reaction systems comprising several chemical species through stochastic particle simulations. The generation of novel states is observed; it is caused by the extinction of some molecular species due to the discreteness in their number. We demonstrate that the reaction dynamics are switched by a single molecule, which leads to the reconstruction of the acting network structure. We also show the strong dependence of the chemical concentrations on the system size, which is caused by transitions to discreteness-induced novel states

Linezolid desensitization for a patient with multiple medication hypersensitivity reactions.

Science.gov (United States)

Bagwell, Autumn D; Stollings, Joanna L; White, Katie D; Fadugba, Olajumoke O; Choi, Jane J

2013-01-01

To describe a case in which a linezolid desensitization protocol was successfully used for a polymicrobial surgical wound infection in a patient with multiple drug hypersensitivity reactions. A 24-year-old woman with vocal cord dysfunction requiring tracheostomy was admitted for a surgical wound infection following a tracheostomy fistula closure procedure. The patient reported multiple antibiotic allergies including penicillins (rash), sulfonamides (rash), vancomycin (anaphylaxis), azithromycin (rash), cephalosporins (anaphylaxis), levofloxacin (unspecified), clindamycin (unspecified), and carbapenems (unspecified). Gram stain of the purulent wound drainage demonstrated mixed gram-negative and gram-positive flora, and bacterial cultures were overgrown with Proteus mirabilis, which precluded identification of other pathogens. Following failed test doses of linezolid, tigecycline, and daptomycin, all of which resulted in hypersensitivity reactions, a 16-step linezolid desensitization protocol was developed and successfully implemented without adverse reactions. The patient completed a 2-week course of antibiotic therapy that included linezolid upon finishing the desensitization protocol. Linezolid is useful in treating complicated and uncomplicated skin and soft tissue infections caused by gram-positive bacteria. With precautions, including premedication, a monitored nursing unit, and immediate availability of an emergency anaphylaxis kit, drug desensitization allows patients the ability to safely use medications to which they may have an immediate hypersensitivity reaction. Minimal data exist on linezolid desensitization protocols. Linezolid desensitization can be a viable option in patients requiring antimicrobial therapy for complicated gram-positive skin infections.

Site-specific growth of Au-Pd alloy horns on Au nanorods: A platform for highly sensitive monitoring of catalytic reactions by surface enhancement raman spectroscopy

KAUST Repository

Huang, Jianfeng

2013-06-12

Surface-enhanced Raman scattering (SERS) is a highly sensitive probe for molecular detection. The aim of this study was to develop an efficient platform for investigating the kinetics of catalytic reactions with SERS. To achieve this, we synthesized a novel Au-Pd bimetallic nanostructure (HIF-AuNR@AuPd) through site-specific epitaxial growth of Au-Pd alloy horns as catalytic sites at the ends of Au nanorods. Using high-resolution electron microscopy and tomography, we successfully reconstructed the complex three-dimensional morphology of HIF-AuNR@AuPd and identified that the horns are bound with high-index {11l} (0.25 < l < 0.43) facets. With an electron beam probe, we visualized the distribution of surface plasmon over the HIF-AuNR@AuPd nanorods, finding that strong longitudinal surface plasmon resonance concentrated at the rod ends. This unique crystal morphology led to the coupling of high catalytic activity with a strong SERS effect at the rod ends, making HIF-AuNR@AuPd an excellent bifunctional platform for in situ monitoring of surface catalytic reactions. Using the hydrogenation of 4-nitrothiophenol as a model reaction, we demonstrated that its first-order reaction kinetics could be accurately determined from this platform. Moreover, we clearly identified the superior catalytic activity of the rod ends relative to that of the rod bodies, owing to the different SERS activities at the two positions. In comparison with other reported Au-Pd bimetallic nanostructures, HIF-AuNR@AuPd offered both higher catalytic activity and greater detection sensitivity. © 2013 American Chemical Society.

Resident Reactions to Person-Centered Communication by Long-Term Care Staff.

Science.gov (United States)

Savundranayagam, Marie Y; Sibalija, Jovana; Scotchmer, Emma

2016-09-01

Long-term care staff caregivers who are person centered incorporate the life history, preferences, and feelings of residents with dementia during care interactions. Communication is essential for person-centered care. However, little is known about residents' verbal reactions when staff use person-centered communication. Accordingly, this study investigated the impact of person-centered communication and missed opportunities for such communication by staff on resident reactions. Conversations (N = 46) between staff-resident dyads were audio-recorded during routine care tasks over 12 weeks. Staff utterances were coded for person-centered communication and missed opportunities. Resident utterances were coded for positive reactions, such as cooperation, and negative reactions, such as distress. Linear regression analyses revealed that the more staff used person-centered communication, the more likely that residents reacted positively. Additionally, the more missed opportunities in a conversation, the more likely that the residents reacted negatively. Conversation illustrations elaborate on the quantitative findings and implications for staff training are discussed. © The Author(s) 2016.

Penicillin sensitivity among children without a positive history for penicillin allergy.

Science.gov (United States)

Cetinkaya, Feyzullah; Cag, Yakup

2004-06-01

To establish the prevalence of positive penicillin skin tests among outpatients without any drug reaction history. Skin testing was performed in 147 children (aged 6-13 years) who had had received a penicillin preparation at least three times in the last 12 months without any allergic reaction. Before testing, detailed pediatric and allergy history were learned and then all children were tested with benzyl penicilloyl polylysin (PPL) and mixture of minor antigenic determinants. The test procedures were made epidermally and intradermally subsequently in every subject. The overall frequency of positive skin reactions to penicillin antigens was 10.2%. A mild systemic reaction was observed in one of the children during testing with PPL. We concluded that frequent use of penicillin and other beta-lactam antibiotics leads to sensitization of children in our study population despite these children seem to be asymptomatic during testing time. Copyright 2004 Blackwell Munksgaard

Factors affecting the actions and emotional reactions of nursing teachers following encounters with students who present them with Internet information.

Science.gov (United States)

Itzhaki, Michal; Bluvstein, Irit; Raz, Shai; Barnoy, Sivia

2013-08-01

The Internet is a preferred source of information for nursing students. The purpose of the research was to identify teachers' reactions towards students who present them with information retrieved from the Internet. A total of 137 nursing teachers from 15 nursing schools in Israel were surveyed by a questionnaire. The dependent variable was nursing teachers' actions following encounters with students who present them with information from the Internet. Independent variables were: teacher's emotional reactions, teachers' Internet efficacy, Internet anxiety, and perceived student Internet efficacy. The intensity of positive emotional reactions was the only predictor of teachers' actions towards Internet information retrieved by students. When teachers perceived students as having higher Internet efficacy, their emotional reactions were more positive and they took more actions. Teachers' Internet anxiety was negatively correlated with their positive emotional reactions and actions. No correlation was found between nursing teachers' Internet self efficacy and their reactions or actions following an encounter with students presenting Internet information. Positive emotional reactions mediated correlations between teachers' Internet anxiety, perceived student Internet efficacy, and teachers' actions. Nursing teachers' positive emotions foster openness and acceptance of Internet information retrieved by students. Copyright © 2012 Elsevier Ltd. All rights reserved.

Attention to Intentions--How to Stimulate Strong Intentions to Change

Science.gov (United States)

Dam, M.; Janssen, F. J. J. M.; van Driel, J. H.

2018-01-01

The implementation of educational reforms requires behavioral changes from the teachers involved. Theories on successful behavioral change prescribe the following conditions: teachers need to possess the necessary knowledge and skills, form strong positive intentions to perform the new behavior, and have a supporting environment for change.…

Mutagenicity of heated sugar-casein systems: effect of the Maillard reaction.

Science.gov (United States)

Brands, C M; Alink, G M; van Boekel, M A; Jongen, W M

2000-06-01

The formation of mutagens after the heating of sugar-casein model systems at 120 degrees C was examined by the Ames test, using Salmonella typhimurium strain TA100. Several sugars (glucose, fructose, galactose, tagatose, lactose, and lactulose) were compared in their mutagenicities. Mutagenicity could be fully ascribed to Maillard reaction products and strongly varied with the kind of sugar. The differences in mutagenicity among the sugar-casein systems were caused by a difference in reaction rate and a difference in reaction mechanism. Sugars with a comparable reaction mechanism (glucose and galactose) showed a higher mutagenic activity corresponding with a higher Maillard reactivity. Disaccharides showed no mutagenic activity (lactose) or a lower mutagenic activity (lactulose) than their corresponding monosaccharides. Ketose sugars (fructose and tagatose) showed a remarkably higher mutagenicity compared with their aldose isomers (glucose and galactose), which was due to a difference in reaction mechanism.

Effects of self-schema elaboration on affective and cognitive reactions to self-relevant information.

Science.gov (United States)

Petersen, L E; Stahlberg, D; Dauenheimer, D

2000-02-01

The basic assumption of the integrative self-schema model (ISSM; L.-E. Petersen, 1994; L.-E. Petersen, D. Stahlberg, & D. Dauenheimer, 1996; D. Stahlberg, L.-E. Petersen, & D. Dauenheimer, 1994, 1999) is that self-schema elaboration (schematic vs. aschematic) affects reactions to self-relevant information. This assumption is based on the idea that schematic dimensions occupy a more central position in the cognitive system than aschematic dimensions. In the first study, this basic prediction could be clearly confirmed: The results showed that schematic dimensions possessed stronger cognitive associations with other self-relevant cognitions as well as a higher resistance to change than aschematic dimensions did. In the second study, the main assumptions of the ISSM concerning the affective and cognitive reactions to self-relevant feedback were tested: The ISSM proposes that, on schematic dimensions, reactions to self-relevant feedback will most likely follow principles of self-consistency theory, whereas on aschematic dimensions positive feedback should elicit the most positive reactions that self-enhancement theory would predict. The experimental results clearly confirmed the hypotheses derived from the ISSM for affective reactions. Cognitive reactions, however, were in line with self-consistency principles and were not modified by the elaboration of the self-schema dimension involved.

Highly concentrated zinc oxide nanocrystals sol with strong blue emission

International Nuclear Information System (INIS)

Vafaee, M.; Sasani Ghamsari, M.; Radiman, S.

2011-01-01

Highly concentrated ZnO sol was synthesized by an improved sol-gel method. Water was used as a modifier to control the sol-gel reaction and provide a way to increase the sol concentration. Concentration of ZnO in the prepared sol is higher than from other methods. Optical absorption and photoluminescence were used to investigate optical properties of the prepared sol. FTIR test was performed to study the influence of water on the compounds of as-prepared sol. The size and morphology of ZnO nanoparticles have been studied by HRTEM. The prepared colloidal ZnO nanocrystals have narrow size distribution (5-8 nm) and showed strong blue emission. The prepared sol has enough potential for optoelectronic applications. - Research highlights: → Novel sol-gel route has been employed to prepare highly concentrated ZnO colloidal nanocrystals. → Water has been used to control the sources of emission in synthesized material. → A strong blue luminescent material has been obtained.

Uncharged positive electrode composition

Science.gov (United States)

Kaun, Thomas D.; Vissers, Donald R.; Shimotake, Hiroshi

1977-03-08

An uncharged positive-electrode composition contains particulate lithium sulfide, another alkali metal or alkaline earth metal compound other than sulfide, e.g., lithium carbide, and a transition metal powder. The composition along with a binder, such as electrolytic salt or a thermosetting resin is applied onto an electrically conductive substrate to form a plaque. The plaque is assembled as a positive electrode within an electrochemical cell opposite to a negative electrode containing a material such as aluminum or silicon for alloying with lithium. During charging, lithium alloy is formed within the negative electrode and transition metal sulfide such as iron sulfide is produced within the positive electrode. Excess negative electrode capacity over that from the transition metal sulfide is provided due to the electrochemical reaction of the other than sulfide alkali metal or alkaline earth metal compound.

Splitting Schemes & Segregation In Reaction-(Cross-)Diffusion Systems

OpenAIRE

Carrillo, José A.; Fagioli, Simone; Santambrogio, Filippo; Schmidtchen, Markus

2017-01-01

One of the most fascinating phenomena observed in reaction-diffusion systems is the emergence of segregated solutions, i.e. population densities with disjoint supports. We analyse such a reaction cross-diffusion system. In order to prove existence of weak solutions for a wide class of initial data without restriction about their supports or their positivity, we propose a variational splitting scheme combining ODEs with methods from optimal transport. In addition, this approach allows us to pr...

Emotional reactions to human reproductive cloning.

Science.gov (United States)

May, Joshua

2016-01-01

Extant surveys of people's attitudes towards human reproductive cloning focus on moral judgements alone, not emotional reactions or sentiments. This is especially important given that some (especially Leon Kass) have argued against such cloning on the ground that it engenders widespread negative emotions, like disgust, that provide a moral guide. To provide some data on emotional reactions to human cloning, with a focus on repugnance, given its prominence in the literature. This brief mixed-method study measures the self-reported attitudes and emotions (positive or negative) towards cloning from a sample of participants in the USA. Most participants condemned cloning as immoral and said it should be illegal. The most commonly reported positive sentiment was by far interest/curiosity. Negative emotions were much more varied, but anxiety was the most common. Only about a third of participants selected disgust or repugnance as something they felt, and an even smaller portion had this emotion come to mind prior to seeing a list of options. Participants felt primarily interested and anxious about human reproductive cloning. They did not primarily feel disgust or repugnance. This provides initial empirical evidence that such a reaction is not appropriately widespread. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

We maintain a strong market position

International Nuclear Information System (INIS)

Blahutova, Z.

2010-01-01

Increasing efficiency, continuous improvement, ambitious investment plans. How we (Slovenske elektrarne) succeeded in overcoming crisis impacts and achieved excellent results, about the necessity to increase the company's safety culture - these issues were discussed at the Goal Setting Meeting 2010. The introductory meeting was held on 9 March 2010 in Bratislava. (author)

Characterization of strong (241)Am sources.

Science.gov (United States)

Vesterlund, Anna; Chernikova, Dina; Cartemo, Petty; Axell, Kåre; Nordlund, Anders; Skarnemark, Gunnar; Ekberg, Christian; Ramebäck, Henrik

2015-05-01

Gamma ray spectra of strong (241)Am sources may reveal information about the source composition as there may be other radioactive nuclides such as progeny and radioactive impurities present. In this work the possibility to use gamma spectrometry to identify inherent signatures in (241)Am sources in order to differentiate sources from each other, is investigated. The studied signatures are age, i.e. time passed since last chemical separation, and presence of impurities. The spectra of some sources show a number of Doppler broadened peaks in the spectrum which indicate the presence of nuclear reactions on light elements within the sources. The results show that the investigated sources can be differentiated between by age and/or presence of impurities. These spectral features would be useful information in a national nuclear forensics library (NNFL) in cases when the visual information on the source, e.g. the source number, is unavailable. Copyright © 2015 Elsevier Ltd. All rights reserved.

Barriers to condom purchasing: Effects of product positioning on reactions to condoms.

Science.gov (United States)

Scott-Sheldon, Lori A J; Glasford, Demis E; Marsh, Kerry L; Lust, Sarah A

2006-12-01

Correct and consistent condom use has been promoted as a method to prevent sexually transmitted infections including HIV. Yet research has repeatedly shown that people fail to use condoms consistently. One influence on the pervasive lack of condom use that has received relatively little attention is the context in which consumers are exposed to condoms (i.e., how condoms are displayed in retail settings). In this paper we present two studies explored variations in condom shelf placement and its effects on people's condom attitudes and acquisition. Study 1 explored the shelf placement of condoms in 59 retail outlets in Connecticut, USA and found that condoms were typically located in areas of high visibility (e.g., next to the pharmacy counter) and on shelves adjacent to feminine hygiene and disease treatment products. In Study 2, 120 heterosexual undergraduate students at the University of Connecticut were randomly assigned to evaluate condoms adjacent to sensual, positive, neutral, or negative products and found that overall men reported more positive attitudes and acquired more condoms when exposed to condoms in a sensual context compared to women in the same condition. Among women, condom attitudes were more positive in the context of neutral products; condom acquisition was strongest for women exposed to condoms in the positive aisles. These results suggest a gender-specific approach to condom promotion. Implications of these studies for HIV prevention, public health, and condom marketing strategies are discussed.

kinetics of the coupled gas-iron reactions involving silicon and carbon

African Journals Online (AJOL)

user

1985-09-01

Sep 1, 1985 ... out for the system involving liquid iron containing carbon and silicon and a gas ... in content with liquid iron at. 15600C, the ... of carbon monoxide bubbles at the. Slag - metal ..... equilibrium strongly make chemical reactions.

An in vitro-identified high-affinity nucleosome-positioning signal is capable of transiently positioning a nucleosome in vivo

Directory of Open Access Journals (Sweden)

Gracey Lia E

2010-07-01

Full Text Available Abstract Background The physiological function of eukaryotic DNA occurs in the context of nucleosomal arrays that can expose or obscure defined segments of the genome. Certain DNA sequences are capable of strongly positioning a nucleosome in vitro, suggesting the possibility that favorable intrinsic signals might reproducibly structure chromatin segments. As high-throughput sequencing analyses of nucleosome coverage in vitro and in vivo have become possible, a vigorous debate has arisen over the degree to which intrinsic DNA:nucleosome affinities orchestrate the in vivo positions of nucleosomes, thereby controlling physical accessibility of specific sequences in DNA. Results We describe here the in vivo consequences of placing a synthetic high-affinity nucleosome-positioning signal, the 601 sequence, into a DNA plasmid vector in mice. Strikingly, the 601 sequence was sufficient to position nucleosomes during an early phase after introduction of the DNA into the mice (when the plasmid vector transgene was active. This positioning capability was transient, with a loss of strong positioning at a later time point when the transgenes had become silent. Conclusions These results demonstrate an ability of DNA sequences selected solely for nucleosome affinity to organize chromatin in vivo, and the ability of other mechanisms to overcome these interactions in a dynamic nuclear environment.

Ionic Liquids: An Environmentally Friendly Media for Nucleophilic Substitution Reactions

International Nuclear Information System (INIS)

Jorapur, Yogesh R.; Chi, Dae Yoon

2006-01-01

Ionic liquids are alternative reaction media of increasing interest and are regarded as an eco-friendly alternatives, of potential use in place of the volatile organic solvents typically used in current chemical processing methods. They are emerging as the smart and excellent solvents, which are made of positive and negative ions that they are liquids near room temperature. The nucleophilic substitution reaction is one of the important method for inserting functional groups into a carbon skeleton. Many nucleophilic substitution reactions have been found with enhanced reactivity and selectivity in ionic liquid. In this review, some recent interesting results of nucleophilic substitution reactions such as hydroxylations, ether cleavages, carbon-X (X = carbon, oxygen, nitrogen, fluorine) bond forming reactions, and ring opening of epoxides in ionic liquids are discussed

Specific Reaction Patterns to Distinct Positive Emotional Cues Related to Incentive Motivation in Dependence of the Taq1A-Polymorphism: Molecular Genetic Associations of Early and Late Event-Related Potentials.

Science.gov (United States)

Munk, Aisha J L; Wielpuetz, Catrin; Osinsky, Roman; Müller, Erik M; Grant, Phillip; Hennig, Jürgen

2016-01-01

Early and late event-related potential (ERP) responses, representing early subconscious and late motivational processes, were recorded for positive emotional words related to 'wanting' and 'liking', in dependence of the dopamine-related Taq1A genotype (ANKK1/DRD2). Research suggests that 'wanting' as opposed to 'liking' is related to dopaminergic processes. Therefore, it was hypothesized that risk allele carriers of the Taq1A polymorphism exhibit late ERP changes in reaction to words representing incentive motivation, i.e. 'wanting' (word categories 'lust' and 'anticipation'), but not to words representing 'liking' ('closeness'). Seventy-two male participants performed an emotional-word Stroop task during EEG recording and were genotyped according to the Taq1A polymorphism of ANKK1/DRD2. Positive emotional words related to anticipation and lust revealed blunted responses in the late positive potential (LPP) in carriers of the A1 allele, an effect absent in response to 'liking'-related words. These differences were not evident in the earlier posterior negativity (EPN). As no differences in dependence of the Taq1A genotype were observed in reaction to 'wanting'- and 'liking'-related words in the EPN, but merely in the LPP, it can be assumed that incentive-motivational stimuli only modify motivation-related ERP responses in carriers of the A1 allele of the Taq1A polymorphism, indicating the role of dopamine in late ERP components. © 2016 S. Karger AG, Basel.

Studies of nuclear second moments for pre-equilibrium nuclear reaction theories

International Nuclear Information System (INIS)

Sato, K.; Yoshida, S.

1987-01-01

The nuclear second moments, important inputs to pre-equilibrium reaction theories, are evaluated by assuming a simple model. The positive definite nature of the second moments is examined, and the nuclear level densities are calculated using positive definite second moments. (orig.)

Research progress on trifluoromethyl-based radical reaction process

Science.gov (United States)

Song, Hao

2017-12-01

Due to the unique properties imparted by the trifluoromethyl group, such as high electron density and strong lipotropy, which effectively improve acidity, lipophilicity and metabolic stability of the molecule itself, trifluoromethyl-substituted organic compounds are becoming increasingly important as structural motifs in pharmaceuticals, agrochemicals and organic materials. In this review, we present several methods developed for the direct introduction of a trifluoromethyl group, beginning with its rich and storied history. Then the present article addresses mechanism and process in carbon-carbon bond forming reaction based on radical process which is divided into three parts according to the way of CF3 radical generation. Finally, challenges and opportunities of researches on trifluoromethylation reactions facing are prospected.

Modification of the performance of WO{sub 3}-ZrO{sub 2} catalysts by metal addition in hydrocarbon reactions

Energy Technology Data Exchange (ETDEWEB)

Torres, Gerardo Carlos; Manuale, Debora Laura; Benitez, Viviana Monica; Vera, Carlos Roman; Yori, Juan Carlos, E-mail: jyori@fiq.unl.edu.ar [Instituto de Investigaciones en Catalisis y Petroquimica, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Consejo Nacional de Investigaciones Cientifica y Tecnicas, Santiago del Estero Santa Fe (Argentina)

2012-07-01

A study of the different hydrocarbon reactions over Ni doped WO{sub 3}-ZrO{sub 2} catalysts was performed. Ni was found as NiO at low Ni concentration while at high Ni concentrations a small fraction was present as a metal. For both cases, Ni strongly modified total acidity and concentration of strong acid sites. In the cyclohexane dehydrogenation reaction, Ni addition promotes both benzene and methyl cyclopentane production. The hydroconversion activity (n-butane and n-octane) increases with the augment of total acidity produced by Ni. The selectivity to reaction products is modified according to the acid strength distribution changes produced by Ni addition. (author)

Hopf bifurcation in a delayed reaction-diffusion-advection population model

Science.gov (United States)

Chen, Shanshan; Lou, Yuan; Wei, Junjie

2018-04-01

In this paper, we investigate a reaction-diffusion-advection model with time delay effect. The stability/instability of the spatially nonhomogeneous positive steady state and the associated Hopf bifurcation are investigated when the given parameter of the model is near the principle eigenvalue of an elliptic operator. Our results imply that time delay can make the spatially nonhomogeneous positive steady state unstable for a reaction-diffusion-advection model, and the model can exhibit oscillatory pattern through Hopf bifurcation. The effect of advection on Hopf bifurcation values is also considered, and our results suggest that Hopf bifurcation is more likely to occur when the advection rate increases.

First Novozym 435 lipase-catalyzed Morita-Baylis-Hillman reaction in the presence of amides.

Science.gov (United States)

Tian, Xuemei; Zhang, Suoqin; Zheng, Liangyu

2016-03-01

The first Novozym 435 lipase-catalyzed Morita-Baylis-Hillman (MBH) reaction with amides as co-catalyst was realized. Results showed that neither Novozym 435 nor amide can independently catalyze the reaction. This co-catalytic system that used a catalytic amount of Novozym 435 with a corresponding amount of amide was established and optimized. The MBH reaction strongly depended on the structure of aldehyde substrate, amide co-catalyst, and reaction additives. The optimized reaction yield (43.4%) was achieved in the Novozym 435-catalyzed MBH reaction of 2, 4-dinitrobenzaldehyde and cyclohexenone with isonicotinamide as co-catalyst and β-cyclodextrin as additive only in 2 days. Although enantioselectivity of Novozym 435 was not found, the results were still significant because an MBH reaction using lipase as biocatalyst was realized for the first time. Copyright © 2015 Elsevier Inc. All rights reserved.

Teaching Positive Networking for Life-Long Impact

Science.gov (United States)

Addams, Lon; Woodbury, Denise; Addams, Lindsey

2010-01-01

As college communication instructors, we could further assist students by teaching the value of positive networking. This article provides (1) a foundation for positive networking and (2) several successful ways in which students can begin building a strong long-lasting network of professional relationships during the semester…and for their entire…

HLA Association with Drug-Induced Adverse Reactions

Directory of Open Access Journals (Sweden)

Wen-Lang Fan

2017-01-01

Full Text Available Adverse drug reactions (ADRs remain a common and major problem in healthcare. Severe cutaneous adverse drug reactions (SCARs, such as Stevens–Johnson syndrome (SJS/toxic epidermal necrolysis (TEN with mortality rate ranges from 10% to more than 30%, can be life threatening. A number of recent studies demonstrated that ADRs possess strong genetic predisposition. ADRs induced by several drugs have been shown to have significant associations with specific alleles of human leukocyte antigen (HLA genes. For example, hypersensitivity to abacavir, a drug used for treating of human immunodeficiency virus (HIV infection, has been proposed to be associated with allele 57:01 of HLA-B gene (terms HLA-B∗57:01. The incidences of abacavir hypersensitivity are much higher in Caucasians compared to other populations due to various allele frequencies in different ethnic populations. The antithyroid drug- (ATDs- induced agranulocytosis are strongly associated with two alleles: HLA-B∗38:02 and HLA-DRB1∗08:03. In addition, HLA-B∗15:02 allele was reported to be related to carbamazepine-induced SJS/TEN, and HLA-B∗57:01 in abacavir hypersensitivity and flucloxacillin induced drug-induced liver injury (DILI. In this review, we summarized the alleles of HLA genes which have been proposed to have association with ADRs caused by different drugs.

Positive emotion, appraisal, and the role of appraisal overlap in positive emotion co-occurrence.

Science.gov (United States)

Tong, Eddie M W; Jia, Lile

2017-02-01

Appraisal research has traditionally focused on negative emotions but has not addressed issues concerning the relationships between several positive emotions and appraisals in daily life and the extent to which co-occurrence of positive emotions can be explained by overlap in appraisals. Driven by a priori hypotheses on appraisal-emotion relationships, this study investigated 12 positive emotions and 13 appraisal dimensions using Ecological Momentary Assessment. The results provide strong evidence that positive emotions and appraisals correlate significantly in daily life. Importantly, we found that the positive emotions' overlap on theoretically relevant, as compared to irrelevant, appraisals was stronger and more predictive of their co-occurrence. Furthermore, appraisal overlap on theoretically relevant appraisals predicted the co-occurrence of positive emotions even when the appraisal of pleasantness was excluded, indicating that positive emotions do not co-occur just by virtue of their shared valence. Our findings affirmed and refined the appraisal profiles of positive emotions and underscore the importance of appraisals in accounting for the commonality and differences among positive emotions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Clinical survey on adverse reaction of contrast media, final report

International Nuclear Information System (INIS)

Katayama, Hitoshi; Ishida, Osamu; Osawa, Tadashi

1988-01-01

This report is a final analysis of adverse reactions to iodinated contrast media examined in 33,440 patients from 11 hospitals during the period from October 1983 through June 1986. Adverse reactions, such as nausea, exanthema and vomiting, to contrast media occurred in 2,523 patients (7.5 %), with the higher number occuring in patients aged 40 - 60, irrespective of sex. There were no significant alternations in vital signs. Patients positive for pretesting and having a history of allergy had higher incidences of adverse reactions (48 % and 52 %, respectively). A history of allergy is the most potential predictor for adverse reactions to contrast media. There was no definitive correlation between prior medication of contrast media and the occurrence of their adverse reactions. The relationship between the occurrence of adverse reactions and both kinds and dosage of contrast media was unknown. (Namekawa, K.)

The (p→,t) reaction on 58Ni and 56Fe at 24.6 MeV

International Nuclear Information System (INIS)

Polane, J.H.; Feix, W.F.; Hall, P.J. van; Klein, S.S.; Nijgh, G.J.; Poppema, O.J.; Wassenaar, S.D.

1989-01-01

The (p, t) reactions on 56 Fe and 58 Ni initiated by 24.6 MeV polarised protons has been investigated. The reaction process is described in terms of simultaneous and sequential neutron transfer. For all five final states studied the sequential process competes strongly with simultaneous transfer of a neutron pair. Theoretical values for the spectroscopic amplitudes were derived from shell-model wavefunctions; these seem to give a reliable description of the reaction process. (author)

Reaction calorimetry for the development of ultrasound-induced polymerization processes in CO2-expanded fluids

NARCIS (Netherlands)

Kemmere, M.F.; Kuijpers, M.W.A.; Keurentjes, J.T.F.

2007-01-01

A strong viscosity increase upon polymn. hinders radical formation during an ultrasound-induced bulk polymn. Since CO2 acts as a strong anti-solvent for most polymers, it can be used to reduce the viscosity of the reaction mixt. In this work, a process for the ultrasound-induced polymn. in

Social position and health in old age: the relevance of different indicators of social position

DEFF Research Database (Denmark)

Avlund, Kirsten; Holstein, Bjørn E; Osler, Merete

2003-01-01

for men and women. In men the odds ratios of housing tenure on four health variables were strong and unaffected by education and occupation while in women the odds ratios of income on three health variables were strong and unaffected by education and occupation. CONCLUSION: This study demonstrates strong......AIMS: An analysis was undertaken to investigate social inequalities in health among old men and women in relation to five indicators of social position. METHODS: The study is based on a population-based cross-sectional survey among 748 75-year-old men and women, which was performed as clinical......, consistent associations between variables of material wealth indicators and various measures of health among 75-year-old men and women....

Studies of complex fragment emission in heavy ion reactions

International Nuclear Information System (INIS)

Charity, R.J.; Sobotka, L.G.

1993-01-01

The study of intermediate-energy heavy-ion nuclear reactions is reported. This work has two foci: the properties of nuclear matter under abnormal conditions, in this energy domain, predominately low densities and the study of the relevant reaction mechanisms. Nuclear matter properties, such as phase transitions, are reflected in the dynamics of the reactions. The process leads to an understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. The program has the following objectives: to study energy, mass, and angular momentum deposition by studying incomplete fusion reactions; to gain confidence in the understanding of how highly excited systems decompose by studying all emissions from the highly excited systems; to push these kinds of studies into the intermediate energy domain (where intermediate mass fragment emission is not improbable) with excitation function studies; and to learn about the dynamics of the decays using particle-particle correlations. The last effort focuses on simple systems, where definitive statements are possible. These avenues of research share a common theme, large complex fragment production. It is this feature, more than any other, which distinguishes the intermediate energy domain

/sup 6/Li (e, e'X) reaction

Energy Technology Data Exchange (ETDEWEB)

Taneichi, H; Ueno, H [Yamagata Univ. (Japan); Shoda, K

1974-12-01

The target is a 99.3% enriched /sup 6/Li plate with thickness of 1.82 mg/cm/sup 2/. The energy of the electron beam ranged from 15 MeV to 31.7 MeV. Reaction products were measured by BDM which was set at the position of thetasub( l)=90/sup 0/. The (..gamma.., p) reaction was performed, the cross section was obtained. From the area ratio of P/sub 0/ and P/sub 1/ in a difference spectrum, sigma sub(p/sub 1/)/sigma sub(p/sub 0/)--3 was obtained. The cross section of the (..gamma.., t) reaction was acquired by a deduction method from two reaction spectra at Esub(e)=25 and 30 MeV. From the cross section, a reduced width theta/sup 2/--0.6 was obtained. The (..gamma.., d) reaction was measured at Esub(e)=15 MeV, and the cross section was obtained in the range from Esub(x)=8 MeV to 19 MeV by introducing previous data. The magnitude of the cross section was 0.2 to 0.1 ..mu..b/sr. The deuteron measured in this reaction must be identified whether it comes from T-impurity or E2. For the identification of this deuteron, an angular distribution measurement is needed.

Warmth and legitimacy beliefs contextualize adolescents' negative reactions to parental monitoring.

Science.gov (United States)

LaFleur, Laura K; Zhao, Yinan; Zeringue, Megan M; Laird, Robert D

2016-08-01

This study sought to identify conditions under which parents' monitoring behaviors are most strongly linked to adolescents' negative reactions (i.e., feelings of being controlled and invaded). 242 adolescents (49.2% male; M age = 15.4 years) residing in the United States of America reported parental monitoring and warmth, and their own feelings of being controlled and invaded and beliefs in the legitimacy of parental authority. Analyses tested whether warmth and legitimacy beliefs moderate and/or suppress the link between parents' monitoring behaviors and adolescents' negative reactions. Monitoring was associated with more negative reactions, controlling for legitimacy beliefs and warmth. More monitoring was associated with more negative reactions only at weaker levels of legitimacy beliefs, and at lower levels of warmth. The link between monitoring and negative reactions is sensitive to the context within which monitoring occurs with the strongest negative reactions found in contexts characterized by low warmth and weak legitimacy beliefs. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Applicant reactions to social network web use in personnel selection and assessment

Directory of Open Access Journals (Sweden)

David Aguado

2016-12-01

Full Text Available Human Resource (HR professionals are increasingly using Social Networking Websites (SNWs for personnel recruitment and selection processes. However, evidence is required regarding their psychometric properties and their impact on applicant reactions. In this paper we present and discuss the results of exploring applicant reactions to either the use of a professional SNW (such as LinkedIn or a non-professional SNW (such as Facebook. A scale for assessing applicant reactions was applied to 124 professionals. The results showed more positive attitudes to the use of professional SNWs compared with non-professional SNWs. Both gender and age moderated these results, with females and young applicants having a less positive attitude than males and older participants towards the use of non-professional SNWs.

The effect of strong intermolecular and chemical interactions on the compatibility of polymers

International Nuclear Information System (INIS)

Askadskii, Andrei A

1999-01-01

The data on compatibility and on the properties of polymer blends are generalised. The emphasis is placed on the formation of strong intermolecular interactions (dipole-dipole interaction and hydrogen bonding) between the components of blends, as well as on the chemical reactions between them. A criterion for the prediction of compatibility of polymers is described in detail. Different cases of compatibility are considered and the dependences of the glass transition temperatures on the composition of blends are analysed. The published data on the effect of strong intermolecular interactions between the blend components on the glass transition temperature are considered. The preparation of interpolymers is described whose macromolecules are composed of incompatible polymers, which leads to the so-called 'forced compatibility.' The bibliography includes 80 references.

Synthesis of New Cytotoxic Aminoanthraquinone Derivatives via Nucleophilic Substitution Reactions

Directory of Open Access Journals (Sweden)

Hasimah Alimon

2013-07-01

Full Text Available Aminoanthraquinones were successfully synthesized via two reaction steps. 1,4-Dihydroxyanthraquinone (1 was first subjected to methylation, reduction and acylation to give an excellent yield of anthracene-1,4-dione (3, 1,4-dimethoxyanthracene-9,10-dione (5 and 9,10-dioxo-9,10-dihydroanthracene-1,4-diyl diacetate (7. Treatment of 1, 3, 5 and 7 with BuNH2 in the presence of PhI(OAc2 as catalyst produced seven aminoanthraquinone derivatives 1a, b, 3a, and 5a–d. Amination of 3 and 5 afforded three new aminoanthraquinones, namely 2-(butylaminoanthracene-1,4-dione (3a, 2-(butylaminoanthracene-9,10-dione (5a and 2,3-(dibutylaminoanthracene-9,10-dione (5b. All newly synthesised aminoanthraquinones were examined for their cytotoxic activity against MCF-7 (estrogen receptor positive human breast and Hep-G2 (human hepatocellular liver carcinoma cancer cells using MTT assay. Aminoanthraquinones 3a, 5a and 5b exhibited strong cytotoxicity towards both cancer cell lines (IC50 1.1–13.0 µg/mL.

Communication: State-to-state dynamics of the Cl + H2O → HCl + OH reaction: Energy flow into reaction coordinate and transition-state control of product energy disposal.

Science.gov (United States)

Zhao, Bin; Sun, Zhigang; Guo, Hua

2015-06-28

Quantum state-to-state dynamics of a prototypical four-atom reaction, namely, Cl + H2O → HCl + OH, is investigated for the first time in full dimensionality using a transition-state wave packet method. The state-to-state reactivity and its dependence on the reactant internal excitations are analyzed and found to share many similarities both energetically and dynamically with the H + H2O → H2 + OH reaction. The strong enhancement of reactivity by the H2O stretching vibrational excitations in both reactions is attributed to the favorable energy flow into the reaction coordinate near the transition state. On the other hand, the insensitivity of the product state distributions with regard to reactant internal excitation stems apparently from the transition-state control of product energy disposal.

Communication: State-to-state dynamics of the Cl + H2O → HCl + OH reaction: Energy flow into reaction coordinate and transition-state control of product energy disposal

International Nuclear Information System (INIS)

Zhao, Bin; Guo, Hua; Sun, Zhigang

2015-01-01

Quantum state-to-state dynamics of a prototypical four-atom reaction, namely, Cl + H 2 O → HCl + OH, is investigated for the first time in full dimensionality using a transition-state wave packet method. The state-to-state reactivity and its dependence on the reactant internal excitations are analyzed and found to share many similarities both energetically and dynamically with the H + H 2 O → H 2 + OH reaction. The strong enhancement of reactivity by the H 2 O stretching vibrational excitations in both reactions is attributed to the favorable energy flow into the reaction coordinate near the transition state. On the other hand, the insensitivity of the product state distributions with regard to reactant internal excitation stems apparently from the transition-state control of product energy disposal

Mass transfer and slag-metal reaction in ladle refining : a CFD approach

OpenAIRE

Ramström, Eva

2009-01-01

  In order to optimise the ladle treatment mass transfer modelling of aluminium addition and homogenisation time was carried out. It was stressed that incorporating slag-metal reactions into the mass transfer modelling strongly would enhance the reliability and amount of information to be analyzed from the CFD calculations.   In the present work, a thermodynamic model taking all the involved slag metal reactions into consideration was incorporated into a 2-D fluid flow model of an argon stirr...

Studies of 4He emission in both fusion-like and inelastic reactions of 340-MeV 40Ar + 238U

International Nuclear Information System (INIS)

Kildir, M.; Logan, D.; Kaplan, M.; Zisman, M.S.; Guerreau, D.; Alexander, J.M.; Vaz, L.C.

1982-01-01

The fission-fragment angular correlation technique has been used in conjunction with a position-sensitive avalanche detector to identify the fusion-like and inelastic collisions of 340-MeV 40 Ar + 238 U. For each of these two reaction types, we have characterized the correlated 4 He emission by measuring three-fold coincidences between two fission fragments and the light charged particle. We find an abundance of both evaporation-like and direct 4 He emission, each of which is associated with both fusion-fission and sequential-fission processes. Several comparison tests of both the coincidence and singles data strongly indicate that very little 4 He emission is due to evaporation from accelerated fission fragments in this system. The evaporative 4 He emission appears instead to have a strong contribution originating from the composite system prior to fission. The forward angle 4 He emissions, characterized by prominent forward-peaking and relatively high energies, suggest an origin associated with the very early stages of the collision

Transfer reactions in sup(32,36)S + sup(144,154)Sm

International Nuclear Information System (INIS)

Pacheco, A.J.; Tada, M. di; Fernandez Niello, J.; Testoni, J.E.

1990-01-01

The deformation of spherical nuclei in transfer reactions near to the coulomb barrier is studied. The sup(32,36)S + sup(144,154)Sm reactions were carried out using sup(32)S beams produced by TANDAR accelerator in Buenos Aires with energies of 148 MeV and 160 MeV and sup(36)S beams produced by tandem accelerator of Laboratorio Nazionale di Legnaro with energies of 142 MeV and 155 MeV. The angular distributions were measured for sup(32)S reaction using gas ionization chamber and position sensitive detector. The mass spectra of reaction products were obtained measuring time of flight between time detectors, in the sup(36)S reaction. (M.C.K.)

Nanoscale control of reversible chemical reaction between fullerene C60 molecules using scanning tunneling microscope.

Science.gov (United States)

Nakaya, Masato; Kuwahara, Yuji; Aono, Masakazu; Nakayama, Tomonobu

2011-04-01

The nanoscale control of reversible chemical reactions, the polymerization and depolymerization between C60 molecules, has been investigated. Using a scanning tunneling microscope (STM), the polymerization and depolymerization can be controlled at designated positions in ultrathin films of C60 molecules. One of the two chemical reactions can be selectively induced by controlling the sample bias voltage (V(s)); the application of negative and positive values of V(s) results in polymerization and depolymerization, respectively. The selectivity between the two chemical reactions becomes extremely high when the thickness of the C60 film increases to more than three molecular layers. We conclude that STM-induced negative and positive electrostatic ionization are responsible for the control of the polymerization and depolymerization, respectively.

Scaling Hydrologic Exchange Flows and Biogeochemical Reactions from Bedforms to Basins

Science.gov (United States)

Harvey, J. W.; Gomez-Velez, J. D.

2015-12-01

River water moves in and out of the main channel along pathways that are perpendicular to the channel's main axis that flow across or beneath the ground surface. These hydrologic exchange flows (HEFs) are difficult to measure, yet no less important than a river's downstream flow, or exchanges with the atmosphere and deeper groundwater (Harvey and Gooseff, 2015, WRR). There are very few comprehensive investigations of exchange fluxes to understand patterns with river size and relative importance of specific types of exchanges. We used the physically based model NEXSS to simulate multiple scales of hyporheic flow and their cumulative effects on solute reaction in large basins (on the order of Chesapeake Bay basin or larger). Our goal was to explain where and when particular types of hyporheic flow are important in enhancing key biogeochemical reactions, such as organic carbon respiration and denitrification. Results demonstrate that hyporheic flux (expressed per unit area of streambed) varies surprisingly little across the continuum of first-order streams to eighth-order rivers, and vertical exchange beneath small bedforms dominates in comparison with lateral flow beneath gravel bars and meanders. Also, the river's entire volume is exchanged many times with hyporheic flow within a basin, and the turnover length (after one entire river volume is exchanged) is strongly influenced by hydrogeomorphic differences between physiographic regions as well as by river size. The cumulative effects on biogeochemical reactions were assessed using a the reaction significance factor, RSF, which computes the cumulative potential for hyporheic reactions using a dimensionless index that balances reaction progress in a single hyporheic flow path against overall processing efficiency of river turnover through hyporheic flow paths of that type. Reaction significance appears to be strongly dominated by hydrologic factors rather than biogeochemical factors, and seems to be dominated by

Thermonuclear reaction generation method and device

International Nuclear Information System (INIS)

Imazaki, Kazuo

1998-01-01

The present invention provides a method of and a device for causing thermonuclear reaction capable of obtaining extremely high profits (about 1000 times), capable of forming a target which is strong against instability upon implosion as a problem of an inertia process and capable of realizing utilization of nuclear fusion. Namely, elementary particles such as pion, muon and K particles are deposited a portion or some portion of thermonuclear fuel materials by using high energy ions and highly brilliant γ rays generated from a high energy accelerator. The thermonuclear fuel materials are compressed to high density. The nuclear fusion reaction is promoted to ignite and burn thermonuclear fuels. A portion of nuclear fuels is ignited selectively by the means. High profits can be obtained. Since there is no need to attain implosion rate required for self ignition of nuclear fuels, a target of low aspect ratio can be used. (I.S.)

Opening a Can of Worms: Leprosy Reactions and Complicit Soil-Transmitted Helminths.

Science.gov (United States)

Hagge, Deanna A; Parajuli, Pawan; Kunwar, Chhatra B; Rana, Divya R S J B; Thapa, Ruby; Neupane, Kapil D; Nicholls, Peter; Adams, Linda B; Geluk, Annemieke; Shah, Mahesh; Napit, Indra B

2017-09-01

>94% of new annual leprosy cases are diagnosed in populations co-endemic for soil-transmitted helminths (STH). STH can profoundly dysregulate host immune responses towards Th2 bias, which can be restored over time after deworming. We hypothesize that STH co-infection is associated with leprosy reaction (denoted as simply "reaction" herein) occurrence within a co-endemic population. A cohort study was performed on a cohort of Nepalese leprosy patients across treatment and diagnostic classifications who were screened by routine fecal smear microscopy and multiplex quantitative PCR (qPCR) for Ascaris lumbricoides (Al), Strongyloides stercoralis (Ss), Ancyclostoma duodenale (Ad) and Necator americanus (Na). Among 145 patients, 55% were positive for ≥1 STH (STH+): 34% Al+, 18% Ss+, 17% Ad+and 5% Na+. Significant inverse STH and reaction relationships were evidenced by the bulk of cases: 63% reaction-negative were STH+ of total cases (p=0.030) while 65% reaction-positive were STH- in new cases (96; p=0.023). Strikingly, the majority of STH+ were reaction-negative, even when considering each species: 59% Al+, 60% Ss+, 62% Ad+and 67% Na+of new leprosy cases. Absence of STH co-infection is associated with leprosy reaction at diagnosis within a co-endemic population. This is likely due to immune reconstitution effects after deworming or interruption of chronic STH-mediated immune dysregulation. Copyright © 2017. Published by Elsevier B.V.

Immunologic basis for adverse reactions to radiographic contrast media

Energy Technology Data Exchange (ETDEWEB)

Stejskal, V; Nilsson, R; Grepe, A [Astra Pharmaceuticals AB, Soedertaelje (Sweden). Lab. of Safety Assessment Stockholm Univ. (Sweden). Dept. of Genetic and Cellular Toxicology Stockholm Univ. (Sweden). Wallenberglaboratoriet Danderyds Sjukhus, Danderyd (Sweden). Radiologic Clinic

1990-11-01

The lymphocyte transformation test (LTT) was used to elucidate whether certain side effects induced by radiographic contrast media have an immunologic etiology. Groups studied were: 8 patients who had previously experienced adverse reactions in association with urography, 6 patients who underwent urography without notable side reactions, 17 occupationally exposed nurses, and 9 unexposed controls. The lymphocytes from 2 hypersensitive patients and from 11 nurses exhibited a positive proliferative response to amidotrizoate. Five nurses who had shown a positive response, had a previous history of hypersensitivity reactions when handling contrast media, whereas the remaining 6 were free of symptoms. Amidotrizoatespecific memory cells were absent in patients who underwent urography without signs of hypersensitivity and in 7/9 of unexposed control subjects. Lymphocytes from patients sensitive to amidotrizoate cross-reacted to structurally related ionic contrast media while nonionic contrast agents did not induce proliferation of the lymphocytes. Thus, ionic radiographic contrast agents have antigenic properties in man. Irradiated mixtures of radiographic contrast media and serum proteins were, in general, not effective in inducing an LTT response. (orig.).

Immunologic basis for adverse reactions to radiographic contrast media

International Nuclear Information System (INIS)

Stejskal, V.; Nilsson, R.; Grepe, A.; Stockholm Univ.; Stockholm Univ.; Danderyds Sjukhus, Danderyd

1990-01-01

The lymphocyte transformation test (LTT) was used to elucidate whether certain side effects induced by radiographic contrast media have an immunologic etiology. Groups studied were: 8 patients who had previously experienced adverse reactions in association with urography, 6 patients who underwent urography without notable side reactions, 17 occupationally exposed nurses, and 9 unexposed controls. The lymphocytes from 2 hypersensitive patients and from 11 nurses exhibited a positive proliferative response to amidotrizoate. Five nurses who had shown a positive response, had a previous history of hypersensitivity reactions when handling contrast media, whereas the remaining 6 were free of symptoms. Amidotrizoatespecific memory cells were absent in patients who underwent urography without signs of hypersensitivity and in 7/9 of unexposed control subjects. Lymphocytes from patients sensitive to amidotrizoate cross-reacted to structurally related ionic contrast media while nonionic contrast agents did not induce proliferation of the lymphocytes. Thus, ionic radiographic contrast agents have antigenic properties in man. Irradiated mixtures of radiographic contrast media and serum proteins were, in general, not effective in inducing an LTT response. (orig.)

Strong-Field Physics with Mid-IR Fields

Directory of Open Access Journals (Sweden)

Benjamin Wolter

2015-06-01

Full Text Available Strong-field physics is currently experiencing a shift towards the use of mid-IR driving wavelengths. This is because they permit conducting experiments unambiguously in the quasistatic regime and enable exploiting the effects related to ponderomotive scaling of electron recollisions. Initial measurements taken in the mid-IR immediately led to a deeper understanding of photoionization and allowed a discrimination among different theoretical models. Ponderomotive scaling of rescattering has enabled new avenues towards time-resolved probing of molecular structure. Essential for this paradigm shift was the convergence of two experimental tools: (1 intense mid-IR sources that can create high-energy photons and electrons while operating within the quasistatic regime and (2 detection systems that can detect the generated high-energy particles and image the entire momentum space of the interaction in full coincidence. Here, we present a unique combination of these two essential ingredients, namely, a 160-kHz mid-IR source and a reaction microscope detection system, to present an experimental methodology that provides an unprecedented three-dimensional view of strong-field interactions. The system is capable of generating and detecting electron energies that span a 6 order of magnitude dynamic range. We demonstrate the versatility of the system by investigating electron recollisions, the core process that drives strong-field phenomena, at both low (meV and high (hundreds of eV energies. The low-energy region is used to investigate recently discovered low-energy structures, while the high-energy electrons are used to probe atomic structure via laser-induced electron diffraction. Moreover, we present, for the first time, the correlated momentum distribution of electrons from nonsequential double ionization driven by mid-IR pulses.

Light-matter interaction in the strong coupling regime: configurations, conditions, and applications.

Science.gov (United States)

Dovzhenko, D S; Ryabchuk, S V; Rakovich, Yu P; Nabiev, I R

2018-02-22

Resonance interaction between a molecular transition and a confined electromagnetic field can reach the coupling regime where coherent exchange of energy between light and matter becomes reversible. In this case, two new hybrid states separated in energy are formed instead of independent eigenstates, which is known as Rabi splitting. This modification of the energy spectra of the system offers new possibilities for controlled impact on various fundamental properties of coupled matter (such as the rate of chemical reactions and the conductivity of organic semiconductors). To date, the strong coupling regime has been demonstrated in many configurations under different ambient conditions. However, there is still no comprehensive approach to determining parameters for achieving the strong coupling regime for a wide range of practical applications. In this review, a detailed analysis of various systems and corresponding conditions for reaching strong coupling is carried out and their advantages and disadvantages, as well as the prospects for application, are considered. The review also summarizes recent experiments in which the strong coupling regime has led to new interesting results, such as the possibility of collective strong coupling between X-rays and matter excitation in a periodic array of Fe isotopes, which extends the applications of quantum optics; a strong amplification of the Raman scattering signal from a coupled system, which can be used in surface-enhanced and tip-enhanced Raman spectroscopy; and more efficient second-harmonic generation from the low polaritonic state, which is promising for nonlinear optics. The results reviewed demonstrate great potential for further practical applications of strong coupling in the fields of photonics (low-threshold lasers), quantum communications (switches), and biophysics (molecular fingerprinting).

α,β-D-constrained nucleic acids are strong terminators of thermostable DNA polymerases in polymerase chain reaction.

Directory of Open Access Journals (Sweden)

Olivier Martínez

Full Text Available (S(C5', R(P α,β-D- Constrained Nucleic Acids (CNA are dinucleotide building blocks that can feature either B-type torsional angle values or non-canonical values, depending on their 5'C and P absolute stereochemistry. These CNA are modified neither on the nucleobase nor on the sugar structure and therefore represent a new class of nucleotide with specific chemical and structural characteristics. They promote marked bending in a single stranded DNA so as to preorganize it into a loop-like structure, and they have been shown to induce rigidity within oligonucleotides. Following their synthesis, studies performed on CNA have only focused on the constraints that this family of nucleotides introduced into DNA. On the assumption that bending in a DNA template may produce a terminator structure, we investigated whether CNA could be used as a new strong terminator of polymerization in PCR. We therefore assessed the efficiency of CNA as a terminator in PCR, using triethylene glycol phosphate units as a control. Analyses were performed by denaturing gel electrophoresis and several PCR products were further analysed by sequencing. The results showed that the incorporation of only one CNA was always skipped by the polymerases tested. On the other hand, two CNA units always stopped proofreading polymerases, such as Pfu DNA polymerase, as expected for a strong replication terminator. Non-proofreading enzymes, e.g. Taq DNA polymerase, did not recognize this modification as a strong terminator although it was predominantly stopped by this structure. In conclusion, this first functional use of CNA units shows that these modified nucleotides can be used as novel polymerization terminators of proofreading polymerases. Furthermore, our results lead us to propose that CNA and their derivatives could be useful tools for investigating the behaviour of different classes of polymerases.

Lensless ghost imaging through the strongly scattering medium

International Nuclear Information System (INIS)

Yang Zhe; Zhao Xueliang; Li Junlin; Zhao Lianjie; Qin Wei

2016-01-01

Lensless ghost imaging has attracted much interest in recent years due to its profound physics and potential applications. In this paper we report studies of the robust properties of the lensless ghost imaging system with a pseudo-thermal light source in a strongly scattering medium. The effects of the positions of the strong medium on the ghost imaging are investigated. In the lensless ghost imaging system, a pseudo-thermal light is split into two correlated beams by a beam splitter. One beam goes to a charge-coupled detector camera, labeled as CCD2. The other beam goes to an object and then is collected in another charge-coupled detector camera, labeled as CCD1, which serves as a bucket detector. When the strong medium, a pane of ground glass disk, is placed between the object and CCD1, the bucket detector, the quality of ghost imaging is barely affected and a good image could still be obtained. The quality of the ghost imaging can also be maintained, even when the ground glass is rotating, which is the strongest scattering medium so far. However, when the strongly scattering medium is present in the optical path from the light source to CCD2 or the object, the lensless ghost imaging system hardly retrieves the image of the object. A theoretical analysis in terms of the second-order correlation function is also provided. (paper)

A large area two-dimensional position sensitive multiwire proportional detector

CERN Document Server

Moura, M M D; Souza, F A; Alonso, E E; Fujii, R J; Meyknecht, A B; Added, N; Aissaoui, N; Cardenas, W H Z; Ferraretto, M D; Schnitter, U; Szanto, E M; Szanto de Toledo, A; Yamamura, M S; Carlin, N

1999-01-01

Large area two-dimensional position sensitive multiwire proportional detectors were developed to be used in the study of light heavy-ion nuclear reactions at the University of Sao Paulo Pelletron Laboratory. Each detector has a 20x20 cm sup 2 active area and consists of three grids (X-position, anode and Y-position) made of 25 mu m diameter gold plated tungsten wires. The position is determined through resistive divider chains. Results for position resolution, linearity and efficiency as a function of energy and position for different elements are reported.

Future directions for positive body image research

OpenAIRE

Halliwell, E.

2015-01-01

The emergence of positive body image research during the last 10 years represents an important shift in the body image literature. The existing evidence provides a strong empirical basis for the study of positive body image and research has begun to address issues of age, gender, ethnicity, culture, development, and intervention in relation to positive body image. This article briefly reviews the existing evidence before outlining directions for future research. Specifically, six areas for fu...

Is a strong sense of self-efficacy always beneficial?

Directory of Open Access Journals (Sweden)

Thomas VERHAEREN

2012-01-01

Full Text Available The concept of self-efficacy, introduced by Albert Bandura, has received a lot of attention in psychological research. This comes as no surprise, as it encompasses a person's beliefs about his or her capabilities to successfully do what is necessary for desired goals, which is a central mechanism in human agency. The concept has been linked to many outcomes (e.g. motivation and performance, almost exclusively yielding positive results. Recently, however, arguments have risen that a strong sense of selfefficacy may not always be as beneficial as presumed until now. In this article, I review the core of the positive literature on self-efficacy and highlight studies that question and oppose the dominance of these positive self-efficacy associations. Implications for future research, emphasizing the need of a different research approach, are mentioned.

Isovector couplings for nucleon charge-exchange reactions at intermediate energies

International Nuclear Information System (INIS)

Love, W.G.; Nakayama, K.; Franey, M.A.

1987-01-01

The isovector parts of the effective nucleon-nucleon interaction are studied by examination of the reaction /sup 14/C(p,n) at intermediate energies near zero momentum transfer with use of recently developed G-matrix and free--t-matrix interactions. The spin-independent coupling (V/sub tau/) exhibits a strong energy and density dependence which, in the case of the G matrix based on the Bonn potential, significantly improves the agreement between calculated values of chemical bondV/sub σ//sub tau//V/sub tau/chemical bond 2 at q = 0 and those recently extracted from the reaction /sup 14/C

Ionizing gas breakdown waves in strong electric fields.

Science.gov (United States)

Klingbeil, R.; Tidman, D. A.; Fernsler, R. F.

1972-01-01

A previous analysis by Albright and Tidman (1972) of the structure of an ionizing potential wave driven through a dense gas by a strong electric field is extended to include atomic structure details of the background atoms and radiative effects, especially, photoionization. It is found that photoionization plays an important role in avalanche propagation. Velocities, electron densities, and temperatures are presented as a function of electric field for both negative and positive breakdown waves in nitrogen.

Study of 162Er via the (p , t) and (p ,p') reactions

Science.gov (United States)

Kisliuk, D.; Garrett, P. E.; Finlay, A.; Bianco, L.; Bildstein, V.; Burbadge, C.; Chagnon-Lessard, S.; Diaz Varela, A.; Dunlop, M. R.; Dunlop, R.; Finlay, P.; Jamieson, D.; Jigmeddorj, B.; Maclean, A. D.; Michetti-Wilson, J.; Leach, K. G.; Radich, A. J.; Rand, E.; Svensson, C. E.; Wong, J.; Ball, G. C.; Triambak, S.; Faestermann, T.; Hertenberger, R.; Wirth, H.-F.

2015-10-01

The nature of excited states in well-deformed nuclei pose a challenge in nuclear structure. In light of this, the study of 162Er via the 164Er (p , t) and 162Er (p ,p') reactions has been initiated to shed light on the structure of these excited states. The experiments were performed at the Maier-Leibnitz Laboratory using a 22 MeV proton beam on highly-enriched targets of 162,164Er and the reaction was analyzed with the Q3D spectrograph. Strong population in the (p , t) reaction of the 02+ state, far greater than other 0+ states, has been observed. Transition matrix elements for population of low-lying states in the (p ,p') reaction have also been extracted. Initial results from these experiments will be presented.

Halogenating reaction activity of aromatic organic compounds during disinfection of drinking water

International Nuclear Information System (INIS)

Guo Gaimei; Chen Xiaodong

2009-01-01

The halogenating reactions of five aromatic organic compounds (AOCs) with aqueous chlorine (HOCl/OCl - ) and aqueous bromine (HOBr/OBr - ) were studied with an aim to compare the formation properties of haloacetic acids (HAAs) for the corresponding chlorination or bromination reactions of AOCs, respectively. The experiment results indicated that the HAAs substitution efficiency for the bromination reactions of AOCs was greater than that for the chlorination reactions, and the formation of HAAs had a strong dependence on the chemical structure of AOCs. The chlorination or bromination reaction activities for the AOCs with electron donating functional groups were higher than that for them with electron withdrawing functional groups. The kinetic experiments indicated that the reactions of aqueous bromine with phenol were faster than those of aqueous chlorine with phenol and the halogen consumption exhibited rapid initial and slower consumption stages for the reactions of phenol with aqueous chlorine and bromine, respectively. In addition, the HAAs production for the chlorination reaction of phenol decreased with the increase of pH. These conclusions could provide the valuable information for the effective control of the disinfection by-products during drinking water treatment operation

A Volunteer Program for Abnormal Psychology Students: Eighteen Years and Still Going Strong.

Science.gov (United States)

Scogin, Forrest; Rickard, Henry C.

1987-01-01

A volunteer experience in abnormal psychology is described. The program has been operating for 18 years, and student reactions have been quite positive. The program augments the traditional course offerings and provides reciprocal service for the University of Alabama and mental health facilities. Guidelines for implementing a volunteer program…

The (3He,t) and (d,2He)reactions at intermediate energies

International Nuclear Information System (INIS)

Brockstedt, A.

1987-09-01

The ( 3 He,t) reaction has been studied at 0.6-2.3 GeV at small scattering angles, 0-7 degrees, on various nuclei ( 12 C, 13 C, 26 Mg, 40 Ca, 48 Ca, 54 Fe, 90 Zr, 159 Tb, 208 Pb) including a proton target. The reaction is a single-step reaction and selects the spin-isospin channel. Angular distributions for low-lying states in 12 N are well described by DWIA calculations. From 13 C to 13 N transitions the ratio J στ /J τ , at momentum transfer, q, close to zero, is derived. The ratio remains roughly constant in the region 300 - 700 MeV/nucleon. The position of the quasi-free peak is shifted compared with free nucleon-nucleon scattering. The shift is towards higher excitation energies at q approx 1.4 fm -1 , and towards lower excitation energies at q approx 2.5 fm -1 . The p( 3 He,t)Δ ++ reaction is analysed as one-pion exchange and the ( 3 He,t) form factor is extracted. The shape and position of the Δ resonance seem to be independent of target mass for the targets studied. Compared with the p to Δ ++ transition the position is shifted towards lower excitation energy in nuclei. The (d,2p[ 1 S 0 ]) reaction, with the two protons in an 1 S 0 state labelled 2 He, is studied at 0.65 and 2.0 GeV at small angles, 0-4 degrees, on some of the targets used in the ( 3 He,t) experiment (p, 12 C, 40 Ca, 54 Fe). This reaction is also a one-step reaction that can be used for studies of spin-isospin excitations. Cross sections and tensor analysing powers are determined for the p(d, 2 He)n reaction. These results are compared with PWIA calculations. The Δ resonance in carbon is also here shifted down in excitation energy compared with the proton target. (author)

Kinetic isotope effects in reaction of ferment oxidation of tritium-labelled D-galactosamine

International Nuclear Information System (INIS)

Akulov, G.P.; Korsakova, N.A.

1992-01-01

Primary, secondary and intramolecular kinetic isotopic effects in reaction of ferment oxidation of D-galactosamine labelled by tritium in position 6, were measured. When comparing values of the effects with previously obtained results for similar reaction D-[6- 3 H]galactose, it was ascertained that the presence of aminogroup in galactopyranosyl mainly affects kinetics of substrate-ferment complex formation stage. The possibility to use kinetic isotope effects for increase in molar activity of D-galactosamine, labelled by tritium in position 6, is shown

Cleavage reactions of the complex ions derived from self-complementary deoxydinucleotides and alkali-metal ions using positive ion electrospray ionization with tandem mass spectrometry.

Science.gov (United States)

Xiang, Yun; Abliz, Zeper; Takayama, Mitsuo

2004-05-01

The dissociation reactions of the adduct ions derived from the four self-complementary deoxydinucleotides, d(ApT), d(TpA), d(CpG), d(GpC), and alkali-metal ions were studied in detail by positive ion electrospray ionization multiple-stage mass spectrometry (ESI-MS(n)). For the [M + H](+) ions of the four deoxydinucleotides, elimination of 5'-terminus base or loss of both of 5'-terminus base and a deoxyribose were the major dissociation pathway. The ESI-MS(n) spectra showed that Li(+), Na(+), and Cs(+) bind to deoxydinucleotides mainly by substituting the H(+) of phosphate group, and these alkali-metal ions preferred to bind to pyrimidine bases rather than purine bases. For a given deoxydinucleotide, the dissociation pathway of [M + K](+) ions differed clearly from that of [M + Li](+), [M + Na](+), and [M + Cs](+) ions. Some interesting and characteristic cleavage reactions were observed in the product-ion spectra of [M + K](+) ions, including direct elimination of deoxyribose and HPO(3) from molecular ions. The fragmentation behavior of the [M + K](+) and [M + W](+) (W = Li, Na, Cs) adduct ions depend upon the sequence of bases, the interaction between alkali-metal ions and nucleobases, and the steric hindrance caused by bases.

Anion-π Catalysis of Enolate Chemistry: Rigidified Leonard Turns as a General Motif to Run Reactions on Aromatic Surfaces.

Science.gov (United States)

Cotelle, Yoann; Benz, Sebastian; Avestro, Alyssa-Jennifer; Ward, Thomas R; Sakai, Naomi; Matile, Stefan

2016-03-18

To integrate anion-π, cation-π, and ion pair-π interactions in catalysis, the fundamental challenge is to run reactions reliably on aromatic surfaces. Addressing a specific question concerning enolate addition to nitroolefins, this study elaborates on Leonard turns to tackle this problem in a general manner. Increasingly refined turns are constructed to position malonate half thioesters as close as possible on π-acidic surfaces. The resulting preorganization of reactive intermediates is shown to support the disfavored addition to enolate acceptors to an absolutely unexpected extent. This decisive impact on anion-π catalysis increases with the rigidity of the turns. The new, rigidified Leonard turns are most effective with weak anion-π interactions, whereas stronger interactions do not require such ideal substrate positioning to operate well. The stunning simplicity of the motif and its surprisingly strong relevance for function should render the introduced approach generally useful. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nuclear rotational population patterns in heavy-ion scattering and transfer reactions

Energy Technology Data Exchange (ETDEWEB)

Rasmussen, J O; Stoyer, M A [Lawrence Berkeley Lab., CA (USA); Canto, L F; Donangelo, R [Universidade Federal do Rio de Janeiro, RJ (Brazil); Ring, P [Technische Univ. Muenchen, Garching (Germany, F.R.). Fakultaet fuer Physik

1991-05-01

A model of {sup 239}Pu with decoupled neutron is used for theoretical calculations of rotational population patterns in heavy ion inelastic scattering and one-neutron transfer reactions. The system treated in {sup 90}Zr on {sup 239}Pu at the near-barrier energy of 500 MeV and backscattering angles of 180deg and 140deg. The influence of the complex nuclear optical potential is seen to be very strong, and the Nilsson wave function of the odd neutron produces a distinctive pattern in the transfer reaction. (orig.).

Effective nucleon-nucleon t matrix in the (p,2p) reaction

International Nuclear Information System (INIS)

Kudo, Y.; Kanayama, N.; Wakasugi, T.

1989-01-01

The cross sections and the analyzing powers for the /sup 40/Ca(p-arrow-right,2p) reactions at E/sub p/ = 76.1, 101.3, and 200 MeV are calculated in the distorted-wave impulse approximation using the Love-Franey effective nucleon-nucleon interaction. It is shown that the calculated individual contributions of the central, spin-orbit, and tensor parts in the Love-Franey interaction to the cross sections and the analyzing powers strongly depend on the incident proton energies. The spectroscopic factors extracted are consistent with the other reaction studies

Recurrent Reverse Evolution Maintains Polymorphism after Strong Bottlenecks in Commensal Gut Bacteria.

Science.gov (United States)

Sousa, Ana; Ramiro, Ricardo S; Barroso-Batista, João; Güleresi, Daniela; Lourenço, Marta; Gordo, Isabel

2017-11-01

The evolution of new strains within the gut ecosystem is poorly understood. We used a natural but controlled system to follow the emergence of intraspecies diversity of commensal Escherichia coli, during three rounds of adaptation to the mouse gut (∼1,300 generations). We previously showed that, in the first round, a strongly beneficial phenotype (loss-of-function for galactitol consumption; gat-negative) spread to >90% frequency in all colonized mice. Here, we show that this loss-of-function is repeatedly reversed when a gat-negative clone colonizes new mice. The regain of function occurs via compensatory mutation and reversion, the latter leaving no trace of past adaptation. We further show that loss-of-function adaptive mutants reevolve, after colonization with an evolved gat-positive clone. Thus, even under strong bottlenecks a regime of strong-mutation-strong-selection dominates adaptation. Coupling experiments and modeling, we establish that reverse evolution recurrently generates two coexisting phenotypes within the microbiota that can or not consume galactitol (gat-positive and gat-negative, respectively). Although the abundance of the dominant strain, the gat-negative, depends on the microbiota composition, gat-positive abundance is independent of the microbiota composition and can be precisely manipulated by supplementing the diet with galactitol. These results show that a specific diet is able to change the abundance of specific strains. Importantly, we find polymorphism for these phenotypes in indigenous Enterobacteria of mice and man. Our results demonstrate that natural selection can greatly overwhelm genetic drift at structuring the strain diversity of gut commensals and that competition for limiting resources may be a key mechanism for maintaining polymorphism in the gut. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

The load and release characteristics on a strong cationic ion-exchange fiber: kinetics, thermodynamics, and influences.

Science.gov (United States)

Yuan, Jing; Gao, Yanan; Wang, Xinyu; Liu, Hongzhuo; Che, Xin; Xu, Lu; Yang, Yang; Wang, Qifang; Wang, Yan; Li, Sanming

2014-01-01

Ion-exchange fibers were different from conventional ion-exchange resins in their non-cross-linked structure. The exchange was located on the surface of the framework, and the transport resistance reduced significantly, which might mean that the exchange is controlled by an ionic reaction instead of diffusion. Therefore, this work aimed to investigate the load and release characteristics of five model drugs with the strong cationic ion-exchange fiber ZB-1. Drugs were loaded using a batch process and released in United States Pharmacopoeia (USP) dissolution apparatus 2. Opposing exchange kinetics, suitable for the special structure of the fiber, were developed for describing the exchange process with the help of thermodynamics, which illustrated that the load was controlled by an ionic reaction. The molecular weight was the most important factor to influence the drug load and release rate. Strong alkalinity and rings in the molecular structures made the affinity between the drug and fiber strong, while logP did not cause any profound differences. The drug-fiber complexes exhibited sustained release. Different kinds and concentrations of counter ions or different amounts of drug-fiber complexes in the release medium affected the release behavior, while the pH value was independent of it. The groundwork for in-depth exploration and further application of ion-exchange fibers has been laid.

Reaction of electron-transfer flavoprotein with electron-transfer flavoprotein-ubiquinone oxidoreductase

International Nuclear Information System (INIS)

Beckmann, J.D.; Frerman, F.E.

1985-01-01

The oxidative half-reaction of electron-transfer flavoprotein (ETF), electron transfer from ETF to electron-transfer flavoprotein-ubiquinone oxidoreductase (ETF-QO), is dependent on complementary surface charges on the two proteins. ETF is the positively charged member of the redox pair. The evidence is based on the pH and ionic strength dependencies of the comproportionation of oxidized ETF and ETF hydroquinone catalyzed by ETF-QO and on the effects of chemical modification of ETF on the comproportionation reaction. Acetylation of one and five epsilon-amino groups of lysyl residues results in 3- and 13-fold increases, respectively, in the K/sub m/ of ETF-QO for ETF but no change in V/sub max/. Amidination, which maintains positive charge at modified loci, has no effect on steady-state kinetic constants. These chemical modifications have no effect on the equilibrium constant for equilibration of ETF redox states. The K/sub m/ of ETF-QO for ETF is pH dependent above pH 8.5, suggesting titration of lysyl residues. The ionic strength dependence of TN/KmETF for the reaction follows the limiting Bronsted equation. The ETF-QO-catalyzed comproportionation reaction exhibits a primary deuterium isotope effect in D 2 O, perhaps indicating the participation of solvent water in the electron-transfer reaction

Redox reactions of neptunium in tributyl phosphate-dodecane mixtures

International Nuclear Information System (INIS)

Wehrey, F.

1989-01-01

In relation with the reprocessing of irradiated fuels, disproportionation and oxidation by nitric acid of pentavalent neptunium in tributyl phosphate-dodecane mixtures have been studied. The experimental part of this work is based on spectrophotometric measurements. The disproportionation of pentavalent neptunium in organic perchloric medium is a second order reaction with respect to neptunium V. The reaction rate is strongly influenced by the perchloric acid concentration and has a higher value than in an aqueous medium. The reverse reaction in nitric media is a first order with respect to tetravalent and hexavalent ions. The reaction rate is a function of the reverse of the square of the nitric acid concentration. The energy of activation is the same than in aqueous medium. The oxidation rate of pentavalent neptunium by nitric acid is increased by nitrous acid. When no nitrous acid is added to the mixture, the reaction revealed to be autocatalytic, possesses an induction period. When nitrous and nitric acids are in excess to neptunium the reaction is first order with respect to neptunium. The reaction rate depends on the concentration of nitric acid and is a linear function of the concentration of nitrous acid. In tributyl phosphate dodecane mixtures the reaction occurs spontaneously. It is not the case in aqueous media. The values of thermodynamical and kinetical constants determined in this work could be used in a modelization of the behavior of neptunium in the reprocessing of irradiated fuels, which has to eliminate this element among its tasks [fr

Position displacement effect on the doses in the peripheral head regions

International Nuclear Information System (INIS)

Kortesniemi, M.; Seppaelae, T.; Bjugg, H.; Seren, T.; Kotiluoto, P.; Auterinen, I.; Parkkinen, R.; Savolainen, S.

2000-01-01

Patient positioning is a challenging task in BNCT-treatments due to the use of multiple fields and a static horizontal beam construction. Positioning accuracy of 5 mm is required for acceptable dose delivery within appropriate limits of dose uncertainty (up to 10% of point dose in target volume). The aim of this study was to determine if a patient head position creating a clear gap between the beam port and the head would have a significant effect on the doses to the peripheral regions of the head, e.g. to the eyes. The gamma dose rates were measured in a water filled ellipsoidal phantom with an ionisation chamber (IC). Mn activation wires were used to determine the Mn-55(n, γ) reaction rates. Twelve measurement points were chosen in the phantom and two phantom positions were applied. According to this study the 35 mm position change and the resulting gap has an obvious effect on the peripheral doses in BNCT. The Mn activation reaction rates were on the average 80% higher in the deviation position than in the reference position. Increasing depth from the surface inside the phantom diminished the gamma dose difference between the two positions. Scattering environment changes with position displacement and resulting gap causes differences in neutron fluences and gamma doses. (author)

Cr(III) reactivity and foot dermatitis in Cr(VI) positive patients

DEFF Research Database (Denmark)

Hansen, Malene Barré; Menné, Torkil; Johansen, Jeanne Duus

2006-01-01

Chromium allergy has become synonymous with Cr(VI) allergy. However, real exposure to chromium from leather products may include both Cr(III) and Cr(VI). In this study, we investigate the reactivity to both Cr(VI) and Cr(III) in consecutive patients to analyse the relation between foot eczema/leather...... to Cr(III). The increased risk was not due to a higher degree of sensitivity to Cr(VI). Leather was reported most frequently as the suspected cause of chromium dermatitis (54%). However, Cr(VI) allergics having foot eczema and positive or doubtful Cr(III) reactions often had positive reactions to other...

Reaction mechanism and nuclear correlations study by low energy pion double charge exchange

International Nuclear Information System (INIS)

Weinfeld, Z.

1993-06-01

In pion double-charge-exchange (DCX) reactions, a positive (negative) pion is incident on a nucleus and a negative (positive) pion emerges. These reactions are of fundamental interest since the process must involve at least two nucleons in order to conserve charge. Although two nucleon processes are present in many reactions they are usually masked by the dominant single nucleon processes. DCX is unique in that respect since it is a two nucleon process in lowest order and thus may be sensitive to two-nucleon correlations. Measurements of low energy pion double-charge-exchange reactions to the double-isobaric-analog-state (DIAS) and ground-state (GS) of the residual nucleus provide new means for studying nucleon-nucleon correlations in nuclei. At low energies (T π 7/2 shell at energies ranging from 25 to 65 MeV. Cross sections were measured on 42,44,48 Ca, 46,50 Ti and 54 Fe. The calcium isotopes make a good set of nuclei on which to study the effects of correlations in DCX reactions

Coupled enzyme reactions performed in heterogeneous reaction media: experiments and modeling for glucose oxidase and horseradish peroxidase in a PEG/citrate aqueous two-phase system.

Science.gov (United States)

Aumiller, William M; Davis, Bradley W; Hashemian, Negar; Maranas, Costas; Armaou, Antonios; Keating, Christine D

2014-03-06

The intracellular environment in which biological reactions occur is crowded with macromolecules and subdivided into microenvironments that differ in both physical properties and chemical composition. The work described here combines experimental and computational model systems to help understand the consequences of this heterogeneous reaction media on the outcome of coupled enzyme reactions. Our experimental model system for solution heterogeneity is a biphasic polyethylene glycol (PEG)/sodium citrate aqueous mixture that provides coexisting PEG-rich and citrate-rich phases. Reaction kinetics for the coupled enzyme reaction between glucose oxidase (GOX) and horseradish peroxidase (HRP) were measured in the PEG/citrate aqueous two-phase system (ATPS). Enzyme kinetics differed between the two phases, particularly for the HRP. Both enzymes, as well as the substrates glucose and H2O2, partitioned to the citrate-rich phase; however, the Amplex Red substrate necessary to complete the sequential reaction partitioned strongly to the PEG-rich phase. Reactions in ATPS were quantitatively described by a mathematical model that incorporated measured partitioning and kinetic parameters. The model was then extended to new reaction conditions, i.e., higher enzyme concentration. Both experimental and computational results suggest mass transfer across the interface is vital to maintain the observed rate of product formation, which may be a means of metabolic regulation in vivo. Although outcomes for a specific system will depend on the particulars of the enzyme reactions and the microenvironments, this work demonstrates how coupled enzymatic reactions in complex, heterogeneous media can be understood in terms of a mathematical model.

Phenomenological description of selected elementary chemical reaction mechanisms: An information-theoretic study

International Nuclear Information System (INIS)

Esquivel, R.O.; Flores-Gallegos, N.; Iuga, C.; Carrera, E.M.; Angulo, J.C.; Antolin, J.

2010-01-01

The information-theoretic description of the course of two elementary chemical reactions allows a phenomenological description of the chemical course of the hydrogenic abstraction and the S N 2 identity reactions by use of Shannon entropic measures in position and momentum spaces. The analyses reveal their synchronous/asynchronous mechanistic behavior.

Substance abusers' personality disorders and staff members' emotional reactions

Directory of Open Access Journals (Sweden)

Hesse Morten

2008-04-01

Full Text Available Abstract Background Previous research has indicated that aggressive behaviour and DSM-IV cluster B personality disorders (PD may be associated with professionals' emotional reactions to clients, and that cluster C PD may be associated with positive emotional reactions. Methods Staff members recruited from workshops completed a self-report inventory of emotional reactions to patients, the Feeling Word Checklist-58, and substance abusers completed a self-report of DSM-IV personality disorder, the DSM-IV and ICD-10 Personality Disorder Questionnaire. Correlational analysis and multiple regression analysis was used to assess the associations between personality disorders and emotional reations. Results Cluster B disorder features were associated with feeling distance to patients, and cluster C disorder features were associated with feeling helpful towards patients. Cluster A disorders had no significant impact on emotional reactions. Conclusion The findings confirm clinical experiences that personality disorder features in patients with substance abuse have an impact on staff members reactions to them. These reactions should be considered in supervision of staff, and in treatment models for patients with co-morbid personality disorders and substance abuse.

Kinetics of subdiffusion-assisted reactions: non-Markovian stochastic Liouville equation approach

International Nuclear Information System (INIS)

Shushin, A I

2005-01-01

Anomalous specific features of the kinetics of subdiffusion-assisted bimolecular reactions (time-dependence, dependence on parameters of systems, etc) are analysed in detail with the use of the non-Markovian stochastic Liouville equation (SLE), which has been recently derived within the continuous-time random-walk (CTRW) approach. In the CTRW approach, subdiffusive motion of particles is modelled by jumps whose onset probability distribution function is of a long-tailed form. The non-Markovian SLE allows for rigorous describing of some peculiarities of these reactions; for example, very slow long-time behaviour of the kinetics, non-analytical dependence of the reaction rate on the reactivity of particles, strong manifestation of fluctuation kinetics showing itself in very slowly decreasing behaviour of the kinetics at very long times, etc

A molecular dynamics study of intramolecular proton transfer reaction of malonaldehyde in solution based upon a mixed quantum-classical approximation. II. Proton transfer reaction in non-polar solvent

Science.gov (United States)

Kojima, H.; Yamada, A.; Okazaki, S.

2015-05-01

The intramolecular proton transfer reaction of malonaldehyde in neon solvent has been investigated by mixed quantum-classical molecular dynamics (QCMD) calculations and fully classical molecular dynamics (FCMD) calculations. Comparing these calculated results with those for malonaldehyde in water reported in Part I [A. Yamada, H. Kojima, and S. Okazaki, J. Chem. Phys. 141, 084509 (2014)], the solvent dependence of the reaction rate, the reaction mechanism involved, and the quantum effect therein have been investigated. With FCMD, the reaction rate in weakly interacting neon is lower than that in strongly interacting water. However, with QCMD, the order of the reaction rates is reversed. To investigate the mechanisms in detail, the reactions were categorized into three mechanisms: tunneling, thermal activation, and barrier vanishing. Then, the quantum and solvent effects were analyzed from the viewpoint of the reaction mechanism focusing on the shape of potential energy curve and its fluctuations. The higher reaction rate that was found for neon in QCMD compared with that found for water solvent arises from the tunneling reactions because of the nearly symmetric double-well shape of the potential curve in neon. The thermal activation and barrier vanishing reactions were also accelerated by the zero-point energy. The number of reactions based on these two mechanisms in water was greater than that in neon in both QCMD and FCMD because these reactions are dominated by the strength of solute-solvent interactions.

Investigations of nuclear structure and nuclear reactions induced by complex projectiles. Technical progress report, November 1, 1978-October 31, 1979

International Nuclear Information System (INIS)

Sarantites, D.G.

1979-01-01

Experimental research on nuclear structure and reactions both published and in progress is summarized. Included are fusion reactions, strongly damped heavy ion collisions, and nuclear structure at high angular momentum. A list of publications is included

Social Interaction and Market Reaction to Earnings News

OpenAIRE

Wang, Qiguang

2017-01-01

This study documents strong effects of social interaction on investors’ attention and interpretations of earnings news. I estimate the firm-level investor social network and find that higher connectedness increases the announcement price reaction, reduces post-announcement drift, and decreases the long-run impact of the news on return volatility. I also find that social interaction triggers persistent disagreement-driven volume during and after the announcement. The evidence combined highligh...

Age and size at maturity: a quantitative review of diet-induced reaction norms in insects.

Science.gov (United States)

Teder, Tiit; Vellau, Helen; Tammaru, Toomas

2014-11-01

Optimality models predict that diet-induced bivariate reaction norms for age and size at maturity can have diverse shapes, with the slope varying from negative to positive. To evaluate these predictions, we perform a quantitative review of relevant data, using a literature-derived database of body sizes and development times for over 200 insect species. We show that bivariate reaction norms with a negative slope prevail in nearly all taxonomic and ecological categories of insects as well as in some other ectotherm taxa with comparable life histories (arachnids and amphibians). In insects, positive slopes are largely limited to species, which feed on discrete resource items, parasitoids in particular. By contrast, with virtually no meaningful exceptions, herbivorous and predatory insects display reaction norms with a negative slope. This is consistent with the idea that predictable resource depletion, a scenario selecting for positively sloped reaction norms, is not frequent for these insects. Another source of such selection-a positive correlation between resource levels and juvenile mortality rates-should similarly be rare among insects. Positive slopes can also be predicted by models which integrate life-history evolution and population dynamics. As bottom-up regulation is not common in most insect groups, such models may not be most appropriate for insects. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.

Rb2Na(NO33: A Congruently Melting UV-NLO Crystal with a Very Strong Second-Harmonic Generation Response

Directory of Open Access Journals (Sweden)

Guohong Zou

2016-04-01

Full Text Available Crystals of congruently melting noncentrosymmetric (NCS mixed alkali metal nitrate, Rb2Na(NO33, have been grown through solid state reactions. The material possesses layers with NaO8 hexagonal bipyramids and NO3 triangular units. Rb+ cations are residing in the interlayer space. Each NaO8 hexagonal bipyramid shares its corners and edges with two and three NO3 units, respectively, in order to fulfill a highly dense stacking in the unit cell. The NaO8 groups share their six oxygen atoms in equatorial positions with three different NO3 groups to generate a NaO6-NO3 layer with a parallel alignment. The optimized arrangement of the NO3 groups and their high density in the structure together produce a strong second-harmonic generation (SHG response. Powder SHG measurements indicate that Rb2Na(NO33 has a strong SHG efficiency of five times that of KH2PO4 (KDP and is type I phase-matchable. The calculated average nonlinear optical (NLO susceptibility of Rb2Na(NO33 turns out to be the largest value among the NLO materials composed of only [NO3]− anion. In addition, Rb2Na(NO33 exhibits a wide transparency region ranging from UV to near IR, which suggests that the compound is a promising NLO material.

Persistent Skin Reactions and Aluminium Hypersensitivity Induced by Childhood Vaccines.

Science.gov (United States)

Salik, Elaha; Løvik, Ida; Andersen, Klaus E; Bygum, Anette

2016-11-02

There is increasing awareness of reactions to vaccination that include persistent skin reactions. We present here a retrospective investigation of long-lasting skin reactions and aluminium hypersensitivity in children, based on medical records and questionnaires sent to the parents. In the 10-year period 2003 to 2013 we identified 47 children with persistent skin reactions caused by childhood vaccinations. Most patients had a typical presentation of persisting pruritic subcutaneous nodules. Five children had a complex diagnostic process involving paediatricians, orthopaedics and plastic surgeons. Two patients had skin biopsies performed from their skin lesions, and 2 patients had the nodules surgically removed. Forty-two children had a patch-test performed with 2% aluminium chloride hexahydrate in petrolatum and 39 of them (92%) had a positive reaction. The persistent skin reactions were treated with potent topical corticosteroids and disappeared slowly. Although we advised families to continue vaccination of their children, one-third of parents omitted or postponed further vaccinations.

Tuning Catalytic Performance through a Single or Sequential Post-Synthesis Reaction(s) in a Gas Phase

Energy Technology Data Exchange (ETDEWEB)

Shan, Junjun [Department; Department; Zhang, Shiran [Department; Department; Choksi, Tej [Department; Nguyen, Luan [Department; Department; Bonifacio, Cecile S. [Department; Li, Yuanyuan [Department; Zhu, Wei [Department; Department; College; Tang, Yu [Department; Department; Zhang, Yawen [College; Yang, Judith C. [Department; Greeley, Jeffrey [Department; Frenkel, Anatoly I. [Department; Tao, Franklin [Department; Department

2016-12-05

Catalytic performance of a bimetallic catalyst is determined by geometric structure and electronic state of the surface or even the near-surface region of the catalyst. Here we report that single and sequential postsynthesis reactions of an as-synthesized bimetallic nanoparticle catalyst in one or more gas phases can tailor surface chemistry and structure of the catalyst in a gas phase, by which catalytic performance of this bimetallic catalyst can be tuned. Pt–Cu regular nanocube (Pt–Cu RNC) and concave nanocube (Pt–Cu CNC) are chosen as models of bimetallic catalysts. Surface chemistry and catalyst structure under different reaction conditions and during catalysis were explored in gas phase of one or two reactants with ambient-pressure X-ray photoelectron spectroscopy (AP-XPS) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The newly formed surface structures of Pt–Cu RNC and Pt–Cu CNC catalysts strongly depend on the reactive gas(es) used in the postsynthesis reaction(s). A reaction of Pt–Cu RNC-as synthesized with H2 at 200 °C generates a near-surface alloy consisting of a Pt skin layer, a Cu-rich subsurface, and a Pt-rich deep layer. This near-surface alloy of Pt–Cu RNC-as synthesized-H2 exhibits a much higher catalytic activity in CO oxidation in terms of a low activation barrier of 39 ± 4 kJ/mol in contrast to 128 ± 7 kJ/mol of Pt–Cu RNC-as synthesized. Here the significant decrease of activation barrier demonstrates a method to tune catalytic performances of as-synthesized bimetallic catalysts. A further reaction of Pt–Cu RNC-as synthesized-H2 with CO forms a Pt–Cu alloy surface, which exhibits quite different catalytic performance in CO oxidation. It suggests the capability of generating a different surface by using another gas. The capability of tuning surface chemistry and structure of bimetallic catalysts was also demonstrated in restructuring of Pt–Cu CNC-as synthesized.

Permanent make-up colorants may cause severe skin reactions.

Science.gov (United States)

Wenzel, Sabrina M; Welzel, Julia; Hafner, Christian; Landthaler, Michael; Bäumler, Wolfgang

2010-10-01

In recent years, cosmetic tattoos [permanent make-up (PMU)] on eyelids, eyebrows and lips have become increasingly popular. However, most colorants are manufactured for non-medical purposes, without any established history of safe use in humans. To investigate severe adverse reactions, such as swelling, burning, and the development of papules, of the lips and the surrounding area in 4 patients who had had at least two PMU procedures on their lips. Adverse skin reactions were examined with patch and prick testing of the colorants. In addition, skin biopsies were taken in the centre of the prick test for histology. One patient declined prick testing. Beauticians tended to use various PMU products, but all contained Pigment Red 181 (CI 73360). All patients tested showed a clear delayed reaction to Pigment Red 181 or the tattoo ink, or both, after prick testing. Histology indicated an allergic reaction. Each lip lesion slowly abated after several months of topical or systemic therapy with steroids in combination with tacrolimus, but none has yet completely resolved. In light of the severe and often therapy-resistant skin reactions, we strongly recommend the regulation and control of the substances used in PMU colorants. © 2010 John Wiley & Sons A/S.

Model of deep centers formation and reactions in electron irradiated InP

International Nuclear Information System (INIS)

Sibille, A.; Suski, J.; Gilleron, M.

1986-01-01

We present a model of the production of deep centers and their reactions following electron irradiations in InP. We propose that the dominant hole traps in p-InP and electron traps in p + n InP junctions are complexes between shallow acceptors and a common intrinsic entity, the phosphorus interstitial or vacancy. The reactions observed below and above room temperature are then due to a local mobility of this entity, which can be obtained as well by thermal as by electronic stimulation of the reactions. This model implies the long-range migration (at least down to 16 K) of this entity, and explains the strongly different behavior of n-InP compared to p-InP samples

Synthesis and optoelectronic characterization of some triphenylamine-based compounds containing strong acceptor substituents

Energy Technology Data Exchange (ETDEWEB)

Grigoras, Mircea, E-mail: grim@icmpp.ro; Ivan, Teofilia; Vacareanu, Loredana; Catargiu, Ana Maria; Tigoianu, Radu

2014-09-15

Three novel triphenylamine-based compounds containing strong electron acceptor groups have been synthesized and their comparative photophysical properties are presented. These compounds were obtained by a two-step method: (i) triphenylamine compounds with one, two and three phenylacetylene arms were synthesized by Sonogashira reaction between iodine-substituted triphenylamines and phenylacetylene, followed by (ii) post-modification of these electron-rich alkynes by addition of the strong electron acceptor, tetracyanoethylene. Characterization of all oligomers was made by FTIR, {sup 1}H-NMR, UV–vis and fluorescence spectroscopy. A batochromic shifting of the UV and photoluminescence maxima was observed with the increase of the acceptor group number. The electrochemical behavior was studied by cyclic voltammetry. The cyclic voltammograms have evidenced that triphenylamine-phenylacetylene compounds undergo only oxidation processes while compounds modified with tetracyanoethylene show both oxidation and reduction peaks associated with donor and acceptor groups, respectively. The donor–acceptor compounds coordinate metal ions (i.e., Hg{sup 2+} and Sn{sup 2+}) by cyano groups resulting in the decreasing of charge transfer band intensity, and they can be used as chemosensors. - Highlights: • Three triphenylamine-based ethynylene compounds were prepared by Sonogashira reaction. • Post-modification of ethynylene linkages by tetracyanethylene cycloaddition and retroconversion led to donor–acceptor compounds. • Photophysical properties of donor–acceptor oligomers were studied in different solvents.

Theoretical study of the oxidation mechanisms of naphthalene initiated by hydroxyl radicals: the O2 addition reaction pathways.

Science.gov (United States)

Shiroudi, A; Deleuze, M S; Canneaux, S

2015-05-28

Atmospheric oxidation of the naphthalene-OH adduct [C10H8OH]˙ (R1) by molecular oxygen in its triplet electronic ground state has been studied using density functional theory along with the B3LYP, ωB97XD, UM05-2x and UM06-2x exchange-correlation functionals. From a thermodynamic viewpoint, the most favourable process is O2 addition at the C2 position in syn mode, followed by O2 addition at the C2 position in anti mode, O2 addition at the C4 position in syn mode, and O2 addition at the C4 position in anti mode, as the second, third and fourth most favourable processes. The syn modes of addition at these positions are thermodynamically favoured over the anti ones by the formation of an intramolecular hydrogen bond between the hydroxyl and peroxy substituents. Analysis of the computed structures, bond orders and free energy profiles demonstrate that the reaction steps involved in the oxidation of the naphthalene-OH adduct by O2 satisfy Hammond's principle. Kinetic rate constants and branching ratios under atmospheric pressure and in the fall-off regime have been supplied, using transition state and RRKM theories. By comparison with experiment, these data confirm the relevance of a two-step reaction mechanism. Whatever the addition mode, O2 addition in C4 position is kinetically favoured over O2 addition in C2 position, in contrast with the expectations drawn from thermodynamics and reaction energies. Under a kinetic control of the reaction, and in line with the computed reaction energy barriers, the most efficient process is O2 addition at the C4 position in syn mode, followed by O2 addition at the C2 position in syn mode, O2 addition at the C4 position in anti mode, and O2 addition at the C2 position in anti mode as the second, third and fourth most rapid processes. The computed branching ratios also indicate that the regioselectivity of the reaction decreases with increasing temperatures and decreasing pressures.

Spectral radiance of strong lines in positive column mercury discharges with argon carrier gas

International Nuclear Information System (INIS)

Sansonetti, Craig J; Reader, Joseph

2006-01-01

The spectral radiance of the 185 and 254 nm lines in two positive column mercury discharge lamps was measured over a wide range of operating conditions. The lamps had internal diameters of 5 and 23 mm. Argon was used as a carrier gas. The lamps were operated with cold spot temperatures of 20, 40 and 60 0 C. At each of these temperatures, results were obtained for five currents ranging from 20 to 100 mA for the 5 mm lamp and from 200 to 1000 mA for the 23 mm lamp. For each current studied, results were determined for argon pressures ranging from 66.6 to 666 Pa (0.5 to 5.0 Torr) in the 5 mm lamp and 26.6 to 666 Pa (0.2 to 5.0 Torr) in the 23 mm lamp. An argon miniarc was used as the radiometric standard. By calibrating the spectral response of the optical system with a well-characterized mercury pencil lamp, results were obtained for 12 additional Hg lines from 289 to 579 nm. For the 23 mm lamp the electric field in the positive column was measured. For this lamp the radiated power as a percentage of input power was also determined. The results provide an experimental basis for validating computer models of Hg fluorescent lamp discharges

Homogenization technique for strongly heterogeneous zones in research reactors

International Nuclear Information System (INIS)

Lee, J.T.; Lee, B.H.; Cho, N.Z.; Oh, S.K.

1991-01-01

This paper reports on an iterative homogenization method using transport theory in a one-dimensional cylindrical cell model developed to improve the homogenized cross sections fro strongly heterogeneous zones in research reactors. The flux-weighting homogenized cross sections are modified by a correction factor, the cell flux ratio under an albedo boundary condition. The albedo at the cell boundary is iteratively determined to reflect the geometry effects of the material properties of the adjacent cells. This method has been tested with a simplified core model of the Korea Multipurpose Research Reactor. The results demonstrate that the reaction rates of an off-center control shroud cell, the multiplication factor, and the power distribution of the reactor core are close to those of the fine-mesh heterogeneous transport model

Rejection of unfair offers in the ultimatum game is no evidence of strong reciprocity

Science.gov (United States)

Yamagishi, Toshio; Horita, Yutaka; Mifune, Nobuhiro; Hashimoto, Hirofumi; Li, Yang; Shinada, Mizuho; Miura, Arisa; Inukai, Keigo; Takagishi, Haruto; Simunovic, Dora

2012-01-01

The strong reciprocity model of the evolution of human cooperation has gained some acceptance, partly on the basis of support from experimental findings. The observation that unfair offers in the ultimatum game are frequently rejected constitutes an important piece of the experimental evidence for strong reciprocity. In the present study, we have challenged the idea that the rejection response in the ultimatum game provides evidence of the assumption held by strong reciprocity theorists that negative reciprocity observed in the ultimatum game is inseparably related to positive reciprocity as the two sides of a preference for fairness. The prediction of an inseparable relationship between positive and negative reciprocity was rejected on the basis of the results of a series of experiments that we conducted using the ultimatum game, the dictator game, the trust game, and the prisoner’s dilemma game. We did not find any correlation between the participants’ tendencies to reject unfair offers in the ultimatum game and their tendencies to exhibit various prosocial behaviors in the other games, including their inclinations to positively reciprocate in the trust game. The participants’ responses to postexperimental questions add support to the view that the rejection of unfair offers in the ultimatum game is a tacit strategy for avoiding the imposition of an inferior status. PMID:23188801

Rejection of unfair offers in the ultimatum game is no evidence of strong reciprocity.

Science.gov (United States)

Yamagishi, Toshio; Horita, Yutaka; Mifune, Nobuhiro; Hashimoto, Hirofumi; Li, Yang; Shinada, Mizuho; Miura, Arisa; Inukai, Keigo; Takagishi, Haruto; Simunovic, Dora

2012-12-11

The strong reciprocity model of the evolution of human cooperation has gained some acceptance, partly on the basis of support from experimental findings. The observation that unfair offers in the ultimatum game are frequently rejected constitutes an important piece of the experimental evidence for strong reciprocity. In the present study, we have challenged the idea that the rejection response in the ultimatum game provides evidence of the assumption held by strong reciprocity theorists that negative reciprocity observed in the ultimatum game is inseparably related to positive reciprocity as the two sides of a preference for fairness. The prediction of an inseparable relationship between positive and negative reciprocity was rejected on the basis of the results of a series of experiments that we conducted using the ultimatum game, the dictator game, the trust game, and the prisoner's dilemma game. We did not find any correlation between the participants' tendencies to reject unfair offers in the ultimatum game and their tendencies to exhibit various prosocial behaviors in the other games, including their inclinations to positively reciprocate in the trust game. The participants' responses to postexperimental questions add support to the view that the rejection of unfair offers in the ultimatum game is a tacit strategy for avoiding the imposition of an inferior status.

Roles of multi-step transfer in fusion process induced by heavy-ion reactions

International Nuclear Information System (INIS)

Imanishi, B.; Oertzen, W. von.

1993-06-01

In nucleus-nucleus collisions of the systems, 12 C+ 13 C and 13 C+ 16 O- 12 C+ 17 O, the effects of the multi-step transfers and inelastic excitations on the fusion cross sections are investigated in the framework of the coupled-reaction-channel (CRC) method. Strong CRC effects of the multi-step processes are observed. Namely, the valence neutron in 13 C or 17 O plays an important role in the enhancement of the fusion. The potential barrier is effectively lowered with the formation of the covalent molecule of the configuration, 12 C+n+ 12 C or 12 C+n+ 16 O. In the analyses of the system 12 C+ 13 C, however, it is still required to introduce core-core optical potential of lower barrier height in the state of the positive total parity. This could be due to the neck formation with the nucleons contained in two core nuclei. (author)

Angular evolution of peripheral heavy ion reactions at intermediate energies

International Nuclear Information System (INIS)

Blumenfeld, Y.; Chomaz, P.; Frascaria, N.; Garron, J.P.; Jacmart, J.C; Roynette, J.C

1985-01-01

Energy spectra and angular distributions of projectile-like fragments have been measured in the vicinity of the grazing angle for the 40 Ar+ 40 Ca and 40 Ar+ 208 Pb reactions at 44MeV/nucleon. Measurements of the 40 Ar+ 40 Ca system at 27MeV/nucleon and 20 Ne+ 208 Pb reaction at 44MeV/nucleon at one angle have also been performed. For fragments with charge and mass close to the projectile numerous deviations from the standard fragmentation model have been observed including rapidly changing shapes of the angular distributions with the fragment mass. Moreover the isotopic distributions and mean fragment velocities are strongly dependent on detection angle. A surface transfer reaction component dominant at the grazing angle can be separated from a second component which cannot be entirely accounted for by a simple fragmentation mechanism

Light particle and gamma ray emission measurements in heavy-ion reactions. Progress report

International Nuclear Information System (INIS)

Petitt, G.A.

1982-01-01

The development of a position-sensitive neutron detector and a data acquisition system at HHIRF for studying light particle emission in heavy ion reactions is described. Results are presented and discussed for the reactions 12 C + 158 Gd, 13 C + 157 Gd, and 20 Ne + 150 Nd

Experimental Study of Na based Titanium Nanofluid-Water Reaction

Energy Technology Data Exchange (ETDEWEB)

Park, Gunyeop; Kim, Soo Jae; Baek, Jehyun; Kim, Hyun Soo; Oh, Sun Ryung; Park, Hyun Sun; Kim, Moo Hwan [POSTECH, Pohang (Korea, Republic of)

2015-10-15

In KALIMER-600, a sodium-cooled fast reactor designed by KAERI, thermal energy is transported from high-temperature liquid Na (526 .deg. C at 0.1 MPa) to low temperature water (230 .deg. C at - 19.5 MPa) through a heat exchanger. If any leakage or rupture occurs during the operation of this heat exchanger, highly pressurized liquid water can penetrate into the liquid Na channels; this contact should instantly cause SWR. As reaction continues, liquid water is soon vaporized by pressure drop and huge amount of reaction heat. This generated water vapor expands large reaction area and increases sodium-water vapor reaction process. Therefore, the rapid generation of reaction product (like H{sub 2}) and water vapor increases the system pressure that can cause the system failure in SFR. To reduce this strong chemical reaction phenomena between Na and water, some we have focused on suppressing the chemical reactivity of liquid Na by dispersing nanoparticles (NPs). For the real application of NaTiNF, the pressure change induced by NaTiNF-water reaction is compared with Na-water reaction in the present study. NaTiNF contains 100nm of Ti NPs at 0.2 vol. %. The reaction rate of NaTiNF-water reaction is also investigated as reaction temperature increases. Sodium-water vapor reaction (SVR) will occur when an SWR accident occurs in SFR. In this manner, NaTiNF-water vapor reaction is experimentally performed for ensuring the suppression of chemical reactivity of NaTiNF in contact with water vapor. In the basic step for reducing risk of an SWR in SFR, we have experimentally verified the suppressed chemical reactivity of liquid sodium using Ti NPs through SWR and SVR experiments. In SWR, Na based titanium nanofluid (NaTiNF) shows lower pressure change than Na. As T{sub R} increases, P{sub max} in Na-water reaction increases while NaTiNF does not. The reaction rate of NaTiNF shows twice slower than that of Na. In SVR, NaTiNF shows slower temperature increase than Na. The distinct

Ozonation of norfloxacin and levofloxacin in water: Specific reaction rate constants and defluorination reaction.

Science.gov (United States)

Ling, Wencui; Ben, Weiwei; Xu, Ke; Zhang, Yu; Yang, Min; Qiang, Zhimin

2018-03-01

The degradation kinetics and mechanism of two typical fluoroquinolones (FQs), norfloxacin (NF) and levofloxacin (LOF), by ozone in water were investigated. Semi-continuous mode and competition kinetics mode experiments were conducted to determine the reaction rate constants of target FQs with ozone and OH, separately. Results indicate that both NF and LOF were highly reactive toward ozone, and the reactivity was strongly impacted by the solution pH. The specific reaction rate constants of the diprotonated, monoprotonated and deprotonated species were determined to be 7.20 × 10 2 , 8.59 × 10 3 , 4.54 × 10 5  M -1  s -1 respectively for NF and 1.30 × 10 3 , 1.40 × 10 4 , 1.33 × 10 6  M -1  s -1 respectively for LOF. The reaction rate constants of target FQs toward OH were measured to be (4.81-7.41) × 10 9  M -1  s -1 in the pH range of 6.3-8.3. Furthermore, NF was selected as a model compound to clarify the degradation pathways, with a particular focus on the defluorination reaction. The significant release of F - ions and the formation of three F-free organic byproducts indicated that defluorination was a prevalent pathway in ozonation of FQs, while six F-containing organic byproducts indicated that ozone also attacked the piperazinyl and quinolone moieties. Escherichia coli growth inhibition tests revealed that ozonation could effectively eliminate the antibacterial activity of target FQ solutions, and the residual antibacterial activity had a negative linear correlation with the released F - concentration. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gentle Human Touch and Yakson: The Effect on Preterm's Behavioral Reactions

Science.gov (United States)

Bahman Bijari, Bahare; Iranmanesh, Sedigheh; Eshghi, Fateme; Baneshi, Mohammad Reza

2012-01-01

Objective. Touch is one of the first strong positive senses that develop in neonate. Therapeutic touch could be considered as a complementary treatment in Neonate intensive care units (NICU). Methods. This quasi-experimental study was conducted to compare the effect of Yakson and GHT on behavioral reaction of preterm infants hospitalized in NICU in south-east of Iran. 90 preterm infants participated in this study. They are randomly divided into 3 groups: (1) Yakson group, n = 30, (2) GHT group, n = 30, (3) control group, n = 30. Each infant received the GHT and Yakson interventions twice a day for 5 days. Each session lasted 15 minutes. The control group received routine nursing care. Results. In interventional group, an increase was found in sleep state score after the Yakson and GHT intervention. Their awake and fussy states' scores decreased after both interventions. No significant difference was found between Yakson and GHT group in their behavioral state scores. Conclusion. The findings suggest that Yakson and GHT had soothing and calming effect on preterm infants and could be beneficial in nursing interventions. PMID:22792482

SOLVENT EFFECTS IN THE LIQUID-PHASE HYDRATION OF CYCLOHEXENE CATALYZED BY A MACROPOROUS STRONG ACID ION-EXCHANGE RESIN

NARCIS (Netherlands)

PANNEMAN, HJ; BEENACKERS, AACM

1992-01-01

The liquid-phase hydration of cyclohexene, a pseudo first order reversible reaction catalyzed by a strong acid ion exchange resin, macroporous Amberlite XE 307, was investigated in solvent mixtures of water and sulfolane. A decrease by a factor of 3 and 6 is observed in the experimentally measured

Photon and photon reactions: elementary theoretical introduction

International Nuclear Information System (INIS)

Diu, B.

The electromagnetic field and associated quanta, the photons, are simply and briefly studied. The conventional electromagnetism laws are recalled. Fundamental concepts such as gauge invariance, the electromagnetic current conservation, and photon behavior against the internal symmetries of strong interactions are simply introduced. Results and notations are applied to analysis of reactions where photons intervene in initial or final states (photoproduction) within the limits of amplitude properties in the conventional space-time. The helicity and invariant amplitude formalisms are compared [fr

Strong and Electromagnetic Interactions at SPS Energies

CERN Document Server

Ribicki, Andrzej

2009-01-01

Particle production in peripheral Pb+Pb collisions has been measured at a beam energy of 158 GeV per nucleon, corresponding to psNN 17.3 GeV. The measurements provide full double differential coverage in a wide range of longitudinal and transverse momenta, including the central (“mid-rapidity”) area and extending far into the projectile fragmentation region. The resulting analysis shows the heavy ion reaction as a mixture of different processes. In particular, surprising phenomena, like the presence of large and strongly varying structures in the shape of the double differential cross section d2s /dxFd pT , are induced by the final state electromagnetic interaction between produced particles and the charged spectator system. This effect is largest at low transverse momenta, where it results in a deep valley in the xF -dependence of the produced p+/p− ratio. The basic characteristics of the electromagnetic phenomenon described above agree with the results of a theoretical analysis, performed by means of ...

The water decomposition reactions on boron-doped diamond electrodes

International Nuclear Information System (INIS)

Suffredini, Hugo B.; Machado, Sergio A.S; Avaca, Luis A.

2004-01-01

The electrochemical processes occurring at both edges of the wide electrochemical window of the boron doped diamond (BDD) electrode were studied by polarization curves experiments to evaluate the apparent energy of activation for the rate determining step in each reaction. It was found that the hydrogen evolution reaction occurs by a Volmer-Heyrovsky mechanism with the first step being the RDS. Moreover, the apparent energy of activation calculated from the Tafel plots presented a value as high as 150 kJ mol -1 , indicating the formation of the M-H intermediate that is characteristic for the Volmer step. On the other hand, the apparent energy of activation for the oxygen evolution reaction was found to be 106 kJ mol -1 suggesting that the RDS in this mechanism is the initial adsorption step. In this way, it was demonstrated that the interaction between water molecules and the electrode surface is strongly inhibited on BDD thus justifying the extended potential window observed for this material. (author)

The water decomposition reactions on boron-doped diamond electrodes

Directory of Open Access Journals (Sweden)

Suffredini Hugo B

2004-01-01

Full Text Available The electrochemical processes occurring at both edges of the wide electrochemical window of the boron doped diamond (BDD electrode were studied by polarization curves experiments to evaluate the apparent energy of activation for the rate determining step in each reaction. It was found that the hydrogen evolution reaction occurs by a Volmer-Heyrovsky mechanism with the first step being the RDS. Moreover, the apparent energy of activation calculated from the Tafel plots presented a value as high as 150 kJ mol-1, indicating the formation of the M-H intermediate that is characteristic for the Volmer step. On the other hand, the apparent energy of activation for the oxygen evolution reaction was found to be 106 kJ mol-1 suggesting that the RDS in this mechanism is the initial adsorption step. In this way, it was demonstrated that the interaction between water molecules and the electrode surface is strongly inhibited on BDD thus justifying the extended potential window observed for this material.

Control of dynamical self-assembly of strongly Brownian nanoparticles through convective forces induced by ultrafast laser

Science.gov (United States)

Ilday, Serim; Akguc, Gursoy B.; Tokel, Onur; Makey, Ghaith; Yavuz, Ozgun; Yavuz, Koray; Pavlov, Ihor; Ilday, F. Omer; Gulseren, Oguz

We report a new dynamical self-assembly mechanism, where judicious use of convective and strong Brownian forces enables effective patterning of colloidal nanoparticles that are almost two orders of magnitude smaller than the laser beam. Optical trapping or tweezing effects are not involved, but the laser is used to create steep thermal gradients through multi-photon absorption, and thereby guide the colloids through convective forces. Convective forces can be thought as a positive feedback mechanism that helps to form and reinforce pattern, while Brownian motion act as a competing negative feedback mechanism to limit the growth of the pattern, as well as to increase the possibilities of bifurcation into different patterns, analogous to the competition observed in reaction-diffusion systems. By steering stochastic processes through these forces, we are able to gain control over the emergent pattern such as to form-deform-reform of a pattern, to change its shape and transport it spatially within seconds. This enables us to dynamically initiate and control large patterns comprised of hundreds of colloids. Further, by not relying on any specific chemical, optical or magnetic interaction, this new method is, in principle, completely independent of the material type being assembled.

Complex Reaction Kinetics in Chemistry: A Unified Picture Suggested by Mechanics in Physics

Directory of Open Access Journals (Sweden)

Elena Agliari

2018-01-01

Full Text Available Complex biochemical pathways can be reduced to chains of elementary reactions, which can be described in terms of chemical kinetics. Among the elementary reactions so far extensively investigated, we recall the Michaelis-Menten and the Hill positive-cooperative kinetics, which apply to molecular binding and are characterized by the absence and the presence, respectively, of cooperative interactions between binding sites. However, there is evidence of reactions displaying a more complex pattern: these follow the positive-cooperative scenario at small substrate concentration, yet negative-cooperative effects emerge as the substrate concentration is increased. Here, we analyze the formal analogy between the mathematical backbone of (classical reaction kinetics in Chemistry and that of (classical mechanics in Physics. We first show that standard cooperative kinetics can be framed in terms of classical mechanics, where the emerging phenomenology can be obtained by applying the principle of least action of classical mechanics. Further, since the saturation function plays in Chemistry the same role played by velocity in Physics, we show that a relativistic scaffold naturally accounts for the kinetics of the above-mentioned complex reactions. The proposed formalism yields to a unique, consistent picture for cooperative-like reactions and to a stronger mathematical control.

Perceptual Sensitivity and Response to Strong Stimuli Are Related

Directory of Open Access Journals (Sweden)

Anna C. Bolders

2017-09-01

Full Text Available To shed new light on the long-standing debate about the (independence of sensitivity to weak stimuli and overreactivity to strong stimuli, we examined the relation between these tendencies within the neurobehavioral framework of the Predictive and Reactive Control Systems (PARCS theory (Tops et al., 2010, 2014. Whereas previous studies only considered overreactivity in terms of the individual tendency to experience unpleasant affect (punishment reactivity resulting from strong sensory stimulation, we also took the individual tendency to experience pleasant affect (reward reactivity resulting from strong sensory stimulation into account. According to PARCS theory, these temperamental tendencies overlap in terms of high reactivity toward stimulation, but oppose each other in terms of the response orientation (approach or avoid. PARCS theory predicts that both types of reactivity to strong stimuli relate to sensitivity to weak stimuli, but that these relationships are suppressed due to the opposing relationship between reward and punishment reactivity. We measured punishment and reward reactivity to strong stimuli and sensitivity to weak stimuli using scales from the Adult Temperament Questionnaire (Evans and Rothbart, 2007. Sensitivity was also measured more objectively using the masked auditory threshold. We found that sensitivity to weak stimuli (both self-reported and objectively assessed was positively associated with self-reported punishment and reward reactivity to strong stimuli, but only when these reactivity measures were controlled for each other, implicating a mutual suppression effect. These results are in line with PARCS theory and suggest that sensitivity to weak stimuli and overreactivity are dependent, but this dependency is likely to be obscured if punishment and reward reactivity are not both taken into account.

Gas phase reactions of nitrogen oxides with olefins

Energy Technology Data Exchange (ETDEWEB)

Altshuller, A P; Cohen, I

1961-01-01

The nature of the condensation products formed in the gas phase reactions of nitrogen dioxide and nitric oxide with pentene-1, 2-methylbutene-2, and 2-methylbutadiene-1,3 was investigated. The reactants were combined at partial pressures in the range of 0.1 to 2.5 mm with the total pressure at one atmosphere. The products were determined by infrared and ultraviolet spectroscopy and colorimetry. The condensates included primary and secondary nitro compounds and alkyl nitrates. Strong hydroxyl and single bond carbon to oxygen stretching vibrations indicate the presence of either nitroalcohols or simple aliphatic alcohols formed through oxidation reactions. Carbonyl stretching frequencies observable in some of the reactions support the conclusion that a portion of the reactants disappear by oxidation rather than by nitration processes. The available results do not indicate the presence of appreciable amounts of tert.-nitro compounds, conjugated nitro-olefins, or gem-dinitro-alkanes. The reactivities of the olefins with the nitrogen oxides are in the decreasing order: 2-methyl-butadiene-1,3, 2-methylbutene-2, pentene-1. 20 references.

Numerical simulation of flow in De-NOx catalyst honeycomb with NOx reduction reaction

Energy Technology Data Exchange (ETDEWEB)

Tanno, K.; Makino, H. [Electric Power Industry, Kanagawa (Japan). Energy Engineering Research Lab.; Kurose, R.; Komori, S. [Kyoto Univ. (Japan). Dept. of Mechanical Engineering and Science

2013-07-01

The effect of flow behavior in a De-NOx honeycomb with NOx reduction reaction is investigated by direct numerical simulation (DNS). As the inlet flow, fully developed turbulent or laminar flow is given. The results show that the surface reaction is strongly affected by inner flow behavior. The surface reaction rate for the turbulent flow is higher than that for the laminar flow. This is due to the difference of inner flow behavior that the diffusion of NOx in the vicinity of the wall is dominated only by molecular diffusion for the laminar flow, whereas it is enhanced by turbulent motions for the turbulent flow. Moreover, surface reaction is suppressed towards downstream even though inlet flow is turbulent. This is due to the flow transition from turbulent to laminar.

Coulomb reacceleration as a clock for nuclear reactions -- II

International Nuclear Information System (INIS)

Bertulani, C.A.; Bertsch, G.F.

1994-01-01

Reacceleration effects in the Coulomb breakup of nuclei are modeled with the two-dimensional time-dependent Schroedinger equation, extending a previous one-dimensional study. The present model better describes the individual contributions of longitudinal and transverse forces to the breakup and reacceleration. Reacceleration effects are found to preserve a strong memory of the pre-breakup phase of the reaction, as was concluded with the one-dimensional model

Bacillus anthracis o-succinylbenzoyl-CoA synthetase: reaction kinetics and a novel inhibitor mimicking its reaction intermediate.

Science.gov (United States)

Tian, Yang; Suk, Dae-Hwan; Cai, Feng; Crich, David; Mesecar, Andrew D

2008-11-25

o-Succinylbenzoyl-CoA (OSB-CoA) synthetase (EC 6.2.1.26) catalyzes the ATP-dependent condensation of o-succinylbenzoate (OSB) and CoA to form OSB-CoA, the fourth step of the menaquinone biosynthetic pathway in Bacillus anthracis. Gene knockout studies have highlighted this enzyme as a potential target for the discovery of new antibiotics. Here we report the first studies on the kinetic mechanism of B. anthracis OSB-CoA synthetase, classifying it as an ordered bi uni uni bi ping-pong mechanism. Through a series of pre-steady-state and steady-state kinetic studies in conjunction with direct binding studies, it is demonstrated that CoA, the last substrate to bind, strongly activates the first half-reaction after the first round of turnover. The activation of the first half-reaction is most likely achieved by CoA stabilizing conformations of the enzyme in the "F" form, which slowly isomerize back to the E form. Thus, the kinetic mechanism of OSB-CoA synthetase may be more accurately described as an ordered bi uni uni bi iso ping-pong mechanism. The substrate specificity of OSB-CoA synthetase was probed using a series of OSB analogues with alterations in the carboxylate groups. OSB-CoA shows a strong preference for OSB over all of the analogues tested as none were active except 4-[2-(trifluoromethyl)phenyl]-4-oxobutyric acid which exhibited a 100-fold decrease in k(cat)/K(m). On the basis of an understanding of OSB-CoA synthetase's kinetic mechanism and substrate specificity, a reaction intermediate analogue of OSB-AMP, 5'-O-{N-[2-(trifluoromethyl)phenyl]-4-oxobutyl}adenosine sulfonamide (TFMP-butyl-AMS), was designed and synthesized. This inhibitor was found to be an uncompetitive inhibitor to CoA and a mixed-type inhibitor to ATP and OSB with low micromolar inhibition constants. Collectively, these results should serve as an important forerunner to more detailed and extensive inhibitor design studies aimed at developing lead compounds against the OSB-CoA synthetase

Hydroamination reactions of alkynes with ortho-substituted anilines in ball mills: synthesis of benzannulated N-heterocycles by a cascade reaction.

Science.gov (United States)

Weiße, Maik; Zille, Markus; Jacob, Katharina; Schmidt, Robert; Stolle, Achim

2015-04-20

It was demonstrated that ortho-substituted anilines are prone to undergo hydroamination reactions with diethyl acetylenedicarboxylate in a planetary ball mill. A sequential coupling of the intermolecular hydroamination reaction with intramolecular ring closure was utilized for the syntheses of benzooxazines, quinoxalines, and benzothiazines from readily available building blocks, that is, electrophilic alkynes and anilines with OH, NH, or SH groups in the ortho position. For the heterocycle formation, it was shown that several stress conditions were able to initiate the reaction in the solid state. Processing in a ball mill seemed to be advantageous over comminution with mortar and pestle with respect to process control. In the latter case, significant postreaction modification occurred during solid-state analysis. Cryogenic milling proved to have an adverse effect on the molecular transformation of the reagents. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A strategy for the preparation of thioantimonates based on the concept of weak acids and corresponding strong bases.

Science.gov (United States)

Anderer, Carolin; Delwa de Alarcón, Natalie; Näther, Christian; Bensch, Wolfgang

2014-12-15

By following a new synthetic approach, which is based on the in situ formation of a basic medium by the reaction between the strong base Sb(V)S4 (3-) and the weak acid H2 O, it was possible to prepare three layered thioantimonate(III) compounds of composition [TM(2,2'-bipyridine)3 ][Sb6 S10 ] (TM=Ni, Fe) and [Ni(4,4'-dimethyl-2,2'-bipyridine)3 ][Sb6 S10 ] under hydrothermal conditions featuring two different thioantimonate(III) network topologies. The antimony source, Na3 SbS4 ⋅ 9 H2 O, undergoes several decomposition reactions and produces the Sb(III) S3 species, which condenses to generate the layered anion. The application of transition-metal complexes avoids crystallization of dense phases. The reactions are very fast compared to conventional hydrothermal/solvothermal syntheses and are much less sensitive to changes of the reaction parameters. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Individual differences in response to positive and negative stimuli: endocannabinoid-based insight on approach and avoidance behaviors

Directory of Open Access Journals (Sweden)

Daniela eLaricchiuta

2014-12-01

Full Text Available Approach and avoidance behaviors - the primary responses to the environmental stimuli of danger, novelty and reward - are associated with the brain structures that mediate cognitive functionality, reward sensitivity and emotional expression. Individual differences in approach and avoidance behaviors are modulated by the functioning of amygdaloid-hypothalamic-striatal and striatal-cerebellar networks implicated in action and reaction to salient stimuli. The nodes of these networks are strongly interconnected and by acting on them the endocannabinoid and dopaminergic systems increase the intensity of appetitive or defensive motivation. This review analyzes the approach and avoidance behaviors in humans and rodents, addresses neurobiological and neurochemical aspects of these behaviors, and proposes a possible synaptic plasticity mechanism, related to endocannabinoid-dependent long-term potentiation and depression that allows responding to salient positive and negative stimuli.

Strong correlation effects in theoretical STM studies of magnetic adatoms

Science.gov (United States)

Dang, Hung T.; dos Santos Dias, Manuel; Liebsch, Ansgar; Lounis, Samir

2016-03-01

We present a theoretical study for the scanning tunneling microscopy (STM) spectra of surface-supported magnetic nanostructures, incorporating strong correlation effects. As concrete examples, we study Co and Mn adatoms on the Cu(111) surface, which are expected to represent the opposite limits of Kondo physics and local moment behavior, using a combination of density functional theory and both quantum Monte Carlo and exact diagonalization impurity solvers. We examine in detail the effects of temperature T , correlation strength U , and impurity d electron occupancy Nd on the local density of states. We also study the effective coherence energy scale, i.e., the Kondo temperature TK, which can be extracted from the STM spectra. Theoretical STM spectra are computed as a function of STM tip position relative to each adatom. Because of the multiorbital nature of the adatoms, the STM spectra are shown to consist of a complicated superposition of orbital contributions, with different orbital symmetries, self-energies, and Kondo temperatures. For a Mn adatom, which is close to half-filling, the STM spectra are featureless near the Fermi level. On the other hand, the quasiparticle peak for a Co adatom gives rise to strongly position-dependent Fano line shapes.

Test analysis and research on static choice reaction ability of commercial vehicle drivers

Science.gov (United States)

Zhang, Lingchao; Wei, Lang; Qiao, Jie; Tian, Shun; Wang, Shengchang

2017-03-01

Drivers' choice reaction ability has a certain relation with safe driving. It has important significance to research its influence on traffic safety. Firstly, the paper uses a choice reaction detector developed by research group to detect drivers' choice reaction ability of commercial vehicles, and gets 2641 effective samples. Then by using mathematical statistics method, the paper founds that average reaction time from accident group has no difference with non-accident group, and then introduces a variance rate of reaction time as a new index to replace it. The result shows that the test index choice reaction errors and variance rate of reaction time have positive correlations with accidents. Finally, according to testing results of the detector, the paper formulates a detection threshold with four levels for helping transportation companies to assess commercial vehicles drivers.

A new branch of advertising: reviewing factors that influence reactions to product placement

NARCIS (Netherlands)

van Reijmersdal, E.; Neijens, P.; Smit, E.G.

2009-01-01

This iiterature review presents a quantitative synthesis of 57 studies on product placement and shows which factors are most effective, it shows that placement characteristics, such as placement commerciality, modality, and prominence, have a strong impact on audience reactions. Audience

A computational cognitive model for political positioning and reactions in web media

NARCIS (Netherlands)

Fernandes de Mello Araujo, E.; Klein, Michel

2017-01-01

This paper presents a computational cognitive model about political positioning inspired on recent insights from neuroscience and psychology. We describe a model that takes into consideration the individual structures of the brain and the environmental influences that may interfere on how a

The reactivity of anion-exchange resins by applying OT-for-OH exchange reaction in the equilibrium state

International Nuclear Information System (INIS)

Kano, Naoki; Nihei, Makoto; Imaizumi, Hiroshi

1996-01-01

In order to reveal the behavior of hydroxyl group in isotope exchange reaction, OT-for-OH exchange reaction between each anion-exchange resin (OH - form) and tritiated water (abbreviated as HTO water below) was observed at 80degC under the equilibrium. Anion-exchange resins used were Amberlite IRA-400, IRA-410 (both strongly basic), and IRA-94S (weakly basic). It can be thought that an HTO molecule dissociates into H + +OT - (or T + +OH - ). The activity of each resin based on OT-for-OH exchange reaction was measured with a liquid scintillation counter. From the above-mentioned, the following five were found. Isotope exchange reaction as 'atomic group' occurred between the OH group in each anion-exchange resin and the OT group in HTO water. The reactivity of strongly basic anion-exchange resin is larger than that of weakly basic one. The ratio of the reactivity of these resins can roughly be expressed as follows: (IRA-410): (IRA-400): (IRA-94S)=42: 7: 1. The degree of OT-for-OH exchange reaction may be smaller than that of T-for-H exchange reaction. The method used and results obtained in this work may be helpful to obtain the data for the prevention of T-contamination, especially to obtain the data from certain atomic groups including T. (author)

Instability induced by cross-diffusion in reaction-diffusion systems

DEFF Research Database (Denmark)

Tian, Canrong; Lin, Zhigui; Pedersen, Michael

2010-01-01

In this paper the instability of the uniform equilibrium of a general strongly coupled reaction–diffusion is discussed. In unbounded domain and bounded domain the sufficient conditions for the instability are obtained respectively. The conclusion is applied to the ecosystem, it is shown that cros...... can induce the instability of an equilibrium which is stable for the kinetic system and for the self-diffusion–reaction system.......In this paper the instability of the uniform equilibrium of a general strongly coupled reaction–diffusion is discussed. In unbounded domain and bounded domain the sufficient conditions for the instability are obtained respectively. The conclusion is applied to the ecosystem, it is shown that cross-diffusion...

Mechanism of degradation and discoloration reaction of L-ascorbic acid

International Nuclear Information System (INIS)

Kurata, Tadao

1976-01-01

The mechanisms of decomposition and coloration reaction of L-ascorbic acid are reviewed. At the initial stage of the decomposition, it can be classified roughly into oxidative and non-oxidative processes of decomposition. ASA forms furfural by being heated and decomposed in strong acid. The mechanism of the production of furfural at varying pH in acidic region was discussed. Furfural was produced through the enol form of 3-deoxy-L-pentosulose(3DP). 3DP seemed to be produced by two different routes: the one route consists of successive reactions from ASA through lactone ring-opening, dehydration, decarboxylation, to 3DP, and the other consists of reactions from the 3-keto form of ASA, through lactone ring-opening, decarboxylation, and dehydration, to the enol form of 3DP. ASA is easily reduced and decomposed through dehydro-ASA(DHA) by the presence of an oxidizing agent. The decomposition of DHA is discussed in cases of the systems of DHA alone, DHA and α-aminoacid, and DHA and amine. DHA was decomposed by the same reaction scheme as the decomposition of ASA and yielded 2-furoic acid. In the presence of an amino acid, DHA was decomposed by the Strecker decomposition, and yielded a red compound and a radical. In the presence of an amine, the discoloration reaction seemed to take place through radical reaction mechanism. The coloration reaction of ASA occurs in an acidic medium, and is accelerated by the oxidative process of decomposition. (Nishino, S.)

Strong Convergence Bound of the Pareto Index Estimator under Right Censoring

Directory of Open Access Journals (Sweden)

Peng Zuoxiang

2010-01-01

Full Text Available Let be a sequence of positive independent and identically distributed random variables with common Pareto-type distribution function as , where represents a slowly varying function at infinity. In this note we study the strong convergence bound of a kind of right censored Pareto index estimator under second-order regularly varying conditions.

Use of chemistry software to teach and assess model-based reaction and equation knowledge

Directory of Open Access Journals (Sweden)

Kevin Pyatt

2014-12-01

Full Text Available This study investigated the challenges students face when learning chemical reactions in a first-year chemistry course and the effectiveness of a curriculum and software implementation that was used to teach and assess student understanding of chemical reactions and equations. This study took place over a two year period in a public suburban high-school, in southwestern USA. Two advanced placement (AP chemistry classes participated, referred to here as study group A (year 1, N = 14; and study group B (year 2, N = 21. The curriculum for a first-year chemistry course (group A was revised to include instruction on reaction-types. The second year of the study involved the creation and implementation of a software solution which promoted mastery learning of reaction-types. Students in both groups benefited from the reaction-type curriculum and achieved proficiency in chemical reactions and equations.  The findings suggest there was an added learning benefit to using the reaction-type software solution. This study also found that reaction knowledge was a moderate to strong predictor of chemistry achievement. Based on regression analysis, reaction knowledge significantly predicted chemistry achievement for both groups.

Methanetrisulfonic Acid: A Highly Efficient Strongly Acidic Catalyst for Wagner-Meerwein Rearrangement, Friedel-Crafts Alkylation and Acylation Reactions. Examples from Vitamin E Synthesis

Directory of Open Access Journals (Sweden)

Francesco Pace

2009-04-01

Full Text Available Methanetrisulfonic acid had been prepared for the first time over 140 years ago, but it was used only scarcely in chemical transformations. In the course of our activities dealing with key-steps of industrial syntheses of vitamins, e.g. economically important vitamin E (acetate, we found that methanetrisulfonic acid is an extremely effective catalyst in a variety of reactions. Examples of its applications are Wagner-Meerwein rearrangements, Friedel-Crafts alkylations and ring closures, as well as acylation reactions. Use of this catalyst in truly catalytic amounts (0.04-1.0 mol% resulted in highly selective transformations and yields over 95%. (Remark by the authors: We are describing only one example each for the various types of reactions. Therefore, it would be more appropriate to write (here and in the Introduction and in the Conclusion sections: “Wagner-Meerwein rearrangement, Friedel-Crafts alkylation and ring closure, as well as acylation reactions”

The GC/AED studies on the reactions of sulfur mustard with oxidants

International Nuclear Information System (INIS)

Popiel, StanisIaw; Witkiewicz, Zygfryd; Szewczuk, Aleksander

2005-01-01

A gas chromatograph coupled with an atomic emission detector was used to identify and to determine the products formed on oxidation of sulfur mustard. The oxidation rate and the resulting oxidates were studied in relation to oxidant type and reaction medium parameters. Hydrogen peroxide, sodium hypochlorite, sodium perborate, potassium monopercarbonate, ammonium peroxydisulfate, potassium peroxymonosulfate (oxone), and tert-butyl peroxide were used as oxidants. Oxidations were run in aqueous media or in solvents of varying polarities. The oxidation rate was found to be strongly related to oxidant type: potassium peroxymonosulfate (oxone) and sodium hypochlorite were fast-acting oxidants; sodium perborate, hydrogen peroxide, ammonium peroxydisulfate, and sodium monopercarbonate were moderate oxidants; tert-butyl peroxide was the slowest-acting oxidant. In non-aqueous solvents, the oxidation rate was strongly related to solvent polarity. The higher the solvent polarity, the faster the oxidation rate. In the acid and neutral media, the mustard oxidation rates were comparable. In the alkaline medium, oxidation was evidently slower. A suitable choice of the initial oxidant-to-mustard concentration ratio allowed to control the type of the resulting mustard oxidates. As the pH of the reaction medium was increased, the reaction of elimination of hydrogen chloride from mustard oxidates becomes more and more intensive

Spin-polarized states in neutron matter in a strong magnetic field

International Nuclear Information System (INIS)

Isayev, A. A.; Yang, J.

2009-01-01

Spin-polarized states in neutron matter in strong magnetic fields up to 10 18 G are considered in the model with the Skyrme effective interaction. By analyzing the self-consistent equations at zero temperature, it is shown that a thermodynamically stable branch of solutions for the spin-polarization parameter as a function of density corresponds to the negative spin polarization when the majority of neutron spins are oriented opposite to the direction of the magnetic field. Besides, beginning from some threshold density dependent on magnetic field strength, the self-consistent equations also have two other branches of solutions for the spin-polarization parameter with the positive spin polarization. The free energy corresponding to one of these branches turns out to be very close to that of the thermodynamically preferable branch. As a consequence, in a strong magnetic field, the state with the positive spin polarization can be realized as a metastable state in the high-density region in neutron matter, which, under decreasing density, at some threshold density changes to a thermodynamically stable state with the negative spin polarization.

The OH-initiated atmospheric chemical reactions of polyfluorinated dibenzofurans and polychlorinated dibenzofurans: A comparative theoretical study.

Science.gov (United States)

Zeng, Xiaolan; Chen, Jing; Qu, Ruijuan; Pan, Xiaoxue; Wang, Zunyao

2017-02-01

The atmospheric chemical reactions of some polyfluorinated dibenzofurans (PFDFs) and polychlorinated dibenzofurans (PCDFs), initiated by OH radical, were investigated by performing theoretical calculations using density functional theory (DFT) and B3LYP/6-311++G(2df,p) method. The obtained results indicate that OH addition reactions of PFDFs and PCDFs occurring at C 1∼4 and C A sites are thermodynamic spontaneous changes and the branching ratio of the PF(C)DF-OH adducts is decided primarily by kinetic factor. The OH addition reactions of PFDFs taking place at fluorinated C 1∼4 positions are kinetically comparable with those occurring at nonfluorinated C 1∼4 positions, while OH addition reactions of PCDFs occurring at chlorinated C 1∼4 sites are negligible. The total rate constants of the addition reactions of PFDFs or PCDFs become smaller with consecutive fluorination or chlorination, and substituting at C 1 position has more adverse effects than substitution at other sites. The succedent O 2 addition reactions of PF(C)DF-OH adducts are thermodynamic nonspontaneous processes under the atmospheric conditions, and have high Gibbs free energies of activation (Δ r G ≠ ). The substituted dibenzofuranols are the primary oxidation products for PCDFs under the atmospheric conditions. However, other oxidative products may also be available for PFDFs besides substituted dibenzofuranols. Copyright © 2016 Elsevier Ltd. All rights reserved.

Analysis of Reaction Times and Aerobic Capacities of Soccer Players According to Their Playing Positions

Science.gov (United States)

Taskin, Cengiz; Karakoc, Onder; Taskin, Mine; Dural, Murat

2016-01-01

70 soccer players in Gaziantep amateur league voluntarily participated in this study, (average of their ages 19,17±1,34years, average of their heights 181,28±5,06 cm, average of their body weights 76,75±4,43 kg and average of their sports experiences 3,78±0,95 years) to analyze visual and auditory reaction times and aerobic capacities of amateur…

Polyneutron Chain Reactions

International Nuclear Information System (INIS)

John C. Fisher

2000-01-01

Although helium atoms do not form molecules, a sufficiently large number will bind into a stable liquid droplet. A comparable situation is expected for neutrons, with a sufficiently large number binding into a stable droplet of neutron matter. Such polyneutron droplets can be viewed as isotopes of an element with nuclear charge Z=0, tentatively denoted neutrium, symbol Nt. Because of the relatively weak binding of neutrons compared with that of a mix of neutrons and protons, the minimum number of neutrons required for stability of a droplet is fairly large. Early estimates of ∼60 may be reduced to a dozen or so by the BCS pairing interaction. The Nt entries with N≥12 are new to the table of isotopes. Because all of them are beta-unstable, none is expected to persist as a free particle. Yet, some may occasionally be produced by means to be described below, and it is of interest to examine their decay chains and their interactions with charged nuclei to ascertain how their presence might be revealed. Although these reactions are interesting, they cannot be taken seriously without identifying a source for the initial Nt isotope that begins the chain. Here, we consider possible interactions between 16 O and A Nt. Although there is no strong interaction between them, we can expect a very weak residual attraction that can form a loosely bound 16 O A Nt nuclear molecule. This is not a compound nucleus in the usual sense because, considered as fluids, the 16 O and A Nt droplets are immiscible. For a droplet with fewer than about 60 neutrons, beta decay of A Nt is prevented by the buildup of Coulomb energy associated with transforming A Nt into A H in close proximity to 16 O. Thus, it is possible that 16 O A Nt molecules can persist indefinitely and that a few of them may be present in ordinary water as supermassive oxygen nuclei. Because the binding of these molecules is weak, the A Nt component can tunnel to an adjacent nucleus, and if the adjacent nucleus is 18 O, a

Induced abortion among HIV-positive women in Northern Vietnam

DEFF Research Database (Denmark)

Gammeltoft, Tine; Rasch, Vibeke; Nguyen Thi, Thuy Hanh

2010-01-01

an abortion after being diagnosed as HIV-positive, exploring their reflections, concerns and dilemmas. The results show that the HIV-positive pregnant women sought to balance their desires for a child with their worries of being unable to fulfill their responsibilities as mothers. Even while strongly desiring...

The Type 1 Homodimeric Reaction Center in Heliobacterium modesticaldum

Energy Technology Data Exchange (ETDEWEB)

Golbeck, John [Pennsylvania State Univ., University Park, PA (United States)

2018-01-15

In this funding period, we (i) found that strong illumination of Heliobacterium modesticaldum cells results in saturation of the electron acceptor pool, leading to reduction of the acceptor side and the creation of a back-reacting state that gives rise to delayed fluorescence; (ii) noted that when the FX cluster is reduced in purified reaction centers, no electron transfer occurs beyond A0, even though a quinone is present; (iii) observed by photochemically induced dynamic nuclear polarization (photo-CIDNP) studies of whole cells of Heliobacterium mobilis that primary charge separation is retained even after conversion of the majority of BChl g to Chl aF. ; and (iv) purified a homogeneous preparation of reaction center cores, which led to promising crystallization trials to obtain a three-dimensional structure.

High-energy nuclear reaction mechanisms - fission, fragmentation and spallation

International Nuclear Information System (INIS)

Kaufman, S.B.

1987-01-01

Measurements of the correlations in kinetic energy, mass, charge, and angle of coincident fragments formed in high-energy nuclear reactions have helped to characterize the processes of fission, fragmentation and spallation. For example, fission or fission-like two-body breakup mechanisms result in a strong angular correlation between two heavy fragments; in addition, the momentum transfer in the reaction can be deduced from the correlation. Another example is the multiplicity of light charged particles associated with a given heavy fragment, which is a measure of the violence of the collision, thus distinguishing between central and peripheral collisions. A summary of what has been learned about these processes from such studies will be given, along with some suggestions for further experiments

Novel binder-free forming of Al2O3 ceramics by microwave-assisted hydration reaction

International Nuclear Information System (INIS)

Shirai, Takashi; Yasuoka, Masaki; Watari, Koji

2008-01-01

A novel binder-free forming of ceramics via microwave irradiation is developed. The irradiation of microwave to an alumina green body enhances the hydration reaction strongly between water and particle surfaces, creating surface aluminum trihydroxides structure adjacent to particles that bind them together tightly. This process makes it possible to manufacture mechanically strong green bodies with excellent shape retention ability without the use of organic binders

Numerical solution of a reaction-diffusion equation

International Nuclear Information System (INIS)

Moyano, Edgardo A.; Scarpettini, Alberto F.

2000-01-01

The purpose of the present work to continue the observations and the numerical experiences on a reaction-diffusion model, that is a simplified form of the neutronic flux equation. The model is parabolic, nonlinear, with Dirichlet boundary conditions. The purpose is to approximate non trivial solutions, asymptotically stables for t → ∞, that is solutions that tend to the elliptic problem, in the Lyapunov sense. It belongs to the so-called reaction-diffusion equations of semi linear kind, that is, linear equations in the heat operator and they have a nonlinear reaction function, in this case f (u, a, b) = u (a - b u), being u concentration, a and b parameters. The study of the incidence of these parameters take an interest to the neutronic flux physics. So that we search non trivial, positive and bounded solutions. The used algorithm is based on the concept of monotone and ordered sequences, and on the existence theorem of Amann and Sattinger. (author)

Strong transthyretin immunostaining: potential pitfall in cardiac amyloid typing.

Science.gov (United States)

Satoskar, Anjali A; Efebera, Yvonne; Hasan, Ayesha; Brodsky, Sergey; Nadasdy, Gyongyi; Dogan, Ahmet; Nadasdy, Tibor

2011-11-01

Although systemic amyloidosis commonly presents with renal disease, cardiac involvement usually determines the patient's prognosis. Cardiac involvement is seen in light chain amyloid and transthyretin amyloidosis. Distinguishing between these two is critical because prognosis and treatment differ. Our study demonstrates the unreliability of transthyretin immunostaining in subtyping cardiac amyloid. Between January 2003 and August 2010, we retrieved 229 native endomyocardial biopsies, of which 24 had amyloid. Immunohistochemistry for κ, λ, transthyretin, and serum amyloid A protein was performed on formalin-fixed, paraffin-embedded sections. Staining was graded as weak (trace to 1+) or strong (2 to 3+). Mass spectrometry (MS)-based proteomic typing of microdissected amyloid material was performed on selected cases. Fifteen patients had monoclonal gammopathy/plasma cell dyscrasia with cardiac amyloid. Eight of them (53%) showed strong transthyretin staining in the cardiac amyloid deposits. MS was performed in 5 of these 8 biopsies, and all 5 biopsies revealed light chain amyloid-type amyloid. Two of these 5 light chain amyloid biopsies did not even have concomitant strong staining for the appropriate light chain. Among the 15 cases with plasma cell dyscrasia, only 7 biopsies showed strong staining for the corresponding monoclonal light chain. Strong, false-positive immunostaining for transthyretin in cardiac amyloid is a potential pitfall, augmented by the frequent lack of staining for immunoglobulin light chains. Therefore, the presence of amyloid in the cardiac biopsy should prompt a search for plasma cell dyscrasia irrespective of transthyretin staining. Confirmation with MS should be sought, particularly if there is any discrepancy between κ/λ staining and serum immunofixation results.

Strongly increasing solutions of cyclic systems of second order differential equations with power-type nonlinearities

Directory of Open Access Journals (Sweden)

Jaroslav Jaroš

2015-01-01

Full Text Available We consider \\(n\\-dimensional cyclic systems of second order differential equations \\[(p_i(t|x_{i}'|^{\\alpha_i -1}x_{i}'' = q_{i}(t|x_{i+1}|^{\\beta_i-1}x_{i+1},\\] \\[\\quad i = 1,\\ldots,n, \\quad (x_{n+1} = x_1 \\tag{\\(\\ast\\}\\] under the assumption that the positive constants \\(\\alpha_i\\ and \\(\\beta_i\\ satisfy \\(\\alpha_1{\\ldots}\\alpha_n \\gt \\beta_1{\\ldots}\\beta_n\\ and \\(p_i(t\\ and \\(q_i(t\\ are regularly varying functions, and analyze positive strongly increasing solutions of system (\\(\\ast\\ in the framework of regular variation. We show that the situation for the existence of regularly varying solutions of positive indices for (\\(\\ast\\ can be characterized completely, and moreover that the asymptotic behavior of such solutions is governed by the unique formula describing their order of growth precisely. We give examples demonstrating that the main results for (\\(\\ast\\ can be applied to some classes of partial differential equations with radial symmetry to acquire accurate information about the existence and the asymptotic behavior of their radial positive strongly increasing solutions.

NavMol 3.0: enabling the representation of metabolic reactions by blind users.

Science.gov (United States)

Binev, Yuri; Peixoto, Daniela; Pereira, Florbela; Rodrigues, Ian; Cavaco, Sofia; Lobo, Ana M; Aires-de-Sousa, João

2018-01-01

The representation of metabolic reactions strongly relies on visualization, which is a major barrier for blind users. The NavMol software renders the communication and interpretation of molecular structures and reactions accessible by integrating chemoinformatics and assistive technology. NavMol 3.0 provides a molecular editor for metabolic reactions. The user can start with templates of reactions and build from such cores. Atom-to-atom mapping enables changes in the reactants to be reflected in the products (and vice-versa) and the reaction centres to be automatically identified. Blind users can easily interact with the software using the keyboard and text-to-speech technology. NavMol 3.0 is free and open source under the GNU general public license (GPLv3), and can be downloaded at http://sourceforge.net/projects/navmol as a JAR file. joao@airesdesousa.com. © The Author (2017). Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Directed Neutron Beams From Inverse Kinematic Reactions

Science.gov (United States)

Vanhoy, J. R.; Guardala, N. A.; Glass, G. A.

2011-06-01

Kinematic focusing of an emitted fairly mono-energetic neutron beam by the use of inverse-kinematic reactions, i.e. where the projectile mass is greater than the target atom's mass, can provide for the utilization of a significant fraction of the fast neutron yield and also provide for a safer radiation environment. We examine the merit of various neutron production reactions and consider the practicalities of producing the primary beam using the suitable accelerator technologies. Preliminary progress at the NSWC-Carderock Positive Ion Accelerator Facility is described. Possible important applications for this type of neutron-based system can be both advanced medical imaging techniques and active "stand-off" interrogation of contraband items.

[Pulmonary reaction after furazidin (Furagin). Case report].

Science.gov (United States)

Zielonka, T M; Demkow, U; Kuś, J

1997-05-01

For the first time in Poland we present the case of pulmonary reaction to furazidin which is by chemical structure closely related to nitrofurantoin. 63 years old woman presented generalized symptoms of acute hypersensitivity reaction induced by furazidin as well as features of chronic pulmonary fibrosis. After few months of treatment with this drug patients complained of weight loss, dyspnea on effort, non-productive cough, chills and fever. Radiological and functional evaluation of respiratory system confirmed features of lung fibrosis. Drug provocation test was positive. In vitro furazidin in low concentrations stimulated proliferation of patient's lymphocytes. After cessation of treatment we have observed rapid improvement of clinical, radiological, biochemical and functional parameters.

Chemical modifications and reactions in DNA nanostructures

DEFF Research Database (Denmark)

Gothelf, Kurt Vesterager

2017-01-01

such as hydrocarbons or steroids have been introduced to change the surface properties of DNA origami structures, either to protect the DNA nanostructure or to dock it into membranes and other hydrophobic surfaces. DNA nanostructures have also been used to control covalent chemical reactions. This article provides......DNA nanotechnology has the power to form self-assembled and well-defined nanostructures, such as DNA origami, where the relative positions of each atom are known with subnanometer precision. Our ability to synthesize oligonucleotides with chemical modifications in almost any desired position...... provides rich opportunity to incorporate molecules, biomolecules, and a variety of nanomaterials in specific positions on DNA nanostructures. Several standard modifications for oligonucleotides are available commercially, such as dyes, biotin, and chemical handles, and such modified oligonucleotides can...

Unravelling Site-Specific Photo-Reactions of Ethanol on Rutile TiO2(110)

Science.gov (United States)

Hansen, Jonas Ø.; Bebensee, Regine; Martinez, Umberto; Porsgaard, Soeren; Lira, Estephania; Wei, Yinying; Lammich, Lutz; Li, Zheshen; Idriss, Hicham; Besenbacher, Flemming; Hammer, Bjørk; Wendt, Stefan

2016-01-01

Finding the active sites of catalysts and photo-catalysts is crucial for an improved fundamental understanding and the development of efficient catalytic systems. Here we have studied the photo-activated dehydrogenation of ethanol on reduced and oxidized rutile TiO2(110) in ultrahigh vacuum conditions. Utilizing scanning tunnelling microscopy, various spectroscopic techniques and theoretical calculations we found that the photo-reaction proceeds most efficiently when the reactants are adsorbed on regular Ti surface sites, whereas species that are strongly adsorbed at surface defects such as O vacancies and step edges show little reaction under reducing conditions. We propose that regular Ti surface sites are the most active sites in photo-reactions on TiO2. PMID:26915303

Price and Service Competition in the Supply Chain with both Pure Play Internet and Strong Bricks-and-Mortar Retailers

OpenAIRE

Dan, B.; Qu, Z.J.; Liu, C.; Zhang, X.M.; Zhang, H.Y.

2014-01-01

In the traditional retail industry, some supermarket chains and department stores have been maintaining strong positions as the market comes to maturity. They can make use of the strong positions to squeeze their suppliers and obtain extra earnings. This situation may be challenged by the rapid development of e-commerce. Consumers’ purchase habits have been changing and many manufacturers are starting to sell goods through electronic retailers, in addition to their traditional distribution ch...

Strong interactions and electromagnetism in low-energy hadron physics

International Nuclear Information System (INIS)

Kubis, B.

2002-10-01

In the present work, we study various aspects of the entanglement of the strong and electromagnetic interactions as it is manifest in low-energy hadron physics. In the framework of chiral perturbation theory, two aspects are investigated: the test of the structure of baryons as probed by external electromagnetic currents, and the modification of reactions mediated by the strong interactions in the presence of internal (virtual) photons. In the first part of this work, we study the electromagnetic form factors of nucleons and the ground state baryon octet, as well as strangeness form factors of the nucleon. Emphasis is put on the comparison of a new relativistic scheme for the calculation of loop diagrams to the heavy-baryon formalism, and on the convergence of higher-order corrections in both schemes. The new scheme is shown to yield both a phenomenologically more successful description of the data and better convergence behaviour. In the second part, we study isospin violation in pion-kaon scattering as mediated by virtual photon effects and the light quark mass difference. This investigation is of particular importance for the extraction of scattering lengths from measurements of lifetime and energy levels in pion-kaon atoms. The isospin breaking corrections are shown to be small and sufficiently well under control. (orig.)

Severe allergic hair dye reactions in 8 children

DEFF Research Database (Denmark)

Sosted, Heidi; Johansen, Jeanne Duus; Andersen, Klaus Ejner

2006-01-01

Serious adverse skin reactions to permanent hair dyes and temporary black tattoos have been reported. As temporary tattoos have become fashionable among adolescents, the risk profile for p-phenylenediamine (PPD) sensitization of the population has changed simultaneously with an increasing use...... of hair dyes in this age group. This investigation reports PPD sensitization in children with regard to cause of sensitization, clinical presentation and consequences. Clinical history and patch test results for consecutive children below 16 years of age with suspected hair dye allergic reactions...... and positive patch tests to PPD were collected over 2 years in 2 Danish dermatology clinics. 8 children aged 12-15 years were collected, and they all reacted to several hair dye ingredients. 5 of the patients were hospitalized, 1 in the intensive care unit. 6 of the patients gave a history of prior reaction...

The nuclear structure dependence of (p,α) reactions on light nuclei

International Nuclear Information System (INIS)

Leitner, W.

1985-01-01

As the theoretical predictions on nuclear structure and on nucleon-nucleon correlations implied by the nuclear wave functions are not subject to an immediate experimental verification the authors require a reaction theory connecting these state functions with observable quantities. The application of (rho,α) reactions as a spectroscopic tool has found widespread interest, as a number of microscopic descriptions of the reaction mechanism have facilitated the extraction of nuclear structure information. A microscopic formulation results in a strong dependence of the cross section on the nuclear structure of the reaction partners. The different basic configurations of the transferred nucleon system contribute coherently, thus causing a great sensitivity to the relative phases of the wave functions' amplitudes. A major disadvantage inherent to these microscopic theories of multinucleon-transfer reactions is based on the destruction of the transition amplitude's formal symmetry in the dynamic and in the nuclear structure part. In order to retain the factorization of the reaction amplitude, the authors applied the cluster ansatz to the microscopic theory of an earlier studies. The attractive features of this procedure are the conservation of the coherence properties of the structure term and the straightforward determination of transition strengths, independent of an elaborate DWBA treatment

Strong-back safety latch

International Nuclear Information System (INIS)

DeSantis, G.N.

1995-01-01

The calculation decides the integrity of the safety latch that will hold the strong-back to the pump during lifting. The safety latch will be welded to the strong-back and will latch to a 1.5-in. dia cantilever rod welded to the pump baseplate. The static and dynamic analysis shows that the safety latch will hold the strong-back to the pump if the friction clamps fail and the pump become free from the strong-back. Thus, the safety latch will meet the requirements of the Lifting and Rigging Manual for under the hook lifting for static loading; it can withstand shock loads from the strong-back falling 0.25 inch

Mass-positioning of Nanodiamonds Using Squeegee Technique

OpenAIRE

Cui, Ran; Shalaginov, Mikhail Y.; Shalaev, Vladimir M.

2015-01-01

Fluorescent color centers in diamond nanocrystals have recently become the focus of researchers because of their potential applications in quantum information processing, nano-sensing, biomarking, and bioimaging. One of the biggest challenges in working with nanodiamonds is how to position them precisely and efficiently to create strong interaction with nanoscale photonic structures. The most popular methods to position nanodiamonds are spin-coating and transporting via scanning probe microsc...

The reaction of stock market returns to anticipated unemployment

OpenAIRE

Taamouti, Abderrahim; Gonzalo Muñoz, Jesús

2012-01-01

We empirically investigate the short-run impact of anticipated and unanticipated unemployment rates on stock prices. We particularly examine the nonlinearity in stock market's reaction to unemployment rate and study the effect at each individual point (quantile) of stock return distribution. Using nonparametric Granger causality and quantile regression based tests, we find that, contrary to the general findings in the literature, only anticipated unemployment rate has a strong impact on stock...

Reaction time for trimolecular reactions in compartment-based reaction-diffusion models

Science.gov (United States)

Li, Fei; Chen, Minghan; Erban, Radek; Cao, Yang

2018-05-01

Trimolecular reaction models are investigated in the compartment-based (lattice-based) framework for stochastic reaction-diffusion modeling. The formulae for the first collision time and the mean reaction time are derived for the case where three molecules are present in the solution under periodic boundary conditions. For the case of reflecting boundary conditions, similar formulae are obtained using a computer-assisted approach. The accuracy of these formulae is further verified through comparison with numerical results. The presented derivation is based on the first passage time analysis of Montroll [J. Math. Phys. 10, 753 (1969)]. Montroll's results for two-dimensional lattice-based random walks are adapted and applied to compartment-based models of trimolecular reactions, which are studied in one-dimensional or pseudo one-dimensional domains.

Form factors in (HI,HI') direct reactions

International Nuclear Information System (INIS)

Chu, Y.H.

1981-01-01

Using the semiclassical theory, the inelastic transition form factors are analyzed. For the first order form factors, we find that: (i) In the strong absorption limit, the Austern-Blair theory is a good approximation to the inelastic form factor--even in highly mismatched reactions. (ii) In weak to moderate absorption, the amplitude of the inelastic form factor oscillates due to overlapping potential resonances. The internal part of the form factor can be expressed in a simple form, which may easily be used to analyze heavy-ion inelastic scattering. (iii) In the presence of an isolated resonance, the inelastic form factor is enhanced greatly at the resonance due to multiple reflections inside the potential well. The second order form factors contain two terms, i.e. the one-step direct process (OSD) term and the two-step process (TS) term. It is found that: (i) In the strong absorption limit, OSD and TS form factors are equally important and interfere destructively near the grazing angular momentum. The Austern-Blair theory gives satisfactory results for well-matched reactions. The angular distributions of the mutual and double excitations are out of phase compared with that of the single excitation. (ii) For the weak absorption case, the internal part of the TS form factor is so enhanced that the OSD form factor can simply be neglected. The internal TS form factor can be parameterized in a form proportional to the internal-wave elastic Smatrix, where the angular distribution shows characteristically refractive phenomenon

Community College Recruitment: An Analysis of Applicant Reactions.

Science.gov (United States)

Winter, Paul A.; Kjorlien, Chad L.

The purpose of this study was to: (1) conduct an empirical examination of applicant reactions to faculty jobs described in recruitment advertisements for business faculty vacancies at community colleges; and (2) assess factors that potentially impact applicant decisions to apply for and pursue position vacancies. The results of this study have…

The Absence of CYP3A5*3 Is a Protective Factor to Anticonvulsants Hypersensitivity Reactions: A Case-Control Study in Brazilian Subjects.

Science.gov (United States)

Tanno, Luciana Kase; Kerr, Daniel Shikanai; dos Santos, Bernardo; Talib, Leda Leme; Yamaguti, Célia; Rodrigues, Helcio; Gattaz, Wagner Farid; Kalil, Jorge

2015-01-01

Although aromatic anticonvulsants are usually well tolerated, they can cause cutaneous adverse drug reactions in up to 10% of patients. The clinical manifestations of the antiepileptics-induced hypersensitivity reactions (AHR) vary from mild skin rashes to severe cutaneous drug adverse reactions which are related to high mortality and significant morbidity. Genetic polymorphisms in cytochrome P450 genes are associated with altered enzymatic activity and may contribute to the risk of AHR. Here we present a case-control study in which we genotyped SNPs of CYP2C19, 2C9 and 3A5 of 55 individuals with varying severities of AHR, 83 tolerant, and 366 healthy control subjects from São Paulo, Brazil. Clinical characterization was based on standardized scoring systems and drug patch test. All in vivo investigation followed the ENDA (European Network of Drug Allergy) recommendations. Genotype was determined by real time PCR using peripheral blood DNA as a template. Of all 504 subjects, 65% were females, 45% self-identified as Afro-American, 38% as Caucasian and 17% as having non-African mixed ascendancy. Amongst 55 subjects with AHR, 44 had severe cutaneous drug adverse reactions. Of the 46 drug patch tests performed, 29 (63%) were positive. We found a strong association between the absence of CYP3A5*3 and tolerant subjects when compared to AHR (p = 0.0002, OR = 5.28 [CI95% 2.09-14.84]). None of our groups presented positive association with CYP2C19 and 2C9 polymorphisms, however, both SNPs contributed to separation of cases and tolerants in a Classification and Regression Tree. Our findings indicate that drug metabolism genes can contribute in the tolerability of antiepileptics. CYP3A5*3 is the most prevalent CYP3A5 allele associated with reduced enzymatic function. The current study provides evidence that normal CYP3A5 activity might be a protective factor to aromatic antiepileptics-induced hypersensitivity reactions in Brazilian subjects.

Neutrino reactions in hot and dense matter

Energy Technology Data Exchange (ETDEWEB)

Lohs, Andreas

2015-04-13

new neutrino reactions should be included in future dynamic CCSN-simulations to achieve quantitative conclusions of their impact on neutrino transport. Also we recommend the use of more precise computation schemes for neutrino rates when studying neutrino-nucleon interactions at large densities, where the strong interaction between nucleons becomes important.

Neutrino reactions in hot and dense matter

International Nuclear Information System (INIS)

Lohs, Andreas

2015-01-01

new neutrino reactions should be included in future dynamic CCSN-simulations to achieve quantitative conclusions of their impact on neutrino transport. Also we recommend the use of more precise computation schemes for neutrino rates when studying neutrino-nucleon interactions at large densities, where the strong interaction between nucleons becomes important.

Incidence of adverse drug reactions in human immune deficiency virus-positive patients using highly active antiretroviral therapy

Directory of Open Access Journals (Sweden)

B Akshaya Srikanth

2012-01-01

Full Text Available To estimate the incidence of adverse drug reactions (ADRs in Human immune deficiency virus (HIV patients on highly active antiretroviral therapy (HAART. To identify the risk factors associated with ADRs in HIV patients. To analyze reported ADRs based on various parameters like causality, severity, predictability, and preventability. Retrospective case-control study. An 18-month retrospective case-control study of 208 patients newly registered in ART center, RIMS hospital, Kadapa, were intensively monitored for ADRs to HAART. Predictability was calculated based on the history of previous exposure to drug. Multivariate logistic regressions were used to identify the risk factors for ADRs. Data were analyzed using the chi-square test for estimating the correlation between ADRs and different variables. All statistical calculations were performed using EpiInfo version 3.5.3. Monitoring of 208 retrospective patients by active Pharmacovigilance identified 105 ADRs that were identified in 71 patients. Skin rash and anemia were the most commonly observed ADRs. The organ system commonly affected by ADR was skin and appendages (31.57%. The ADRs that were moderate were 90.14% of cases. The incidence of ADRs (53.52% was higher with Zidovudine + Lamivudine + Nevirapine combination. CD4 cell count less than <250 cells/μl were 80.28%, male gender were observed to be the risk factors for ADRs. Our study finding showed that there is a need of active pharmaceutical care with intensive monitoring for ADRs in Indian HIV-positive patients who are illiterate, of male and female gender, with CD4 count ≤250 cells/mm 3 with comorbid conditions.

Bacillus anthracis o-succinylbenzoyl-CoA synthetase: reaction kinetics and a novel inhibitor mimicking its reaction intermediate †

Science.gov (United States)

Tian, Yang; Suk, Dae-Hwan; Cai, Feng; Crich, David; Mesecar, Andrew D.

2009-01-01

O-succinylbenzoyl-CoA (OSB-CoA) synthetase (EC 6.2.1.26) catalyzes the ATP-dependent condensation of o-succinylbenzoate (OSB) and CoA to form OSB-CoA, the fourth step of the menaquinone biosynthetic pathway in Bacillus anthracis. Gene knockout studies have highlighted this enzyme as a potential target for the discovery of new antibiotics. Here we report the first studies on the kinetic mechanism of B. anthracis OSB-CoA synthetase, classifying it as an ordered Bi Uni Uni Bi ping-pong mechanism. Through a series of pre-steady-state and steady-state kinetic studies in conjunction with direct-binding studies, it is demonstrated that CoA, the last substrate to bind, strongly activates the first half-reaction after the first round of turnover. The activation of the first-half reaction is most likely achieved by CoA stabilizing conformations of the enzyme in the ‘F’ form, which slowly isomerize back to the E form. Thus, the kinetic mechanism of OSB-CoA synthetase may be more accurately described as an ordered Bi Uni Uni Bi Iso ping-pong mechanism. The substrate specificity of OSB-CoA synthetase was probed using a series of OSB analogs with alterations in the carboxylate groups. OSB-CoA shows a strong preference for OSB over all of the analogs tested as none were active except 4-(2-trifluoromethylphenyl)-4-oxobutyric acid which exhibited a 100-fold decrease in kcat/Km. Based on an understanding of OSB-CoA synthetase’s kinetic mechanism and substrate specificity, a reaction intermediate analog of OSB-AMP, 5’-O-(N-(2-trifluoromethylphenyl)-4-oxobutyl) adenosine sulfonamide (TFMP-butyl-AMS), was designed and synthesized. This inhibitor was found to be an uncompetitive inhibitor to CoA and a mixed-type inhibitor to ATP and OSB with low micromolar inhibition constants. Collectively, these results should serve as an important forerunner to more detailed and extensive inhibitor design studies aimed at developing lead compounds against the OSB-CoA synthetase class of

Effect of exotic long-lived sub-strongly interacting massive particles in big bang nucleosynthesis and a new solution to the Li problem

Directory of Open Access Journals (Sweden)

Kawasaki Masahiro

2012-02-01

Full Text Available The plateau of 7Li abundance as a function of the iron abundance by spectroscopic observations of metal-poor halo stars (MPHSs indicates its primordial origin. The observed abundance levels are about a factor of three smaller than the primordial 7Li abundance predicted in the standard Big Bang Nucleosynthesis (BBN model. This discrepancy might originate from exotic particle and nuclear processes operating in BBN epoch. Some particle models include heavy (m >> 1 GeV long-lived colored particles which would be confined inside exotic heavy hadrons, i.e., strongly interacting massive particles (SIMPs. We have found reactions which destroy 7Be and 7Li during BBN in the scenario of BBN catalyzed by a long-lived sub-strongly interacting massive particle (sub-SIMP, X. The reactions are non radiative X captures of 7 Be and 7Li which can be operative if the X particle interacts with nuclei strongly enough to drive 7 Be destruction but not strongly enough to form a bound state with 4 He of relative angular momentum L = 1. We suggest that 7Li problem can be solved as a result of a new process beyond the standard model through which the observable signature was left on the primordial Li abundance.

Methods for forming complex oxidation reaction products including superconducting articles

International Nuclear Information System (INIS)

Rapp, R.A.; Urquhart, A.W.; Nagelberg, A.S.; Newkirk, M.S.

1992-01-01

This patent describes a method for producing a superconducting complex oxidation reaction product of two or more metals in an oxidized state. It comprises positioning at least one parent metal source comprising one of the metals adjacent to a permeable mass comprising at least one metal-containing compound capable of reaction to form the complex oxidation reaction product in step below, the metal component of the at least one metal-containing compound comprising at least a second of the two or more metals, and orienting the parent metal source and the permeable mass relative to each other so that formation of the complex oxidation reaction product will occur in a direction towards and into the permeable mass; and heating the parent metal source in the presence of an oxidant to a temperature region above its melting point to form a body of molten parent metal to permit infiltration and reaction of the molten parent metal into the permeable mass and with the oxidant and the at least one metal-containing compound to form the complex oxidation reaction product, and progressively drawing the molten parent metal source through the complex oxidation reaction product towards the oxidant and towards and into the adjacent permeable mass so that fresh complex oxidation reaction product continues to form within the permeable mass; and recovering the resulting complex oxidation reaction product

The effects of acute bout of cycling on auditory & visual reaction times.

Science.gov (United States)

Ashnagar, Zinat; Shadmehr, Azadeh; Jalaei, Shohreh

2015-04-01

The purpose of this study was to investigate the effects of an acute bout of cycling exercise on auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction time. 29 subjects were randomly divided into experimental and control groups. The subjects of the experimental group carried out a single bout of submaximal cycling exercise. The auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction times were measured before and after the exercise session. The reaction time tests were taken from the subjects by using Speed Anticipation and Reaction Tester (SART) software. In the control group, the reaction time tests were performed by the subjects with an interval of 30 min. In the experimental group, the percentage changes of mean auditory choice and complex choice reaction time values were significantly decreased in comparison with the control group (P visual choice and complex choice reaction times were decreased after the exercise, the changes were not significant (P > 0.05). An acute bout of cycling exercise improved the speed of auditory and visual reaction times in healthy young females. However, these positive changes were significantly observed only in the auditory reaction time tests in comparison with the control group. Copyright © 2014 Elsevier Ltd. All rights reserved.

SiC Conversion Coating Prepared from Silica-Graphite Reaction

Directory of Open Access Journals (Sweden)

Back-Sub Sung

2017-01-01

Full Text Available The β-SiC conversion coatings were successfully synthesized by the SiO(v-graphite(s reaction between silica powder and graphite specimen. This paper is to describe the effects on the characteristics of the SiC conversion coatings, fabricated according to two different reaction conditions. FE-SEM, FE-TEM microstructural morphologies, XRD patterns, pore size distribution, and oxidation behavior of the SiC-coated graphite were investigated. In the XRD pattern and SAD pattern, the coating layers showed cubic SiC peak as well as hexagonal SiC peak. The SiC coatings showed somewhat different characteristics with the reaction conditions according to the position arrangement of the graphite samples. The SiC coating on graphite, prepared in reaction zone (2, shows higher intensity of beta-SiC main peak (111 in XRD pattern as well as rather lower porosity and smaller main pore size peak under 1 μm.

Influence of irradiation on reaction products of nitrite in foodstuffs

International Nuclear Information System (INIS)

Mirna, A.; Rau, G.

1982-01-01

Nitro alkanes and nitrolic acids are formed in foods by nitrosation reactions with nitrite. Among TEA-responsive compounds nitrolic acid behave to irradiation similar to N-nitrosamines. Some substances, extracted from spices, especially garlic, are also detectable by GC/TEA-chromatogramms of meat products and of reaction products from spices with nitrite show retention times not always clearly differentiated from those of NDMA, NDEA, NPIP and NPYR, respectively. Additional confirmation of such TEA positive compounds, therefore, is necessary. (orig.) [de

Immediate allergic and nonallergic reactions to Christmas and Easter cacti

DEFF Research Database (Denmark)

Andersen, F; Bindslev-Jensen, C; Stahl Skov, P

1999-01-01

BACKGROUND: Occupational exposure to Christmas cacti has been reported as a cause of type I allergy. Therefore, the prevalence of immediate-type mucosal and skin reactions related to cactus exposure was studied in 103 employees in a cactus nursery. METHODS: The study was based on a questionnaire ...... and mucosal symptoms. CONCLUSIONS: Christmas and Easter cacti seemed to be able to induce contact urticaria and rhinoconjunctivitis on both an immunologic and a nonimmunologic basis. Personal atopy was associated with positive reactions to cacti....

Reaction rate and composition dependence of the stability of thermonuclear burning on accreting neutron stars

International Nuclear Information System (INIS)

Keek, L.; Cyburt, R. H.; Heger, A.

2014-01-01

The stability of thermonuclear burning of hydrogen and helium accreted onto neutron stars is strongly dependent on the mass accretion rate. The burning behavior is observed to change from Type I X-ray bursts to stable burning, with oscillatory burning occurring at the transition. Simulations predict the transition at a 10 times higher mass accretion rate than observed. Using numerical models we investigate how the transition depends on the hydrogen, helium, and CNO mass fractions of the accreted material, as well as on the nuclear reaction rates of 3α and the hot-CNO breakout reactions 15 O(α, γ) 19 Ne and 18 Ne(α, p) 21 Na. For a lower hydrogen content the transition is at higher accretion rates. Furthermore, most experimentally allowed reaction rate variations change the transition accretion rate by at most 10%. A factor 10 decrease of the 15 O(α, γ) 19 Ne rate, however, produces an increase of the transition accretion rate of 35%. None of our models reproduce the transition at the observed rate, and depending on the true 15 O(α, γ) 19 Ne reaction rate, the actual discrepancy may be substantially larger. We find that the width of the interval of accretion rates with marginally stable burning depends strongly on both composition and reaction rates. Furthermore, close to the stability transition, our models predict that X-ray bursts have extended tails where freshly accreted fuel prolongs nuclear burning.

Reduced Reactivity of Amines against Nucleophilic Substitution via Reversible Reaction with Carbon Dioxide