Evaluating the role of phase I expansion cohorts in oncologic drug development.

PubMed

Norris, Robin E; Behtaj, Mohadese; Fu, Pingfu; Dowlati, Afshin

2017-02-01

Importance Use of expansion cohorts (EC) in phase I trials is increasing. However, the utility of phase I EC in aiding drug development is unclear. We sought to determine factors associated with the inclusion of EC in phase I studies and the impact of EC on subsequent clinical development. Methods We performed a systematic review of all phase I trials published in the Journal of Clinical Oncology between June 2004 and May 2014. Presence of an EC, number of participants, funding source, class of agent, tumor type, and maximum tolerated dose (MTD)/recommended phase 2 dose (RP2D) were identified. Subsequent conduct of phase II studies and FDA approval of the study agent was also assessed. Results We identified 252 phase I studies. An EC was included in 105 studies. Average accrual on EC studies was 47 compared to 31 in studies without EC (p < 0.0001). There was no impact of time on the inclusion of EC. Only 4 % of phase I studies with an EC provided sample size justification. Source of funding had the only significant association with inclusion of EC. Addition of a phase I EC did not impact the phase I MTD/RP2D, subsequent phase II trial, or FDA approval. Conclusion The importance of including an EC in phase I trials is subject to ongoing debate. Our results demonstrated little benefit to including EC in phase I studies. These findings support that innovative design strategies are needed to optimize the utility of EC in phase I studies.

A Study of the Spin-State Transition and Phase Transformation in [Fe(bpp)(2)][CF(3)SO(3)](2).H(2)O and [Fe(bpp)(2)][BF(4)](2) Using Mn(2+) Electron Spin Resonance.

PubMed

Sung, Raymond C. W.; McGarvey, Bruce R.

1999-08-09

X-band ESR powder studies have been done on the spin transition in Mn(2+)-doped [Fe(bpp)(2)][CF(3)SO(3)](2).H(2)O and [Fe(bpp)(2)][BF(4)](2) (bpp = 2,6-bis(pyrazol-3-yl) pyridine). The change in D value of Mn(2+) during the thermally induced high-spin (HS) <--> low-spin (LS) transition shows that the spin transition is accompanied by a phase transformation involving a domain mechanism. Irradiation experiments at 77 K have shown that a LS --> HS spin change occurs without a change in the crystalline phase. The rate of the change from the HS phase to the LS phase in the vicinity of 100 K has been measured and is found to be the same as that measured for the corresponding spin change obtained from Mössbauer spectroscopy and magnetic susceptibility studies.

Contributions of phase, sulfur vacancies, and edges to the hydrogen evolution reaction catalytic activity of porous molybdenum disulfide nanosheets

DOE PAGES

Yin, Ying; Han, Jiecai; Zhang, Yumin; ...

2016-06-07

Molybdenum disulfide (MoS 2) is a promising nonprecious catalyst for the hydrogen evolution reaction (HER) that has been extensively studied due to its excellent performance, but the lack of understanding of the factors that impact its catalytic activity hinders further design and enhancement of MoS 2-based electrocatalysts. Here, by using novel porous (holey) metallic 1T phase MoS 2 nanosheets synthesized by a liquid-ammonia-assisted lithiation route, we systematically investigated the contributions of crystal structure (phase), edges, and sulfur vacancies (S-vacancies) to the catalytic activity toward HER from five representative MoS 2 nanosheet samples, including 2H and 1T phase, porous 2H andmore » 1T phase, and sulfur-compensated porous 2H phase. Superior HER catalytic activity was achieved in the porous 1T phase MoS 2 nanosheets that have even more edges and S-vacancies than conventional 1T phase MoS 2. A comparative study revealed that the phase serves as the key role in determining the HER performance, as 1T phase MoS 2 always outperforms the corresponding 2H phase MoS 2 samples, and that both edges and S-vacancies also contribute significantly to the catalytic activity in porous MoS 2 samples. Then, using combined defect characterization techniques of electron spin resonance spectroscopy and positron annihilation lifetime spectroscopy to quantify the S-vacancies, the contributions of each factor were individually elucidated. Furthermore, this study presents new insights and opens up new avenues for designing electrocatalysts based on MoS 2 or other layered materials with enhanced HER performance.« less

Contributions of phase, sulfur vacancies, and edges to the hydrogen evolution reaction catalytic activity of porous molybdenum disulfide nanosheets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yin, Ying; Han, Jiecai; Zhang, Yumin

Molybdenum disulfide (MoS 2) is a promising nonprecious catalyst for the hydrogen evolution reaction (HER) that has been extensively studied due to its excellent performance, but the lack of understanding of the factors that impact its catalytic activity hinders further design and enhancement of MoS 2-based electrocatalysts. Here, by using novel porous (holey) metallic 1T phase MoS 2 nanosheets synthesized by a liquid-ammonia-assisted lithiation route, we systematically investigated the contributions of crystal structure (phase), edges, and sulfur vacancies (S-vacancies) to the catalytic activity toward HER from five representative MoS 2 nanosheet samples, including 2H and 1T phase, porous 2H andmore » 1T phase, and sulfur-compensated porous 2H phase. Superior HER catalytic activity was achieved in the porous 1T phase MoS 2 nanosheets that have even more edges and S-vacancies than conventional 1T phase MoS 2. A comparative study revealed that the phase serves as the key role in determining the HER performance, as 1T phase MoS 2 always outperforms the corresponding 2H phase MoS 2 samples, and that both edges and S-vacancies also contribute significantly to the catalytic activity in porous MoS 2 samples. Then, using combined defect characterization techniques of electron spin resonance spectroscopy and positron annihilation lifetime spectroscopy to quantify the S-vacancies, the contributions of each factor were individually elucidated. Furthermore, this study presents new insights and opens up new avenues for designing electrocatalysts based on MoS 2 or other layered materials with enhanced HER performance.« less

First-principles surface interaction studies of aluminum-copper and aluminum-copper-magnesium secondary phases in aluminum alloys

NASA Astrophysics Data System (ADS)

da Silva, Thiago H.; Nelson, Eric B.; Williamson, Izaak; Efaw, Corey M.; Sapper, Erik; Hurley, Michael F.; Li, Lan

2018-05-01

First-principles density functional theory-based calculations were performed to study θ-phase Al2Cu, S-phase Al2CuMg surface stability, as well as their interactions with water molecules and chloride (Cl-) ions. These secondary phases are commonly found in aluminum-based alloys and are initiation points for localized corrosion. Density functional theory (DFT)-based simulations provide insight into the origins of localized (pitting) corrosion processes of aluminum-based alloys. For both phases studied, Cl- ions cause atomic distortions on the surface layers. The nature of the distortions could be a factor to weaken the interlayer bonds in the Al2Cu and Al2CuMg secondary phases, facilitating the corrosion process. Electronic structure calculations revealed not only electron charge transfer from Cl- ions to alloy surface but also electron sharing, suggesting ionic and covalent bonding features, respectively. The S-phase Al2CuMg structure has a more active surface than the θ-phase Al2Cu. We also found a higher tendency of formation of new species, such as Al3+, Al(OH)2+, HCl, AlCl2+, Al(OH)Cl+, and Cl2 on the S-phase Al2CuMg surface. Surface chemical reactions and resultant species present contribute to establishment of local surface chemistry that influences the corrosion behavior of aluminum alloys.

LiOH - H2O2 - H2O trinary system study for the selection of optimal conditions of lithium peroxide synthesis

NASA Astrophysics Data System (ADS)

Nefedov, R. A.; Ferapontov, Yu A.; Kozlova, N. P.

2016-01-01

Using solubility method the decay kinetics of peroxide products contained in liquid phase of LiOH - H2O2 - H2O trinary system with 2 to 6% by wt hydrogen peroxide content in liquid phase in 21 to 33 °C temperature range has been studied. Conducted studies have allowed to determine temperature and concentration limits of solid phase existence of Li2O2·H2O content, distinctness of which has been confirmed using chemical and qualitative X- ray phase analysis. Stabilizing effect of solid phase of Li2O2·H2O content on hydrogen peroxide decay contained in liquid phase of LiOH - H2O2 - H2O trinary system under conditions of experiments conducted has been shown.

Fourier transform infrared study of the phase transitions in (NH4)3VO2FO4

NASA Astrophysics Data System (ADS)

de Waal, D.; Heyns, A. M.

1994-01-01

Ammonium oxofluorovanadate compounds are known to show some potential as ferroelectric materials. The whole series of ammonium and sodium oxofluorovanadate compounds including Na3VO2F4 have already been prepared and investigated by means of various techniques including x-ray diffraction, EPR, and vibrational spectroscopy. It was established that the pure ammonium compound shows the two above mentioned transitions from phase A (below 200 K) to phase B (between 200 and 400 K) and phase C (above 400 K) while Na(NH4)2VO2F4 has only one transition from phase A to phase B around 400 K4. In the present study various aspects regarding the nature of the structures of (NH4)3VO2F3 and Na(NH4)2VO2F4 and its influence on the phase transitions have been investigated.

Blocking carbohydrate absorption and weight loss: a clinical trial using Phase 2 brand proprietary fractionated white bean extract.

PubMed

Udani, Jay; Hardy, Mary; Madsen, Damian C

2004-03-01

Phase 2' starch neutralizer brand bean extract product ("Phase 2") is a water-extract of a common white bean (Phaseolus vulgaris) that has been shown in vitro to inhibit the digestive enzyme alpha-amylase. Inhibiting this enzyme may prevent the digestion of complex carbohydrates, thus decreasing the number of carbohydrate calories absorbed and potentially promoting weight loss. Fifty obese adults were screened to participate in a randomized, double-blind, placebo-controlled study evaluating the effects of treatment with Phase 2 versus placebo on weight loss. Participants were randomized to receive either 1500 mg Phase 2 or an identical placebo twice daily with meals. The active study period was eight weeks. Thirty-nine subjects completed the initial screening process and 27 subjects completed the study. The results after eight weeks demonstrated the Phase 2 group lost an average of 3.79 lbs (average of 0.47 lb per week) compared with the placebo group, which lost an average of 1.65 lbs (average of 0.21 lb per week), representing a difference of 129 percent (p=0.35). Triglyceride levels in the Phase 2 group were reduced an average of 26.3 mg/dL, more than three times greater a reduction than observed in the placebo group (8.2 mg/dL) (p=0.07). No adverse events during the study were attributed to the study medication. Clinical trends were identified for weight loss and a decrease in triglycerides, although statistical significance was not reached. Phase 2 shows potential promise as an adjunct therapy in the treatment of obesity and hypertriglyceridemia and further studies with larger numbers of subjects are warranted to conclusively demonstrate effectiveness.

Open-Label, Multicenter, Phase 1/2 Study of Tazemetostat (EZH2 Histone Methyl Transferase [HMT] Inhibitor) as a Single Agent in Subjects With Adv. Solid Tumors or With B-cell Lymphomas and Tazemetostat in Combination With Prednisolone in Subjects With DLBCL

ClinicalTrials.gov

2018-05-31

B-cell Lymphomas (Phase 1); Advanced Solid Tumors (Phase 1); Diffuse Large B-cell Lymphoma (Phase 2); Follicular Lymphoma (Phase 2); Transformed Follicular Lymphoma; Primary Mediastinal Large B-Cell Lymphoma

CARBON DIOXIDE SEPARATION BY PHASE ENHANCED GAS-LIQUID ABSORPTION

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liang Hu

A new process called phase enhanced gas-liquid absorption has been developed in its early stage. It was found that adding another phase into the absorption system of gas/aqueous phase could enhance the absorption rate. A system with three phases was studied. In the system, gas phase was carbon dioxide. Two liquid phases were used. One was organic phase. Another was aqueous phase. By addition of organic phase into the absorption system of CO{sub 2}-aqueous phase, the absorption rate of CO{sub 2} was increased significantly. CO{sub 2} finally accumulated into aqueous phase. The experimental results proved that (1) Absorption rate ofmore » carbon dioxide was enhanced by adding organic phase into gas aqueous phase system; (2) Organic phase played the role of transportation of gas solute (CO{sub 2}). Carbon dioxide finally accumulated into aqueous phase.« less

Using Clickers to Increase On-Task Behaviors of Middle School Students with Behavior Problems

ERIC Educational Resources Information Center

Xin, Joy F.; Johnson, Mary L.

2015-01-01

This study examined the effect of using a remote device, a Clicker, on the on-task behavior of middle school students with behavior problems. Five students with behavior problems participated in the study. A single-subject research design with ABAB (phase A: baseline 1, phase B: intervention 1, phase A: baseline 2, phase B: intervention 2) phases…

Bulk and dispersed aqueous behaviour of an endogenous lipid, selachyl alcohol: Effect of Tween 80 and Pluronic F127 on nanostructure.

PubMed

Younus, Mohammad; Hawley, Adrian; Boyd, Ben J; Rizwan, Shakila B

2018-05-07

Tween 80 has been reported to provide a means of targeting drug nanocarriers to the blood- brain barrier. This study investigated the influence of addition of Tween 80 on the formation of different bulk and dispersed lyotropic liquid crystalline phases in selachyl alcohol-based systems. The effect of increasing concentrations of Tween 80 and Pluronic F127 (as a control) (0-25% w/w relative to SA) on the bulk phase behaviour and dispersions of selachyl alcohol (SA) were investigated using small angle X-ray scattering, dynamic light scattering, and cryogenic transmission electron microscopy. The addition of Tween 80 to SA bulk phase samples triggered concentration-dependent phase changes with the structure sequentially evolving from a reverse hexagonal phase (H 2 ) to a mixed H 2 and inverse bicontinuous cubic (V 2 ) then a V 2 phase alone. In contrast, the addition of Pluronic F127 resulted in a phase change from H 2 phase to a mixed lamellar and H 2 phase system. The mean particle size of internally structured particles was 125-190 nm with low polydispersity indices (0.1-0.2). Nanoparticles retained the bulk phase internal structure in the presence of Tween 80, whereas in the presence of Pluronic F127, the additional lamellar phase that formed in bulk phase systems was not observed. Cryo-TEM revealed the formation of cubosomes and hexosomes by SA in excess water in the presence of Tween 80 and Pluronic F127 respectively. In summary, it was shown that stabilisation of SA dispersions using Tween 80 resulted in a decrease in negative curvature leading to a change in internal structure from H 2 to V 2 phase. The studies provide the core understanding of particle structure to progress these structured lipid nanocarriers into delivery studies with Tween 80 as a mechanism to target the blood-brain barrier. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

Re Doping in 2D Transition Metal Dichalcogenides as a New Route to Tailor Structural Phases and Induced Magnetism

DOE PAGES

Kochat, Vidya; Apte, Amey; Hachtel, Jordan A.; ...

2017-10-09

Alloying in 2D results in the development of new, diverse, and versatile systems with prospects in bandgap engineering, catalysis, and energy storage. Tailoring structural phase transitions using alloying is a novel idea with implications in designing all 2D device architecture as the structural phases in 2D materials such as transition metal dichalcogenides are correlated with electronic phases. In this paper, this study develops a new growth strategy employing chemical vapor deposition to grow monolayer 2D alloys of Re-doped MoSe 2 with show composition tunable structural phase variations. The compositions where the phase transition is observed agree well with the theoreticalmore » predictions for these 2D systems. Finally, it is also shown that in addition to the predicted new electronic phases, these systems also provide opportunities to study novel phenomena such as magnetism which broadens the range of their applications.« less

Examination of Rotating Spoke Instability in a Cross-Field Discharge

DTIC Science & Technology

2013-07-08

leader), L. Balika, J. Vaudolon EMAU R. Schneider, K. Matyash PPPL Y. Raitses, A. Diallo, Y. Shi Distribution A: Approved for public...the spoke. The project was originally divided into three successive phases, namely: Phase 1: Time-averaged LIF study on the CHT at PPPL Phase 2...Time-resolved LIF study on the CHT at ICARE Phase 3: Time-resolved LIF study on a 2 kW HT at PPPL (Optional) Distribution A: Approved for public

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kochat, Vidya; Apte, Amey; Hachtel, Jordan A.

Alloying in 2D results in the development of new, diverse, and versatile systems with prospects in bandgap engineering, catalysis, and energy storage. Tailoring structural phase transitions using alloying is a novel idea with implications in designing all 2D device architecture as the structural phases in 2D materials such as transition metal dichalcogenides are correlated with electronic phases. In this paper, this study develops a new growth strategy employing chemical vapor deposition to grow monolayer 2D alloys of Re-doped MoSe 2 with show composition tunable structural phase variations. The compositions where the phase transition is observed agree well with the theoreticalmore » predictions for these 2D systems. Finally, it is also shown that in addition to the predicted new electronic phases, these systems also provide opportunities to study novel phenomena such as magnetism which broadens the range of their applications.« less

Organisational justice and change in justice as predictors of employee health: the Whitehall II study.

PubMed

Kivimäki, Mika; Ferrie, Jane E; Head, Jenny; Shipley, Martin J; Vahtera, Jussi; Marmot, Michael G

2004-11-01

Organisational justice has been proposed as a new way to examine the impact of psychosocial work environment on employee health. This article studied the justice of interpersonal treatment by supervisors (the relational component of organisational justice) as a predictor of health. Prospective cohort study. Phase 1 (1985-88) measured relational justice, job demands, job control, social support at work, effort-reward imbalance, and self rated health. Relational justice was assessed again at phase 2 (1989-90) and self rated health at phase 2 and phase 3 (1991-93). 20 civil service departments originally located in London. 10 308 civil servants (6895 men, 3413 women) aged 35-55. Self rated health. Men exposed to low justice at phase 1 or adverse change in justice between phase 1 and phase 2 were at higher risk of poor health at phase 2 and phase 3. A favourable change in justice was associated with reduced risk. Adjustment for other stress indicators had little effect on results. In women, low justice at phase 1 predicted poor health at phase 2 and phase 3 before but not after adjustment for other stress indicators. Adverse change in justice was associated with worse health prospects irrespective of adjustments. The extent to which people are treated with justice in workplaces seems to predict their health independently of established stressors at work. Evidence on reduced health risk after favourable change in organisational justice implies a promising area for health interventions at workplace.

Studies on the structural stability of Co2P2O7 under pressure

NASA Astrophysics Data System (ADS)

Wang, W. P.; Pang, H.; Jin, M. L.; Shen, X.; Yao, Y.; Wang, Y. G.; Li, Y. C.; Li, X. D.; Jin, C. Q.; Yu, R. C.

2018-05-01

The crystal structural evolution of Co2P2O7 was studied by using in situ high pressure angle dispersive x-ray diffraction with synchrotron radiation. The results demonstrate that the α phase of Co2P2O7 goes through a partially irreversible structural transformation to β phase under pressure. The pressure is conductive to reduce the longest Cosbnd O bond length of the α phase, and then more uniform Cosbnd O bonds and regular hexagonal arrangement of CoO6 octahedra of the β phase are favored. According to the Birch-Murnaghan equation, the fitted bulk modulus B0 is 158.1(±5.6) GPa for α phase and 276.5(±6.5) GPa for β phase. Furthermore, the first-principles calculations show that these two phases of Co2P2O7 have almost equal total energies, and also have similar band structures and spin-polarized density of states at their ground states. This may be the reason why these two phases of Co2P2O7 can coexist in the pressure released state. It is found that the band gap energies decrease with increasing pressure for both phases.

Intrinsic crystal phase separation in the antiferromagnetic superconductor Rb(y)Fe(2-x)Se2: a diffraction study.

PubMed

Yu Pomjakushin, V; Krzton-Maziopa, A; Pomjakushina, E V; Conder, K; Chernyshov, D; Svitlyk, V; Bosak, A

2012-10-31

The crystal and magnetic structures of the superconducting iron-based chalcogenides Rb(y)Fe(2-x)Se(2) have been studied by means of single-crystal synchrotron x-ray and high-resolution neutron powder diffraction in the temperature range 2-570 K. The ground state of the crystal is an intrinsically phase-separated state with two distinct-by-symmetry phases. The main phase has the iron vacancy ordered √5 × √5 superstructure (I4/m space group) with AFM ordered Fe spins. The minority phase does not have √5 × √5-type of ordering and has a smaller in-plane lattice constant a and larger tetragonal c-axis and can be well described by assuming the parent average vacancy disordered structure (I4/mmm space group) with the refined stoichiometry Rb(0.60(5))(Fe(1.10(5))Se)(2). The minority phase amounts to 8-10% mass fraction. The unit cell volume of the minority phase is 3.2% smaller than the one of the main phase at T = 2 K and has quite different temperature dependence. The minority phase merges with the main vacancy ordered phase on heating above the phase separation temperature T(P) = 475 K. The spatial dimensions of the phase domains strongly increase above T(P) from 1000 to >2500 Å due to the integration of the regions of the main phase that were separated by the second phase at low temperatures. Additional annealing of the crystals at a temperature T = 488 K, close to T(P), for a long time drastically reduces the amount of the minority phase.

Effect of CO2 partial pressure and different CO2 phases on carbon steel corrosion

NASA Astrophysics Data System (ADS)

Mahlobo, MGR; Premlall, K.; Olubambi, PA

2017-12-01

Carbon capture and storage (CCS) is the recent promising technology aimed at reducing greenhouse gas emission. Like many other developed technologies, CCS is faced with great challenges such as pipeline transportation failure due to corrosion. There are many factors contributing to steel corrosion during the pipeline transportation of carbon dioxide (CO2). This study focuses on CO2 partial pressure and different phases of CO2 as some of the factors contributing to steel corrosion. Carbon steel was used as a testing specimen. High pressure reactor was used in this study to compress CO2 from low to high pressures ultimately changing the CO2 from gaseous phase to gas/liquid phase (subcritical) and to dense phase (supercritical). Weight loss method was employed to determine the corrosion rate while scanning electron microscopy (SEM) and X-Ray diffraction (XRD) were used to study the carbon steel morphology and phase analysis. Using low magnification digital camera, the type of corrosion that took place on the carbon steel surface was identified.

Harnessing Implementation Science to Increase the Impact of Health Equity Research.

PubMed

Chinman, Matthew; Woodward, Eva N; Curran, Geoffrey M; Hausmann, Leslie R M

2017-09-01

Health disparities are differences in health or health care between groups based on social, economic, and/or environmental disadvantage. Disparity research often follows 3 steps: detecting (phase 1), understanding (phase 2), and reducing (phase 3), disparities. Although disparities have narrowed over time, many remain. We argue that implementation science could enhance disparities research by broadening the scope of phase 2 studies and offering rigorous methods to test disparity-reducing implementation strategies in phase 3 studies. We briefly review the focus of phase 2 and phase 3 disparities research. We then provide a decision tree and case examples to illustrate how implementation science frameworks and research designs could further enhance disparity research. Most health disparities research emphasizes patient and provider factors as predominant mechanisms underlying disparities. Applying implementation science frameworks like the Consolidated Framework for Implementation Research could help disparities research widen its scope in phase 2 studies and, in turn, develop broader disparities-reducing implementation strategies in phase 3 studies. Many phase 3 studies of disparity-reducing implementation strategies are similar to case studies, whose designs are not able to fully test causality. Implementation science research designs offer rigorous methods that could accelerate the pace at which equity is achieved in real-world practice. Disparities can be considered a "special case" of implementation challenges-when evidence-based clinical interventions are delivered to, and received by, vulnerable populations at lower rates. Bringing together health disparities research and implementation science could advance equity more than either could achieve on their own.

Cell cycle regulation in Schizosaccharomyces pombe.

PubMed

Moser, B A; Russell, P

2000-12-01

Cdc2, a cyclin-dependent kinase, controls cell cycle progression in fission yeast. New details of Cdc2 regulation and function have been uncovered in recent studies. These studies involve cyclins that associate with Cdc2 in G1-phase and the proteins that regulate inhibitory phosphorylation of Cdc2 during S-phase and G2-phase. Recent investigations have also provided a better understanding of proteins that regulate DNA replication and that are directly or indirectly controlled by Cdc2.

New Findings on the Phase Transitions in Li(sub 1-x)CoO(sub 2) and Li(sub 1-x)NiO(sub 2) Cathode Materials During Cycling: In Situ Synchrotron X-Ray Diffraction Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, X. Q.; Sun, X.; McBreen, J.

The authors have utilized synchrotron x-ray radiation to perform ''in situ'' x-ray diffraction studies on Li{sub 1-x}CoO{sub 2} and Li{sub 1-x}NiO{sub 2} cathodes. A C/10 charging rate was used for a Li/Li{sub 1-x}CoO{sub 2} cell. For the Li/Li{sub 1-x}NiO{sub 2} cells, C/13 and C/84 rates were applied. The in situ XRD data were collected during the first charge from 3.5 to 5.2 V. For the Li{sub 1-x}CoO{sub 2} cathode, in the composition range of x = 0 to x = 0.5, a new intermediate phase H2a was observed in addition to the two expected hexagonal phases H1 and H2. Inmore » the region very close to x = 0.5, some spectral signatures for the formation of a monoclinic phase M1 were also observed. Further, in the x = 0.8 to x = 1 region, the formation of a CdI{sub 2} type hexagonal phase has been confirmed. However, this new phase is transformed from a CdCl{sub 2} type hexagonal phase, rather than from a monoclinic phase M2 as previously reported in the literature. For the Li{sub 1-x}NiO{sub 2} system, by taking the advantage of the high resolution in 2{theta} angles through the synchrotron based XRD technique, they were able to identify a two-phase coexistence region of hexagonal phase H1 and H2, which has been mistakenly indexed as a single phase region for monoclinic phase M1. Interesting similarities and differences between these two systems are also discussed.« less

Synthesis of monoclinic IrTe 2 under high pressure and its physical properties

DOE PAGES

Li, X.; Yan, J. -Q.; Singh, D. J.; ...

2015-10-12

In a pressure-temperature (P-T) diagram for synthesizing IrTe 2 compounds, the well-studied trigonal (H) phase with the CdI 2-type structure is stable at low pressures. The superconducting cubic (C) phase can be synthesized under higher temperatures and pressures. A rhombohedral phase with the crystal structure similar to the C phase can be made at ambient pressure; but the phase contains a high concentration of Ir deficiency. Here, we report that a rarely studied monoclinic (M) phase can be stabilized in narrow ranges of pressure and temperature in this P-T diagram. Moreover, the peculiar crystal structure of the M-IrTe 2 eliminatesmore » the tendency to form Ir-Ir dimers found in the H phase. The M phase has been fully characterized by structural determination and measurements of electrical resistivity, thermoelectric power, DC magnetization, and specific heat. These physical properties have been compared with those in the H and C phases of Ir 1-xTe 2. Finally, we present magnetic and transport properties and specific heat of the M-IrTe 2 can be fully justified by calculations with the density-functional theory.« less

A simulation study of Large Area Crop Inventory Experiment (LACIE) technology

NASA Technical Reports Server (NTRS)

Ziegler, L. (Principal Investigator); Potter, J.

1979-01-01

The author has identified the following significant results. The LACIE performance predictor (LPP) was used to replicate LACIE phase 2 for a 15 year period, using accuracy assessment results for phase 2 error components. Results indicated that the (LPP) simulated the LACIE phase 2 procedures reasonably well. For the 15 year simulation, only 7 of the 15 production estimates were within 10 percent of the true production. The simulations indicated that the acreage estimator, based on CAMS phase 2 procedures, has a negative bias. This bias was too large to support the 90/90 criterion with the CV observed and simulated for the phase 2 production estimator. Results of this simulation study validate the theory that the acreage variance estimator in LACIE was conservative.

Volume 1: Survey of Available Information in Support of the Energy-Water Bandwidth Study of Desalination Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, Prakash; Aghajanzadeh, Arian; Sheaffer, Paul

The U.S. Department of Energy (DOE) has set a goal to reduce the cost of seawater desalination systems to $0.50/ cubic meter (m 3) through the development of technology pathways to reduce energy, capital, operating, soft, and system integration costs.1 In support of this goal and to evaluate the technology pathways to lower the energy and carbon intensity of desalination while also reducing the total water cost, DOE is undertaking a comprehensive study of the energy consumption and carbon dioxide (CO 2) emissions for desalination technologies and systems. This study is being undertaken in two phases. Phase 1, Survey ofmore » Available Information in Support of the Energy-Water Bandwidth Study of Desalination Systems, collected the background information that will underpin Phase 2, the Energy Water Bandwidth Study for Desalination Systems. This report (Volume 1) summarizes the results from Phase 1. The results from Phase 2 will be summarized in Volume 2: Energy Water Bandwidth Study for Desalination Systems (Volume 2). The analysis effort for Phase 2 will utilize similar methods as other industry-specific Energy Bandwidth Studies developed by DOE,2 which has provided a framework to evaluate and compare energy savings potentials within and across manufacturing sectors at the macroscale. Volume 2 will assess the current state of desalination energy intensity and reduction potential through the use of advanced and emerging technologies. For the purpose of both phases of study, energy intensity is defined as the amount of energy required per unit of product water output (for example, kilowatt-hours per cubic meter of water produced). These studies will expand the scope of previous sectorial bandwidth studies by also evaluating CO 2 intensity and reduction opportunities and informing a techno-economic analysis of desalination systems. Volume 2 is expected to be completed in 2017.« less

The Study of the Phase Characteristics of Bragg Cells for Acousto-Optic Signal Processing

DTIC Science & Technology

1998-01-01

contractor will determine the relationship of phase characteristics between TeO2 and GaAs cells with their constructive and technical parameters. Design a...Braggcell TeO2 with minimal phase distortions operating near 100 MHz. Experimentally investigate the phase characteristics for a Bragg cell on TeO2 ...follows: The contractor will determine the relationship of phase characteristics between TeO2 and GaAs cells with their constructive and technical

A phase 1/2 dose-finding, safety, and activity study of cabazitaxel in pediatric patients with refractory solid tumors including tumors of the central nervous system.

PubMed

Manley, Peter E; Trippett, Tanya; Smith, Amy A; Macy, Margaret E; Leary, Sarah E S; Boklan, Jessica; Cohen, Kenneth J; Goldman, Stewart; Kilburn, Lindsay B; Dhall, Girish; Devin, Jeanne; Herzog, Cynthia E; Partap, Sonia; Fauchet, Floris; Badreddine, Emmy; Bernard, John P; Chi, Susan N

2018-05-11

This phase 1/2 study (NCT01751308) evaluated cabazitaxel in pediatric patients. Phase 1 determined the maximum tolerated dose (MTD) in patients with recurrent/refractory solid tumors, including central nervous system (CNS) tumors. Phase 2 evaluated activity in pediatric recurrent high-grade glioma (HGG) or diffuse intrinsic pontine glioma (DIPG). In phase 1, a 3 + 3 dose-escalation study design was followed. Cabazitaxel was administered at a starting dose of 20 mg/m 2 . Dose-limiting toxicities (DLTs) during cycle 1 were assessed to determine the MTD. Tumor response and cabazitaxel pharmacokinetics were also assessed. In phase 2, patients received cabazitaxel at the MTD determined in phase 1. Tumor responses were assessed every 9 weeks (modified Response Assessment in Neuro-oncology criteria). Progression-free survival and cabazitaxel pharmacokinetics were evaluated, and overall survival was estimated. In phase 1, 23 patients were treated, including 19 with CNS tumors. One patient had a partial response; five had stable disease for >3 cycles. Common adverse events included fatigue, diarrhea, nausea and vomiting, febrile neutropenia, and hypersensitivity reactions. Two of three DLTs (febrile neutropenia) occurred with a dose of 35 mg/m 2 ; the MTD was 30 mg/m 2 . Slightly higher cabazitaxel clearance was observed compared with adult trials. In phase 2, 16 patients (eight HGG and eight DIPG) were enrolled; 11 were evaluable for response and five withdrew (three due to anaphylaxis). All 11 patients progressed within four cycles. No responses were observed; the study was stopped due to futility. The safety profile of cabazitaxel was consistent with previous studies. The MTD (30 mg/m 2 ) was higher than the adult MTD. Cabazitaxel did not demonstrate activity in recurrent/refractory HGG or DIPG. © 2018 Wiley Periodicals, Inc.

Transformation of the θ-phase in Mg-Li-Al alloys: a density functional theory study.

PubMed

Zhang, Caili; Han, Peide; Zhang, Zhuxia; Dong, Minghui; Zhang, Lili; Gu, Xiangyang; Yang, Yanqing; Xu, Bingshe

2012-03-01

In Mg-Li-Al alloys, θ-phase MgAlLi(2) is a strengthening and metastable phase which is liable to be transformed to the equilibrium phase AlLi on overaging. While the structural details of the θ-phase MgAlLi(2) and the microscopic transformation are still unknown. In this paper, the structure of MgAlLi(2) unit cell was determined through X-ray powder diffraction simulation. Microscopic transformation process of θ-phase MgAlLi(2) was discussed in detail using first principles method.

In Situ X-ray Diffraction Studies of Li(sub x)Mn(sub 2)O(sub 4) Cathode Materials by Synchrotron X-ray Radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, X. Q.; Sun, X.; Lee, S. J.

In Situ x-ray diffraction studies on Li{sub x}Mn{sub 2}O{sub 4} spinel cathode materials during charge-discharge cycles were carried out by using a synchrotron as x-ray source. Lithium rich (x = 1.03-1.06) spinel materials obtained from two different sources were studied. Three cubic phases with different lattice constants were observed during charge-discharge cycles in all the samples when a Sufficiently low charge-discharge rate (C/10) was used. There are two regions of two-phase coexistence between these three phases, indicating that both phase transitions are first order. The separation of the Bragg peaks representing these three phases varies from sample to sample andmore » also depends on the charge-discharge rate. These results show that the de-intercalation of lithium in lithium-rich spinel cathode materials proceeds through a series of phase transitions from a lithium-rich phase to a lithium-poor phase and finally to a {lambda}-MnO{sub 2} like cubic phase, rather than through a continuous lattice constant contraction in a single phase.« less

Mesomorphic phase transitions of 3F7HPhF studied by complementary methods

NASA Astrophysics Data System (ADS)

Deptuch, Aleksandra; Jaworska-Gołąb, Teresa; Marzec, Monika; Pociecha, Damian; Fitas, Jakub; Żurowska, Magdalena; Tykarska, Marzena; Hooper, James

2018-02-01

Physical properties and the phase sequence of (S)-4‧-(1-methylheptyloxycarbonyl)biphenyl-4-yl 4-[7-(2,2,3,3,4,4,4-heptafluorobutoxy) heptyl-1-oxy]-2-fluorobenzoate exhibiting the liquid crystalline paraelectric smectic A*, ferroelectric smectic C* and antiferroelectric smectic CA* phases were studied by complementary methods in the temperature range from -125 to 120 °C. Differential scanning calorimetry measurements together with polarizing optical microscopy provided the phase sequence, including the glass transition and a cold crystallization. X-ray diffraction was used to obtain the unit-cell parameters of the crystal phase, as well as the layer thickness and correlation length in the liquid crystalline smectic phases. The tilt angle was found to reach 45°, as determined from the measurements of the layer thickness and molecular modeling. Relaxation processes in the smectic phases and the fragility parameter were studied using frequency-domain dielectric spectroscopy.

G2 phase-specific proteins of HeLa cells.

PubMed Central

Al-Bader, A A; Orengo, A; Rao, P N

1978-01-01

The objective of this study was to determine if HeLa cells irreversibly arrested in G2 phase of the cell cycle by a brief exposure to a nitrosourea compound were deficient in certain proteins when compared with G2-synchronized cells. Total cellular proteins of G2-synchronized, G2-arrested, and S phase-synchronized cells were compared by two-dimensional polyacrylamide gel electrophoresis. The S phase cells differed from the G2-synchronized and G2-arrested cells by the absence of about 35 and 25 protein spots, respectively, of a total of nearly 150. At least nine protein spots in the molecular weight range of 4--5 X 10(4) that were present in the G2-synchronized cells were absent in both the G2-arrested and the S phase cells. Thus, these studies suggest that the missing proteins are probably necessary for the transition of cells from G2 phase to mitosis. Supplying the missing proteins to the G2-arrested cells by fusion with G2-synchronized cells facilitated the entry of the former into mitosis. Images PMID:282623

Maintenance Procedure Display: Head Mounted Display (HMD) Evaluations

NASA Technical Reports Server (NTRS)

Whitmore, Milrian; Litaker, Harry L., Jr.; Solem, Jody A.; Holden, Kritina L.; Hoffman, Ronald R.

2007-01-01

A viewgraph presentation describing maintenance procedures for head mounted displays is shown. The topics include: 1) Study Goals; 2) Near Eye Displays (HMDs); 3) Design; 4) Phase I-Evaluation Methods; 5) Phase 1 Results; 6) Improved HMD Mounting; 7) Phase 2 -Evaluation Methods; 8) Phase 2 Preliminary Results; and 9) Next Steps.

Phase equilibria in the Bi 2TeO 5Bi 2SeO 5 system and a high temperature neutron powder diffraction study of Bi 2SeO 5

NASA Astrophysics Data System (ADS)

Dityatyev, Oleg A.; Smidt, Peer; Stefanovich, Sergey Yu; Lightfoot, Philip; Dolgikh, Valery A.; Opperman, Heinrich

2004-09-01

Phase equilibria in the Bi 2TeO 5Bi 2SeO 5 system were studied by X-ray, DTA and second harmonic generation (SHG). The samples were synthesized by solid state reactions of the Bi, Te and Se oxides. The phase diagram is interpreted as a quasibinary peritectic one with wide ranges of solid solutions on the basis of both compounds. The SHG study showed Bi 2SeO 5 to undergo a phase transition at about 250 °C. Neutron diffraction (25-650 °C) showed no major changes in the structure of Bi 2SeO 5 at high temperatures. However, the analysis of the oxygen atom thermal factors and site occupancies suggested that the mechanism of the phase transformation is an order-disorder transition involving reorientation of the SeO 3 group.

Overcoming ecologic bias using the two-phase study design.

PubMed

Wakefield, Jon; Haneuse, Sebastien J-P A

2008-04-15

Ecologic (aggregate) data are widely available and widely utilized in epidemiologic studies. However, ecologic bias, which arises because aggregate data cannot characterize within-group variability in exposure and confounder variables, can only be removed by supplementing ecologic data with individual-level data. Here the authors describe the two-phase study design as a framework for achieving this objective. In phase 1, outcomes are stratified by any combination of area, confounders, and error-prone (or discretized) versions of exposures of interest. Phase 2 data, sampled within each phase 1 stratum, provide accurate measures of exposure and possibly of additional confounders. The phase 1 aggregate-level data provide a high level of statistical power and a cross-classification by which individuals may be efficiently sampled in phase 2. The phase 2 individual-level data then provide a control for ecologic bias by characterizing the within-area variability in exposures and confounders. In this paper, the authors illustrate the two-phase study design by estimating the association between infant mortality and birth weight in several regions of North Carolina for 2000-2004, controlling for gender and race. This example shows that the two-phase design removes ecologic bias and produces gains in efficiency over the use of case-control data alone. The authors discuss the advantages and disadvantages of the approach.

The mediation effect of menstrual phase on negative emotion processing: evidence from N2.

PubMed

Wu, Haiyan; Chen, Chunping; Cheng, Dazhi; Yang, Suyong; Huang, Ruiwang; Cacioppo, Stephanie; Luo, Yue-Jia

2014-01-01

Numerous studies have shown a 'negativity bias' in emotion processing and effect of menstrual phase on emotion processing. Most of these results, however, did not match the arousal of different types of stimuli. The present study examined the time course of negative emotion processing across different menstrual phases (e.g., late luteal/premenstrual phase and follicular phase) when the arousal level of negative and neutral stimuli was equal. Following previous studies, an oddball paradigm was utilized in present study. Participants viewed neutral and negative (highly (HN) and moderately negative (MN)) stimuli with matched arousal and were asked to make deviant vs. standard judgments. The behavioral results showed a higher accuracy for HN stimuli than neutral stimuli, and the other comparisons were not significant. The major event-related potential (ERP) finding was that N2 amplitude was larger for MN than neutral in the late luteal phase, whereas such difference was absent during the follicular phase. Moreover, The N2 for HN stimuli was larger in late luteal phase than in follicular phase. Therefore, female may be with higher sensitivity to MN stimuli during late luteal phase than during follicular phase when the arousal of stimuli was well controlled. These results provide additional insight to premenstrual affective syndrome and affective disorder.

Organisational justice and change in justice as predictors of employee health: the Whitehall II study

PubMed Central

Kivimaki, M.; Ferrie, J.; Head, J.; Shipley, M.; Vahtera, J.; Marmot, M.

2004-01-01

Objective: Organisational justice has been proposed as a new way to examine the impact of psychosocial work environment on employee health. This article studied the justice of interpersonal treatment by supervisors (the relational component of organisational justice) as a predictor of health. Design: Prospective cohort study. Phase 1 (1985–88) measured relational justice, job demands, job control, social support at work, effort-reward imbalance, and self rated health. Relational justice was assessed again at phase 2 (1989–90) and self rated health at phase 2 and phase 3 (1991–93). Setting: 20 civil service departments originally located in London. Participants: 10 308 civil servants (6895 men, 3413 women) aged 35–55. Outcome measure: Self rated health. Main results: Men exposed to low justice at phase 1 or adverse change in justice between phase 1 and phase 2 were at higher risk of poor health at phase 2 and phase 3. A favourable change in justice was associated with reduced risk. Adjustment for other stress indicators had little effect on results. In women, low justice at phase 1 predicted poor health at phase 2 and phase 3 before but not after adjustment for other stress indicators. Adverse change in justice was associated with worse health prospects irrespective of adjustments. Conclusions: The extent to which people are treated with justice in workplaces seems to predict their health independently of established stressors at work. Evidence on reduced health risk after favourable change in organisational justice implies a promising area for health interventions at workplace. PMID:15483310

Point defects in the 1 T' and 2 H phases of single-layer MoS2: A comparative first-principles study

NASA Astrophysics Data System (ADS)

Pizzochero, Michele; Yazyev, Oleg V.

2017-12-01

The metastable 1 T' phase of layered transition metal dichalcogenides has recently attracted considerable interest due to electronic properties, possible topological phases, and catalytic activity. We report a comprehensive theoretical investigation of intrinsic point defects in the 1 T' crystalline phase of single-layer molybdenum disulfide (1 T'-MoS2 ) and provide comparison to the well-studied semiconducting 2 H phase. Based on density functional theory calculations, we explore a large number of configurations of vacancy, adatom, and antisite defects and analyze their atomic structure, thermodynamic stability, and electronic and magnetic properties. The emerging picture suggests that, under thermodynamic equilibrium, 1 T'-MoS2 is more prone to hosting lattice imperfections than the 2 H phase. More specifically, our findings reveal that the S atoms that are closer to the Mo atomic plane are the most reactive sites. Similarly to the 2 H phase, S vacancies and adatoms in 1 T'-MoS2 are very likely to occur while Mo adatoms and antisites induce local magnetic moments. Contrary to the 2 H phase, Mo vacancies in 1 T'-MoS2 are expected to be an abundant defect due to the structural relaxation that plays a major role in lowering the defect formation energy. Overall, our study predicts that the realization of high-quality flakes of 1 T'-MoS2 should be carried out under very careful laboratory conditions but at the same time the facile defects introduction can be exploited to tailor physical and chemical properties of this polymorph.

Comparing oncology clinical programs by use of innovative designs and expected net present value optimization: Which adaptive approach leads to the best result?

PubMed

Parke, Tom; Marchenko, Olga; Anisimov, Vladimir; Ivanova, Anastasia; Jennison, Christopher; Perevozskaya, Inna; Song, Guochen

2017-01-01

Designing an oncology clinical program is more challenging than designing a single study. The standard approaches have been proven to be not very successful during the last decade; the failure rate of Phase 2 and Phase 3 trials in oncology remains high. Improving a development strategy by applying innovative statistical methods is one of the major objectives of a drug development process. The oncology sub-team on Adaptive Program under the Drug Information Association Adaptive Design Scientific Working Group (DIA ADSWG) evaluated hypothetical oncology programs with two competing treatments and published the work in the Therapeutic Innovation and Regulatory Science journal in January 2014. Five oncology development programs based on different Phase 2 designs, including adaptive designs and a standard two parallel arm Phase 3 design were simulated and compared in terms of the probability of clinical program success and expected net present value (eNPV). In this article, we consider eight Phase2/Phase3 development programs based on selected combinations of five Phase 2 study designs and three Phase 3 study designs. We again used the probability of program success and eNPV to compare simulated programs. For the development strategies, we considered that the eNPV showed robust improvement for each successive strategy, with the highest being for a three-arm response adaptive randomization design in Phase 2 and a group sequential design with 5 analyses in Phase 3.

Sundstrand’s Precision Metal Forming Cell. Industrial Modernization Incentive Program (IMIP). Phase 2

DTIC Science & Technology

1991-03-01

1-2 1.4 CONCLUSIONS AND RECOMMENDATIONS ....................... 1-2 20. PHASE II MANAGEMENT PLAN...2-1 2.1 PROGRAM MANAGEMENT ................................... 2-1 2.2 IM IP TEAM...Barbier, reference Section 2.0 (Phase II Management Plan), is complete and this report provides the results of the Phase II study. 1.2 OBJECTIVES The

High pressure spectroscopic studies of phase transition in VO2

NASA Astrophysics Data System (ADS)

Basu, Raktima; Mishra, K. K.; Ravindran, T. R.; Dhara, Sandip

2018-04-01

Vanadium dioxide (VO2) exhibits a reversible first-order metal to insulator transition (MIT) at a technologically important temperature of 340K. A structural phase transition (SPT) from monoclinic M1 to rutile tetragonal R is also reported via another two intermediate phases of monoclinic M2 and triclinic T. Metastable monoclinic M2 phase of VO2 was synthesized by Mg doping in the vapour transport process. Raman spectroscopic measurements were carried out at high pressure on V1-xMgxO2 microrods. Two reversible structural phase transitions from monoclinic M2 to triclinic T at 1.6 GPa and T to monoclinic M1 at 3.2 GPa are observed and are explained by structural relaxation of the strained phases.

A study of space-rated connectors using a robot end-effector

NASA Technical Reports Server (NTRS)

Nguyen, Charles C.

1995-01-01

The main research activities have been directed toward the study of the Robot Operated Materials Processing System (ROMPS), developed at GSFC under a flight project to investigate commercially promising in-space material processes and to design reflyable robot automated systems to be used in the above processes for low-cost operations. The research activities can be divided into two phases. Phase 1 dealt with testing of ROMPS robot mechanical interfaces and compliant device using a Stewart Platform testbed and Phase 2 with computer simulation study of the ROMPS robot control system. This report provides a summary of the results obtained in Phase 1 and Phase 2.

Pressure-induced phase transitions of exposed curved surface nano-TiO{sub 2} with high photocatalytic activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Yanwei, E-mail: yanwei.huang@hpstar.ac.cn, E-mail: wangling@hpstar.ac.cn; College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018; Chen, Fengjiao

We report a unique phase transition in compressed exposed curved surface nano-TiO{sub 2} with high photocatalytic activity using in situ synchrotron X-ray diffraction and Raman Spectroscopy. High-pressure studies indicate that the anatase phase starts to transform into baddeleyite phase upon compression at 19.4 GPa, and completely transforms into the baddeleyite phase above 24.6 GPa. Upon decompression, the baddeleyite phase was maintained until the pressure was released to 6.4 GPa and then transformed into the α-PbO{sub 2} phase at 2.7 GPa. Together with the results of high-resolution transmission electron microscopy and the pressure-volume relationship, this phase transition's characteristics during the compression-decompression cycle demonstrate that themore » truncated biconic morphology possessed excellent stability. This study may provide an insight to the mechanisms of stability for high photocatalytic activity of nano-TiO{sub 2}.« less

Harnessing Implementation Science to Increase the Impact of Health Disparity Research

PubMed Central

Chinman, Matthew; Woodward, Eva N.; Curran, Geoffrey M.; Hausmann, Leslie R. M.

2017-01-01

Background Health disparities are differences in health or health care between groups based on social, economic, and/or environmental disadvantage. Disparity research often follows three steps: detecting (Phase 1), understanding (Phase 2), and reducing (Phase 3), disparities. While disparities have narrowed over time, many remain. Objectives We argue that implementation science could enhance disparities research by broadening the scope of Phase 2 studies and offering rigorous methods to test disparity-reducing implementation strategies in Phase 3 studies. Methods We briefly review the focus of Phase 2 and Phase 3 disparities research. We then provide a decision tree and case examples to illustrate how implementation science frameworks and research designs could further enhance disparity research. Results Most health disparities research emphasizes patient and provider factors as predominant mechanisms underlying disparities. Applying implementation science frameworks like the Consolidated Framework for Implementation Research could help disparities research widen its scope in Phase 2 studies and, in turn, develop broader disparities-reducing implementation strategies in Phase 3 studies. Many Phase 3 studies of disparity reducing implementation strategies are similar to case studies, whose designs are not able to fully test causality. Implementation science research designs offer rigorous methods that could accelerate the pace at which equity is achieved in real world practice. Conclusions Disparities can be considered a “special case” of implementation challenges—when evidence-based clinical interventions are delivered to, and received by, vulnerable populations at lower rates. Bringing together health disparities research and implementation science could advance equity more than either could achieve on their own. PMID:28806362

Effect of impurity on high pressure behavior of nano indium titanate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chitnis, Abhishek, E-mail: abhishekchitnis87@gmail.com; Garg, Nandini; Mishra, A. K.

2015-06-24

Angle dispersive x-ray diffraction studies were carried out on a mixture of nano particles of indium titanate, indium oxide, and disordered TiO{sub 2} upto pressures of ∼ 45 GPa. Our studies show that indium titanate undergoes a partial decomposition to its constituent high pressure oxides. However, concomitantly a very small fraction of indium titanate transforms to a denser phase at ∼ 27.5 GPa. This transformation to new phase was found to be irreversible. At this pressure even cubic In{sub 2}O{sub 3} transformed to the In{sub 2}O{sub 3} (II) (iso-structural to Rh{sub 2}O{sub 3} (II)) phase, without any signature of themore » intermediate corundum phase. The high pressure In{sub 2}O{sub 3} (II) phase transforms to the corundum structure on release of pressure. These studies indicate that the presence of a large fraction of seed impurities could have facilitated the decomposition of indium titanate into its constituent oxides at the cost of its incomplete transformation to the high pressure denser phase.« less

An evaluation of North Carolina Department of Transportation wetland mitigation sites : selected case studies, phase 2 report.

DOT National Transportation Integrated Search

2012-03-01

Phase 1 of this study evaluated 50 NCDOT wetland compensatory mitigation sites and 11 reference sites in 1999. The : Phase 2 component (this report) examines five of the compensatory mitigation sites to provide a more in-depth analysis. The : objecti...

New Baxter phase in the Ashkin-Teller model on a cubic lattice

NASA Astrophysics Data System (ADS)

Santos, J. P.; Rosa, D. S.; Sá Barreto, F. C.

2018-02-01

The mean field theory results are obtained from the Bogoliubov inequality for the spin-1/2 Ashkin-Teller model on a cubic lattice for different cluster sizes. The phase diagram, magnetization and free energy are obtained. From those expressions we observed a new phase in the model. Denoted in the course of this work by Baxter(2) this new phase presents 〈 S 〉 ≠ 〈 σ 〉 ≠ 0. The phase transitions between the Baxter(2) and the others well known phases for the model are studied and classified.

Phase diagram of URu 2-xFe xSi 2 in high magnetic fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ran, S.; Jeon, I.; Kanchanavatee, N.

2017-03-01

The search for the order parameter of the hidden order (HO) phase in URu 2Si 2 has attracted an enormous amount of attention for the past three decades. Measurements in high magnetic fields H up to 45~T reveal that URu 2Si 2 displays behavior that is consistent with quantum criticality at a field near 35~T, where a cascade of novel quantum phases was found at and around the quantum critical point, suggesting the existence of competing order parameters. Experiments at high pressure P reveal that a first order transition from the HO phase to a large moment antiferromagnetic (LMAFM) phasemore » occurs under pressure at a critical pressure Pc. We have recently demonstrated that tuning URu 2Si 2 by substitution of Fe for Ru offers an opportunity to study the HO and LMAFM phases at atmospheric pressure. In this study, we conducted electrical resistance measurements on URu 2-xFe xSi 2 for H < 65 T using the pulsed field facility at the NHMFL in Los Alamos, in order to establish the temperature T vs. H phase diagram of URu 2-xFe xSi 2 under magnetic fields.« less

Western Wind and Solar Integration Study Phase 2 (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lew, D.; Brinkman, G.; Ibanez, E.

This presentation accompanies Phase 2 of the Western Wind and Solar Integration Study, a follow-on to Phase 1, which examined the operational impacts of high penetrations of variable renewable generation on the electric power system in the West and was one of the largest variable generation studies to date. High penetrations of variable generation can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 calculated these costs and emissions, and simulated grid operations for a year to investigate the detailed impact of variable generation on the fossil-fueled fleet. The presentation highlights the scopemore » of the study and results.« less

Prevalence of musculoskeletal diseases in Guatemala, Central America: the COPCORD study of 2 populations.

PubMed

Obregón-Ponce, Ariel; Iraheta, Isa; García-Ferrer, Helga; Mejia, Bayardo; García-Kutzbach, Abraham

2012-06-01

Guatemala is a multiethnic, multilingual, and multicultural country. We have evaluated 2 different ethnic groups from (1) San Juan Sacatepéquez County (SJSC), a rural population (30% illiterate), with 65% from Kaqchiquel ethnic group; and (2) Zone 5 of Guatemala City (Z5GC), an urban population (6.6% illiterate), with 95.5% mestizos. This study aimed to measure simultaneously the prevalence of rheumatic diseases in these 2 Guatemalan populations, both located in the State of Guatemala. A convenience sample of 4000 inhabitants 15 years and older was selected in each group. The Core Community Oriented Program for Control of Rheumatic Diseases Questionnaire was used in this survey. Phase 1 was for screening (identification of study subjects), phase 2 was for obtaining information from subjects with musculoskeletal complaints, and phase 3 was for rheumatologic diagnostic purposes. Phases 1 and 2 were performed by 6 interviewers. Phase 3 was completed by 4 rheumatologists. In phase I, 8000 subjects were identified in both groups. In phase II, 949 subjects reported musculoskeletal complaints: 371 (39%) in Z5GC and 578 (61%) in SJSC. In phase III, 419 patients were clinically evaluated: 141 (34%) in Z5GC and 278 (66%) in SJSC. The most prevalent musculoskeletal diseases were (1) osteoarthritis, (2) soft tissue rheumatism, (3) rheumatoid arthritis, (4) low back pain, and (5) arthralgias of unknown etiology. Osteoarthritis and soft tissue rheumatism were significantly more common in the rural population. The most prevalent musculoskeletal diseases in Guatemala seem to be similar to those in most previous Community Oriented Program for Control of Rheumatic Diseases studies. Most subjects were still working. Further studies examining medical care received and impact on function can now be of interest.

Collapse of superconductivity in cuprates via ultrafast quenching of phase coherence

DOE PAGES

Boschini, F.; da Silva Neto, E. H.; Razzoli, E.; ...

2018-04-02

The possibility of driving phase transitions in low-density condensates through the loss of phase coherence alone has far-reaching implications for the study of quantum phases of matter. This has inspired the development of tools to control and explore the collective properties of condensate phases via phase fluctuations. Electrically gated oxide interfaces, ultracold Fermi atoms and cuprate superconductors, which are characterized by an intrinsically small phase stiffness, are paradigmatic examples where these tools are having a dramatic impact. In this study, we use light pulses shorter than the internal thermalization time to drive and probe the phase fragility of the Bimore » 2Sr 2CaCu 2O 8+δ cuprate superconductor, completely melting the superconducting condensate without affecting the pairing strength. The resulting ultrafast dynamics of phase fluctuations and charge excitations are captured and disentangled by time-resolved photoemission spectroscopy. This work demonstrates the dominant role of phase coherence in the superconductor-to-normal state phase transition and offers a benchmark for non-equilibrium spectroscopic investigations of the cuprate phase diagram.« less

Collapse of superconductivity in cuprates via ultrafast quenching of phase coherence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boschini, F.; da Silva Neto, E. H.; Razzoli, E.

The possibility of driving phase transitions in low-density condensates through the loss of phase coherence alone has far-reaching implications for the study of quantum phases of matter. This has inspired the development of tools to control and explore the collective properties of condensate phases via phase fluctuations. Electrically gated oxide interfaces, ultracold Fermi atoms and cuprate superconductors, which are characterized by an intrinsically small phase stiffness, are paradigmatic examples where these tools are having a dramatic impact. In this study, we use light pulses shorter than the internal thermalization time to drive and probe the phase fragility of the Bimore » 2Sr 2CaCu 2O 8+δ cuprate superconductor, completely melting the superconducting condensate without affecting the pairing strength. The resulting ultrafast dynamics of phase fluctuations and charge excitations are captured and disentangled by time-resolved photoemission spectroscopy. This work demonstrates the dominant role of phase coherence in the superconductor-to-normal state phase transition and offers a benchmark for non-equilibrium spectroscopic investigations of the cuprate phase diagram.« less

Efficacy and safety of tofacitinib in patients with active rheumatoid arthritis: review of key Phase 2 studies.

PubMed

Fleischmann, Roy; Kremer, Joel; Tanaka, Yoshiya; Gruben, David; Kanik, Keith; Koncz, Tamas; Krishnaswami, Sriram; Wallenstein, Gene; Wilkinson, Bethanie; Zwillich, Samuel H; Keystone, Edward

2016-12-01

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). Here, the safety and efficacy data from five Phase 2 studies of tofacitinib in patients with RA are summarized. Tofacitinib 1-30 mg twice daily was investigated, as monotherapy and in combination with methotrexate, in patients with RA. Tofacitinib 20 mg once daily was investigated in one study. Tofacitinib 5 and 10 mg twice daily were selected for investigation in Phase 3 studies; therefore, the efficacy and safety of tofacitinib 5 and 10 mg twice daily in Phase 2 studies are the focus of this review. Tofacitinib ≥ 5 mg twice daily was efficacious in a dose-dependent manner, with statistically significant and clinically meaningful reductions in the signs and symptoms of RA and patient-reported outcomes. The safety profile was consistent across studies. The efficacy and safety profile of tofacitinib in Phase 2 studies supported its further investigation and the selection of tofacitinib 5 mg twice daily and tofacitinib 10 mg twice daily for evaluation in Phase 3 studies. © 2016 The Authors. International Journal of Rheumatic Diseases published by Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.

Spin ordering and electronic texture in the bilayer iridate Sr3Ir2O7

NASA Astrophysics Data System (ADS)

Dhital, Chetan; Khadka, Sovit; Yamani, Z.; de la Cruz, Clarina; Hogan, T. C.; Disseler, S. M.; Pokharel, Mani; Lukas, K. C.; Tian, Wei; Opeil, C. P.; Wang, Ziqiang; Wilson, Stephen D.

2012-09-01

Through a neutron scattering, charge transport, and magnetization study, the correlated ground state in the bilayer iridium oxide Sr3Ir2O7 is explored. Our combined results resolve scattering consistent with a high temperature magnetic phase that persists above 600 K, reorients at the previously defined TAF=280 K, and coexists with an electronic ground state whose phase behavior suggests the formation of a fluctuating charge or orbital phase that freezes below T*≈70 K. Our study provides a window into the emergence of multiple electronic order parameters near the boundary of the metal to insulator phase transition of the 5d Jeff=1/2 Mott phase.

Mineralogical changes of a well cement in various H2S-CO2(-brine) fluids at high pressure and temperature.

PubMed

Jacquemet, Nicolas; Pironon, Jacques; Saint-Marc, Jérémie

2008-01-01

The reactivity of a crushed well cement in contact with (1) a brine with dissolved H2S-CO2; (2) a dry H2S-CO2 supercritical phase; (3) a two-phase fluid associating a brine with dissolved H2S-CO2 and a H2S-CO2 supercritical phase was investigated in batch experiments at 500 bar and 120, 200 degrees C. All of the experiments showed that following 15-60 days cement carbonation occurred. The H2S reactivity with cement is limited since it only transformed the ferrites (minor phases) by sulfidation. It appeared that the primary parameter controlling the degree of carbonation (i.e., the rate of calcium carbonates precipitation and CSH (Calcium Silicate Hydrates) decalcification) is the physical state of the fluid phase contacting the minerals. The carbonation degree is complete when the minerals contact at least the dry H2S-CO2 supercritical phase and partial when they contactthe brine with dissolved H2S-CO2. Aragonite (calcium carbonate polymorph) precipitated specifically within the dry H2S-CO2 supercritical phase. CSH cristallinity is improved by partial carbonation while CSH are amorphized by complete carbonation. However, the features evidenced in this study cannot be directly related to effective features of cement as a monolith. Further studies involving cement as a monolith are necessary to ascertain textural, petrophysical, and mechanical evolution of cement.

Impact of a multidimensional infection control approach on catheter-associated urinary tract infection rates in an adult intensive care unit in Lebanon: International Nosocomial Infection Control Consortium (INICC) findings.

PubMed

Kanj, Souha S; Zahreddine, Nada; Rosenthal, Victor Daniel; Alamuddin, Lamia; Kanafani, Zeina; Molaeb, Bassel

2013-09-01

The objective of this study was to assess the impact of a multidimensional infection control approach for the reduction of catheter-associated urinary tract infection (CAUTI) in an adult intensive care unit (ICU) of a hospital member of the International Nosocomial Infection Control Consortium (INICC) in Lebanon. A before-after prospective active surveillance study was carried out to determine rates of CAUTI in 1506 ICU patients, hospitalized during 10 291 bed-days. The study period was divided into two phases: phase 1 (baseline) and phase 2 (intervention). During phase 1, surveillance was performed applying the definitions of the US Centers for Disease Control and Prevention National Healthcare Safety Network (CDC/NHSN). In phase 2, we adopted a multidimensional approach that included: (1) a bundle of infection control interventions, (2) education, (3) surveillance of CAUTI rates, (4) feedback on CAUTI rates, (5) process surveillance, and (6) performance feedback. We used random effects Poisson regression to account for clustering of CAUTI rates across time-periods. We recorded a total of 9829 urinary catheter-days: 306 in phase 1 and 9523 in phase 2. The rate of CAUTI was 13.07 per 1000 urinary catheter-days in phase 1, and was decreased by 83% in phase 2 to 2.21 per 1000 urinary catheter-days (risk ratio 0.17; 95% confidence interval 0.06-0.5; p=0.0002). Our multidimensional approach was associated with a significant reduction in the CAUTI rate. Copyright © 2013. Published by Elsevier Ltd.

Impact of a multidimensional infection control strategy on catheter-associated urinary tract infection rates in the adult intensive care units of 15 developing countries: findings of the International Nosocomial Infection Control Consortium (INICC).

PubMed

Rosenthal, V D; Todi, S K; Álvarez-Moreno, C; Pawar, M; Karlekar, A; Zeggwagh, A A; Mitrev, Z; Udwadia, F E; Navoa-Ng, J A; Chakravarthy, M; Salomao, R; Sahu, S; Dilek, A; Kanj, S S; Guanche-Garcell, H; Cuéllar, L E; Ersoz, G; Nevzat-Yalcin, A; Jaggi, N; Medeiros, E A; Ye, G; Akan, Ö A; Mapp, T; Castañeda-Sabogal, A; Matta-Cortés, L; Sirmatel, F; Olarte, N; Torres-Hernández, H; Barahona-Guzmán, N; Fernández-Hidalgo, R; Villamil-Gómez, W; Sztokhamer, D; Forciniti, S; Berba, R; Turgut, H; Bin, C; Yang, Y; Pérez-Serrato, I; Lastra, C E; Singh, S; Ozdemir, D; Ulusoy, S

2012-10-01

We aimed to evaluate the impact of a multidimensional infection control strategy for the reduction of the incidence of catheter-associated urinary tract infection (CAUTI) in patients hospitalized in adult intensive care units (AICUs) of hospitals which are members of the International Nosocomial Infection Control Consortium (INICC), from 40 cities of 15 developing countries: Argentina, Brazil, China, Colombia, Costa Rica, Cuba, India, Lebanon, Macedonia, Mexico, Morocco, Panama, Peru, Philippines, and Turkey. We conducted a prospective before-after surveillance study of CAUTI rates on 56,429 patients hospitalized in 57 AICUs, during 360,667 bed-days. The study was divided into the baseline period (Phase 1) and the intervention period (Phase 2). In Phase 1, active surveillance was performed. In Phase 2, we implemented a multidimensional infection control approach that included: (1) a bundle of preventive measures, (2) education, (3) outcome surveillance, (4) process surveillance, (5) feedback of CAUTI rates, and (6) feedback of performance. The rates of CAUTI obtained in Phase 1 were compared with the rates obtained in Phase 2, after interventions were implemented. We recorded 253,122 urinary catheter (UC)-days: 30,390 in Phase 1 and 222,732 in Phase 2. In Phase 1, before the intervention, the CAUTI rate was 7.86 per 1,000 UC-days, and in Phase 2, after intervention, the rate of CAUTI decreased to 4.95 per 1,000 UC-days [relative risk (RR) 0.63 (95% confidence interval [CI] 0.55-0.72)], showing a 37% rate reduction. Our study showed that the implementation of a multidimensional infection control strategy is associated with a significant reduction in the CAUTI rate in AICUs from developing countries.

Integrative health care - Toward a common understanding: A mixed method study.

PubMed

Leach, Matthew J; Wiese, Marlene; Thakkar, Manisha; Agnew, Tamara

2018-02-01

To generate a multidisciplinary stakeholder-informed definition of integrative health care (IHC). A mixed-method study design was used, employing the use of focus groups/semi-structured interviews (phase-1) and document analysis (phases 2 and 3). Phase-1 recruited a purposive sample of Australian health consumers/health providers. Phase-2 interrogated websites of international IHC organisations for definitions of IHC. Phase-3 systematically searched bibliographic databases for articles defining IHC. Data were analysed using thematic analysis. Data were drawn from 54 health consumers/providers (phase-1), 23 IHC organisation webpages (phase-2) and 23 eligible articles (phase-3). Seven themes emerged from the data. Consensus was reached on a single, 65-word definition of IHC. An unambiguous definition of IHC is critical to establishing a clearer identity for IHC, as well as providing greater clarity for consumers, health providers and policy makers. In recognising the need for a clearer description, we propose a scientifically-grounded, multi-disciplinary stakeholder-informed definition of IHC. Copyright © 2017 Elsevier Ltd. All rights reserved.

Theoretical calculations of high-pressure phases of NiF2: An ab initio constant-pressure study

NASA Astrophysics Data System (ADS)

Kürkçü, Cihan; Merdan, Ziya; Öztürk, Hülya

2016-12-01

We have studied the structural properties of the antiferromagnetic NiF2 tetragonal structure with P42/ mnm symmetry using density functional theory (DFT) under rapid hydrostatic pressure up to 400 GPa. For the exchange correlation energy we used the local density approximation (LDA) of Ceperley and Alder (CA). Two phase transformations are successfully observed through the simulations. The structures of XF2-type compounds crystallize in rutile-type structure. NiF2 undergoes phase transformations from the tetragonal rutile-type structure with space group P42/ mnm to orthorhombic CaCl2-type structure with space group Pnnm and from this orthorhombic phase to monoclinic structure with space group C2/ m at 152 GPa and 360 GPa, respectively. These phase changes are also studied by total energy and enthalpy calculations. According to these calculations, we perdict these phase transformations at about 1.85 and 30 GPa.

Injustice at work and incidence of psychiatric morbidity: the Whitehall II study.

PubMed

Ferrie, J E; Head, J; Shipley, M J; Vahtera, J; Marmot, M G; Kivimäki, M

2006-07-01

Previous studies of organisational justice and mental health have mostly examined women and have not examined the effect of change in justice. To examine effects of change in the treatment of employees by supervisors (the relational component of organisational justice) on minor psychiatric morbidity, using a cohort with a large proportion of men. Data are from the Whitehall II study, a prospective cohort of 10 308 white-collar British civil servants (3143 women and 6895 men, aged 35-55 at baseline) (Phase 1, 1985-88). Employment grade, relational justice, job demands, job control, social support at work, effort-reward imbalance, physical illness, and psychiatric morbidity were measured at baseline. Relational justice was assessed again at Phase 2 (1989-90). The outcome was cases of psychiatric morbidity by Phases 2 and 3 (1991-93) among participants case-free at baseline. In analyses adjusted for age, grade, and baseline physical illness, women and men exposed to low relational justice at Phase 1 were at higher risk of psychiatric morbidity by Phases 2 and 3. Adjustment for other psychosocial work characteristics, particularly social support and effort-reward imbalance, partially attenuated these associations. A favourable change in justice between Phase 1 and Phase 2 reduced the immediate risk (Phase 2) of psychiatric morbidity, while an adverse change increased the immediate and longer term risk (Phase 3). This study shows that unfair treatment by supervisors increases risk of poor mental health. It appears that the employers' duty to ensure that employees are treated fairly at work also has benefits for health.

GNOSIS: guidelines for neuro-oncology: standards for investigational studies-reporting of phase 1 and phase 2 clinical trials.

PubMed

Chang, Susan M; Reynolds, Sharon L; Butowski, Nicholas; Lamborn, Kathleen R; Buckner, Jan C; Kaplan, Richard S; Bigner, Darell D

2005-10-01

We present guidelines to standardize the reporting of phase 1 and phase 2 neuro-oncology trials. The guidelines are also intended to assist with accurate interpretation of results from these trials, to facilitate the peer-review process, and to expedite the publication of important and accurate manuscripts. Our guidelines are summarized in a checklist format that can be used as a framework from which to construct a phase 1 or 2 clinical trial.

Dielectric Study of the Phase Transitions in [P(CH3)4]2CuY4 (Y = Cl, Br)

NASA Astrophysics Data System (ADS)

Gesi, Kazuo

2002-05-01

Phase transitions in [P(CH3)4]2CuY4 (Y = Cl, Br) have been studied by dielectric measurements. In [P(CH3)4]2CuCl4, a slight break and a discontinuous jump on the dielectric constant vs. temperature curve are seen at the normal-incommensurate and the incommensurate-commensurate phase transitions, respectively. A small peak of dielectric constant along the b-direction exists just above the incommensurate-to-commensurate transition temperature. The anisotropic dielectric anomalies of [P(CH3)4]2CuBr4 at phase transitions were measured along the three crystallographic axes. The pressure-temperature phase diagram of [P(CH3)4]2CuCl4 was determined. The initial pressure coefficients of the normal-to-incommensurate and the incommensurate-to-commensurate transition temperatures are 0.19 K/MPa and 0.27 K/MPa, respectively. The incommensurate phase in [P(CH3)4]2CuCl4 disappears at a triple point which exists at 335 MPa and 443 K. The stability and the pressure effects of the incommensurate phases are much different among the four [Z(CH3)4]2CuY4 crystals (Z = N, P; Y = Cl, Br).

orbital selective correlation reduce in collapse tetragonal phase of CaFe2(As0.935P0.065)2 and electronic structure reconstruction studied by angel resolved photoemission spectroscopy

NASA Astrophysics Data System (ADS)

Zeng, Lingkun

We performed an angle-resolved photoemission spectroscopy (ARPES) study of the CaFe2(As0.935P0.065)2 in the collapse tetragonal(CT) phase and uncollapse tetragonal(UCT) phase. We find in the CT phase the electronic correlation dramatically reduces respective to UCT phase. Meanwhile, the reduction of correlation in CT phase show an orbital selective effect: correlation in dxy reduces the most, and then dxz/yz, while the one in dz2-r2 almost keeps the same. In CT phase, almost all bands sink downwards to higher binding energy, leading to the hole like bands around Brillouin zone(BZ) center sink below EF compared with UCT phase. However, the electron pocket around Brillouin Zone(BZ) corner(M) in UCT phase, forms a hole pocket around BZ center(Z point) in CT phase. Moreover, the dxy exhibits larger movement down to higher binding energy, resulting in farther away from dyz/xz and closer to dxy.We propose the electron filling ,namely high spin state in UCT phase to low spin state in CT phase(due to competing between crystal structure field and Hund's coupling), other than the Fermi surface nesting might be responsible for the absent of magnetic ordering.

B-70 Aircraft Study. Volume 1

NASA Technical Reports Server (NTRS)

Johnson, V. T.

1972-01-01

This Phase 2 final report for the B-70 aircraft study contains the data location matrix, which provides a summary of the major cost, schedule, and technical items provided in the report; work breakdown structure; cost definitions; and B-70 program level summary data. The Phase 2 objective was to provide the B-70 aircraft data in accordance with the approved study plan. Several minor modifications to the original plan have been made as the result of the Phase 2 effort.

Fabrication of single phase 2D homologous perovskite microplates by mechanical exfoliation

NASA Astrophysics Data System (ADS)

Li, Junze; Wang, Jun; Zhang, Yingjun; Wang, Haizhen; Lin, Gaoming; Xiong, Xuan; Zhou, Weihang; Luo, Hongmei; Li, Dehui

2018-04-01

The two-dimensional (2D) Ruddlesden-Popper type perovskites have attracted intensive interest for their great environmental stability and various potential optoelectronic applications. Fundamental understanding of the photophysical and electronic properties of the 2D perovskites with pure single phase is essential for improving the performance of the optoelectronic devices and designing devices with new architectures. Investigating the optical and electronic properties of these materials with pure single phase is required to obtain pure single phase 2D perovskites. Here, we report on an alternative approach to fabricate (C4H9NH3)2(CH3NH3) n-1Pb n I3n+1 microplates with pure single n-number perovskite phase for n  >  2 by mechanical exfoliation. Micro-photoluminescence and absorption spectroscopy studies reveal that the as-synthesized 2D perovskite plates for n  >  2 are comprised by dominant n-number phase and small inclusions of hybrid perovskite phases with different n values, which is supported by excitation power dependent photoluminescence. By mechanical exfoliation method, 2D perovskite microplates with the thickness of around 20 nm are obtained, which surprisingly have single n-number perovskite phase for n  =  2-5. In addition, we have demonstrated that the exfoliated 2D perovskite microplates can be integrated with other 2D layered materials such as boron nitride, and are able to be transferred to prefabricated electrodes for photodetections. Our studies not only provide a strategy to prepare 2D perovskites with a single n-number perovskite phase allowing us to extract the basic optical and electronic parameters of pure phase perovskites, but also demonstrate the possibility to integrate the 2D perovskites with other 2D layered materials to extend the device’s functionalities.

CH5424802 (RO5424802) for patients with ALK-rearranged advanced non-small-cell lung cancer (AF-001JP study): a single-arm, open-label, phase 1-2 study.

PubMed

Seto, Takashi; Kiura, Katsuyuki; Nishio, Makoto; Nakagawa, Kazuhiko; Maemondo, Makoto; Inoue, Akira; Hida, Toyoaki; Yamamoto, Nobuyuki; Yoshioka, Hiroshige; Harada, Masao; Ohe, Yuichiro; Nogami, Naoyuki; Takeuchi, Kengo; Shimada, Tadashi; Tanaka, Tomohiro; Tamura, Tomohide

2013-06-01

Currently, crizotinib is the only drug that has been approved for treatment of ALK-rearranged non-small-cell lung cancer (NSCLC). We aimed to study the activity and safety of CH5424802, a potent, selective, and orally available ALK inhibitor. In this multicentre, single-arm, open-label, phase 1-2 study of CH5424802, we recruited ALK inhibitor-naive patients with ALK-rearranged advanced NSCLC from 13 hospitals in Japan. In the phase 1 portion of the study, patients received CH5424802 orally twice daily by dose escalation. The primary endpoints of the phase 1 were dose limiting toxicity (DLT), maximum tolerated dose (MTD), and pharmacokinetic parameters. In the phase 2 portion of the study, patients received CH5424802 at the recommended dose identified in the phase 1 portion of the study orally twice a day. The primary endpoint of the phase 2 was the proportion of patients who had an objective response. Treatment was continued in 21-day cycles until disease progression, intolerable adverse events, or withdrawal of consent. The analysis was done by intent to treat. This study is registered with the Japan Pharmaceutical Information Center, number JapicCTI-101264. Patients were enrolled between Sept 10, 2010, and April 18, 2012. The data cutoff date was July 31, 2012. In the phase 1 portion, 24 patients were treated at doses of 20-300 mg twice daily. No DLTs or adverse events of grade 4 were noted up to the highest dose; thus 300 mg twice daily was the recommended phase 2 dose. In the phase 2 portion of the study, 46 patients were treated with the recommended dose, of whom 43 achieved an objective response (93.5%, 95% CI 82.1-98.6) including two complete responses (4.3%, 0.5-14.8) and 41 partial responses (89.1%, 76.4-96.4). Treatment-related adverse events of grade 3 were recorded in 12 (26%) of 46 patients, including two patients each experiencing decreased neutrophil count and increased blood creatine phosphokinase. Serious adverse events occurred in five patients (11%). No grade 4 adverse events or deaths were reported. The study is still ongoing, since 40 of the 46 patients in the phase 2 portion remain on treatment. CH5424802 is well tolerated and highly active in patients with advanced ALK-rearranged NSCLC. Chugai Pharmaceutical Co, Ltd. Copyright © 2013 Elsevier Ltd. All rights reserved.

Phase study of SiO2-ZrO2 composites prepared from polymorphic combination of starting powders via a ball-milling followed by calcination

NASA Astrophysics Data System (ADS)

Musyarofah; Nurlaila, R.; Muwwaqor, N. F.; Saukani, M.; Kuswoyo, A.; Triwikantoro; Pratapa, S.

2017-04-01

The effects of SiO2-ZrO2 polymorphic combinations as starting powders and calcination temperature on phase composition of the SiO2-ZrO2 composites were studied. Stoichiometric (1:1 mol%) mixtures of the SiO2-ZrO2 composites were mechanically activated using a ball-milling for 5 h followed by calcinations at 1000, 1100 and 1200 °C for 3 h. The composites used in the present study were a-SiO2+ a-ZrO2, a-SiO2+ t-ZrO2, c-SiO2+ a-ZrO2 and c-SiO2+ t-ZrO2 which were symbolized by AA, AT, CA and CT, respectively. Prefixes a, t and c denote amorphous, tetragonal and cristobalite, respectively. The phase composition was determined by Rietveld analysis of X-ray diffraction (XRD) data using Rietica software. The identified phases for all calcined samples were a combination among t-ZrO2, c-SiO2, m-ZrO2 and zircon (ZrSiO4). Amorphous zirconia formed a transient tetragonal zirconia phase during heating, which reacted with silica to form zircon. The zircon phase was not found to form even at 1200 °C in the AT and CT mixtures and at 1100 °C in the CA mixture. The AA mixture in particular crystallized to form zircon at a lower temperature with more composition fraction than the others, ca 82.9 (14) mol%.

Monte Carlo Simulation Study of Atomic Structure of alnico Permanent Magnets

NASA Astrophysics Data System (ADS)

Nguyen, Manh Cuong; Wang, Cai-Zhuang; Ho, Kai-Ming

Lattice Monte Carlo simulation based on quinternary cluster expansion energy model is used to investigate nano-scale structure of alnico alloy, which is considered as a candidate material for rare-earth free high performance permanent magnets, especially for high or elevated temperature applications such as electric motor for vehicles. We observe phase decomposition of the master alnico alloy into FeCo-rich magnetic (α1) and NiAl-rich matrix (α2) phases. Concentrations of Fe and Co in α1 phase and Ni and Al in α2 phase are higher for lower annealing temperature. Ti is residing mostly in the α2 phase. The phase boundary between α1 and α2 phases are quite sharp with only few atomic layers. The α1 phase is in B2 ordering with Fe and Al occupying the α-site and Ni and Co occupying the β-site. The α2 phase is in L21 ordering with Al occupying the 4a-site. The phase composition profile again annealing temperature suggests that lower annealing temperature would improve the magnetism of α2 and diminish the magnetism of α2 phase, hence improve shape anisotropy of α1 phase rods and that of alnico.

Part 2: A field study of enhanced remediation of Toluene in the vadose zone using a nutrient solution

USGS Publications Warehouse

Tindall, J.A.; Weeks, E.P.; Friedel, M.

2005-01-01

The objective of this study was to test the effectiveness of a nitrate-rich nutrient solution and hydrogen peroxide (H2O2) to enhance in-situ microbial remediation of toluene in the unsaturated zone. Three sand-filled plots were tested in three phases (each phase lasting approximately 2 weeks). During the control phase, toluene was applied uniformly via sprinkler irrigation. Passive remediation was allowed to occur during this phase. A modified Hoagland nutrient solution, concentrated in 150 L of water, was tested during the second phase. The final phase involved addition of 230 moles of H2O2 in 150 L of water to increase the available oxygen needed for aerobic biodegradation. During the first phase, measured toluene concentrations in soil gas were reduced from 120 ppm to 25 ppm in 14 days. After the addition of nutrients during the second phase, concentrations were reduced from 90 ppm to about 8 ppm within 14 days, and for the third phase (H 2O2), toluene concentrations were about 1 ppm after only 5 days. Initial results suggest that this method could be an effective means of remediating a contaminated site, directly after a BTEX spill, without the intrusiveness and high cost of other abatement technologies such as bioventing or soil-vapor extraction. However, further tests need to be completed to determine the effect of each of the BTEX components. ?? Springer 2005.

Dietary protein modulates circadian changes in core body temperature and metabolic rate in rats.

PubMed

Yamaoka, Ippei; Nakayama, Mitsuo; Miki, Takanori; Yokoyama, Toshifumi; Takeuchi, Yoshiki

2008-02-01

We assessed the contribution of dietary protein to circadian changes in core body temperature (Tb) and metabolic rate in freely moving rats. Daily changes in rat intraperitoneal temperature, locomotor activity (LMA), whole-body oxygen consumption (VO2), and carbon dioxide production (VCO2) were measured before and during 4 days of consuming a 20% protein diet (20% P), a protein-free diet (0% P), or a pair-fed 20% P diet (20% P-R). Changes in Tb did not significantly differ between the 20% P and 20% P-R groups throughout the study. The Tb in the 0% P group remained elevated during the dark (D) phase throughout the study, but VO2, VCO2, and LMA increased late in the study when compared with the 20% P-R group almost in accordance with elevated Tb. By contrast, during the light (L) phase in the 0% P group, Tb became elevated early in the study and thereafter declined with a tendency to accompany significantly lower VO2 and VCO2 when compared with the 20% P group, but not the 20% P-R group. The respiratory quotient (RQ) in the 0% P group declined throughout the D phase and during the early L phase. By contrast, RQ in the 20% P-R group consistently decreased from the late D phase to the end of the L phase. Our findings suggest that dietary protein contributes to the maintenance of daily oscillations in Tb with modulating metabolic rates during the D phase. However, the underlying mechanisms of Tb control during the L phase remain obscure.

Phase relations in KxFe2-ySe2 and the structure of superconducting KxFe2Se2 via high-resolution synchrotron diffraction

NASA Astrophysics Data System (ADS)

Shoemaker, Daniel P.; Chung, Duck Young; Claus, Helmut; Francisco, Melanie C.; Avci, Sevda; Llobet, Anna; Kanatzidis, Mercouri G.

2012-11-01

Superconductivity in iron selenides has experienced a rapid growth, but not without major inconsistencies in the reported properties. For alkali-intercalated iron selenides, even the structure of the superconducting phase is a subject of debate, in part because the onset of superconductivity is affected much more delicately by stoichiometry and preparation than in cuprate or pnictide superconductors. If high-quality, pure, superconducting intercalated iron selenides are ever to be made, the intertwined physics and chemistry must be explained by systematic studies of how these materials form and by and identifying the many coexisting phases. To that end, we prepared pure K2Fe4Se5 powder and superconductors in the KxFe2-ySe2 system, and examined differences in their structures by high-resolution synchrotron and single-crystal x-ray diffraction. We found four distinct phases: semiconducting K2Fe4Se5, a metallic superconducting phase KxFe2Se2 with x ranging from 0.38 to 0.58, the phase KFe1.6Se2 with full K occupancy and no Fe vacancy ordering, and a oxidized phase K0.51(5)Fe0.70(2)Se that forms the PbClF structure upon exposure to moisture. We find that the vacancy-ordered phase K2Fe4Se5 does not become superconducting by doping, but the distinct iron-rich minority phase KxFe2Se2 precipitates from single crystals upon cooling from above the vacancy ordering temperature. This coexistence of separate metallic and semiconducting phases explains a broad maximum in resistivity around 100 K. Further studies to understand the solubility of excess Fe in the KxFe2-ySe2 structure will shed light on the maximum fraction of superconducting KxFe2Se2 that can be obtained by solid state synthesis.

Phase Restructuring in Transition Metal Dichalcogenides for Highly Stable Energy Storage.

PubMed

Leng, Kai; Chen, Zhongxin; Zhao, Xiaoxu; Tang, Wei; Tian, Bingbing; Nai, Chang Tai; Zhou, Wu; Loh, Kian Ping

2016-09-28

Achieving homogeneous phase transition and uniform charge distribution is essential for good cycle stability and high capacity when phase conversion materials are used as electrodes. Herein, we show that chemical lithiation of bulk 2H-MoS 2 distorts its crystalline domains in three primary directions to produce mosaic-like 1T' nanocrystalline domains, which improve phase and charge uniformity during subsequent electrochemical phase conversion. 1T'-Li x MoS 2 , a macroscopic dense material with interconnected nanoscale grains, shows excellent cycle stability and rate capability in a lithium rechargeable battery compared to bulk or exfoliated-restacked MoS 2 . Transmission electron microscopy studies reveal that the interconnected MoS 2 nanocrystals created during the phase change process are reformable even after multiple cycles of galvanostatic charging/discharging, which allows them to play important roles in the long term cycling performance of the chemically intercalated TMD materials. These studies shed light on how bulk TMDs can be processed into quasi-2D nanophase material for stable energy storage.

Carbon-doped Ge2Sb2Te5 phase change material: A candidate for high-density phase change memory application

NASA Astrophysics Data System (ADS)

Zhou, Xilin; Wu, Liangcai; Song, Zhitang; Rao, Feng; Zhu, Min; Peng, Cheng; Yao, Dongning; Song, Sannian; Liu, Bo; Feng, Songlin

2012-10-01

Carbon-doped Ge2Sb2Te5 material is proposed for high-density phase-change memories. The carbon doping effects on electrical and structural properties of Ge2Sb2Te5 are studied by in situ resistance and x-ray diffraction measurements as well as optical spectroscopy. C atoms are found to significantly enhance the thermal stability of amorphous Ge2Sb2Te5 by increasing the degree of disorder of the amorphous phase. The reversible electrical switching capability of the phase-change memory cells is improved in terms of power consumption with carbon addition. The endurance of ˜2.1 × 104 cycles suggests that C-doped Ge2Sb2Te5 film will be a potential phase-change material for high-density storage application.

Effects of Co and Mn doping in K0.8Fe2-ySe2 revisited.

PubMed

Zhou, Tingting; Chen, Xiaolong; Guo, Jiangang; Jin, Shifeng; Wang, Gang; Lai, Xiaofang; Ying, Tianping; Zhang, Han; Shen, Shijie; Wang, Shunchong; Zhu, Kaixing

2013-07-10

Accumulated evidence indicates that phase separation occurs in potassium intercalated iron selenides, a superconducting phase coexisting with the antiferromagnetic phase K2Fe4Se5, the so-called '245 phase'. Here, we report a comparative study of substitution effects by Co and Mn for Fe sites in K0.8Fe2-ySe2 within the phase separation scenario. Our results demonstrate that Co and Mn dopants have distinct differences in occupancy and hence in the suppression mechanism of superconductivity upon doping of Fe sites. In K0.8Fe2-xCoxSe2, Co prefers to occupy the lattice of the superconducting phase and suppresses superconductivity very quickly, obeying the magnetic pair-breaking mechanism or the collapse of the Fermi surface nesting mechanism. In contrast, in K0.8Fe1.7-xMnxSe2, Mn shows no preferential occupancy in the superconducting phase or the 245 phase. The suppression of superconductivity can be attributed to restraining of the superconducting phase and meanwhile inducing another non-superconducting phase by Mn doping.

Plastic behavior of two-phase intermetallic compounds based on L1{sub 2}-type (Al,Cr){sub 3}Ti

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, J.Y.; Wee, D.M.; Oh, M.H.

Plastic behavior of two-phase intermetallic compounds based on L1{sub 2}-type (Al,Cr){sub 3}Ti was investigated using compression test at R.T. and 77K. L1{sub 2} single phase alloys and two-phase alloys consisting of mainly L1{sub 2} phase and a few or 20% (mole percent) second phases were selected from Al-Ti-Cr phase diagram. In general, compared with L1{sub 2} single phase, two-phase alloys consisting of 20% second phase showed relatively high yield strength and poor ductility. Among the alloys, however, Al-21Ti-23Cr alloy consisting of 20% Cr{sub 2}Al phase showed available ductility as well as high yield strength. Plastic behavior of L1{sub 2} singlemore » phase alloys and two-phase alloys consisting of a few Cr{sub 2}Al was also investigated. Homogenization of arc melted ingots substantially reduced the amount of second phases but introduced extensive pore. When Cr content increased in L1{sub 2} single phase alloys after the homogenization, the volume fraction of pores in the alloys decreased, and no residual porosity was observed in two-phase alloys consisting of a few% Cr{sub 2}Al phase. Environmental effect on the ductility of the alloys was investigated using compression test at different strain rates (1.2 {times} 10{sup {minus}4}/s and 1.2 {times} 10{sup {minus}2}/s). Environmental embrittlement was least significant in Al-25Ti-10Cr alloy consisting of L1{sub 2} single phase among the alloys tested in this study. However, based on the combined estimation of the pore formation, environmental embrittlement and ingot cast structure, it could be supposed that Al-21Ti-23Cr alloy consisting of 20% Cr{sub 2}Al as a second phase is expected to show the best tensile elongation behavior among the materials tested.« less

Value of digit ratio 2D:4D, a biomarker of prenatal hormone exposure, is stable across the menstrual cycle.

PubMed

Klimek, Magdalena; Marcinkowska, Urszula M; Jasienska, Grazyna

2017-07-01

Digit ratio (2D:4D) is used as a marker of prenatal hormone exposure and, consequently, as a predictor of many characteristics throughout a woman's lifespan. A previous study has suggested that values of 2D:4D vary across menstrual cycles and further questioned the reliability of a single measurement of 2D:4D among cycling women, while another study failed to confirm these results. However, these studies estimated the timing of cycle phases based on a date of menstruation reported by participants and also had small sample sizes. For our study, we evaluated potential changes in 2D:4D values across a menstrual cycle in a group of women among whom the phases of the menstrual cycle were determined by hormonal (luteinizing hormone based) ovulation tests. We studied 32 naturally cycling women aged 22-37 from rural Poland. Lengths of second and fourth digits were measured based on scans of both hands taken three times (i.e. in the follicular phase, peri-ovulatory phase and luteal phase of the cycle) for each participant. No differences in 2D:4D value across the menstrual cycle were detected either when right-hand, left-hand, and mean 2D:4D for both hands were analysed, nor when difference in the 2D:4D value between hands (D left-right ) was evaluated. We documented that 2D:4D is independent of the phase of the menstrual cycle and these findings suggest that among naturally cycling women, a value of 2D:4D can be reliably obtained from measurements taken during any day of the menstrual cycle. Copyright © 2017 Elsevier B.V. All rights reserved.

Phase diagram, chemical stability and physical properties of the solid-solution Ba{sub 4}Nb{sub 2-x}Ta{sub x}O{sub 9}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dunstan, Matthew T., E-mail: m.dunstan@chem.usyd.edu.au; Southon, Peter D.; Kepert, Cameron J.

Through the construction of the Ba{sub 4}Nb{sub 2-x}Ta{sub x}O{sub 9} phase diagram, it was discovered that the unique high-temperature {gamma} phase is a thermodynamic intermediate between the low-temperature {alpha} phase (Sr{sub 4}Ru{sub 2}O{sub 9}-type) and a 6H-perovskite. Refined site occupancies for the {gamma} phase across the Ba{sub 4}Nb{sub 2-x}Ta{sub x}O{sub 9} solid-solution indicate that Nb preferentially occupies the tetrahedral sites over the octahedral sites in the structure. When annealed in a CO{sub 2}-rich atmosphere, all of the phases studied absorb large amounts of CO{sub 2} at high temperatures between {approx}700 and 1300 K. In situ controlled-atmosphere diffraction studies show thatmore » this behaviour is linked to the formation of BaCO{sub 3} on the surface of the material, accompanied by a Ba{sub 5}(Nb,Ta){sub 4}O{sub 15} impurity phase. In situ diffraction in humid atmospheres also confirms that these materials hydrate below {approx}1273K, and that this plays a critical role in the various reconstructive phase transitions as well as giving rise to proton conduction. - Graphical abstract: Thermodynamic phase diagram of Ba{sub 4}Nb{sub 2-x}Ta{sub x}O{sub 9}. Highlights: > {gamma}-Ba{sub 4}Nb{sub 2}O{sub 9} phase is a structural intermediate between the {alpha} and 6H-perovskite phases. > Ba{sub 4}Nb{sub 2}O{sub 9} and Ba{sub 4}Ta{sub 2}O{sub 9} decompose at high temperatures in the presence of CO{sub 2}. > These materials all absorb between 5% and 6% of CO{sub 2} by mass between {approx}800 and 1200 K.« less

Orbit transfer rocket engine technology program. Phase 2: Advanced engine study

NASA Technical Reports Server (NTRS)

Erickson, C.; Martinez, A.; Hines, B.

1987-01-01

In Phase 2 of the Advanced Engine Study, the Failure Modes and Effects Analysis (FMEA) maintenance-driven engine design, preliminary maintenance plan, and concept for space operable disconnects generated in Phase 1 were further developed. Based on the results of the vehicle contractors Orbit Transfer Vehicle (OTV) Concept Definition and System Analysis Phase A studies, minor revisions to the engine design were made. Additional refinements in the engine design were identified through further engine concept studies. These included an updated engine balance incorporating experimental heat transfer data from the Enhanced Heat Load Thrust Chamber Study and a Rao optimum nozzle contour. The preliminary maintenance plan of Phase 1 was further developed through additional studies. These included a compilation of critical component lives and life limiters and a review of the Space Shuttle Main Engine (SSME) operations and maintenance manual in order to begin outlining the overall maintenance procedures for the Orbit Transfer Vehicle Engine and identifying technology requirements for streamlining space-based operations. Phase 2 efforts also provided further definition to the advanced fluid coupling devices including the selection and preliminary design of a preferred concept and a preliminary test plan for its further development.

Observation of polyamorphism in the phase change alloy Ge1Sb2Te4

NASA Astrophysics Data System (ADS)

Kalkan, B.; Sen, S.; Cho, J.-Y.; Joo, Y.-C.; Clark, S. M.

2012-10-01

A high-pressure synchrotron x-ray diffraction study of the phase change alloy Ge1Sb2Te4 demonstrates the existence of a polyamorphic phase transition between the "as deposited" low density amorphous (LDA) phase and a high density amorphous (HDA) phase at ˜10 GPa. The entropy of the HDA phase is expected to be higher than that of the LDA phase resulting in a negative Clapeyron slope for this transition. These phase relations may enable the polyamorphic transition to play a role in the memory and data storage applications.

Phase 1/2 Study of the CD56-Targeting Antibody-Drug Conjugate Lorvotuzumab Mertansine (IMGN901) in Combination With Carboplatin/Etoposide in Small-Cell Lung Cancer Patients With Extensive-Stage Disease.

PubMed

Socinski, Mark A; Kaye, Frederic J; Spigel, David R; Kudrik, Fred J; Ponce, Santiago; Ellis, Peter M; Majem, Margarita; Lorigan, Paul; Gandhi, Leena; Gutierrez, Martin E; Nepert, Dale; Corral, Jesus; Ares, Luis Paz

2017-01-01

This trial assessed the safety and efficacy of LM in combination with carboplatin/etoposide therapy compared to carboplatin/etoposide treatment alone in patients with previously untreated extensive-disease small-cell lung cancer (ED-SCLC). A run-in phase 1 stage was used to determine the recommended phase 2 dose and characterize the dose-limiting toxicities of LM in combination with carboplatin/etoposide followed by LM alone in patients with CD56-positive solid tumors. In phase 2, chemotherapy-naive ED-SCLC patients were randomized 2:1 to carboplatin AUC (area under the plasma concentration vs. time curve) of 5 day 1 + etoposide 100 mg/m 2 days 1 to 3 plus LM (arm 1) or alone (arm 2). In the phase 1 study (n = 33), a dose of LM at 112 mg/m 2 with carboplatin/etoposide was identified as the recommended phase 2 dose. However, because of an increased incidence of peripheral neuropathy events during early phase 2, this dose was reduced to 90 mg/m 2 . In phase 2, a total of 94 and 47 evaluable patients were assigned to arms 1 and 2, respectively. No difference in median progression-free survival was observed between arms 1 and 2 (6.2 vs. 6.7 months). The most common treatment-emergent adverse event leading to discontinuation was peripheral neuropathy (29%). A total of 21 patients had a treatment-emergent adverse event leading to death (18 in arm 1 and 3 in arm 2); for 10 individuals, this was an infection (pneumonia or sepsis) deemed to be related to the study drug. The combination of LM plus carboplatin/etoposide did not improve efficacy over standard carboplatin/etoposide doublet therapy in ED-SCLC patients and showed increased toxicity, including a higher incidence of serious infections with fatal outcomes. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Hepatocellular carcinoma Early Detection Strategy study — EDRN Public Portal

Cancer.gov

Part 1: The first part of this study is to conduct follow-up for patients that were enrolled in the EDRN Phase 2 Validation Study called DCP (13). For this part of the study, four groups are defined as follows: a) Vanguard Controls are cirrhotic controls, from the Phase 2 trial that have not developed HCC and sign a new consent form for HEDS participation. These patients will be followed for a minimum of an additional 24 months and have biospecimens collected every 6 months. b) Vanguard Interval Controls are cirrhotic controls, from the Phase 2 trial that have not developed HCC and do not sign a new consent form for HEDS participation. This group will have outcome data abstracted from their medical records. c) Vanguard Interval Cases are cirrhotic controls from the Phase 2 trial that developed HCC after completion of the Phase 2 trial but prior to the current study. This group will have outcome data abstracted from their medical records. d) Vanguard Cases are HCC cases from the Phase 2 trial. This group will have outcome data abstracted from their medical records. Part 2: New Controls - The second part of this study is the new accrual of cirrhotic controls at the seven participating sites. These patients will be followed for a minimum of 24 months and have biospecimens collected every 6 months. Data will be collected every 6 months: ultrasound, AFP, liver function tests, complete blood counts, MELD scores and any changes in medical history, personal cancer history and family cancer history.

Contingency Management for Adolescent Smokers: An Exploratory Study

ERIC Educational Resources Information Center

Tevyaw, Tracy O'Leary; Gwaltney, Chad; Tidey, Jennifer W.; Colby, Suzanne M.; Kahler, Christopher W.; Miranda, Robert; Barnett, Nancy P.; Rohsenow, Damaris J.; Monti, Peter M.

2007-01-01

This exploratory study investigated the efficacy and feasibility of a contingency management (CM) protocol for adolescent smokers that included use of a reduction phase. Using a within-participants design, 19 adolescents completed three 7-day phases: (1) reinforcement for attendance and provision of breath samples (RA) phase, (2) a washout phase,…

Study on Ultrafast Photodynamics of Novel Multilayered Thin Films for Device Applications

DTIC Science & Technology

2004-07-31

study ultrafast phase-transition of VO2 thin film. This part of work was started right after the new laser installed. With better laser output...1-3]. With the purpose of combined effect that the proposed ultrafast phase-transition VO2 thin film deposited on a substrate of heavy metal...second point of focus was to study ultrafast phase-transition of VO2 thin film. This part of work was started right after the new laser installed

High pressure studies of A{sub 2}Mo{sub 3}O{sub 12} negative thermal expansion materials (A{sub 2}=Al{sub 2}, Fe{sub 2}, FeAl, AlGa)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, Lindsay; Gadient, Jennifer; Gao, Xiaodong

2016-05-15

High pressure powder X-ray diffraction studies of several A{sub 2}Mo{sub 3}O{sub 12} materials (A{sub 2}=Al{sub 2}, Fe{sub 2}, FeAl, and AlGa) were conducted up to 6–7 GPa. All materials adopted a monoclinic structure under ambient conditions, and displayed similar phase transition behavior upon compression. The initial isotropic compressibility first became anisotropic, followed by a small but distinct drop in cell volume. These patterns could be described by a distorted variant of the ambient pressure polymorph. At higher pressures, a distinct high pressure phase formed. Indexing results confirmed that all materials adopted the same high pressure phase. All changes were reversiblemore » on decompression, although some hysteresis was observed. The similarity of the high pressure cells to previously reported Ga{sub 2}Mo{sub 3}O{sub 12} suggested that this material undergoes the same sequence of transitions as all materials investigated in this paper. It was found that the transition pressures for all phase changes increased with decreasing radius of the A-site cations. - Graphical abstract: Overlay of variable pressure X-ray diffraction data of Al{sub 2}Mo{sub 3}O{sub 12} collected in a diamond anvil cell. Both subtle and discontinuous phase transitions are clearly observed. - Highlights: • The high pressure behavior of A{sub 2}Mo{sub 3}O{sub 12} (A=Al, Fe, (AlGa), (AlFe)) was studied. • All compounds undergo the same sequence of pressure-induced phase transitions. • The phase transition pressures correlate with the average size of the A-site cation. • All transitions were reversible with hysteresis. • Previously studied Ga{sub 2}Mo{sub 3}O{sub 12} undergoes the same sequence of transitions.« less

First-principles study of the liquid and amorphous phases of In2Te3

NASA Astrophysics Data System (ADS)

Dragoni, D.; Gabardi, S.; Bernasconi, M.

2017-08-01

Structural, dynamical, and electronic properties of the liquid and amorphous phase of the In2Te3 compound have been studied by means of density functional molecular dynamics simulations. This system is of interest as a phase change material, undergoing a fast and reversible change between the crystalline and amorphous phases upon heating. It can be seen as a constituent of ternary InSbTe alloys which are receiving attention for application in electronic phase change memories. Amorphous models of In2Te3 300 -atom large have been generated by quenching from the melt by using different exchange and correlation functionals and different descriptions of the van der Waals interaction. It turns out the local bonding geometry of the amorphous phase is mostly tetrahedral with corner and edge sharing tetrahedra similar to those found in the crystalline phases of the InTe, In2Te3 , and In2Te5 compounds. Benchmark calculations on the crystalline α phase of In2Te3 in the defective zincblend geometry have also been performed. The calculations reveal that the high symmetric F 4 ¯3 m structure inferred experimentally from x-ray diffraction for the α phase must actually result from a random distribution of Te-Te bonds in different octahedral cages formed by the coalescence of vacancies in the In sublattice.

Optimization of intermolecular potential parameters for the CO2/H2O mixture.

PubMed

Orozco, Gustavo A; Economou, Ioannis G; Panagiotopoulos, Athanassios Z

2014-10-02

Monte Carlo simulations in the Gibbs ensemble were used to obtain optimized intermolecular potential parameters to describe the phase behavior of the mixture CO2/H2O, over a range of temperatures and pressures relevant for carbon capture and sequestration processes. Commonly used fixed-point-charge force fields that include Lennard-Jones 12-6 (LJ) or exponential-6 (Exp-6) terms were used to describe CO2 and H2O intermolecular interactions. For force fields based on the LJ functional form, changes of the unlike interactions produced higher variations in the H2O-rich phase than in the CO2-rich phase. A major finding of the present study is that for these potentials, no combination of unlike interaction parameters is able to adequately represent properties of both phases. Changes to the partial charges of H2O were found to produce significant variations in both phases and are able to fit experimental data in both phases, at the cost of inaccuracies for the pure H2O properties. By contrast, for the Exp-6 case, optimization of a single parameter, the oxygen-oxygen unlike-pair interaction, was found sufficient to give accurate predictions of the solubilities in both phases while preserving accuracy in the pure component properties. These models are thus recommended for future molecular simulation studies of CO2/H2O mixtures.

Pressure induced phase transformations in NaZr{sub 2}(PO{sub 4}){sub 3} studied by X-ray diffraction and Raman spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamali, K.; Ravindran, T.R., E-mail: trr@igcar.gov.in; Chandra Shekar, N.V.

2015-01-15

Raman spectroscopic and x-ray diffraction measurements on NaZr{sub 2}(PO{sub 4}){sub 3} were carried out up to 30 GPa at close intervals of pressure, revealing two structural phase transformations around 5 and 6.6 GPa. The second phase at 5.4 GPa is indexed to R3 space group similar to that of RbTi{sub 2}(PO{sub 4}){sub 3}. Bulk modulus decreases abruptly from 53 GPa (B′=4) to 36 GPa (B′=4) in the second phase above 5 GPa. The structure of the phase III at 8.2 GPa is indexed as orthorhombic similar to the case of high temperature phase of monoclinic LiZr{sub 2}(PO{sub 4}){sub 3}. Bulkmore » modulus of this phase III is found to be 65 GPa (B′=4), which is higher than that of the ambient phase. In high pressure Raman studies, modes corresponding to 72 and 112 cm{sup −1} soften in the ambient phase whereas around 5 GPa, the ones at 60, 105, 125 and 190 cm{sup −1} soften with pressure contributing negatively to overall thermal expansion. - Graphical abstract: High pressure study of NaZr{sub 2}(PO{sub 4}){sub 3} shows a reversible phase transition from R-3c to R3 structure at 5 GPa accompanied by an increase in compressibility signaling a polyhedral tilt transition. - Highlights: • NaZr{sub 2}(PO{sub 4}){sub 3} undergoes two reversible phase transitions at 5 and 6.7 GPa. • The transition at 5 is from rhombohedral R-3c to R3 structure. • Bulk modulus of NaZr{sub 2}(PO{sub 4}){sub 3} is lower than that for the isostructural RbTi{sub 2}(PO{sub 4}){sub 3.} • Compressibility increases with substitution of a smaller cation (Na). • Zr-translational and PO{sub 4} librational modes contribute to phase transition.« less

A fluorescence correlation spectroscopy study of the diffusion of an organic dye in the gel phase and fluid phase of a single lipid vesicle.

PubMed

Ghosh, Subhadip; Adhikari, Aniruddha; Sen Mojumdar, Supratik; Bhattacharyya, Kankan

2010-05-06

The mobility of the organic dye DCM (4-dicyanomethylene-2-methyl-6-p-dimethyl aminostyryl-4H-pyran) in the gel and fluid phases of a lipid vesicle is studied by fluorescence correlation spectroscopy (FCS). Using FCS, translational diffusion of DCM is determined in the gel phase and fluid phase of a single lipid vesicle adhered to a glass surface. The size of a lipid vesicle (average diameter approximately 100 nm) is smaller than the diffraction limited spot size (approximately 250 nm) of the microscope. Thus, the vesicle is confined within the laser focus. Three lipid vesicles (1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC)) having different gel transition temperatures (-1, 23, and 41 degrees C, respectively) were studied. The diffusion coefficient of the dye DCM in bulk water is approximately 300 microm(2)/s. In the lipid vesicle, the average D(t) decreases markedly to approximately 5 microm(2)/s (approximately 60 times) in the gel phase (for DPPC at 20 degrees C) and 40 microm(2)/s ( approximately 8 times) in the fluid phase (for DLPC at 20 degrees C). This clearly demonstrates higher mobility in the fluid phase compared with the gel phase of a lipid. It is observed that the D(t) values vary from lipid to lipid and there is a distribution of D(t) values. The diffusion of the hydrophobic dye DCM (D(t) approximately 5 microm(2)/s) in the DPPC vesicle is found to be 8 times smaller than that of a hydrophilic anioinic dye C343 (D(t) approximately 40 microm(2)/s). This is attributed to different locations of the hydrophobic (DCM) and hydrophilic (C343) dyes.

Magnetic domain tuning and the emergence of bubble domains in the bilayer manganite La 2 - 2 x Sr 1 + 2 x Mn 2 O 7 ( x = 0.32 )

DOE PAGES

Jeong, Juyoung; Yang, Ilkyu; Yang, Jinho; ...

2015-08-17

Here, we report a magnetic force microscopy study of the magnetic domain evolution in the layered manganite La 2–2xSr 1+2xMn 2O 7 (with x = 0.32). This strongly correlated electron compound is known to exhibit a wide range of magnetic phases, including a recently uncovered biskyrmion phase. We observe a continuous transition from dendritic to stripelike domains, followed by the formation of magnetic bubbles due to a field- and temperature-dependent competition between in-plane and out-of-plane spin alignments. The magnetic bubble phase appears at comparable field and temperature ranges as the biskyrmion phase, suggesting a close relation between both phases. Basedmore » on our real-space images we construct a temperature-field phase diagram for this composition.« less

Electronic properties of in-plane phase engineered 1T'/2H/1T' MoS2

NASA Astrophysics Data System (ADS)

Thakur, Rajesh; Sharma, Munish; Ahluwalia, P. K.; Sharma, Raman

2018-04-01

We present the first principles studies of semi-infinite phase engineered MoS2 along zigzag direction. The semiconducting (2H) and semi-metallic (1T') phases are known to be stable in thin-film MoS2. We described the electronic and structural properties of the infinite array of 1T'/2H/1T'. It has been found that 1T'phase induced semi-metallic character in 2H phase beyond interface but, only Mo atoms in 2H phase domain contribute to the semi-metallic nature and S atoms towards semiconducting state. 1T'/2H/1T' system can act as a typical n-p-n structure. Also high holes concentration at the interface of Mo layer provides further positive potential barriers.

Aging behavior of an in-situ TiB{sub 2}/Al-Cu-Li-x matrix composite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shen, Yanwei; Hong, Tianran; Geng, Jiwei

Transmission electron microscopy, differential scanning calorimetry and hardness tests have been performed on an in-situ TiB{sub 2}/Al-3.3Cu-1.0Li-0.60Mg-0.40Ag-0.14Zr-0.13Si composite to study its aging behavior at 175 °C. A cubic phase suspected to be the σ (Al{sub 5}Cu{sub 6}Mg{sub 2}) phase or its variant is precipitated at all aging stages studied, and this phase is not typically observed in the Al-Cu-Li alloys. The primary hardening (aging for 3 h) phases consist of δ′ (Al{sub 3}Li), β′ (Al{sub 3}Zr) and the cubic phase. After aging for 18 h, all precipitates including T{sub 1} (Al{sub 2}CuLi), S (Al{sub 2}CuMg), θ′ (Al{sub 2}Cu), δ′, β′more » and the cubic phase have appeared, and the formation of T{sub 1} and S results in a rapid increase in hardness. With prolonging of aging time, the apparent coarsening of T{sub 1} and S results in a decline in hardness. - Highlights: •The aging behavior of an in-situ TiB{sub 2}/Al-Cu-Li-x composite was studied. •A cubic phase suspected to be σ (Al{sub 5}Cu{sub 6}Mg{sub 2}) or its variant was precipitated. •The hardness change was dominated by the evolution of T{sub 1} (Al{sub 2}CuLi) and S (Al{sub 2}CuMg).« less

Formation of Al15Mn3Si2 Phase During Solidification of a Novel Al-12%Si-4%Cu-1.2%Mn Heat-Resistant Alloy and Its Thermal Stability

NASA Astrophysics Data System (ADS)

Suo, Xiaojing; Liao, Hengcheng; Hu, Yiyun; Dixit, Uday S.; Petrov, Pavel

2018-02-01

The formation of Al15Mn3Si2 phase in Al-12Si-4Cu-1.2Mn (wt.%) alloy during solidification was investigated by adopting CALPHAD method and microstructural observation by optical microscopy, SEM-EDS, TEM-EDS/SAD and XRD analysis; SEM fixed-point observation method was applied to evaluate its thermal stability. As-cast microstructural observation consistently demonstrates the solidification sequence of the studied alloy predicted by phase diagram calculation. Based on the phase diagram calculation, SEM-EDS, TEM-EDS/SAD and XRD analysis, as well as evidences on Al-Si-Mn-Fe compounds from the literature, the primary and eutectic Mn-rich phases with different morphologies in the studied alloy are identified to be Al15Mn3Si2 that has a body-centered cubic (BCC) structure with a lattice constant of a = 1.352 nm. SEM fixed-point observation and XRD analysis indicate that Al15Mn3Si2 phase has more excellent thermal stability at high temperature than that of CuAl2 phase and can serve as the major strengthening phase in heat-resistant aluminum alloy that has to face a high-temperature working environment. Results of tension test show that addition of Mn can improve the strength of Al-Si-Cu alloy, especially at elevated temperature.

Electronic structure and insulating gap in epitaxial VO 2 polymorphs

DOE PAGES

Lee, Shinbuhm; Meyer, Tricia L.; Sohn, Changhee; ...

2015-12-24

Here, determining the origin of the insulating gap in the monoclinic VO 2(M1) is a long-standing issue. The difficulty of this study arises from the simultaneous occurrence of structural and electronic transitions upon thermal cycling. Here, we compare the electronic structure of the M1 phase with that of single crystalline insulating VO 2(A) and VO 2(B) thin films to better understand the insulating phase of VO 2. As these A and B phases do not undergo a structural transition upon thermal cycling, we comparatively study the origin of the gap opening in the insulating VO 2 phases. By x-ray absorptionmore » and optical spectroscopy, we find that the shift of unoccupied t 2g orbitals away from the Fermi level is a common feature, which plays an important role for the insulating behavior in VO 2 polymorphs. The distinct splitting of the half-filled t 2g orbital is observed only in the M1 phase, widening the bandgap up to ~0.6 eV. Our approach of comparing all three insulating VO 2 phases provides insight into a better understanding of the electronic structure and the origin of the insulating gap in VO 2.« less

Raman investigation of molybdenum disulfide with different polytypes

NASA Astrophysics Data System (ADS)

Lee, Jae-Ung; Kim, Kangwon; Han, Songhee; Ryu, Gyeong Hee; Lee, Zonghoon; Cheong, Hyeonsik

The Raman spectra of molybdenum disulfide (MoS2) with different polytypes are investigated. Although 2H-MoS2 is most common in nature, the 3R phase can exist due to a small difference in the formation energy. However, only a few studies are reported for the 3R phase, and most studies have focused on the 2H phase. We found the 2H, 3R and mixed phases of exfoliated few-layer MoS2 from natural molybdenite crystals. The crystal structures of 2H- and 3R-MoS2 are confirmed by the HR-TEM measurements. By using 3 different excitation energies, we compared the Raman spectra of different polytypes in detail. We show that the Raman spectroscopy can be used to identify not only the number of layers but also the polytypes of MoS2.

Phase transformations involving the [alpha][sub 2] and O phases in Ti-Al-Nb alloys. [Ti-28. 5Al-13Nb

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muraleedharan, K.; Banerjee, D.

1993-08-15

An orthorhombic (O) phase with Cmcm space group and Ti[sub 2]AlNb composition has ben established in the Ti-Al-Nb system. Efforts to develop alloys with this orthorhombic phase as a major phase, in place of the [alpha][sub 2] (Ti[sub 3]Al) phase, resulted in compositions with superior combinations of strength and toughness. The determination of phase diagrams for the Ti-Al-Nb system is a continuing effort. Bendersky et al. considered possible transformation paths and the hierarchy of structures in going from the [beta] phase to [alpha][sub 2] or O phases through displacive or replacive reactions. Microstructures predicted by these considerations have been documentedmore » in the particularly well investigated [beta]-->O transformation. Very little work has however been carried out on the [alpha][sub 2]-->O phase transformation. In this paper, the authors report preliminary results of isothermal aging study of this transformation.« less

Extraction of heavy metal (Ba, Sr) and high silica glass powder synthesis from waste CRT panel glasses by phase separation.

PubMed

Xing, Mingfei; Wang, Jingyu; Fu, Zegang; Zhang, Donghui; Wang, Yaping; Zhang, Zhiyuan

2018-04-05

In this study, a novel process for the extraction of heavy metal Ba and Sr from waste CRT panel glass and synchronous preparation of high silica glass powder was developed by glass phase separation. CRT panel glass was first remelted with B 2 O 3 under air atmosphere to produce alkali borosilicate glass. During the phase separation process, the glass separated into two interconnected phases which were B 2 O 3 -rich phase and SiO 2 -rich phase. Most of BaO, SrO and other metal oxides including Na 2 O, K 2 O, Al 2 O 3 and CaO were mainly concentrated in the B 2 O 3 -rich phase. The interconnected B 2 O 3 -rich phase can be completely leached out by 5mol/L HNO 3 at 90 ℃. The remaining SiO 2 -rich phase was porous glasses consisting almost entirely of silica. The maximum Ba and Sr removal rates were 98.84% and 99.38% and high silica glass powder (SiO 2 purity > 90 wt%) was obtained by setting the temperature, B 2 O 3 added amount and holding time at 1000-1100 ℃, 20-30% and 30 min, respectively. Thus this study developed an potential economical process for detoxification and reclamation of waste heavy metal glasses. Copyright © 2017 Elsevier B.V. All rights reserved.

Injustice at work and incidence of psychiatric morbidity: the Whitehall II study

PubMed Central

Ferrie, J E; Head, J; Shipley, M J; Vahtera, J; Marmot, M G; Kivimäki, M

2006-01-01

Background Previous studies of organisational justice and mental health have mostly examined women and have not examined the effect of change in justice. Aim To examine effects of change in the treatment of employees by supervisors (the relational component of organisational justice) on minor psychiatric morbidity, using a cohort with a large proportion of men. Methods Data are from the Whitehall II study, a prospective cohort of 10 308 white‐collar British civil servants (3143 women and 6895 men, aged 35–55 at baseline) (Phase 1, 1985–88). Employment grade, relational justice, job demands, job control, social support at work, effort–reward imbalance, physical illness, and psychiatric morbidity were measured at baseline. Relational justice was assessed again at Phase 2 (1989–90). The outcome was cases of psychiatric morbidity by Phases 2 and 3 (1991–93) among participants case‐free at baseline. Results In analyses adjusted for age, grade, and baseline physical illness, women and men exposed to low relational justice at Phase 1 were at higher risk of psychiatric morbidity by Phases 2 and 3. Adjustment for other psychosocial work characteristics, particularly social support and effort–reward imbalance, partially attenuated these associations. A favourable change in justice between Phase 1 and Phase 2 reduced the immediate risk (Phase 2) of psychiatric morbidity, while an adverse change increased the immediate and longer term risk (Phase 3). Conclusion This study shows that unfair treatment by supervisors increases risk of poor mental health. It appears that the employers' duty to ensure that employees are treated fairly at work also has benefits for health. PMID:16698805

Enhancement of macroscopic quantum tunneling in the higher-order phase switches of Bi2212 intrinsic Josephson junctions

NASA Astrophysics Data System (ADS)

Kitano, Haruhisa; Yamaguchi, Ayami; Takahashi, Yusaku; Umegai, Shunpei; Watabe, Yuji; Ohnuma, Haruka; Hosaka, Kazutaka; Kakehi, Daiki

2018-03-01

The macroscopic quantum tunneling (MQT) in the current-biased intrinsic Josephson junctions (IJJs) of high-T c cuprates has attracted much attention for decades. Although the MQT for the phase switches from the zero to the first voltage state (1st SW) in the multiple-branched I-V curves is well explained by the conventional theory, the occurrence of MQT for the higher order switches such as the switch from the 1st to 2nd voltage state (2nd SW) has been still debated. Here, we present an experimental study on the phase switches of small IJJs fabricated from underdoped Bi2Sr2(Ca,Y)Cu2Oy. We observed the single photon transition between quantized energy levels in the 3rd phase switches at 59.15 GHz and 2 K. The comparison with the previous studies on the nearly optimal-doped Bi2Sr2CaCu2Oy clearly suggests a possibility that the MQT rate for the higher-order phase switches is commonly enhanced by the effective suppression of the energy barrier for the higher-order phase escape due to the phase-running state after the 1st SW, in spite of the large difference in a critical current density and T c.

Phase transition in NK-Kauffman networks and its correction for Boolean irreducibility

NASA Astrophysics Data System (ADS)

Zertuche, Federico

2014-05-01

In a series of articles published in 1986, Derrida and his colleagues studied two mean field treatments (the quenched and the annealed) for NK-Kauffman networks. Their main results lead to a phase transition curve Kc 2 pc(1-pc)=1 (0

Metal dioxides as analogue of SiO2 under strong compression studied by synchrotron XRD and simulations

NASA Astrophysics Data System (ADS)

Liu, H.; Liu, L. L.

2017-12-01

The phase transition sequence of SiO2 inducing by high pressure was theoretically predicted as coordination number (CN=6) structures (rutile, pyrite), CN=8 (Pnma) and CN=9 (P-62m) structures, but only the phases up to pyrite structure in SiO2 were observed experimentally up to now. The CN8 phase and CN9 phases of SiO2 were predicted to be stable at least 650 GPa, which is challenging to achieve in the static DAC experiment at present. In other metal dioxide systems, such as TiO2, the ambient rutile and anatase phases first transform to pyrite (CN6), then to the baddeleyite (CN7) phase, to a Pnma (CN8) phase and P-62m(CN9) phase. In this report, under strong compression at room temperature, several metal dioxides were studied experimentally and theoretically, to verify whether this theoretical predicted trend is common transition path under strong compression. This work was supported by Natural Science Foundation of China (11374075), Heilongjiang Province Science Fund for Distinguished Young Scholars (JC201005), Longjiang Scholar, the Fundamental Research Funds for the Central Universities (HIT. BRET1.2010002, HIT. IBRSEM.A.201403).

Study of phase development and thermal stability in as synthesized TiO2 nanoparticles by laser pyrolysis: ethylene uptake and oxygen enrichment

NASA Astrophysics Data System (ADS)

Ilie, Alina Georgiana; Scarisoreanu, Monica; Dutu, Elena; Dumitrache, Florian; Banici, Ana-Maria; Fleaca, Claudiu Teodor; Vasile, Eugenia; Mihailescu, Ion

2018-01-01

Laser pyrolysis has proven a viable and trustworthy method of TiO2 nanoparticles fabrication, ensuring good quality and wide variety of nanoparticle morphologies and sizes. This work is aimed to phase control, experimentally studied, by parameter modulation, during one step laser pyrolysis synthesis or in combination with thermal annealing. High phase purity anatase and rutile TiO2 nanoparticles, oxygen abundant, are synthesized from TiCl4 and C2H4 gas mixtures, in the presence of air as oxygen donor, under CO2 laser radiation. The nano-titania samples are analyzed by X-ray Diffraction, EDAX, TEM and Raman spectroscopy and reveal good phase stability and distinct morphology. This study extends the method applicability onto rutile majoritarian TiO2 synthesis and generation of thermally stable anatase titania, a well-known catalyst.

Crystalline Structure and Vacancy Ordering across a Surface Phase Transition in Sn/Cu(001).

PubMed

Martínez-Blanco, J; Joco, V; Quirós, C; Segovia, P; Michel, E G

2018-01-18

We report a surface X-ray diffraction study of the crystalline structure changes and critical behavior across the (3√2 × √2)R45° → (√2 × √2)R45° surface phase transition at 360 K for 0.5 monolayers of Sn on Cu(100). The phase transition is of the order-disorder type and is due to the disordering of the Cu atomic vacancies present in the low temperature phase. Two different atomic sites for Sn atoms, characterized by two different heights, are maintained across the surface phase transition.

Types, Problems and Their Causes, and Solutions to the Offences against the Environmental Laws by Probationers in Maha Sarakham Province

ERIC Educational Resources Information Center

Wanlu, Somchai; Singseewo, Adisak; Suksringarm, Paitool

2015-01-01

This study aimed to explore types, problems and their causes, and solutions to the offences against the environmental laws of probationers in Maha Sarakham Province. The study comprised 2 phases: Phase 1 was a study of types of the offences against the environmental laws: and phase 2 was an interview with 25 people directly dealing with the…

Effect of Laughter Yoga on Psychological Well-being and Physiological Measures.

PubMed

Miles, Cindy; Tait, Elizabeth; Schure, Marc B; Hollis, Marianne

2016-01-01

In 2014, laughter yoga (LY) achieved the intermediate level, tier 2, under the Title III-D Evidence-based Disease Prevention and Health Promotion Program through the Administration on Aging (AOA). Further research is needed to qualify LY under the criteria for the highest tier, tier 3, to assure continued funding for LY classes at senior centers. The study intended to demonstrate further the benefits of LY and to qualify LY as tier 3 under Title III-D. Using a quasi-experimental design, the research team conducted a preintervention/postintervention study in 3 phases. The study was done in a variety of community centers. Phase 1, a pilot phase, was limited to North Carolina, and phase 2 was conducted in multiple states. Phase 3 was held at the North Carolina Area Agency on Aging's annual Volunteer Appreciation meeting. Participants in phases 1 (n = 109) and 2 (n = 247) enrolled in LY classes. Classes were advertised by fliers posted in community and in retirement centers. The ability of participants to participate in a class was based solely on their desire to participate, regardless of age, ability, health status, or physical impairment. Phase 3 (n = 23) was a convenience sample only. All phases were voluntary. The pre- and posttests for all 3 phases were Likert-scale surveys, 10 questions on the Psychological Outcomes of Well-being (POWB) survey. Pulse and other physiological measurements were also assessed pre- and postintervention. Analysis included a t test on each of the 10 POWB and physiological measures for all phases. All 10 POWB measures for phases 1 and 2 showed significant improvements between the pre- and postintervention testing (P < .001). Phase 3, the control, showed no significant improvement. The initial study demonstrated that LY meets the criteria to qualify for tier 3 under the Title III-D Evidence-based Disease Prevention and Health Promotion Program and that a large number of Americans, regardless of age and physical ability, could benefit from LY.

A new phase of ThC at high pressure predicted from a first-principles study

NASA Astrophysics Data System (ADS)

Guo, Yongliang; Qiu, Wujie; Ke, Xuezhi; Huai, Ping; Cheng, Cheng; Han, Han; Ren, Cuilan; Zhu, Zhiyuan

2015-08-01

The phase transition of thorium monocarbide (ThC) at high pressure has been studied by means of density functional theory. Through structure search, a new phase with space group P 4 / nmm has been predicted. The calculated phonons demonstrate that this new phase and the previous B2 phase are dynamically stable as the external pressure is greater than 60 GPa and 120 GPa, respectively. The transformation from B1 to P 4 / nmm is predicted to be a first-order transition, while that from P 4 / nmm to B2 is found to be a second-order transition.

Highly noise-tolerant hybrid algorithm for phase retrieval from a single-shot spatial carrier fringe pattern

NASA Astrophysics Data System (ADS)

Dong, Zhichao; Cheng, Haobo

2018-01-01

A highly noise-tolerant hybrid algorithm (NTHA) is proposed in this study for phase retrieval from a single-shot spatial carrier fringe pattern (SCFP), which effectively combines the merits of spatial carrier phase shift method and two dimensional continuous wavelet transform (2D-CWT). NTHA firstly extracts three phase-shifted fringe patterns from the SCFP with one pixel malposition; then calculates phase gradients by subtracting the reference phase from the other two target phases, which are retrieved respectively from three phase-shifted fringe patterns by 2D-CWT; finally, reconstructs the phase map by a least square gradient integration method. Its typical characters include but not limited to: (1) doesn't require the spatial carrier to be constant; (2) the subtraction mitigates edge errors of 2D-CWT; (3) highly noise-tolerant, because not only 2D-CWT is noise-insensitive, but also the noise in the fringe pattern doesn't directly take part in the phase reconstruction as in previous hybrid algorithm. Its feasibility and performances are validated extensively by simulations and contrastive experiments to temporal phase shift method, Fourier transform and 2D-CWT methods.

Equilibrium aluminium hydroxo-oxalate phases during initial clay formation; H +-Al 3+-oxalic acid-Na + system

NASA Astrophysics Data System (ADS)

Bilinski, Halka; Horvath, Laszlo; Ingri, Nils; Sjöberg, Staffan

1986-09-01

The conditions necessary for initial clay formation have been studied in different model systems comprising different organic acids besides Si and Al. In the present paper the solid phases and the precipitation boundary characterizing the subsystem H +-Al 3+-oxalic acid (H 2L) are discussed. pH and tyndallometric measurements were performed in an ionic medium of 0.6 M Na(Cl) at 25 °C. The two phases Al 3(OH) 7(C 2O 4) · 3H 2O (phase I) and NaAl(OH) 2(C 2O 4) · 3H 2O (phase II) determine the precipitation boundary. The following formation constants for the two phases were deduced: lgβ1 = lg([ Al3+] -3[ H2C2O4] -1[ H+] 9 = -21.87 ± 0.08 and lgβ11 = lg([ Al3+] -1[ H2C2O4] -1[ H+] 4 = -5.61 ± 0.06. Phase I exists in the range [ Al] tot≥ 10 -4.4moldm-3,[ H2C2O4] tot ≥ 10 -4.9moldm-3 and at pH < 6.8, thus being a possible precipitate in oxalic-rich natural waters. The more soluble sodium phase is unlikely to exist in natural waters. The two phases are metastable relative to crystalline gibbsite and may be considered as the first precipitation step in the transition from aqueous Al oxalates down to stable Al hydroxide. Model calculations illustrating these competing hydrolysis-complexation reactions are discussed in terms of predominance and speciation diagrams. The solid phases have been characterized by X-ray analysis of powders, TGA and IR spectra, and tentative structures are proposed. Phase I seems to be an octahedral layer structure, in which 3/5 of the octahedral sites between two close packed oxygen sheets are occupied by Al 3+ and the oxalate ion acts as a bridge ligand between two aluminium atoms. Phase II forms a more open sheet structure and has ion exchange properties. Powder data for a phase crystallized from the studied solution after a year are also presented. This phase, Na 4Al 2(OH) 2(C 2O 4) 4 · 10H 2O, supports the results from the equilibrium analysis of recent solution data by SJöBERG and ÖHMAN (1985), who have found the dinuclear complex Al 2(OH) 2(C 2O 4) 44- to exist in a solution in which the ligand is in excess.

Insight into the Am-O Phase Equilibria: A Thermodynamic Study Coupling High-Temperature XRD and CALPHAD Modeling.

PubMed

Epifano, Enrica; Guéneau, Christine; Belin, Renaud C; Vauchy, Romain; Lebreton, Florent; Richaud, Jean-Christophe; Joly, Alexis; Valot, Christophe; Martin, Philippe M

2017-07-03

In the frame of minor actinide transmutation, americium can be diluted in UO 2 and (U, Pu)O 2 fuels burned in fast neutron reactors. The first mandatory step to foresee the influence of Am on the in-reactor behavior of transmutation targets or fuel is to have fundamental knowledge of the Am-O binary system and, in particular, of the AmO 2-x phase. In this study, we coupled HT-XRD (high-temperature X-ray diffraction) experiments with CALPHAD thermodynamic modeling to provide new insights into the structural properties and phase equilibria in the AmO 2-x -AmO 1.61+x -Am 2 O 3 domain. Because of this approach, we were able for the first time to assess the relationships between temperature, lattice parameter, and hypostoichiometry for fcc AmO 2-x . We showed the presence of a hyperstoichiometric existence domain for the bcc AmO 1.61+x phase and the absence of a miscibility gap in the fcc AmO 2-x phase, contrary to previous representations of the phase diagram. Finally, with the new experimental data, a new CALPHAD thermodynamic model of the Am-O system was developed, and an improved version of the phase diagram is presented.

Study of liquid?liquid demixing from drug solution

NASA Astrophysics Data System (ADS)

Lafferrère, Laurent; Hoff, Christian; Veesler, Stéphane

2004-09-01

In pharmaceutical industry, a deep understanding of the phase diagram is required in design of crystallization processes. We have investigated the phase diagram of a pharmaceutical compound (C 35H 41Cl 2N 3O 2) in a mixture of ethanol/water. This phase diagram exhibits a solid-solid (polymorphism) and a liquid-liquid-phase separation (LLPS) as a function of temperature and drug substance concentration. This study focuses on the LLPS which is metastable with respect to the crystallization of the two polymorphs FI and FII of C 35H 41Cl 2N 3O 2 in an ethanol/water mixture. The LLPS is metastable towards the solubility curve on the whole solvent-solute concentrations and temperature range studied. The LLPS occurred within the metastable zone for crystallization. In our experiments the liquid-liquid-phase transition prevented the drug from crystallizing, while it changed the medium and the conditions of crystallization, which consequently affected the process. The coexistence curves for the liquid phases, also named TL-L boundary, and the spinodal line were measured for a ternary mixture of water-drug-ethanol at atmospheric pressure over a temperature range of 10-50°C. This temperature range corresponds to that used in the crystallization process. Static Light Scattering, HPLC measurements and Karl-Fischer titration were applied to investigate the drug-phase diagram. The isoplethe section of the phase diagram exhibits four regions: one homogeneous (one liquid) and three two-phases (two regions with one liquid+one solid and one region with two liquids), the two solids phases being two polymorphs.

Effects of germanium and nitrogen incorporation on crystallization of N-doped Ge2+xSb2Te5 (x = 0,1) thin films for phase-change memory

NASA Astrophysics Data System (ADS)

Cheng, Limin; Wu, Liangcai; Song, Zhitang; Rao, Feng; Peng, Cheng; Yao, Dongning; Liu, Bo; Xu, Ling

2013-01-01

The phase-change behavior and microstructure changes of N-doped Ge3Sb2Te5 [N-GST(3/2/5)] and Ge2Sb2Te5 [GST(2/2/5)] films during the phase transition from an amorphous to a crystalline phase were studied using in situ temperature-dependent sheet resistance measurements, X-ray diffraction, and transmission electron microscopy. The optical band gaps of N-GST(3/2/5) films are higher than that of GST(2/2/5) film in both the amorphous and face-centered-cubic (fcc) phases. Ge nitride formation by X-ray photoelectron spectroscopy analysis increased the optical band gap and suppressed crystalline grain growth, resulting in an increase in the crystallization temperature and resistance in the fcc phase. As a result, the Ge- and N-doped GST(2/2/5) composite films can be considered as a promising material for phase-change memory application because of improved thermal stability and reduced power consumption.

Quantum phases of dimerized and frustrated Heisenberg spin chains with s = 1/2, 1 and 3/2: an entanglement entropy and fidelity study.

PubMed

Goli, V M L Durga Prasad; Sahoo, Shaon; Ramasesha, S; Sen, Diptiman

2013-03-27

We study here different regions in phase diagrams of the spin-1/2, spin-1 and spin-3/2 one-dimensional antiferromagnetic Heisenberg systems with frustration (next-nearest-neighbor interaction J2) and dimerization (δ). In particular, we analyze the behaviors of the bipartite entanglement entropy and fidelity at the gapless to gapped phase transitions and across the lines separating different phases in the J2-δ plane. All the calculations in this work are based on numerical exact diagonalizations of finite systems.

Raman scattering study on the hidden order and antiferromagnetic phases in URu2-xFexSi2

NASA Astrophysics Data System (ADS)

Kung, Hsiang-Hsi; Ran, Sheng; Kanchanavatee, Noravee; Lee, Alexander; Krapivin, Viktor; Haule, Kristjan; Maple, M. Brian; Blumberg, Girsh

The heavy fermion compound URu2Si2 possesses an unusual ground state known as the ``hidden order'' (HO) phase below T = 17 . 5 K, which evolves into an large moment antiferromagnetic (LMAFM) phase under pressure. A recent Raman scattering study shows that an A2 g symmetry (D4 h) in-gap mode emerges in the HO phase, characterizing the excitation from a chirality density wave. Here, we report Raman scattering results for single crystal URu2-xFexSi2 with x <= 0 . 2 , where the Fe substitution acts as chemical pressure, shifting the system's ground state from HO to LMAFM. We found that the A2 g mode softens with doping, vanishes at the HO and LMAFM phase boundary, then re-emerges and hardens with doping in the LMAFM phase. The relations between the A2 g mode energy and the strength of the HO/LMAFM order parameters will be discussed in this talk. GB and HHK acknowledge support from DOE BES Award DE-SC0005463. AL and VK acknowledge NSF Award DMR-1104884. KH acknowledges NSF Award DMR-1405303. MBM, SR and NK acknowledge DOE BES Award DE-FG02-04ER46105 and NSF Award DMR 1206553.

High-pressure phases transitions in SnO2 to 117 GPa: Implications for silica

NASA Astrophysics Data System (ADS)

Shieh, S. R.; Kubo, A.; Duffy, T. S.; Prakapenka, V. B.; Shen, G.

2005-12-01

Cassiterite (SnO2) is regarded to be a good analog material for silica as both SnO2 and SiO2 are group IV-B metal dioxides. The high-pressure behavior of SnO2 has been the subject of many previous investigations extending up to 49 GPa and in addition to the rutile structure, three high-pressure phases, CaCl2-type, α-PbO2-type, and pyrite-type were observed. Better knowledge of high-pressure phases of SnO2 will be useful to understand the behavior of silica at deep mantle conditions. In addition, high-pressure metal dioxide phases may qualify as superhard solids. Our study will also provide insights into interpretation of shock compression data. Pure natural cassiterite (SnO2) powder was compressed in a diamond anvil cell using an argon medium. Pressure was determined from the equation of state of platinum. In situ monochromatic x-ray diffraction at high pressure was carried out at the GSECARS, Advanced Photon Source. High temperatures were achieved using double-sided laser heating . Three heating cycles were conducted with total heating times up to 30 minutes. Our diffraction results on SnO2 demonstrate the existence of four phase transitions to 117 GPa. The observed sequence of high-pressure phases for SnO2 is rutile-type, CaCl2-type, pyrite-type, ZrO2 orthorhombic phase I (Pbca), cotunnite-type. Our observations of the first three phases are generally in agreement with earlier studies. The orthorhombic phase I and cotunnite-type structures were observed in SnO2 for the first time. The Pbca phase is found at 50-74 GPa during room-temperature compression. The cotunnite-type structure was synthesized when SnO2 was heated at 74 GPa and 1200 K. The cotunnite-type form was observed during compression between 54-117 GPa. Fitting the pressure-volume data for the high-pressure phases to the second-order Birch-Murnaghan equation of state yields a bulk modulus of 259(26) GPa for the Pbca phase and 417(7) GPa for the cotunnite-type phase. Rietveld profile refinements were also carried out successfully for these two phases.

Phase transition in crystalline benzil : an infrared study of vibrational excitons.

NASA Astrophysics Data System (ADS)

Le Roy, A.; Et-Tabti, O.; Guérin, R.

1993-03-01

The molecular crystal of benzil, [C 6 H 5 CO] 2, is known to undergo a phase transition at T c = 84 K. The phase transition is from a high temperature trigonal phase with space group D 43 (P3 121) to a low temperature monoclinic phase with space group C 32 (C 2). This paper reports a study of the exciton structure of the infrared bands of benzil as a function of temperature in the vicinity of T c = 84 K. The benzil molecule belongs to the C 2 molecular point group. Group theoretical analysis of the exciton structure of infrared bands predicts two components for molecular B modes and one component for molecular A modes in the high temperature phase. Below T c all the internal modes of benzil are expected to split into two components. Our experimental results show that the A molecular modes are resolved in a doublet structure in the low temperature phase whereas only one component is observed above T c. The doublet structure of infrared bands is studied as a function of temperature in the vicinity of T c. These splittings of crystal states in the low temperature phase are found to be described by a ¦T c - T¦ β law. The temperature dependence of the doublet structure of internal B modes is also studied below and above T c.

Tuning Phase Composition of TiO2 by Sn(4+) Doping for Efficient Photocatalytic Hydrogen Generation.

PubMed

Wang, Fenglong; Ho, Jie Hui; Jiang, Yijiao; Amal, Rose

2015-11-04

The anatase-rutile mixed-phase photocatalysts have attracted extensive research interest because of the superior activity compared to their single phase counterparts. In this study, doping of Sn(4+) ions into the lattice of TiO2 facilitates the phase transformation from anatase to rutile at a lower temperature while maintaining the same crystal sizes compared to the conventional annealling approach. The mass ratios between anatase and rutile phases can be easily manipulated by varying the Sn-dopant content. Characterization results reveal that the Sn(4+) ions entered into the lattice of TiO2 by substituting some of the Ti(4+) ions and distributed evenly in the matrix of TiO2. The substitution induced the distortion of the lattice structure, which realized the phase transformation from anatase to rutile at a lower temperature and the close-contact phase junctions were consequently formed between anatase and rutile, accounting for the efficient charge separations. The mixed-phase catalysts prepared by doping Sn(4+) ions into the TiO2 exhibit superior activity for photocatalytic hydrogen generation in the presence of Au nanoparticles, relatively to their counterparts prepared by the conventional annealling at higher temperatures. The band allignment between anatase and rutile phases is established based on the valence band X-ray photoelectron spectra and diffuse reflectance spectra to understand the spatial charge separation process at the heterojunction between the two phases. The study provides a new route for the synthesis of mixed-phase TiO2 catalysts for photocatalytic applications and advances the understanding on the enhanced photocatalytic properties of anatase-rutile mixtures.

Operant models of relapse in zebrafish (Danio rerio): Resurgence, renewal, and reinstatement.

PubMed

Kuroda, Toshikazu; Mizutani, Yuto; Cançado, Carlos R X; Podlesnik, Christopher A

2017-09-29

Zebrafish are a widely used animal model in biomedical research, as an alternative to mammals, for having features such as a fully sequenced genome, high fecundity, and low-cost maintenance, but behavioral research with these fish remains scarce. The present study investigated whether zebrafish could be a new animal model for studies on the relapse of behavior (e.g., addiction and overeating) after the behavior has been extinguished. Specifically, we examined whether zebrafish would show three different types of relapse commonly studied with other species: resurgence, renewal, and reinstatement. For resurgence, a target response (i.e., approaching a sensor) was established by presenting a reinforcer (i.e., shrimp eggs) contingent upon the response in Phase 1; the target response was extinguished while introducing reinforcement for an alternative response in Phase 2; neither response produced the reinforcer in Phase 3. For renewal, a target response was established under Context A in Phase 1 and was extinguished under Context B in Phase 2; the fish were placed back in Context A in Phase 3, where extinction remained in effect. For reinstatement, a target response was established in Phase 1 and was extinguished in Phase 2; the reinforcer was presented independently of responding in Phase 3. Each type of relapse occurred in Phase 3. These results replicate and extend previous findings on relapse to a new species and suggest that zebrafish can be a useful animal model for studying the interactions of biological and environmental factors that lead to relapse. Copyright © 2017 Elsevier B.V. All rights reserved.

Treatment of chronic myelogenous leukemia with interleukin-2: a phase II study in 21 patients.

PubMed

Vey, N; Blaise, D; Lafage, M; Olive, D; Viens, P; Baume, D; Camerlo, J; Stoppa, A M; Gabus, R; Brandely, M; Hercend, T; Maraninchi, D

1999-03-01

We designed a phase II study to assess the activity of recombinant interleukin-2 (rIL-2) in patients with chronic myelogenous leukemia (CML). Study population included 11 patients in the chronic phase of CML (6 in hematologic remission and 5 with active disease), 6 patients in the accelerated phase, and 4 in blastic phase of CML. Patients received three 5-day cycles administrated every other week. rIL-2 was given as intravenous bolus infusions of 8 x 10(6) IU/m2 three times a day during cycle 1 and twice a day during cycles 2 and 3. Response to rIL-2 was assessed on day 45. No hematologic response was achieved in the patients with evaluable disease. One patient in hematologic remission with rIL-2 achieved a major response (from 72% to 9% Ph+ metaphases), and two patients had some degree of reduction of Ph+ metaphases. Responses were short-lived (< 6 months), but two of these three patients achieved a new cytogenetic response with interferon given post-rIL-2. A significant immune activation was achieved with rIL-2 including a marked increase in CD3+/CD25+ cells, CD56+ cells, and in natural killer/lymphokine activated killer cell cytotoxic activity. These results confirm preclinical studies, which showed that IL-2 has antileukemic activity in CML. However, the responses observed were short lived and restricted to a subgroup of patients with low disease burden. This invites further studies testing its impact in situations of minimal disease or in combination with other cytokines.

Oxytocin and Naltrexone Successfully Treat Hypothalamic Obesity in a Boy Post-Craniopharyngioma Resection.

PubMed

Hsu, Eugenie A; Miller, Jennifer L; Perez, Francisco A; Roth, Christian L

2018-02-01

Hypothalamic obesity, a treatment-resistant condition common to survivors of craniopharyngioma (CP), is strongly associated with a poor quality of life in this population. Oxytocin (OT), a hypothalamic neuropeptide, has been shown to play a role in the regulation of energy balance and to have anorexigenic effects in animal studies. Naltrexone (NAL), an opiate antagonist, has been shown to deter hedonic eating and to potentiate OT's effects. In this parent-observed study, we tested the administration of intranasal OT for 10 weeks (phase 1), followed by a combination of intranasal OT and NAL for 38 weeks (phase 2) in a 13-year-old male with confirmed hypothalamic obesity and hyperphagia post-CP resection. Treatment resulted in 1) reduction in body mass index (BMI) z score from 1.77 to 1.49 over 10 weeks during phase 1; 2) reduction in BMI z score from 1.49 to 0.82 over 38 weeks during phase 2; 3) reduced hyperphagia during phases 1 and 2; 4) continued hedonic high-carbohydrate food-seeking in the absence of hunger during phases 1 and 2; and 5) sustained weight reduction during decreased parental monitoring and free access to unlocked food in the home during the last 10 weeks of phase 2. This successful intervention of CP-related hypothalamic obesity and hyperphagia by OT alone and in combination with NAL is promising for conducting future studies of this treatment-recalcitrant form of obesity. Copyright © 2017 Endocrine Society

Comprehensive assessment of long-term effects of reducing intake of energy phase 2 (CALERIE Phase 2) screening and recruitment: Methods and results

USDA-ARS?s Scientific Manuscript database

The Comprehensive Assessment of the Long-term Effects of Reducing Intake of Energy Phase 2 (CALERIE) study is a systematic investigation of sustained 25% calorie restriction (CR) in non-obese humans. CALERIE is a multicenter (3 clinical sites, one coordinating center), parallel group, randomized con...

First-principles calculations, experimental study, and thermodynamic modeling of the Al-Co-Cr system.

PubMed

Liu, Xuan L; Gheno, Thomas; Lindahl, Bonnie B; Lindwall, Greta; Gleeson, Brian; Liu, Zi-Kui

2015-01-01

The phase relations and thermodynamic properties of the condensed Al-Co-Cr ternary alloy system are investigated using first-principles calculations based on density functional theory (DFT) and phase-equilibria experiments that led to X-ray diffraction (XRD) and electron probe micro-analysis (EPMA) measurements. A thermodynamic description is developed by means of the calculations of phase diagrams (CALPHAD) method using experimental and computational data from the present work and the literature. Emphasis is placed on modeling the bcc-A2, B2, fcc-γ, and tetragonal-σ phases in the temperature range of 1173 to 1623 K. Liquid, bcc-A2 and fcc-γ phases are modeled using substitutional solution descriptions. First-principles special quasirandom structures (SQS) calculations predict a large bcc-A2 (disordered)/B2 (ordered) miscibility gap, in agreement with experiments. A partitioning model is then used for the A2/B2 phase to effectively describe the order-disorder transitions. The critically assessed thermodynamic description describes all phase equilibria data well. A2/B2 transitions are also shown to agree well with previous experimental findings.

Phase restructuring in transition metal dichalcogenides for highly stable energy storage

DOE PAGES

Leng, Kai; Chen, Zhongxin; Zhao, Xiaoxu; ...

2016-09-16

Achieving homogeneous phase transition and uniform charge distribution is essential for good cycle stability and high capacity when phase conversion materials are used as electrodes. Herein, we show that chemical lithiation of bulk 2H-MoS 2 distorts its crystalline domains in three primary directions to produce mosaic-like 1T' nanocrystalline domains, which improve phase and charge uniformity during subsequent electrochemical phase conversion. 1T'-Li xMoS 2, a macroscopic dense material with interconnected nanoscale grains, shows excellent cycle stability and rate capability in a lithium rechargeable battery compared to bulk or exfoliated-restacked MoS 2. Transmission electron microscopy studies reveal that the interconnected MoS 2more » nanocrystals created during the phase change process are reformable even after multiple cycles of galvanostatic charging/discharging, which allows them to play important roles in the long term cycling performance of the chemically intercalated TMD materials. Finally, these studies shed light on how bulk TMDs can be processed into quasi-2D nanophase material for stable energy storage.« less

Findings of the International Nosocomial Infection Control Consortium (INICC), Part I: Effectiveness of a multidimensional infection control approach on catheter-associated urinary tract infection rates in pediatric intensive care units of 6 developing countries.

PubMed

Rosenthal, Victor D; Ramachandran, Bala; Dueñas, Lourdes; Alvarez-Moreno, Carlos; Navoa-Ng, J A; Armas-Ruiz, Alberto; Ersoz, Gulden; Matta-Cortés, Lorena; Pawar, Mandakini; Nevzat-Yalcin, Ata; Rodríguez-Ferrer, Marena; Bran de Casares, Ana Concepción; Linares, Claudia; Villanueva, Victoria D; Campuzano, Roberto; Kaya, Ali; Rendon-Campo, Luis Fernando; Gupta, Amit; Turhan, Ozge; Barahona-Guzmán, Nayide; de Jesús-Machuca, Lilian; Tolentino, María Corazon V; Mena-Brito, Jorge; Kuyucu, Necdet; Astudillo, Yamileth; Saini, Narinder; Gunay, Nurgul; Sarmiento-Villa, Guillermo; Gumus, Eylul; Lagares-Guzmán, Alfredo; Dursun, Oguz

2012-07-01

A before-after prospective surveillance study to assess the impact of a multidimensional infection control approach for the reduction of catheter-associated urinary tract infection (CAUTI) rates. Pediatric intensive care units (PICUs) of hospital members of the International Nosocomial Infection Control Consortium (INICC) from 10 cities of the following 6 developing countries: Colombia, El Salvador, India, Mexico, Philippines, and Turkey. PICU inpatients. We performed a prospective active surveillance to determine rates of CAUTI among 3,877 patients hospitalized in 10 PICUs for a total of 27,345 bed-days. The study was divided into a baseline period (phase 1) and an intervention period (phase 2). In phase 1, surveillance was performed without the implementation of the multidimensional approach. In phase 2, we implemented a multidimensional infection control approach that included outcome surveillance, process surveillance, feedback on CAUTI rates, feedback on performance, education, and a bundle of preventive measures. The rates of CAUTI obtained in phase 1 were compared with the rates obtained in phase 2, after interventions were implemented. During the study period, we recorded 8,513 urinary catheter (UC) days, including 1,513 UC-days in phase 1 and 7,000 UC-days in phase 2. In phase 1, the CAUTI rate was 5.9 cases per 1,000 UC-days, and in phase 2, after implementing the multidimensional infection control approach for CAUTI prevention, the rate of CAUTI decreased to 2.6 cases per 1,000 UC-days (relative risk, 0.43 [95% confidence interval, 0.21-1.0]), indicating a rate reduction of 57%. Our findings demonstrated that implementing a multidimensional infection control approach is associated with a significant reduction in the CAUTI rate of PICUs in developing countries.

A comparison of different algorithms for phasing haplotypes using Holstein cattle genotypes and pedigree data.

PubMed

Miar, Younes; Sargolzaei, Mehdi; Schenkel, Flavio S

2017-04-01

Phasing genotypes to haplotypes is becoming increasingly important due to its applications in the study of diseases, population and evolutionary genetics, imputation, and so on. Several studies have focused on the development of computational methods that infer haplotype phase from population genotype data. The aim of this study was to compare phasing algorithms implemented in Beagle, Findhap, FImpute, Impute2, and ShapeIt2 software using 50k and 777k (HD) genotyping data. Six scenarios were considered: no-parents, sire-progeny pairs, sire-dam-progeny trios, each with and without pedigree information in Holstein cattle. Algorithms were compared with respect to their phasing accuracy and computational efficiency. In the studied population, Beagle and FImpute were more accurate than other phasing algorithms. Across scenarios, phasing accuracies for Beagle and FImpute were 99.49-99.90% and 99.44-99.99% for 50k, respectively, and 99.90-99.99% and 99.87-99.99% for HD, respectively. Generally, FImpute resulted in higher accuracy when genotypic information of at least one parent was available. In the absence of parental genotypes and pedigree information, Beagle and Impute2 (with double the default number of states) were slightly more accurate than FImpute. Findhap gave high phasing accuracy when parents' genotypes and pedigree information were available. In terms of computing time, Findhap was the fastest algorithm followed by FImpute. FImpute was 30 to 131, 87 to 786, and 353 to 1,400 times faster across scenarios than Beagle, ShapeIt2, and Impute2, respectively. In summary, FImpute and Beagle were the most accurate phasing algorithms. Moreover, the low computational requirement of FImpute makes it an attractive algorithm for phasing genotypes of large livestock populations. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of hydration and continuous urinary drainage on urine production in children.

PubMed

Galetseli, Marianthi; Dimitriou, Panagiotis; Tsapra, Helen; Moustaki, Maria; Nicolaidou, Polyxeni; Fretzayas, Andrew

2008-01-01

Although urine production depends on numerous physiological variables there are no quantitative data regarding the effect of bladder decompression, by means of continuous catheter drainage, on urine production. The aim of this study was to investigate this effect. The study was carried out in two stages, each consisting of two phases. The effect of two distinct orally administered amounts of water was recorded in relation to continuous bladder decompression on the changes with time of urine volume and the urine production rate. In the first stage, 35 children were randomly divided into two groups and two different hydration schemes (290 and 580 ml of water/m2) were used. After the second urination of Phase 1, continuous drainage was employed in the phase that followed (Phase 2). In the second stage, a group of 10 children participated and Phase 2 was carried out 1 day after the completion of Phase 1. It was shown that the amount of urine produced increased in accordance with the degree of hydration and doubled or tripled with continual urine drainage by catheter for the same degree of hydration and within the same time interval. This was also true for Stage 2, in which Phase 2 was performed 24 h after Phase 1, indicating that diuresis during Phase 2 (as a result of Phase 1) was negligible. It was shown that during continuous drainage of urine with bladder catheterization there is an increased need for fluids, which should be administered early.

NO—CO—O2 Reaction on a Metal Catalytic Surface using Eley—Rideal Mechanism

NASA Astrophysics Data System (ADS)

Waqar, Ahmad

2008-10-01

Interactions among the reacting species NO, CO and O2 on metal catalytic surfaces are studied by means of Monte Carlo simulation using the Eley-Rideal (ER) mechanism. The study of this three-component system is important for understanding of the reaction kinetics by varying the relative ratios of the reactants. It is found that contrary to the conventional Langmuir-Hinshelwood (LH) thermal mechanism in which two irreversible phase transitions are obtained between active states and poisoned states, a single phase transition is observed when the ER mechanism is combined with the LH mechanism. The phase diagrams of the surface coverage and the steady state production of CO2, N2 and N2 O are evaluated as a function of the partial pressures of the reactants in the gas phase. The continuous production of CO2 starts as soon as the CO pressure is switched on and the second order phase transition at the first critical point is eliminated, which is in agreement with the experimental findings.

Subsurface imaging and cell refractometry using quantitative phase/ shear-force feedback microscopy

NASA Astrophysics Data System (ADS)

Edward, Kert; Farahi, Faramarz

2009-10-01

Over the last few years, several novel quantitative phase imaging techniques have been developed for the study of biological cells. However, many of these techniques are encumbered by inherent limitations including 2π phase ambiguities and diffraction limited spatial resolution. In addition, subsurface information in the phase data is not exploited. We hereby present a novel quantitative phase imaging system without 2 π ambiguities, which also allows for subsurface imaging and cell refractometry studies. This is accomplished by utilizing simultaneously obtained shear-force topography information. We will demonstrate how the quantitative phase and topography data can be used for subsurface and cell refractometry analysis and will present results for a fabricated structure and a malaria infected red blood cell.

Phase I/II trial of 2-weekly docetaxel combined with cisplatin plus fluorouracil in metastatic esophageal cancer (JCOG0807)

PubMed Central

Hironaka, Shuichi; Tsubosa, Yasuhiro; Mizusawa, Junki; Kii, Takayuki; Kato, Ken; Tsushima, Takahiro; Chin, Keisho; Tomori, Akihisa; Okuno, Tatsuya; Taniki, Toshikatsu; Ura, Takashi; Matsushita, Hisayuki; Kojima, Takashi; Doki, Yuichiro; Kusaba, Hitoshi; Fujitani, Kazumasa; Taira, Koichi; Seki, Shiko; Nakamura, Tsutomu; Kitagawa, Yuko

2014-01-01

We carried out a phase I/II trial of adding 2-weekly docetaxel to cisplatin plus fluorouracil (CF) therapy (2-weekly DCF regimen) in esophageal cancer patients to investigate its safety and antimetastatic activity. Patients received 2-weekly docetaxel (30 mg/m2 [dose level (DL)1] or 40 mg/m2 [DL2] with a 3 + 3 design in phase I, on days 1 and 15) in combination with fixed-dose CF (80 mg/m2 cisplatin, day 1; 800 mg/m2 fluorouracil, days 1–5) repeated every 4 weeks. The primary endpoint was dose-limiting toxicity (DLT) in phase I and central peer review-based response rate in phase II. At least 22 responders among 50 patients were required to satisfy the primary endpoint with a threshold of 35%. Sixty-two patients were enrolled in phase I and II. In phase I, 10 patients were enrolled with DLT of 0/3 at DL1 and 2/7 in DL2. Considering DLT and treatment compliance, the recommended phase II dose was determined as DL1. In phase II, the response rate was 62% (P < 0.0001; 95% confidence interval, 48–75%); median overall survival and progression-free survival were 11.1 and 5.8 months, respectively. Common grade 3/4 adverse events were neutropenia (25%), anemia (36%), hyponatremia (29%), anorexia (24%), and nausea (11%). No febrile neutropenia was observed. Pneumonitis caused treatment-related death in one patient. The 2-weekly DCF regimen showed promising antimetastatic activity and tolerability. A phase III study comparing this regimen with CF therapy is planned by the Japan Clinical Oncology Group. This study was registered at the UMIN Clinical Trials Registry as UMIN 000001737. PMID:25041052

Phase diagram of the frustrated J 1 ‑ J 2 transverse field Ising model on the square lattice

NASA Astrophysics Data System (ADS)

Sadrzadeh, M.; Langari, A.

2018-03-01

We study the zero-temperature phase diagram of transverse field Ising model on the J 1 ‑ J 2 square lattice. In zero magnetic field, the model has a classical Néel phase for J 2/J 1 < 0.5 and an antiferromagnetic collinear phase for J 2/J 1 > 0.5. We incorporate harmonic fluctuations by using linear spin wave theory (LSWT) with single spin flip excitations above a magnetic order background and obtain the phase diagram of the model in this approximation. We find that harmonic quantum fluctuations of LSWT fail to lift the large degeneracy at J 2/J 1 = 0.5 and exhibit some inconsistent regions on the phase diagram. However, we show that anharmonic fluctuations of cluster operator approach (COA) resolve the inconsistency of the LSWT, which reveals a string-valence bond solid ordered phase for the highly frustrated region.

Phase quantification by X-ray photoemission valence band analysis applied to mixed phase TiO2 powders

NASA Astrophysics Data System (ADS)

Breeson, Andrew C.; Sankar, Gopinathan; Goh, Gregory K. L.; Palgrave, Robert G.

2017-11-01

A method of quantitative phase analysis using valence band X-ray photoelectron spectra is presented and applied to the analysis of TiO2 anatase-rutile mixtures. The valence band spectra of pure TiO2 polymorphs were measured, and these spectral shapes used to fit valence band spectra from mixed phase samples. Given the surface sensitive nature of the technique, this yields a surface phase fraction. Mixed phase samples were prepared from high and low surface area anatase and rutile powders. In the samples studied here, the surface phase fraction of anatase was found to be linearly correlated with photocatalytic activity of the mixed phase samples, even for samples with very different anatase and rutile surface areas. We apply this method to determine the surface phase fraction of P25 powder. This method may be applied to other systems where a surface phase fraction is an important characteristic.

Top-Down and Bottom-Up Approaches in Engineering 1 T Phase Molybdenum Disulfide (MoS2 ): Towards Highly Catalytically Active Materials.

PubMed

Chua, Chun Kiang; Loo, Adeline Huiling; Pumera, Martin

2016-09-26

The metallic 1 T phase of MoS2 has been widely identified to be responsible for the improved performances of MoS2 in applications including hydrogen evolution reactions and electrochemical supercapacitors. To this aim, various synthetic methods have been reported to obtain 1 T phase-rich MoS2 . Here, the aim is to evaluate the efficiencies of the bottom-up (hydrothermal reaction) and top-down (chemical exfoliation) approaches in producing 1 T phase MoS2 . It is established in this study that the 1 T phase MoS2 produced through the bottom-up approach contains a high proportion of 1 T phase and demonstrates excellent electrochemical and electrical properties. Its performance in the hydrogen evolution reaction and electrochemical supercapacitors also surpassed that of 1 T phase MoS2 produced through a top-down approach. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Expansion of the tetragonal magnetic phase with pressure in the iron arsenide superconductor Ba 1 - x K x Fe 2 As 2

DOE PAGES

Hassinger, Elena; Gredat, G.; Valade, F.; ...

2016-04-01

In the temperature-concentration phase diagram of most iron-based superconductors, antiferromagnetic order is gradually suppressed to zero at a critical point, and a dome of superconductivity forms around that point. The nature of the magnetic phase and its fluctuations is of fundamental importance for elucidating the pairing mechanism. In Ba 1–xK xFe 2As 2 and Ba 1–xNa xFe 2As 2, it has recently become clear that the usual stripelike magnetic phase, of orthorhombic symmetry, gives way to a second magnetic phase, of tetragonal symmetry, near the critical point, in the range from x = 0.24 to x = 0.28 for Bamore » 1–xK xFe 2As 2. In a prior study, an unidentified phase was discovered for x < 0.24 but under applied pressure, whose onset was detected as a sharp anomaly in the resistivity. Here we report measurements of the electrical resistivity of Ba 1–xK xFe 2As 2 under applied hydrostatic pressures up to 2.75 GPa, for x = 0.22, 0.24, and 0.28. The critical pressure above which the unidentified phase appears is seen to decrease with increasing x and vanish at x = 0.24, thereby linking the pressure-induced phase to the tetragonal magnetic phase observed at ambient pressure. In the temperature-concentration phase diagram of Ba 1–xK xFe 2As 2, we find that pressure greatly expands the tetragonal magnetic phase, while the stripelike phase shrinks. As a result, this reveals that pressure may be a powerful tuning parameter with which to explore the interplay between magnetism and superconductivity in this material.« less

Long-acting PEGylated recombinant human growth hormone (Jintrolong) for children with growth hormone deficiency: phase II and phase III multicenter, randomized studies.

PubMed

Luo, Xiaoping; Hou, Ling; Liang, Li; Dong, Guanping; Shen, Shuixian; Zhao, Zhuhui; Gong, Chun Xiu; Li, Yuchuan; Du, Min-Lian; Su, Zhe; Du, Hongwei; Yan, Chaoying

2017-08-01

We assessed the efficacy and safety of a weekly pegylated human growth hormone (PEG-rhGH) (Jintrolong) vs daily rhGH for children with growth hormone deficiency (GHD). Phase II and III, multicenter, open-label, randomized controlled trials. 108 and 343 children with treatment-naive GHD from 6 hospitals in China were enrolled in the phase II and III studies respectively. Patients in the phase II study were randomized 1:1:1 to weekly Jintrolong (0.1 mg/kg/week PEG-rhGH complex), weekly Jintrolong (0.2 mg/kg/week PEG-rhGH complex) or daily rhGH (0.25 mg/kg/week) for 25 weeks. Patients in the phase III study were randomized in a 2:1 ratio to weekly Jintrolong (0.2 mg/kg/week) or daily rhGH (0.25 mg/kg/week) for 25 weeks. The primary endpoint for both studies was height velocity (HV) increase at the end of treatment. Other growth-related parameters, safety and compliance were also monitored. The phase II study established the preliminary efficacy, safety and recommended dose of Jintrolong PEG-rhGH. In the phase III study, we demonstrated significantly greater HV increases in patients receiving Jintrolong treatment (from 2.26 ± 0.87 cm/year to 13.41 ± 3.72 cm/year) vs daily rhGH (from 2.25 ± 0.82 cm/year to 12.55 ± 2.99 cm/year) at the end of treatment ( P  < 0.05). Additionally, significantly greater improvement in the height standard deviation scores was associated with Jintrolong throughout the treatment ( P  < 0.05). Adverse event rates and treatment compliance were comparable between the two groups. Jintrolong PEG-rhGH at a dose of 0.2 mg/kg/week for 25 weeks is effective and safe for GHD treatment and is non-inferior to daily rhGH. © 2017 The authors.

Long-acting PEGylated recombinant human growth hormone (Jintrolong) for children with growth hormone deficiency: phase II and phase III multicenter, randomized studies

PubMed Central

Hou, Ling; Liang, Li; Dong, Guanping; Shen, Shuixian; Zhao, Zhuhui; Gong, Chun Xiu; Li, Yuchuan; Du, Min-lian; Su, Zhe; Du, Hongwei; Yan, Chaoying

2017-01-01

Objective We assessed the efficacy and safety of a weekly pegylated human growth hormone (PEG-rhGH) (Jintrolong) vs daily rhGH for children with growth hormone deficiency (GHD). Design Phase II and III, multicenter, open-label, randomized controlled trials. Methods 108 and 343 children with treatment-naive GHD from 6 hospitals in China were enrolled in the phase II and III studies respectively. Patients in the phase II study were randomized 1:1:1 to weekly Jintrolong (0.1 mg/kg/week PEG-rhGH complex), weekly Jintrolong (0.2 mg/kg/week PEG-rhGH complex) or daily rhGH (0.25 mg/kg/week) for 25 weeks. Patients in the phase III study were randomized in a 2:1 ratio to weekly Jintrolong (0.2 mg/kg/week) or daily rhGH (0.25 mg/kg/week) for 25 weeks. The primary endpoint for both studies was height velocity (HV) increase at the end of treatment. Other growth-related parameters, safety and compliance were also monitored. Results The phase II study established the preliminary efficacy, safety and recommended dose of Jintrolong PEG-rhGH. In the phase III study, we demonstrated significantly greater HV increases in patients receiving Jintrolong treatment (from 2.26 ± 0.87 cm/year to 13.41 ± 3.72 cm/year) vs daily rhGH (from 2.25 ± 0.82 cm/year to 12.55 ± 2.99 cm/year) at the end of treatment (P < 0.05). Additionally, significantly greater improvement in the height standard deviation scores was associated with Jintrolong throughout the treatment (P < 0.05). Adverse event rates and treatment compliance were comparable between the two groups. Conclusion Jintrolong PEG-rhGH at a dose of 0.2 mg/kg/week for 25 weeks is effective and safe for GHD treatment and is non-inferior to daily rhGH. PMID:28566441

Ultrafast Dynamics in Vanadium Dioxide: Separating Spatially Segregated Mixed Phase Dynamics in the Time-domain

NASA Astrophysics Data System (ADS)

Hilton, David

2011-10-01

In correlated electronic systems, observed electronic and structural behavior results from the complex interplay between multiple, sometimes competing degrees-of- freedom. One such material used to study insulator-to-metal transitions is vanadium dioxide, which undergoes a phase transition from a monoclinic-insulating phase to a rutile-metallic phase when the sample is heated to 340 K. The major open question with this material is the relative influence of this structural phase transition (Peirels transition) and the effects of electronic correlations (Mott transition) on the observed insulator-to-metal transition. Answers to these major questions are complicated by vanadium dioxide's sensitivity to perturbations in the chemical structure in VO2. For example, related VxOy oxides with nearly a 2:1 ratio do not demonstrate the insulator-to- metal transition, while recent work has demonstrated that W:VO2 has demonstrated a tunable transition temperature controllable with tungsten doping. All of these preexisting results suggest that the observed electronic properties are exquisitely sensitive to the sample disorder. Using ultrafast spectroscopic techniques, it is now possible to impulsively excite this transition and investigate the photoinduced counterpart to this thermal phase transition in a strongly nonequilibrium regime. I will discuss our recent results studying the terahertz-frequency conductivity dynamics of this photoinduced phase transition in the poorly understood near threshold temperature range. We find a dramatic softening of the transition near the critical temperature, which results primarily from the mixed phase coexistence near the transition temperature. To directly study this mixed phase behavior, we directly study the nucleation and growth rates of the metallic phase in the parent insulator using non-degenerate optical pump-probe spectroscopy. These experiments measure, in the time- domain, the coexistent phase separation in VO2 (spatially separated insulator and metal islands) and, more importantly, their dynamic evolution in response to optical excitation.

Cr6+-containing phases in the system CaO-Al2O3-CrO42--H2O at 23 °C

NASA Astrophysics Data System (ADS)

Pöllmann, Herbert; Auer, Stephan

2012-01-01

Synthesis and investigation of lamellar calcium aluminium hydroxy salts was performed to study the incorporation of chromate ions in the interlayer of lamellar calcium aluminium hydroxy salts. Different AFm-phases (calcium aluminate hydrate with alumina, ferric oxide, mono-anion phase) containing chromate were synthesized. These AFm-phases belong to the group of layered double hydroxides (LDHs). 3CaO·Al2O3·CaCrO4·nH2O and C3A·1/2Ca(OH)2·1/2CaCrO4·12H2O were obtained as pure phases and their different distinct interlayer water contents and properties determined. Solid solution of chromate-containing phases and tetracalcium-aluminate-hydrate (TCAH) were studied. The uptake of chromate into TCAH from solutions was proven. Chromate contents in solution decrease to <0.2 mg/l.

Formation of H2-He substellar bodies in cold conditions. Gravitational stability of binary mixtures in a phase transition

NASA Astrophysics Data System (ADS)

Füglistaler, A.; Pfenniger, D.

2016-06-01

Context. Molecular clouds typically consist of 3/4 H2, 1/4 He and traces of heavier elements. In an earlier work we showed that at very low temperatures and high densities, H2 can be in a phase transition leading to the formation of ice clumps as large as comets or even planets. However, He has very different chemical properties and no phase transition is expected before H2 in dense interstellar medium conditions. The gravitational stability of fluid mixtures has been studied before, but these studies did not include a phase transition. Aims: We study the gravitational stability of binary fluid mixtures with special emphasis on when one component is in a phase transition. The numerical results are aimed at applications in molecular cloud conditions, but the theoretical results are more general. Methods: First, we study the gravitational stability of van der Waals fluid mixtures using linearized analysis and examine virial equilibrium conditions using the Lennard-Jones intermolecular potential. Then, combining the Lennard-Jones and gravitational potentials, the non-linear dynamics of fluid mixtures are studied via computer simulations using the molecular dynamics code LAMMPS. Results: Along with the classical, ideal-gas Jeans instability criterion, a fluid mixture is always gravitationally unstable if it is in a phase transition because compression does not increase pressure. However, the condensed phase fraction increases. In unstable situations the species can separate: in some conditions He precipitates faster than H2, while in other conditions the converse occurs. Also, for an initial gas phase collapse the geometry is essential. Contrary to spherical or filamentary collapses, sheet-like collapses starting below 15 K easily reach H2 condensation conditions because then they are fastest and both the increase of heating and opacity are limited. Conclusions: Depending on density, temperature and mass, either rocky H2 planetoids, or gaseous He planetoids form. H2 planetoids are favoured by high density, low temperature and low mass, while He planetoids need more mass and can form at temperature well above the critical value.

Gapped excitations in the high-pressure antiferromagnetic phase of URu 2 Si 2

DOE PAGES

Williams, Travis J.; Oak Ridge National Lab.; Barath, Harini; ...

2017-05-31

Here, we report a neutron scattering study of the magnetic excitation spectrum in each of the three temperature and pressure driven phases of URu 2Si 2. We also found qualitatively similar excitations throughout the (H0L) scattering plane in the hidden order and large moment phases, with no changes in the hbar-omega-widths of the excitations at the Sigma = (1.407,0,0) and Z = (1,0,0) points, within our experimental resolution. There is, however, an increase in the gap at the Sigma point and an increase in the first moment of both excitations. At 8 meV where the Q-dependence of magnetic scattering inmore » the hidden order phase is extended in Q-space, the excitations in the large moment phase are sharper. Furthermore, the expanded Q-hbar-omega coverage of this study suggest more complete nesting within the antiferromagnetic phase, an important property for future theoretical predictions of a hidden order parameter.« less

Solvent Extraction of Rare Earth Elements from a Nitric Acid Leach Solution of Apatite by Mixtures of Tributyl Phosphate and Di-(2-ethylhexyl) Phosphoric Acid

NASA Astrophysics Data System (ADS)

Ferdowsi, Ali; Yoozbashizadeh, Hossein

2017-12-01

Solvent extraction of rare earths from nitrate leach liquor of apatite using mixtures of tributyl phosphate (TBP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) was studied. The effects of nitrate and hydrogen ion concentration of the aqueous phase as well as the composition and concentration of extractants in the organic phase on the extraction behavior of lanthanum, cerium, neodymium, and yttrium were investigated. The distribution ratio of REEs increases by increasing the nitrate concentration in aqueous phase and concentration of extractants in organic phase, but the hydrogen ion concentration in aqueous phase has a decreasing effect. Yttrium as a heavy rare earth is more sensitive to these parameters than light rare earth elements. Although the composition of organic phase has a minor effect on the extraction of light rare earths, the percent of extraction of yttrium decreases dramatically by increasing the TBP content of organic phase. Mixtures of TBP and D2EHPA can show either synergism or antagonism extraction depending on the concentration and composition of extractants in organic phase. The best condition for separating rare earth elements in groups of heavy and light REEs can be achieved at high nitrate concentration, low H+ concentration, and high concentration of D2EHPA in organic phase. Separation of Ce and La by TBP and D2EHPA is practically impossible in the studied conditions; however, low nitrate concentration and high hydrogen ion concentration in aqueous phase and low concentration of extractants in organic phase favor the separation of Nd from other light rare earth elements.

Dulanermin with rituximab in patients with relapsed indolent B-cell lymphoma: an open-label phase 1b/2 randomised study.

PubMed

Cheah, Chan Yoon; Belada, David; Fanale, Michelle A; Janikova, Andrea; Czucman, Myron S; Flinn, Ian W; Kapp, Amy V; Ashkenazi, Avi; Kelley, Sean; Bray, Gordon L; Holden, Scott; Seymour, John F

2015-04-01

Dulanermin-a non-polyhistidine-tagged soluble recombinant human apoptosis ligand 2 (Apo2L) or tumour-necrosis-factor-related apoptosis-inducing-ligand (TRAIL)-has pro-apoptotic activity in a range of cancers and synergistic preclinical activity with rituximab against lymphoma in vivo. We aimed to assess the safety, pharmacokinetics, and efficacy of dulanermin and rituximab in patients with relapsed indolent B-cell non-Hodgkin lymphoma. We did an open-label phase 1b/2 randomised study. Four study centres in the USA enrolled patients into phase 1b, and 27 study centres in the USA, Italy, Australia, France, Czech Republic, New Zealand, and Poland enrolled patients into phase 2. In phase 1b, patients (age ≥18 years) with indolent B-cell non-Hodgkin lymphoma with stable disease or better lasting at least 6 months after the most recent rituximab-containing regimen were included. In phase 2, patients (age ≥18 years) with follicular lymphoma grades 1-3a were included. In phase 1b, patients received 4 mg/kg or 8 mg/kg intravenous dulanermin on days 1-5 of up to four 21-day cycles and intravenous rituximab 375 mg/m(2) weekly for up to eight doses. In phase 2, patients were randomly assigned (1:1:1) centrally by an interactive voice response system to dulanermin (8 mg/kg for a maximum of four 21-day cycles), rituximab (375 mg/m(2) weekly for up to eight doses), or both in combination, stratified by baseline follicular lymphoma International Prognostic Index (0-3 vs 4-5) and geographic site (USA vs non-USA). The primary endpoints of the phase 1b study were the safety, tolerability, and pharmacokinetics of dulanermin with rituximab. The primary endpoint of phase 2 was the proportion of patients who achieved an objective response. All patients who received any dose of study drug were included in safety analyses. Efficacy analyses were per protocol. Treatment was open label; all patients and investigators were unmasked to treatment allocation. This study is registered with ClinicalTrials.gov, NCT00400764. Between June 6, 2006, and Feb 15, 2007, 12 patients were enrolled in phase 1b, and between April 4, 2007, and April 20, 2009, 60 patients were enrolled in phase 2, of whom 59 were included in safety analyses and 58 in efficacy analyses. No dose-limiting toxic effects were noted in phase 1b. The most common grade 1-2 adverse events in phase 1b were fatigue (nine; 75%), rash (five; 42%), and chills, decreased appetite, diarrhoea, and nausea (four each; 33%). 19 grade 3 or higher adverse effects were noted in five (42%) patients, with 14 occurring in one patient. After treatment with 8 mg/kg of dulanermin, in six patients the mean serum peak concentration was 80 μg/mL, dropping below the minimum detectable concentration (2 ng/mL) within 24 h after the dose. The mean steady state peak and trough concentrations of rituximab were 461 μg/mL (SD 97.5) and 303 μg/mL (92.8), respectively. In phase 2, eight (14%) of 59 patients experienced 12 grade 3 or higher adverse events. In phase 2, objective responses were noted in 14 of 22 (63.6%, 95% CI 41.8-81.3) patients treated with rituximab only, 16 of 25 (64.0%, 43.1-81.5) treated with dulanermin and rituximab, and one of 11 (9.1%, 0.5-39.0) treated with dulanermin only. The study was terminated early, on May 5, 2010, because of an absence of efficacy in the combination group. The addition of dulanermin to rituximab in patients with indolent B-cell non-Hodgkin lymphoma was tolerable but did not lead to increased objective responses. This combination is not being developed further in non-Hodgkin lymphoma. Genentech and Amgen. Copyright © 2015 Elsevier Ltd. All rights reserved.

Microstructure characterization and phase transformation kinetic study of ball-milled m-ZrO 2-30 mol% a-TiO 2 mixture by Rietveld method

NASA Astrophysics Data System (ADS)

Pradhan, S. K.; Dutta, H.

2005-05-01

High-energy ball milling of monoclinic ZrO 2-30 mol% anatase TiO 2 mixture at different durations results in the formation of m-ZrO 2-a-TiO 2 solid solution from which the nucleation of nanocrystalline cubic (c) ZrO 2 polymorphic phase sets in. Post-annealing of 12 h ball-milled sample at different elevated temperatures for 1 h results in almost complete formation of c-ZrO 2 phase. Microstructure of the unmilled, all the ball milled and annealed samples has been characterized by Rietveld's X-ray powder structure refinement method. Particle size, rms lattice strain, change in lattice parameters and phase content of individual phases have been estimated from Rietveld analysis, and are utilized to interpret the results. In course of milling, (1 1 1) of cubic lattice became parallel to ( 1bar 1 1) plane of monoclinic lattice due to the orientation effect and cubic phase may have been formed on the (0 0 1) of the m-ZrO 2-a-TiO 2 solid solution lattice. A comparative study of microstructure and phase transformation kinetics of ZrO 2-10, 20 and 30 mol% a-TiO 2 ball-milled and post-annealed samples reveals that rate of phase transformation m→c-ZrO 2 increases with increasing a-TiO 2 concentration and ∼30 mol% of nanocrystalline c-ZrO 2 phase can be obtained within 4 h of milling time in the presence of 30 mol% of a-TiO 2. The post-annealing treatment at 773, 873 and 973 K for 1 h duration each reveals that rate of c-ZrO 2 formation with increasing temperature is retarded with increasing a-TiO 2 concentration but the amount of c-ZrO 2 becomes almost equal (∼95 mol%) at 973 K. It suggests that almost fully stabilized nanocrystalline c-ZrO 2 can be formed by adding a tetravalent solute to m-ZrO 2.

Collapse of superconductivity in cuprates via ultrafast quenching of phase coherence

NASA Astrophysics Data System (ADS)

Boschini, F.; da Silva Neto, E. H.; Razzoli, E.; Zonno, M.; Peli, S.; Day, R. P.; Michiardi, M.; Schneider, M.; Zwartsenberg, B.; Nigge, P.; Zhong, R. D.; Schneeloch, J.; Gu, G. D.; Zhdanovich, S.; Mills, A. K.; Levy, G.; Jones, D. J.; Giannetti, C.; Damascelli, A.

2018-05-01

The possibility of driving phase transitions in low-density condensates through the loss of phase coherence alone has far-reaching implications for the study of quantum phases of matter. This has inspired the development of tools to control and explore the collective properties of condensate phases via phase fluctuations. Electrically gated oxide interfaces1,2, ultracold Fermi atoms3,4 and cuprate superconductors5,6, which are characterized by an intrinsically small phase stiffness, are paradigmatic examples where these tools are having a dramatic impact. Here we use light pulses shorter than the internal thermalization time to drive and probe the phase fragility of the Bi2Sr2CaCu2O8+δ cuprate superconductor, completely melting the superconducting condensate without affecting the pairing strength. The resulting ultrafast dynamics of phase fluctuations and charge excitations are captured and disentangled by time-resolved photoemission spectroscopy. This work demonstrates the dominant role of phase coherence in the superconductor-to-normal state phase transition and offers a benchmark for non-equilibrium spectroscopic investigations of the cuprate phase diagram.

Phase formation and strain relaxation of Ga2O3 on c-plane and a-plane sapphire substrates as studied by synchrotron-based x-ray diffraction

NASA Astrophysics Data System (ADS)

Cheng, Zongzhe; Hanke, Michael; Vogt, Patrick; Bierwagen, Oliver; Trampert, Achim

2017-10-01

Heteroepitaxial Ga2O3 was deposited on c-plane and a-plane oriented sapphire by plasma-assisted molecular beam epitaxy and probed by ex-situ and in-situ synchrotron-based x-ray diffraction. The investigation on c-plane sapphire determined a critical thickness of around 33 Å, at which the monoclinic β-phase forms on top of the hexagonal α-phase. A 143 Å thick single phase α-Ga2O3 was observed on a-plane sapphire, much thicker than the α-Ga2O3 on c-plane sapphire. The α-Ga2O3 relaxed very fast in the first 30 Å in both out-of-plane and in-plane directions as measured by the in-situ study.

The cephalic phase insulin response to nutritive and low-calorie sweeteners in solid and beverage form.

PubMed

Dhillon, Jaapna; Lee, Janice Y; Mattes, Richard D

2017-11-01

The purpose of the study was to examine the role of the cephalic phase insulin response (CPIR) following exposure to nutritive and low-calorie sweeteners in solid and beverage form in overweight and obese adults. In addition, the role of learning on the CPIR to nutritive and low-calorie sweetener exposure was tested. Sixty-four overweight and obese adults (age: 18-50years, BMI: 24-37kg/m 2 , body fat percentage>25% for men and >32% for women) were sham-fed (at 2-minute intervals for 14min) a randomly assigned test load comprised of a nutritive (sucrose) or low-calorie sweetener (sucralose) in beverage or solid form in phase 1 of the study. A 2-3ml blood sample was collected before and 2, 6, 10, 14, 61, 91 and 121min after oral exposure for serum insulin and glucose analysis. During phase 2, participants underwent a 2-week training period to facilitate associative learning between the sensory properties of test loads and their post-ingestive effects. In phase 3, participants were retested for their cephalic phase responses as in phase 1. Participants were classified as responders if they demonstrated a positive insulin response (rise of serum insulin above baseline i.e. Δ insulin) 2min post-stimulus in phase 1. Among responders exposed to the same sweetener in Phases 1 and 3, the proportion of participants that displayed a rise of insulin with oral exposure to sucralose was significantly greater when the stimulus was in the solid form compared to the beverage form. Sucralose and sucrose exposure elicited similarly significant increases in serum insulin 2min after exposure and significant decreases after 2min in responders in both food forms. The solid food form elicited greater CPIR over 2, 6 and 10min than the beverage form. There was no effect of learning on insulin responses after training. The results indicate the presence of a significant CPIR in a subset of individuals with overweight or obesity after oral exposure to sucralose, especially when present in solid food form. Future studies must confirm the reliability of this response. Copyright © 2017 Elsevier Inc. All rights reserved.

Upregulation of Zinc Absorption Matches Increases in Physiologic Requirements for Zinc in Women Consuming High- or Moderate-Phytate Diets during Late Pregnancy and Early Lactation.

PubMed

Hambidge, K Michael; Miller, Leland V; Mazariegos, Manolo; Westcott, Jamie; Solomons, Noel W; Raboy, Victor; Kemp, Jennifer F; Das, Abhik; Goco, Norman; Hartwell, Ty; Wright, Linda; Krebs, Nancy F

2017-06-01

Background: Estimated physiologic requirements (PRs) for zinc increase in late pregnancy and early lactation, but the effect on dietary zinc requirements is uncertain. Objective: The aim of this study was to determine changes in daily fractional absorbed zinc and total absorbed zinc (TAZ) from ad libitum diets of differing phytate contents in relation to physiologic zinc requirements during pregnancy and lactation. Methods: This was a prospective observational study of zinc absorption at 8 (phase 1) and 34 (phase 2) wk of gestation and 2 (phase 3) and 6 (phase 4) mo of lactation. Participants were indigenous Guatemalan women of childbearing age whose major food staple was maize and who had been randomly assigned in a larger study to either of 2 ad libitum feeding groups: low-phytate maize (LP; 1.6 mg/g; n = 14) or control maize (C; 7.1 mg/g; n = 8). Total dietary zinc (milligrams per day, TDZ) and phytate (milligrams per day) were determined from duplicate diets and fractional absorption (FAZ) by dual isotope ratio technique (TAZ = TDZ × FAZ). All variables were examined longitudinally and by group and compared with PRs. TAZ values at later phases were compared with phase 1. Measured TAZ was compared with predicted TAZ for nonpregnant, nonlactating (NPNL) women. Results: TAZ was greater in the LP group than in the C group at all phases. All variables increased from phase 1 to phases 2 and 3 and declined at phase 4. TAZ increased by 1.25 mg/d ( P = 0.045) in the C group and by 0.81 mg/d ( P = 0.058) in the LP group at phase 2. At phase 3, the increases were 2.66 mg/d ( P = 0.002) in the C group and 2.28 mg/d ( P = 0.0004) in the LP group, compared with a 1.37-mg/d increase in PR. Measured TAZ was greater than predicted values in phases 2-4. Conclusions: Upregulation of zinc absorption in late pregnancy and early lactation matches increases in PRs of pregnant and lactating women, regardless of dietary phytate, which has implications for dietary zinc requirements of pregnant and lactating women. © 2017 American Society for Nutrition.

How good is this food? A study on dogs' emotional responses to a potentially pleasant event using infrared thermography.

PubMed

Travain, Tiziano; Colombo, Elisa Silvia; Grandi, Laura Clara; Heinzl, Eugenio; Pelosi, Annalisa; Prato Previde, Emanuela; Valsecchi, Paola

2016-05-15

Understanding how animals express positive emotions is becoming an interesting and promising area of research in the study of animal emotions and affective experiences. In the present study, we used infrared thermography in combination with behavioral measures, heart rate (HR) and heart rate variability (HRV), to investigate dogs' emotional responses to a potentially pleasant event: receiving palatable food from the owner. Nineteen adult pet dogs, 8 females and 11 males, were tested and their eye temperature, HR, HRV and behavior were recorded during a 30-minutestestconsisting of three 10-minute consecutive phases: Baseline (Phase 1), positive stimulation through the administration of palatable treats (Feeding, Phase 2) and Post-feeding condition following the positive stimulation (Phase 3). Dogs' eye temperature and mean HR significantly increased during the positive stimulation phase compared with both Baseline and Post-feeding phases. During the positive stimulation with food (Phase 2), dogs engaged in behaviors indicating a positive emotional state and a high arousal, being focused on food treats and increasing tail wagging. However, there was no evidence of an increase in HRV during Phase 2 compared to the Phase 1, with SDNN significantly increasing only in Phase 3, after the positive stimulation occurred. Overall results point out that IRT may be a useful tool in assessing emotional states in dogs in terms of arousal but fails to discriminate emotional valence, whose interpretation cannot disregard behavioral indexes. Copyright © 2016 Elsevier Inc. All rights reserved.

Precipitation of T1 and θ′ Phase in Al-4Cu-1Li-0.25Mn During Age Hardening: Microstructural Investigation and Phase-Field Simulation

PubMed Central

Häusler, Ines; Schwarze, Christian; Bilal, Muhammad Umer; Valencia Ramirez, Daniela; Hetaba, Walid; Darvishi Kamachali, Reza; Skrotzki, Birgit

2017-01-01

Experimental and phase field studies of age hardening response of a high purity Al-4Cu-1Li-0.25Mn-alloy (mass %) during isothermal aging are conducted. In the experiments, two hardening phases are identified: the tetragonal θ′ (Al2Cu) phase and the hexagonal T1 (Al2CuLi) phase. Both are plate shaped and of nm size. They are analyzed with respect to the development of their size, number density and volume fraction during aging by applying different analysis techniques in TEM in combination with quantitative microstructural analysis. 3D phase-field simulations of formation and growth of θ′ phase are performed in which the full interfacial, chemical and elastic energy contributions are taken into account. 2D simulations of T1 phase are also investigated using multi-component diffusion without elasticity. This is a first step toward a complex phase-field study of T1 phase in the ternary alloy. The comparison between experimental and simulated data shows similar trends. The still unsaturated volume fraction indicates that the precipitates are in the growth stage and that the coarsening/ripening stage has not yet been reached. PMID:28772481

Phase 1/2 study of cyclin-dependent kinase (CDK)4/6 inhibitor palbociclib (PD-0332991) with bortezomib and dexamethasone in relapsed/refractory multiple myeloma.

PubMed

Niesvizky, Ruben; Badros, Ashraf Z; Costa, Luciano J; Ely, Scott A; Singhal, Seema B; Stadtmauer, Edward A; Haideri, Nisreen A; Yacoub, Abdulraheem; Hess, Georg; Lentzsch, Suzanne; Spicka, Ivan; Chanan-Khan, Asher A; Raab, Marc S; Tarantolo, Stefano; Vij, Ravi; Zonder, Jeffrey A; Huang, Xiangao; Jayabalan, David; Di Liberto, Maurizio; Huang, Xin; Jiang, Yuqiu; Kim, Sindy T; Randolph, Sophia; Chen-Kiang, Selina

2015-01-01

This phase 1/2 study was the first to evaluate the safety and efficacy of the cyclin-dependent kinase (CDK) 4/6-specific inhibitor palbociclib (PD-0332991) in sequential combination with bortezomib and dexamethasone in relapsed/refractory multiple myeloma. The recommended phase 2 dose was palbociclib 100 mg orally once daily on days 1-12 of a 21-day cycle with bortezomib 1.0 mg/m2 (intravenous) and dexamethasone 20 mg (orally 30 min pre-bortezomib dosing) on days 8 and 11 (early G1 arrest) and days 15 and 18 (cell cycle resumed). Dose-limiting toxicities were primarily cytopenias; most other treatment-related adverse events were grade≤3. At a bortezomib dose lower than that in other combination therapy studies, antitumor activity was observed (phase 1). In phase 2, objective responses were achieved in 5 (20%) patients; 11 (44%) achieved stable disease. Biomarker and pharmacodynamic assessments demonstrated that palbociclib inhibited CDK4/6 and the cell cycle initially in most patients.

Relative phase of oscillations of cerebral oxy-hemoglobin and deoxy-hemoglobin concentrations during sleep

NASA Astrophysics Data System (ADS)

Pierro, Michele L.; Sassaroli, Angelo; Bergethon, Peter R.; Fantini, Sergio

2012-02-01

We present a near-infrared spectroscopy study of the instantaneous phase difference between spontaneous oscillations of cerebral deoxy-hemoglobin and oxy-hemoglobin concentrations ([Hb] and [HbO], respectively) in the low-frequency range, namely 0.04-0.12 Hz. We report phase measurements during the transitions between different sleep stages in a whole-night study of a human subject. We have found that the phase difference between [Hb] and [HbO] low-frequency oscillations tends to be greater in deep sleep (by ~96° on average) and REM sleep (by ~77° on average) compared to the awake state. In particular, we have observed progressive phase increases as the subject transitions from awake conditions into non-REM sleep stages N1, N2, and N3. Corresponding phase decreases were recorded in the reversed transitions from sleep stages N3 to N2, and N2 to awake. These results illustrate the physiological information content of phase measurements of [Hb] and [HbO] oscillations that reflect the different cerebral hemodynamic conditions of the different sleep stages, and that can find broader applicability in a wide range of near-infrared spectroscopy brain studies.

Tunable VO{sub 2}/Au hyperbolic metamaterial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Prayakarao, S.; Noginov, M. A., E-mail: mnoginov@nsu.edu; Mendoza, B.

2016-08-08

Vanadium dioxide (VO{sub 2}) is known to have a semiconductor-to-metal phase transition at ∼68 °C. Therefore, it can be used as a tunable component of an active metamaterial. The lamellar metamaterial studied in this work is composed of subwavelength VO{sub 2} and Au layers and is designed to undergo a temperature controlled transition from the optical hyperbolic phase to the metallic phase. VO{sub 2} films and VO{sub 2}/Au lamellar metamaterial stacks have been fabricated and studied in electrical conductivity and optical (transmission and reflection) experiments. The observed temperature-dependent changes in the reflection and transmission spectra of the metamaterials and VO{sub 2}more » thin films are in a good qualitative agreement with theoretical predictions. The demonstrated optical hyperbolic-to-metallic phase transition is a unique physical phenomenon with the potential to enable advanced control of light-matter interactions.« less

NMR signal analysis to characterize solid, aqueous, and lipid phases in baked cakes.

PubMed

Le Grand, F; Cambert, M; Mariette, F

2007-12-26

Proton mobility was studied in molecular fractions of some model systems and of cake using a 1H nuclear magnetic resonance (NMR) relaxation technique. For cake, five spin-spin relaxation times (T2) were obtained from transverse relaxation curves: T2 (1) approximately 20 micros, T2 (2) approximately 0.2 ms, T2 (3) approximately 3 ms, T2 (4) approximately 50 ms, and T2 (2) approximately 165 ms. The faster component was attributed to the solid phase, components 2 and 3 were associated with the aqueous phase, and the two slowest components were linked to the lipid phase. After cooking, the crust contained more fat but less water than the center part of the cake. The amount of gelatinized starch was lower in the crust, and water was more mobile due to less interaction with macromolecules. This preliminary study revealed different effects of storage on the center and crust.

Post Hoc Analyses of the Effect of Crisaborole Topical Ointment, 2% on Atopic Dermatitis: Associated Pruritus from Phase 1 and 2 Clinical Studies.

PubMed

Draelos, Zoe Diana; Stein Gold, Linda F; Murrell, Dedee F; Hughes, Matilda H; Zane, Lee T

2016-02-01

Two post hoc analyses assessed the antipruritic activity of crisaborole topical ointment, 2% (crisaborole; Anacor Pharmaceuticals, Inc., Palo Alto, CA), a first-in-class boron-based phosphodiesterase-4 inhibitor in development for treatment of mild to moderate atopic dermatitis (AD). Two pooled analyses included data from 4 studies evaluating crisaborole in AD (study 1, phase 1b, systemic exposure, safety, and pharmacokinetics [PK] under maximal-use conditions in children and adolescents; study 2, phase 2a, safety and PK in adolescents; study 3, phase 2a, efficacy and safety in adults; study 4, phase 2, efficacy and safety in adolescents). Pooled data from studies 1 and 2 included whole body assessments; studies 3 and 4 included target lesion assessments. Pruritus severity was evaluated using a 4-point rating scale (0=none to 3=severe). Efficacy assessments included percent change from baseline in pruritus severity scores at days 8 (first pooled assessment), 15, 22, and 29 (whole body assessments) or days 15 (first pooled assessment), 22, and 29 (target lesions). Paired t-tests comparing change from baseline against zero were used to calculate P values. Categorical shifts in pruritus severity were also assessed (no to mild pruritus, 0-1.5; moderate to severe pruritus, 2-3). In the pooled analysis of studies 1 and 2 (N=57), the percent change from baseline in pruritus severity scores were 63.0% and 64.9% at days 8 and 29, respectively (P<0.001 for each). Similar results were observed in the pooled analysis of studies 3 and 4 (N=67). In both analyses, most patients had mild to no pruritus from the first time point assessed through the remainder of treatment. Treatment with crisaborole topical ointment, 2% resulted in statistically significant reductions in pruritus severity at the first time point evaluated in both analyses. These findings provide preliminary evidence of the antipruritic activity of crisaborole topical ointment, 2%.

Distribution network connection pricing framework and methodology: identification of areas of improvement for Sarawak Energy Berhad Connection Charges Guidelines through modified delphi method

NASA Astrophysics Data System (ADS)

Tan, J. K.; Abas, N.

2017-07-01

Complaints on issues and matters related to connection charges have been very common for electricity supply utility companies around the world including Sarawak Energy Berhad. In order to identify the areas that can be improved, a mixed method of exploratory research involving qualitative and quantitative methods have been designed and undertaken rather than a single method of survey. This will ensure a more comprehensive and detailed understanding of the issues from various target groups. The method is designed under three phases, employing Modified Delphi Technique for phase 1 through a series of stake holder engagements, online and offline survey questionnaires to be filled by internal wiring contractors for phase 2 whilst under phase 3, case studies shall be carried out on the issues identified from phase 1 and phase 2 of the study. This paper presented the findings from the Modified Delphi Technique. The findings revealed that there are areas of improvement for Sarawak Energy Berhad connection guidelines in term of differentiation of dedicated and shared assets which leads to unfairness to the connecting customers, inconsistency and non-transparent in charging. The findings of Modified Delphi Technique shall be used for implementation of phase 2 and phase 3 of the study.

Observation of a re-entrant phase transition in the molecular complex tris(μ 2-3,5-diisopropyl-1,2,4-triazolato-κ 2 N 1: N 2)trigold(I) under high pressure

DOE PAGES

Woodall, Christopher H.; Christensen, Jeppe; Skelton, Jonathan M.; ...

2016-08-18

We report a molecular crystal that exhibits four successive phase transitions under hydro­static pressure, driven by aurophilic interactions, with the ground-state structure re-emerging at high pressure. The effect of pressure on two polytypes of tris(μ 2-3,5-diiso­propyl-1,2,4-triazolato-κ 2 N 1: N 2)trigold(I) (denoted Form-I and Form-II) has been analysed using luminescence spectroscopy, single-crystal X-ray diffraction and first-principles computation. A unique phase behaviour was observed in Form-I, with a complex sequence of phase transitions between 1 and 3.5 GPa. The ambient C2/c mother cell transforms to a P2 1/n phase above 1 GPa, followed by a P2 1/a phase above 2 GPamore » and a large-volume C2/c supercell at 2.70 GPa, with the previously observed P2 1/n phase then reappearing at higher pressure. The observation of crystallographically identical low- and high-pressure P2 1/n phases makes this a rare example of a re-entrant phase transformation. The phase behaviour has been characterized using detailed crystallographic theory and modelling, and rationalized in terms of molecular structural distortions. The dramatic changes in conformation are correlated with shifts of the luminescence maxima, from a band maximum at 14040 cm –1 at 2.40 GPa, decreasing steeply to 13550 cm –1 at 3 GPa. A similar study of Form-II displays more conventional crystallographic behaviour, indicating that the complex behaviour observed in Form-I is likely to be a direct consequence of the differences in crystal packing between the two polytypes.« less

Observation of a re-entrant phase transition in the molecular complex tris(μ 2-3,5-diisopropyl-1,2,4-triazolato-κ 2 N 1: N 2)trigold(I) under high pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodall, Christopher H.; Christensen, Jeppe; Skelton, Jonathan M.

We report a molecular crystal that exhibits four successive phase transitions under hydro­static pressure, driven by aurophilic interactions, with the ground-state structure re-emerging at high pressure. The effect of pressure on two polytypes of tris(μ 2-3,5-diiso­propyl-1,2,4-triazolato-κ 2 N 1: N 2)trigold(I) (denoted Form-I and Form-II) has been analysed using luminescence spectroscopy, single-crystal X-ray diffraction and first-principles computation. A unique phase behaviour was observed in Form-I, with a complex sequence of phase transitions between 1 and 3.5 GPa. The ambient C2/c mother cell transforms to a P2 1/n phase above 1 GPa, followed by a P2 1/a phase above 2 GPamore » and a large-volume C2/c supercell at 2.70 GPa, with the previously observed P2 1/n phase then reappearing at higher pressure. The observation of crystallographically identical low- and high-pressure P2 1/n phases makes this a rare example of a re-entrant phase transformation. The phase behaviour has been characterized using detailed crystallographic theory and modelling, and rationalized in terms of molecular structural distortions. The dramatic changes in conformation are correlated with shifts of the luminescence maxima, from a band maximum at 14040 cm –1 at 2.40 GPa, decreasing steeply to 13550 cm –1 at 3 GPa. A similar study of Form-II displays more conventional crystallographic behaviour, indicating that the complex behaviour observed in Form-I is likely to be a direct consequence of the differences in crystal packing between the two polytypes.« less

Phase transformations in 40-60-GPa shocked gneisses from the Haughton Crater (Canada): An Analytical Transmission Electron Microscopy (ATEM) study

NASA Technical Reports Server (NTRS)

Martinez, I.; Guyot, F.; Schaerer, U.

1992-01-01

In order to better understand phase transformations, chemical migration, and isotopic disequilibrium in highly shocked rocks, we have performed a microprobe and an ATEM study on gneisses shocked up to 60 GPa from the Haughton Crater. This study reveals the following chemical and structural characteristics: (1) SiO2 dominant areas are formed by a mixture of pure SiO2 polycrystalline quartz identified by electron diffraction pattern and chemical analysis and a silica-rich amorphous phase containing minor amounts of aluminium, potassium, and iron; (2) Areas with biotitelike composition are formed by less than 200-nm grains of iron-rich spinels embedded in a silica-rich amorphous phase that is very similar to the one described above; (3) Layers with feldsparlike composition are constituted by 100-200-nm-sized alumina-rich grains (the indexation of the crystalline structure is under progress) and the silica-rich amorphous phase; (4) Zones characterized by the unusual Al/Si ratio close to 1 are formed by spinel grains (200-nm-sized) embedded in the same silica-rich amorphous phase; and (5) The fracturated sillimanites contain domains with a lamellar structure, defined by the intercalation of 100-nm-wide lamellae of mullite crystals and of a silica-rich amorphous phase. These mullite crystals preserved the crystallographical orientation of the preshock sillimanite. All compositional domains, identified at the microprobe scale, can thus be explained by a mixture in different proportion between the following phases: (1) a silica-rich amorphous phase, with minor Al and K; (2) quartz crystals; (3) spinel crystals and alumina-rich crystals; (4) sillimanite; and (5) mullite. Such mixtures of amorphous phases and crystals in different proportions explain disturbed isotope systems in these rocks and chemical heterogeneities observed on the microprobe.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fernandez-Gutierrez, Sulmer, E-mail: sulmer.a.fernandez.gutierrez@intel.com; Browning, Jim; Lin, Ming-Chieh

Phase-control of a magnetron is studied via simulation using a combination of a continuous current source and a modulated current source. The addressable, modulated current source is turned ON and OFF at the magnetron operating frequency in order to control the electron injection and the spoke phase. Prior simulation work using a 2D model of a Rising Sun magnetron showed that the use of 100% modulated current controlled the magnetron phase and allowed for dynamic phase control. In this work, the minimum fraction of modulated current source needed to achieve a phase control is studied. The current fractions (modulated versusmore » continuous) were varied from 10% modulated current to 100% modulated current to study the effects on phase control. Dynamic phase-control, stability, and start up time of the device were studied for all these cases showing that with 10% modulated current and 90% continuous current, a phase shift of 180° can be achieved demonstrating dynamic phase control.« less

Heavy truck rollover characterization (phase B).

DOT National Transportation Integrated Search

2009-09-01

The Heavy Truck Rollover Characterization Study - Phase-B builds on the results of prior phases of research. Phases 1 and 2 (Funded by Federal Highway Administration) involved heavy truck rollover characterization for a tractor and box-trailer; and P...

Effect of amoxicillin/clavulanate on gastrointestinal motility in children.

PubMed

Gomez, Roberto; Fernandez, Sergio; Aspirot, Ann; Punati, Jaya; Skaggs, Beth; Mousa, Hayat; Di Lorenzo, Carlo

2012-06-01

The aim of the present study was to evaluate the effect of amoxicillin/clavulanate (A/C) on gastrointestinal motility. Twenty consecutive pediatric patients referred for antroduodenal manometry received 20 mg/kg of A/C into the small bowel lumen. In 10 patients (group A), A/C was given 1 hour after and in 10 (group B), 1 hour before ingestion of a meal. Characteristics of the migrating motor complex, including presence, frequency, amplitude, and propagation of duodenal phase III and phase I duration and phase II motility index (MI), were evaluated 30 minutes before and after A/C administration. There were no statistically significant differences in age and sex between the 2 groups. Manometry studies were considered normal in 8 patients in each group. In group A, 2 patients developed duodenal phase III after receiving A/C, and no significant difference was found in the MI before and after the drug administration. In group B, 9 patients developed duodenal phase III (P <0.05 vs group A). All phase III occurred within a few minutes from the medication administration. Most duodenal phase III contractions were preceded by an antral component during fasting but never after the medication was administered in either of the 2 groups (P<0.001 vs fasting). In group B, the duration of duodenal phase I was shorter after drug administration (P<0.05). There was no significant difference in duodenal phase II MI before and after A/C administration for the 2 study groups. In children, administration of A/C directly into the small bowel before a meal induces phase III-type contractions in the duodenum, with characteristics similar to those present in the fasting state. These data suggest the possible use of A/C as a prokinetic agent. Further studies are needed to clarify its specific mechanism of action and the group of patients most likely to benefit from its use.

Nano-phase separation and structural ordering in silica-rich mixed network former glasses.

PubMed

Liu, Hao; Youngman, Randall E; Kapoor, Saurabh; Jensen, Lars R; Smedskjaer, Morten M; Yue, Yuanzheng

2018-06-13

We investigate the structure, phase separation, glass transition, and crystallization in a mixed network former glass series, i.e., B2O3-Al2O3-SiO2-P2O5 glasses with varying SiO2/B2O3 molar ratio. All the studied glasses exhibit two separate glassy phases: droplet phase (G1) with the size of 50-100 nm and matrix phase (G2), corresponding to a lower calorimetric glass transition temperature (Tg1) and a higher one (Tg2), respectively. Both Tg values decrease linearly with the substitution of B2O3 for SiO2, but the magnitude of the decrease is larger for Tg1. Based on nuclear magnetic resonance and Raman spectroscopy results, we infer that the G1 phase is rich in boroxol rings, while the G2 phase mainly involves the B-O-Si network. Both phases contain BPO4- and AlPO4-like units. Ordered domains occur in G2 upon isothermal and dynamic heating, driven by the structural heterogeneity in the as-prepared glasses. The structural ordering lowers the activation energy of crystal growth, thus promoting partial crystallization of G2. These findings are useful for understanding glass formation and phase separation in mixed network former oxide systems, and for tailoring their properties.

Presence of a monoclinic (Pm) phase in the morphotropic phase boundary region of multiferroic (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} solid solution: A Rietveld study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pandey, Rishikesh, E-mail: akhilesh-bhu@yahoo.com, E-mail: aksingh.mst@itbhu.ac.in; Singh, Akhilesh Kumar, E-mail: akhilesh-bhu@yahoo.com, E-mail: aksingh.mst@itbhu.ac.in

2014-07-28

We present here the results of structural studies on multiferroic (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} solid solution using Rietveld analysis on powder x-ray diffraction data in the composition range 0.35 ≤ x ≤ 0.55. The stability region of various crystallographic phases at room temperature for (1 − x)Bi(Ni{sub 1/2}Ti{sub 1/2})O{sub 3}-xPbTiO{sub 3} is determined precisely. Structural transformation from pseudo-cubic (x ≤ 0.40) to tetragonal (x ≥ 0.50) phase is observed via phase coexistence region demarcating the morphotropic phase boundary. The morphotropic phase boundary region consists of coexisting tetragonal and monoclinic structures with space group P4mm and Pm, respectively, stable in composition range 0.41 ≤ x ≤ 0.49 as confirmed by Rietveld analysis. The resultsmore » of Rietveld analysis completely rule out the coexistence of rhombohedral and tetragonal phases in the morphotropic phase boundary region reported by earlier workers. A comparison between the bond lengths for “B-site cations-oxygen anions” obtained after Rietveld refinement, with the bond length calculated using Shannon-Prewitt ionic radii, reveals the ionic nature of B-O (Ni/Ti-O) bonds for the cubic phase and partial covalent character for the other crystallographic phases.« less

Evaluation of phases in Pu-C-O and (U, Pu)-C-O systems by X-ray diffractometry and chemical analysis

NASA Astrophysics Data System (ADS)

Jain, G. C.; Ganguly, C.

1993-12-01

Preparation and characterisation of the carbides of uranium, plutonium and mixed uranium and plutonium form a part of advanced fuel development programs for fast breeder reactors. In the present study, the compositions of the phases of Pu-C-O and (U.Pu)-C-O systems have been determined by chemical analysis and lattice parameter measurement. The carbide samples have been prepared by vacuum carbothermic synthesis of tabletted oxide-graphite powder mixture. Dependence of stoichiometry of Pu 2C 3 phase on the oxygen content of Pu(C,O) phase in Pu(C,O) + Pu 2C 3 phase mixture has been evaluated. Stoichiometry and oxygen solubility of (U 0.3Pu 0.7)(C,O) phase in multiple phase mixture have been determined. Segregation of plutonium in (U,Pu) 2C 3 phase of (U,Pu)(C,O) + (U,Pu) 2C 3 phase mixture and its dependence on the oxygen content of (U,Pu)(C,O) phase have also been determined from the measurement of the lattice parameter of (U,Pu) 2C 3 phase.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brito, W. H.; Aguiar, M. C. O.; Haule, K.

In this study we present a comparative investigation of the electronic structures of NbO 2 and VO 2 obtained within a combination of density functional theory and cluster-dynamical mean-field theory calculations. We investigate the role of dynamic electronic correlations on the electronic structure of the metallic and insulating phases of NbO 2 and VO 2, with a focus on the mechanism responsible for the gap opening in the insulating phases. For the rutile metallic phases of both oxides, we obtain that electronic correlations lead to a strong renormalization of the t 2g subbands, as well as the emergence of incoherentmore » Hubbard subbands, signaling that electronic correlations are also important in the metallic phase of NbO 2. Interestingly, we find that nonlocal dynamic correlations do play a role in the gap formation of the [body-centered-tetragonal (bct)] insulating phase of NbO 2, by a similar physical mechanism as that recently proposed by us in the case of the monoclinic (M 1) dimerized phase of VO 2. Finally, although the effect of nonlocal dynamic correlations in the gap opening of bct phase is less important than in the (M 1 and M 2) monoclinic phases of VO 2, their presence indicates that the former is not a purely Peierls-type insulator, as it was recently proposed.« less

Structural phase transition in d-benzil characterised by capacitance measurements and neutron powder diffraction

NASA Astrophysics Data System (ADS)

Goossens, D. J.; Wu, Xiaodong; Prior, M.

2005-12-01

The ferroelectric phase transition in deuterated benzil, C 14H 10O 2, has been studied using capacitance measurements and neutron powder diffraction. Hydrogenous benzil shows a phase transition at 83.5 K from a high temperature P3 121 phase to a cell-doubled P2 1 phase. The phase transition in d-benzil occurs at 88.1 K, a small isotope effect. Neutron powder diffraction was consistent with a low temperature phase of space group P2 1. Upon deuteration the transition remained first-order and the dynamics of the phenyl ring dominated the behaviour. The isotope effect can be attributed to the difference in mass and moment of inertia between C 6H 5 and C 6D 5.

Inadequate Preoperative Team Briefings Lead to More Intraoperative Adverse Events.

PubMed

Phadnis, Joideep; Templeton-Ward, Oliver

2018-06-01

Implementation of the World Health Organization checklists has reduced major surgical complications and errors; however, the impact of preoperative briefings on intraoperative adverse events has not been assessed. A prospective case-control study assessing the association between preoperative briefings and minor, potentially major, and major adverse intraoperative events was performed in 2 phases. Phase 1 involved prospective data collection for all trauma and orthopedic lists during a 2-week period. Changes were implemented as a result of the findings, and after this, the study was repeated (phase 2) to assess for the effect of the changes made to the practice. Forty-one lists were audited during phase 1 and 47 lists were audited during phase 2 of the study. Adequate preoperative briefings were performed in 10 (24%) of 41 lists in phase 1. There was a significant association between the occurrences of intraoperative adverse events (n = 37) when a briefing was not performed (P = < 0.01) and when a briefing was performed incompletely (P = 0.01). In phase 2, after staff reeducation and policy change, briefings were found to be adequate in 38 (81%) of 47 lists with the occurrence of only 3 adverse events. Team familiarity also improved significantly as a result of better preoperative briefings (P = 0.02). Inadequate preoperative briefings are associated with an increase in minor adverse events and are detrimental to team familiarity. On the basis of our findings, we recommend that all surgical units perform preoperative briefings thoroughly to minimize these factors.

Femtosecond laser pulse induced phase transition of Cr-doped Sb2Te1 films studied with a pump-probe system

NASA Astrophysics Data System (ADS)

Jiang, Minghui; Wang, Qing; Lei, Kai; Wang, Yang; Liu, Bo; Song, Zhitang

2016-10-01

The Femtosecond laser pulse induced phase transition dynamics of Cr-doped Sb2Te1 films was studied by real-time reflectivity measurements with a pump-probe system. It was found that crystallization of the as-deposited CrxSb2Te1 phase-change thin films exhibits a multi-stage process lasting for about 40ns.The time required for the multi-stage process seems to be not related to the contents of Cr element. The durations of the crystallization and amorphization processes are approximately the same. Doping Cr into Sb2Te1 thin film can improve its photo-thermal stability without obvious change in the crystallization rate. Optical images and image intensity cross sections are used to visualize the transformed regions. This work may provide further insight into the phase-change mechanism of CrxSb2Te1 under extra-non-equilibrium conditions and aid to develop new ultrafast phase-change memory materials.

Phase diagram of the isotropic spin-(3)/(2) model on the z=3 Bethe lattice

NASA Astrophysics Data System (ADS)

Depenbrock, Stefan; Pollmann, Frank

2013-07-01

We study an SU(2) symmetric spin-3/2 model on the z=3 Bethe lattice using the infinite time evolving block decimation (iTEBD) method. This model is shown to exhibit a rich phase diagram. We compute several order parameters which allow us to identify a ferromagnetic, a ferrimagnetic, an antiferromagnetic, as well as a dimerized phase. We calculate the entanglement spectra from which we conclude the existence of a symmetry protected topological phase that is characterized by S=1/2 edge spins. Details of the iTEBD algorithm used for the simulations are included.

A pseudo-3D approach based on electron backscatter diffraction and backscatter electron imaging to study the character of phase boundaries between Mg and long period stacking ordered phase in a Mg–2Y–Zn alloy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Afshar, Mehran, E-mail: m.afshar@mpie.de; Zaefferer, Stefan, E-mail: s.zaefferer@mpie.de

2015-03-15

In Mg–2 at.% Y–1 at.% Zn alloys, the LPSO (Long Period Stacking Ordered) phase is important to improve mechanical properties of the material. The aim of this paper is to present a study on the phase boundary character in these two-phase alloys. Using EBSD pattern analysis it was found that the 24R structure is the dominant LPSO phase structure in the current alloy. The phase boundary character between the Mg matrix and the LPSO phase was investigated using an improved pseudo-3D EBSD (electron backscatter diffraction) technique in combination with BSE or SE (backscatter or secondary electron) imaging. A large amountmore » of very low-angle phase boundaries was detected. The (0 0 0 2) plane in the Mg matrix which is parallel to the (0 0 0 24) plane in the LPSO phase was found to be the most frequent plane for these phase boundaries. This plane is supposed to be the habit plane of the eutectic co-solidification of the Mg matrix and the LPSO phase. - Highlights: • It is shown that for the investigated alloy the LPSO phase has mainly 24R crystal structure. • A new method is presented which allows accurate determination of the 5-parameter grain or phase boundary character. • It is found that the low-angle phase boundaries appearing in the alloy all have basal phase boundary planes.« less

Solvation Dynamics in Different Phases of the Lyotropic Liquid Crystalline System.

PubMed

Roy, Bibhisan; Satpathi, Sagar; Gavvala, Krishna; Koninti, Raj Kumar; Hazra, Partha

2015-09-03

Reverse hexagonal (HII) liquid crystalline material based on glycerol monooleate (GMO) is considered as a potential carrier for drugs and other important biomolecules due to its thermotropic phase change and excellent morphology. In this work, the dynamics of encapsulated water, which plays important role in stabilization and formation of reverse hexagonal mesophase, has been investigated by time dependent Stokes shift method using Coumarin-343 as a solvation probe. The formation of the reverse hexagonal mesophase (HII) and transformation to the L2 phase have been monitored using small-angle X-ray scattering and polarized light microscopy experiments. REES studies suggest the existence of different polar regions in both HII and L2 systems. The solvation dynamics study inside the reverse hexagonal (HII) phase reveals the existence of two different types of water molecules exhibiting dynamics on a 120-900 ps time scale. The estimated diffusion coefficients of both types of water molecules obtained from the observed dynamics are in good agreement with the measured diffusion coefficient collected from the NMR study. The calculated activation energy is found to be 2.05 kcal/mol, which is associated with coupled rotational-translational water relaxation dynamics upon the transition from "bound" to "quasi-free" state. The observed ∼2 ns faster dynamics of the L2 phase compared to the HII phase may be associated with both the phase transformation as well as thermotropic effect on the relaxation process. Microviscosities calculated from time-resolved anisotropy studies infer that the interface is almost ∼22 times higher viscous than the central part of the cylinder. Overall, our results reveal the unique dynamical features of water inside the cylinder of reverse hexagonal and inverse micellar phases.

Magnetic Correlations in URu2Si2 under Chemical and Hydrostatic Pressure

NASA Astrophysics Data System (ADS)

Williams, Travis; Aczel, Adam; Broholm, Collin; Buyers, William; Leao, Juscelino; Luke, Graeme; Rodriguez-Riviera, Jose; Stone, Matthew; Wilson, Murray; Yamani, Zahra

URu2Si2 has been an intense area of study for the last 30 years due to a mysterious hidden order phase that appears below T0 = 17.5 K. The hidden order phase has been shown to be extremely sensitive to perturbations, being destroyed quickly by the application of a magnetic field, hydrostatic or uniaxial pressure, and chemical doping. While attempting to understand the properties of URu2Si2, neutron scattering has found spin correlations that are intimately related to this hidden order phase and which are also suppressed with these perturbations. Here, I will outline some recent neutron scattering work to study these correlations in two exceptional cases where the hidden order phase is enhanced: hydrostatic pressure and chemical pressure using Fe- and Os-doping. In both of these cases, T0 increases before an antiferromagnetic phase emerges. By performing a careful analysis of the neutron data, we show that these two phases are much more related than had been previously appreciated. This implies that the hidden order is likely compatible with an antiferromagnetic ground state, placing constraints on the nature of the missing order parameter.

A bundle with a preformatted medical order sheet and an introductory course to reduce prescription errors in neonates.

PubMed

Palmero, David; Di Paolo, Ermindo R; Beauport, Lydie; Pannatier, André; Tolsa, Jean-François

2016-01-01

The objective of this study was to assess whether the introduction of a new preformatted medical order sheet coupled with an introductory course affected prescription quality and the frequency of errors during the prescription stage in a neonatal intensive care unit (NICU). Two-phase observational study consisting of two consecutive 4-month phases: pre-intervention (phase 0) and post-intervention (phase I) conducted in an 11-bed NICU in a Swiss university hospital. Interventions consisted of the introduction of a new preformatted medical order sheet with explicit information supplied, coupled with a staff introductory course on appropriate prescription and medication errors. The main outcomes measured were formal aspects of prescription and frequency and nature of prescription errors. Eighty-three and 81 patients were included in phase 0 and phase I, respectively. A total of 505 handwritten prescriptions in phase 0 and 525 in phase I were analysed. The rate of prescription errors decreased significantly from 28.9% in phase 0 to 13.5% in phase I (p < 0.05). Compared with phase 0, dose errors, name confusion and errors in frequency and rate of drug administration decreased in phase I, from 5.4 to 2.7% (p < 0.05), 5.9 to 0.2% (p < 0.05), 3.6 to 0.2% (p < 0.05), and 4.7 to 2.1% (p < 0.05), respectively. The rate of incomplete and ambiguous prescriptions decreased from 44.2 to 25.7 and 8.5 to 3.2% (p < 0.05), respectively. Inexpensive and simple interventions can improve the intelligibility of prescriptions and reduce medication errors. Medication errors are frequent in NICUs and prescription is one of the most critical steps. CPOE reduce prescription errors, but their implementation is not available everywhere. Preformatted medical order sheet coupled with an introductory course decrease medication errors in a NICU. Preformatted medical order sheet is an inexpensive and readily implemented alternative to CPOE.

MDCT of acute pancreatitis: Intraindividual comparison of single-phase versus dual-phase MDCT for initial assessment of acute pancreatitis using different CT scoring systems.

PubMed

Avanesov, Maxim; Weinrich, Julius M; Kraus, Thomas; Derlin, Thorsten; Adam, Gerhard; Yamamura, Jin; Karul, Murat

2016-11-01

The purpose of the retrospective study was to evaluate the additional value of dual-phase multidetector computed tomography (MDCT) protocols over a single-phase protocol on initial MDCT in patients with acute pancreatitis using three CT-based pancreatitis severity scores with regard to radiation dose. In this retrospective, IRB approved study MDCT was performed in 102 consecutive patients (73 males; 55years, IQR48-64) with acute pancreatitis. Inclusion criteria were CT findings of interstitial edematous pancreatitis (IP) or necrotizing pancreatitis (NP) and a contrast-enhanced dual-phase (arterial phase and portal-venous phase) abdominal CT performed at ≥72h after onset of symptoms. The severity of pancreatic and extrapancreatic changes was independently assessed by 2 observers using 3 validated CT-based scoring systems (CTSI, mCTSI, EPIC). All scores were applied to arterial phase and portal venous phase scans and compared to score results of portal venous phase scans, assessed ≥14days after initial evaluation. For effective dose estimation, volume CT dose index (CTDIvol) and dose length product (DLP) were recorded in all examinations. In neither of the CT severity scores a significant difference was observed after application of a dual-phase protocol compared with a single-phase protocol (IP: CTSI: 2.7 vs. 2.5, p=0.25; mCTSI: 4.0 vs. 4.0, p=0.10; EPIC: 2.0 vs. 2.0, p=0.41; NP: CTSI: 8.0 vs. 7.0, p=0.64; mCTSI: 8.0 vs. 8.0, p=0.10; EPIC: 3.0 vs. 3.0, p=0.06). The application of a single-phase CT protocol was associated with a median effective dose reduction of 36% (mean dose reduction 31%) compared to a dual-phase CT scan. An initial dual-phase abdominal CT after ≥72h after onset of symptoms of acute pancreatitis was not superior to a single-phase protocol for evaluation of the severity of pancreatic and extrapancreatic changes. However, the effective radiation dose may be reduced by 36% using a single-phase protocol. Copyright © 2016. Published by Elsevier Ireland Ltd.

Phase 2 design study of the electronic assembly for the HRUV spectrometer/polarimeter intended for the solar maximum mission. Implementation phase program plan, revision A

NASA Technical Reports Server (NTRS)

1977-01-01

The primary function of the implementation phase is to convert the ERA design of the design study phase into deliverable flight hardware. The development aspects of the experiment logic unit, the dual power converter, the junction box and the cables are considered.

Czochralski growth of LaPd2Al2 single crystals

NASA Astrophysics Data System (ADS)

Doležal, P.; Rudajevová, A.; Vlášková, K.; Kriegner, D.; Václavová, K.; Prchal, J.; Javorský, P.

2017-10-01

The present study is focused on the preparation of single crystalline LaPd2Al2 by the Czochralski method. Differential scanning calorimetry (DSC) and energy dispersive X-ray spectroscopy (EDX) analyses reveal that LaPd2Al2 is an incongruently melting phase which causes difficulties for the preparation of single crystalline LaPd2Al2 by the Czochralski method. Therefore several non-stoichiometric polycrystalline samples were studied for its preparation. Finally the successful growth of LaPd2Al2 without foreign phases has been achieved by using a non-stoichiometric precursor with atomic composition 22:39:39 (La:Pd:Al). X-ray powder diffraction, EDX analysis and DSC were used for the characterisation. A single crystalline sample was separated from the ingot prepared by the Czochralski method using the non-stoichiometric precursor. The presented procedure for the preparation of pure single phase LaPd2Al2 could be modified for other incongruently melting phases.

Magnetic Ordering of Erbium and Uranium NICKEL(2) SILICON(2) by Neutron Scattering

NASA Astrophysics Data System (ADS)

Lin, Hong

The magnetic ordering has been studied in UNi _2Si_2 and erbium single crystals by elastic neutron scattering. Abundant results are given regarding the magnetic structure, magnetic phase transitions, and the effect of a magnetic field on these properties. Three ordered phases are observed in UNi _2Si_2. They have been determined to be an incommensurate longitudinal spin density wave with a magnetic wave vector around q = 0.74c ^* in the high temperature phase, a simple body-centred antiferromagnet in the intermediate temperature phase, and a square wave in the low temperature phase. This square wave can be viewed equivalently as a longitudinal spin density wave with q = 2/3c ^* superimposed on a ferromagnetic component. Hysteresis and sample dependence are observed in the low-temperature phase transition. The two lower temperature phase transitions are both first order. The transition to paramagnetism is second order with a critical exponent beta = 0.35 +/- 0.03. When a magnetic field is applied along the c axis, the intermediate temperature phase is destabilised and disappears above a field of 3.5T. Although there is no new phase induced by the field, there exists a reentrant point where the three ordered phases can coexist. Erbium has three distinct ordered phases: the cone phase at low temperatures, the c-axis modulated (CAM) phase at higher temperatures, and the intermediate phase with moments modulated both along c and perpendicular to c. Within these phases the modulation of the moments may lock in to the lattice. The observed weak harmonics of the wave vector q in the basal plane for the cone phase and the q = 1/4c^* structure in the intermediate phase can be explained by a basal-plane spin slip model. The effect of magnetic field along the c axis on the magnetic structure is to stabilise the cone phase and to destabilise the intermediate phase. A new lock-in structure with q = 1/4c^* in the cone phase is induced by fields above 1.8T. The presence of the field also stabilises the lock-in structure with q = 2/7c^* in both the intermediate and the CAM phases.

Experiment evaluates ocean models and data assimiliation in the Gulf Stream

NASA Astrophysics Data System (ADS)

Willems, Robert C.; Glenn, S. M.; Crowley, M. F.; Malanotte-Rizzoli, P.; Young, R. E.; Ezer, T.; Mellor, G. L.; Arango, H. G.; Robinson, A. R.; Lai, C.-C. A.

Using data sets of known quality as the basis for comparison, a recent experiment explored the Gulf Stream Region at 27°-47°N and 80°-50°W to assess the nowcast/forecast capability of specific ocean models and the impact of data assimilation. Scientists from five universities and the Naval Research Laboratory/Stennis Space Center participated in the Data Assimilation and Model Evaluation Experiment (DAMEÉ-GSR).DAMEÉ-GSR was based on case studies, each successively more complex, and was divided into three phases using case studies (data) from 1987 and 1988. Phase I evaluated models' forecast capability using common initial conditions and comparing model forecast fields with observational data at forecast time over a 2-week period. Phase II added data assimilation and assessed its impact on forecast capability, using the same case studies as in phase I, and phase III added a 2-month case study overlapping some periods in Phases I and II.

Validation of the Samsung SBM-100A and Microlife BP 3BU1-5 wrist blood pressure measuring devices in adults according to the International Protocol.

PubMed

Altunkan, Sekip; Ilman, Nevzat; Altunkan, Erkan

2007-04-01

A variety of automatic blood measurement devices with diverse features have been introduced to the medical markets recently. Among these devices, models that measure at the wrist have become increasingly popular in self measurements. The objective of this study was to evaluate the accuracy of the Samsung SBM-100A and Microlife BP 3BU1-5 wrist blood pressure devices against the mercury sphygmomanometer in adults according to the International Protocol criteria. Fifty-four patients over 30 years of age were studied and classified based on the International Protocol range. Blood pressure measurements at the wrist with the Samsung SBM-100A and Microlife BP 3BU1-5 were compared with the results obtained by two trained observers using a mercury sphygmomanometer. Nine sequential blood pressure measurements were taken. A total of 33 participants with randomly distributed arm circumferences were selected for both of the validation studies. During each validation study, 99 measurements were obtained for comparison from 33 participants. The first phase was performed on 15 participants and if the device passed this phase, 18 more participants were selected. Mean discrepancies and standard deviations of the device-sphygmomanometer were 0.9+/-9.2 and -2.7+/-9.3 mmHg for systolic blood pressure and -1.4+/-8.0 mmHg and 1.4+/-5.7 for diastolic blood pressure in the Samsung and Microlife study groups, respectively. The Samsung SBM-100A passed Phase 1 in 15 participants. Despite the fact that Microlife BP 3BU1-5 passed Phase 1 for diastolic pressure, it failed according to the systolic pressure criteria. Eighteen patients were added and Phase 2 was continued, in which Samsung SBM-100A failed to meet the criteria of Phases 2.1 and 2.2 for adults in systolic and diastolic blood pressure. It was found that the Microlife BP 3BU1-5 does not meet the criteria of either of Phases 2.1 and 2.2 for systolic blood pressure and Phase 2.2 for diastolic blood pressure. In this study, Samsung SBM-100A and Microlife blood pressure 3BU1-5 wrist blood pressure monitoring devices were found to be incompetent to meet the criteria of the International Protocol and it has not been possible to suggest any one of them for clinical use in adults.

Investigation of the physical properties of two Laves phase compounds HRh2 (H = Ca and La): A DFT study

NASA Astrophysics Data System (ADS)

Rahaman, Md. Zahidur; Rahman, Md. Atikur

2018-05-01

By using the first-principle calculations, the structural, elastic, electronic and optical properties of Laves phase intermetallic compounds CaRh2 and LaRh2 prototype with MgCu2 are investigated. The evaluated lattice parameters are consistent with the experimental values. The important elastic properties, such as bulk modulus B, shear modulus G, Young’s modulus Y and the Poisson’s ratio v, are computed by applying the Voigt-Reuss-Hill (VRH) approximation. The analysis of Pugh’s ratio exhibits the ductile nature of both the phases. Electronic conductivity is predicted for both the compounds. Most of the contribution comes from Rh-4d states. The study of bonding characteristics reveals the existence of ionic and metallic bonds in both intermetallics. The study of optical properties indicates that CaRh2 is a better dielectric material than LaRh2. Absorption quality of both the phases is good in the ultraviolet region.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferreira, A. S.; Rovani, P. R.; Lima, J. C. de, E-mail: joao.cardoso.lima@ufsc.br

A nanostructured Ti{sub 50}Ni{sub 25}Fe{sub 25} phase (B2) was formed by mechanical alloying and its structural stability was studied as a function of pressure. The changes were followed by X-ray diffraction. The B2 phase was observed up to 7 GPa; for larger pressures, the B2 phase transformed into a trigonal/hexagonal phase (B19) that was observed up to the highest pressure used (18 GPa). Besides B2 and B19, elemental Ni or a SS-(Fe,Ni) and FeNi{sub 3} were observed. With decompression, the B2 phase was recovered. Using in situ angle-dispersive X-ray diffraction patterns, the single line method was applied to obtain the apparent crystallitemore » size and the microstrain for both the B2 and the B19 phases as a function of the applied pressure. Values of the bulk modulus for the B2, B19, elemental Ni or SS-(Fe,Ni) and FeNi{sub 3} phases were obtained by fitting the pressure dependence of the volume to a Birch–Murnaghan equation of state (BMEOS)« less

Detailed magnetic and structural analysis mapping a robust magnetic C 4 dome in Sr 1 - x Na x Fe 2 As 2

DOE PAGES

Taddei, K. M.; Allred, J. M.; Bugaris, D. E.; ...

2016-04-20

The recently discovered C 4 tetragonal magnetic phase in hole-doped members of the iron-based superconductors provides new insights into the origin of unconventional superconductivity. Previously observed in Ba 1-xNa xFe 2As 2 (with A = K, Na), the C 4 magnetic phase exists within the well studied C 2 spin-density wave (SDW) dome, arising just before the complete suppression of antiferromagnetic (AFM) order but after the onset of superconductivity. Here in this paper, we present detailed x-ray and neutron diffraction studies of Sr 1-xNa xFe 2As 2 (0.10 ≤ x ≤ 0.60) to determine their structural evolution and the extentmore » of the C 4 phase. Spanning Δx ~ 0.14 in composition, the C 4 phase is found to extend over a larger range of compositions, and to exhibit a significantly higher transition temperature, T r ~ 65K, than in either of the other systems in which it has been observed. The onset of this phase is seen near a composition (x~0:30) where the bonding angles of the Fe 2As 2 layers approach the perfect 109.46° tetrahedral angle. We discuss the possible role of this return to a higher symmetry environment for the magnetic iron site in triggering the magnetic reorientation and the coupled re-entrance to the tetragonal structure. Finally, we present a new phase diagram, complete with the C 4 phase, and use its observation in a third hole-doped 122 system to suggest the universality of this phase.« less

In search of the elusive IrB{sub 2}: Can mechanochemistry help?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Zhilin; Blair, Richard G.; Department of Physics, University of Central Florida, Orlando, FL 32816

The previously unknown hexagonal ReB{sub 2}-type IrB{sub 2} diboride and orthorhombic IrB monoboride phases were produced by mechanochemical syntheses. High energy ball milling of elemental Ir and B powder for 30 h, followed by annealing of the powder at 1050 °C for 48 h, resulted in the formation of the desired phases. Both traditional laboratory and high resolution synchrotron X-ray diffraction (XRD) analyses were used for phase identification of the synthesized powder. In addition to XRD, scanning electron microscopy and transmission electron microscopy were employed to further characterize the microstructure of the phases produced. - Graphical abstract: ReB{sub 2}-type IrB{submore » 2} and a new IrB have been successfully synthesized for the first time using mechanochemical method. Crystal structures of IrB{sub 2} and IrB were studied by synchrotron X-ray diffraction. Microstructures of the new phases were characterized by SEM and TEM. - Highlights: • ReB{sub 2}-type IrB{sub 2} and a new IrB have been synthesized by mechanochemical method. • Crystal structures of IrB{sub 2} and IrB were studied by synchrotron XRD. • Microstructures of the new phases were characterized by SEM and TEM.« less

Direct observation of the M2 phase with its Mott transition in a VO2 film

NASA Astrophysics Data System (ADS)

Kim, Hoon; Slusar, Tetiana V.; Wulferding, Dirk; Yang, Ilkyu; Cho, Jin-Cheol; Lee, Minkyung; Choi, Hee Cheul; Jeong, Yoon Hee; Kim, Hyun-Tak; Kim, Jeehoon

2016-12-01

In VO2, the explicit origin of the insulator-to-metal transition is still disputable between Peierls and Mott insulators. Along with the controversy, its second monoclinic (M2) phase has received considerable attention due to the presence of electron correlation in undimerized vanadium ions. However, the origin of the M2 phase is still obscure. Here, we study a granular VO2 film using conductive atomic force microscopy and Raman scattering. Upon the structural transition from monoclinic to rutile, we observe directly an intermediate state showing the coexistence of monoclinic M1 and M2 phases. The conductivity near the grain boundary in this regime is six times larger than that of the grain core, producing a donut-like landscape. Our results reveal an intra-grain percolation process, indicating that VO2 with the M2 phase is a Mott insulator.

The Development of a Student Survey on Attitudes towards Mathematics Teaching-Learning Processes

ERIC Educational Resources Information Center

Mutohir, Toho Cholik; Lowrie, Tom; Patahuddin, Sitti Maesuri

2018-01-01

This study aimed to develop a survey instrument to measure student attitudes towards mathematics teaching-learning processes that is appropriate for the Indonesian context. This study consisted of two phases: Phase 1 (n = 320) was a pilot study to assess the suitability of the instrument items for Indonesian students. Phase 2 (n = 1001) was…

Thermodynamic and Thermoelastic properties of the NAL Phase

NASA Astrophysics Data System (ADS)

Marcondes, M. L.; Yao, C.; Wu, Z.; Wentzcovitch, R.

2017-12-01

Subduction of Mid Ocean Ridge Basalt (MORB) transports crust elements to the deep Earth. Therefore, it is important to study MORB in order to understand geophysical processes in the mantle. The high Al2O3 content of the MORB gives rise to a new aluminous phase (NAL) that constitutes up to 25% of its composition [1]. Phase equilibrium study of MgAl2O4-CaAl2O4 generated the mineral CaMg2Al6O12 with hexagonal symmetry, which was proposed for the NAL phase [2,3]. The NAL chemical composition, however, shows significantly less calcium [1,4] and several compositions have been considered in previous studies of this phase [5,6]. Here we present an ab initio study of NAL phases at high temperatures with several possible compositions. We used the quasiharmonic approximation to address thermodynamic and thermoelastic properties and seismic velocities of this phase as function of composition. References[1] T. Irifune and A. E. Ringwood, Earth Planet. Sci. Lett. 117, 101 (1993). [2] H. Miura, Y. Hamada, T. Suzuki, M. Akaogi, N. Miyajima, and K. Fujino, Am. Mineral. 85, 1799 (2000). [3] M. Akaogi, Y. Hamada, T. Suzuki, M. Kobayashi, and M. Okada, Phys. Earth Planet. Inter. 115, 67 (1999). [4] A. Ricolleau, J. P. Perrillat, G. Fiquet, I. Daniel, J. Matas, A. Addad, N. Menguy, H. Cardon, M. Mezouar, and N. Guignot, J. Geophys. Res. Solid Earth 115, B08202 (2010). [5] M. Mookherjee, B. B. Karki, L. Stixrude, and C. Lithgow-Bertelloni, Geophys. Res. Lett. 39, L19306 (2012). [6] K. Kawai and T. Tsuchiya, Geophys. Res. Lett. 37, L17302 (2010).

The effect of estradiol on granulosa cell responses to FSH in women with polycystic ovary syndrome.

PubMed

Homer, Michael V; Rosencrantz, Marcus A; Shayya, Rana F; Chang, R Jeffrey

2017-02-10

The influence of estradiol (E 2 ) on granulosa cell (GC) function has not been tested clinically in women with polycystic ovary syndrome (PCOS). The objective of this study is to determine if E 2 influences GC responses to FSH in women with PCOS. This is a two phase, single cohort study conducted over a 2-year period at a single academic center. Nine women with PCOS according to NIH criteria. In Phase 1, FSH stimulation of GC responses as measured by E 2 and Inhibin B (Inh B) were assessed before and at 5 and 6 weeks after GnRH agonist administration. In Phase 2, the same protocol was employed with the addition of an aromatase inhibitor (letrozole, LET) administered daily beginning at week 4 for 2 weeks. In Phase 1, recovery of FSH, E 2 and Inh B from ovarian suppression occurred at 5 and 6 weeks after GnRH agonist injection and preceded resumption of LH and androgen secretion. In Phase 2, hormone recovery after GnRH agonist was characterized by elevated FSH and suppressed E 2 levels whereas recovery of LH and androgen levels were unchanged. In Phase 1, FSH stimulated E 2 and Inh B responses were unaltered during recovery from ovarian suppression. In Phase 2, E 2 and Inh B fold changes after FSH were significantly reduced at weeks 5 (p < 0.04) and 6 (p < 0.01), respectively. In anovulatory women with PCOS, chronic, unopposed E 2 secretion may contribute, at least in part, to enhanced ovarian responsiveness to FSH. NCT02389088.

Synthesis of Y1Ba2Cu3O(sub x) superconducting powders by intermediate phase reaction

NASA Technical Reports Server (NTRS)

Moore, C.; Fernandez, J. F.; Recio, P.; Duran, P.

1990-01-01

One of the more striking problems for the synthesis of the Y1Ba2Cu3Ox compound is the high-temperature decomposition of the BaCO3. This compound is present as raw material or as an intermediate compound in chemical processes such as amorphous citrate, coprecipitation oxalate, sol-gel process, acetate pyrolisis, etc. This fact makes difficult the total formation reaction of the Y1Ba2Cu3Ox phase and leads to the presence of undesirable phases such as the BaCuO2 phase, the 'green phase', Y2BaCuO5 and others. Here, a new procedure to overcome this difficulty is studied. The barium cation is previously combined with yttrium and/or copper to form intermediate compounds which can react between them to give Y1Ba2Cu3Ox. BaY2O4 and BaCu2O3 react according to the equation BaY2O4+3BaCu2O3 yields 2Y1Ba2Cu3Ox. BaY2O4 is a stable compound of the Y2O3-BaO system; BaCu2O3 is an intimate mixture of BaCuO2 and uncombined CuO. The reaction kinetics of these phases have been established between 860 and 920 C. The phase evolution has been determined. The crystal structure of the Y1Ba2Cu3Ox obtained powder was studied. According to the results obtained from the kinetics study the Y1Ba2Cu3Ox the synthesis was performed at temperatures of 910 to 920 C for short treatment times (1 to 2 hours). Pure Y1Ba2Cu3Ox was prepared, which develops orthorombic type I structure despite of the cooling cycle. Superconducting transition took place at 91 K. The sintering behavior and the superconducting properties of sintered samples were studied. Density, microstructure and electrical conductivity were measured. Sintering densities higher than 95 percent D(sub th) were attained at temperatures below 940 C. Relatively fine grained microstructure was observed, and little or no-liquid phase was detected.

Ground-state ordering of the J1-J2 model on the simple cubic and body-centered cubic lattices

NASA Astrophysics Data System (ADS)

Farnell, D. J. J.; Götze, O.; Richter, J.

2016-06-01

The J1-J2 Heisenberg model is a "canonical" model in the field of quantum magnetism in order to study the interplay between frustration and quantum fluctuations as well as quantum phase transitions driven by frustration. Here we apply the coupled cluster method (CCM) to study the spin-half J1-J2 model with antiferromagnetic nearest-neighbor bonds J1>0 and next-nearest-neighbor bonds J2>0 for the simple cubic (sc) and body-centered cubic (bcc) lattices. In particular, we wish to study the ground-state ordering of these systems as a function of the frustration parameter p =z2J2/z1J1 , where z1 (z2) is the number of nearest (next-nearest) neighbors. We wish to determine the positions of the phase transitions using the CCM and we aim to resolve the nature of the phase transition points. We consider the ground-state energy, order parameters, spin-spin correlation functions, as well as the spin stiffness in order to determine the ground-state phase diagrams of these models. We find a direct first-order phase transition at a value of p =0.528 from a state of nearest-neighbor Néel order to next-nearest-neighbor Néel order for the bcc lattice. For the sc lattice the situation is more subtle. CCM results for the energy, the order parameter, the spin-spin correlation functions, and the spin stiffness indicate that there is no direct first-order transition between ground-state phases with magnetic long-range order, rather it is more likely that two phases with antiferromagnetic long range are separated by a narrow region of a spin-liquid-like quantum phase around p =0.55 . Thus the strong frustration present in the J1-J2 Heisenberg model on the sc lattice may open a window for an unconventional quantum ground state in this three-dimensional spin model.

Assessment of Musculoskeletal Strength and Levels of Fatigue during Different Phases of Menstrual Cycle in Young Adults

PubMed Central

D Souza, Urban John; Shivaprakash, G

2017-01-01

Introduction Some of the physiological factors and athletic performance might show variation along the phases of menstrual cycle. The alterations seen in these physiological parameters of various systems relating to oscillations in hormonal levels do affect the autonomic nervous system and metabolic functions. Former studies heave inconclusively about the influence of hormones on exercise performance, predominantly muscle strength and rate of fatigue during different phases of the menstrual cycle. Studies regarding influence of these variations during bleeding phase were not done. Aim To evaluate the muscle strength variations and also the rate of fatigue during various phases of the menstrual cycle in young adults. Materials and Methods This was a prospective study conducted among 100 healthy adult female volunteers aged 18-24 years, with normal regular menstrual cycles persistent between 26- 32 days (average of 28 days), for a minimum of last 6 months. Muscle strength was assessed by calculating the work done and fatigue rate using Mosso’s ergograph and by handgrip dynamometer strength. Each subject was evaluated consecutively for two menstrual cycles in all three phases which were classified as Phase 1- Menstrual phase, Phase 2- Follicular phase and Phase 3- Luteal phase. The data obtained was analysed by statistical tool One-way ANOVA followed by a post-hoc Tukeys test. A p-value of ≤ 0.05 was considered significant. Results The amount of work done and handgrip strength was significantly higher in phase 2 (p<0.001) and relatively reduced in phase 1 and 3 (p<0.001) of menstrual cycle. In terms of fatigue rate percentage, phase 2 showed significantly lesser values (p<0.001) as compared to phase 1 and 3 of menstrual cycle. Conclusion We conclude that the cyclical variation in endogenous reproductive hormones increases the muscle strength in follicular phase of the menstrual cycle. Thus provide support for the influence of these hormones in regulation of these parameters in the premenopausal age group. PMID:28384857

Production and associated economics of fingerling to stocker to growout modular phases for farming channel catfish, Ictalurus punctatus, in commercial size ponds

USDA-ARS?s Scientific Manuscript database

A 2-year study was conducted to evaluate fingerling to stocker (phase 2) and stocker to growout (phase 3) of three phases of a modular production system for channel catfish in commercial-scale ponds. Fingerlings (mean = 14.3 kg/1000, 11.9 cm) were stocked into each of six earthen ponds (1.62 ha) at ...

Benefits of Atrial Substrate Modification Guided by Electrogram Similarity and Phase Mapping Techniques to Eliminate Rotors and Focal Sources Versus Conventional Defragmentation in Persistent Atrial Fibrillation.

PubMed

Lin, Yenn-Jiang; Lo, Men-Tzung; Chang, Shih-Lin; Lo, Li-Wei; Hu, Yu-Feng; Chao, Tze-Fan; Chung, Fa-Po; Liao, Jo-Nan; Lin, Chin-Yu; Kuo, Huan-Yu; Chang, Yi-Chung; Lin, Chen; Tuan, Ta-Chuan; Vincent Young, Hsu-Wen; Suenari, Kazuyoshi; Dan Do, Van Buu; Raharjo, Suunu Budhi; Huang, Norden E; Chen, Shih-Ann

2016-11-01

This prospective study compared the efficacy of atrial substrate modification guided by a nonlinear phase mapping technique with that of conventional substrate ablation. The optimal ablation strategy for persistent atrial fibrillation (AF) was unknown. In phase 1 study, we applied a cellular automation technique to simulate the electrical wave propagation to improve the phase mapping algorithm, involving analysis of high-similarity electrogram regions. In addition, we defined rotors and focal AF sources, using the physical parameters of the divergence and curvature forces. In phase 2 study, we enrolled 68 patients with persistent AF undergoing substrate modification into 2 groups, group-1 (n = 34) underwent similarity index (SI) and phase mapping techniques; group-2 (n = 34) received complex fractionated atrial electrogram ablation with commercially available software. Group-1 received real-time waveform similarity measurements in which a phase mapping algorithm was applied to localize the sources. We evaluated the single-procedure freedom from AF. In group-1, we identified an average of 2.6 ± 0.89 SI regions per chamber. These regions involved rotors and focal sources in 65% and 77% of patients in group-1, respectively. Group-1 patients had shorter ablation procedure times, higher termination rates, and significant reduction in AF recurrence compared to group-2 and a trend toward benefit for all atrial arrhythmias. Multivariate analysis showed that substrate mapping using nonlinear similarity and phase mapping was the independent predictor of freedom from AF recurrence (hazard ratio: 0.26; 95% confidence interval: 0.09 to 0.74; p = 0.01). Our study showed that for persistent AF ablation, a specified substrate modification guided by nonlinear phase mapping could eliminate localized re-entry and non-pulmonary focal sources after pulmonary vein isolation. Copyright © 2016 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Comparative risk for cardiovascular diseases of dipeptidyl peptidase-4 inhibitors vs. sulfonylureas in combination with metformin: Results of a two-phase study.

PubMed

Enders, Dirk; Kollhorst, Bianca; Engel, Susanne; Linder, Roland; Verheyen, Frank; Pigeot, Iris

2016-01-01

The aim was to assess whether the use of additional data from the Disease Management Program (DMP) diabetes mellitus type 2 to minimize the potential for residual confounding will alter the estimated risk of either myocardial infarction, ischemic stroke or heart failure in patients with type 2 diabetes using sulfonylureas compared to dipeptidyl peptidase-4 (DPP-4) inhibitors in addition to metformin based on routine health care data. We conducted a nested two-phase case-control study using claims data of one German health insurance from 2004 to 2013 (phase 1) and data of the DMP from 2010 to 2013 (phase 2). Adjusted odds ratios (ORs) for the combined cardiovascular event myocardial infarction, ischemic stroke or heart failure were calculated using a two-phase logistic regression. Phase 1 comprised 3179 patients (289 cases; 2890 controls) and phase 2 comprised 1968 patients (168 cases; 1800 controls). We observed an adjusted OR of 0.83 for the combined cardiovascular event (95% CI: 0.61-1.13). We observed a non-significantly reduced risk for cardiovascular diseases in patients using DPP-4 inhibitors compared to sulfonylureas in addition to metformin. This finding was not altered by the inclusion of additional information of the DMP in the analysis. However, due to the low power of this study, further studies are needed to reproduce our findings. Copyright © 2016 Elsevier Inc. All rights reserved.

An infrared spectroscopic study of the structural phase transition in the perovskite-type layer compound [ n-C 16H 33NH 3] 2CoCl 4

NASA Astrophysics Data System (ADS)

Ning, Guo; Guangfu, Zeng; Shiquan, Xi

1992-12-01

The solid-solid phase transitions in the perovskite-type layer compound [ n-C 16H 33NH 3] 2CoCl 4 have been studied by infrared spectroscopy. A new phase transition at 340 K was found by comparison with differential scanning calorimetry results. A temperature dependence study of the infrared spectra provides evidence of the occurrence of structural phase transitions related to the dynamics of the alkylammonium ions and hydrogen bonds. The main transition at 374 K corresponds to the conformational order-disorder change in the chain, which probably couples with reorientational motions of the NH 3 polar heads. GTG or GTG' defects appear in the high temperature disordered phase.

The Pliocene Model Intercomparison Project - Phase 2

NASA Astrophysics Data System (ADS)

Haywood, Alan; Dowsett, Harry; Dolan, Aisling; Rowley, David; Abe-Ouchi, Ayako; Otto-Bliesner, Bette; Chandler, Mark; Hunter, Stephen; Lunt, Daniel; Pound, Matthew; Salzmann, Ulrich

2016-04-01

The Pliocene Model Intercomparison Project (PlioMIP) is a co-ordinated international climate modelling initiative to study and understand climate and environments of the Late Pliocene, and their potential relevance in the context of future climate change. PlioMIP examines the consistency of model predictions in simulating Pliocene climate, and their ability to reproduce climate signals preserved by geological climate archives. Here we provide a description of the aim and objectives of the next phase of the model intercomparison project (PlioMIP Phase 2), and we present the experimental design and boundary conditions that will be utilised for climate model experiments in Phase 2. Following on from PlioMIP Phase 1, Phase 2 will continue to be a mechanism for sampling structural uncertainty within climate models. However, Phase 1 demonstrated the requirement to better understand boundary condition uncertainties as well as uncertainty in the methodologies used for data-model comparison. Therefore, our strategy for Phase 2 is to utilise state-of-the-art boundary conditions that have emerged over the last 5 years. These include a new palaeogeographic reconstruction, detailing ocean bathymetry and land/ice surface topography. The ice surface topography is built upon the lessons learned from offline ice sheet modelling studies. Land surface cover has been enhanced by recent additions of Pliocene soils and lakes. Atmospheric reconstructions of palaeo-CO2 are emerging on orbital timescales and these are also incorporated into PlioMIP Phase 2. New records of surface and sea surface temperature change are being produced that will be more temporally consistent with the boundary conditions and forcings used within models. Finally we have designed a suite of prioritized experiments that tackle issues surrounding the basic understanding of the Pliocene and its relevance in the context of future climate change in a discrete way.

Polymorphism in 2-X-adamantane derivatives (X = Cl, Br).

PubMed

Negrier, Philippe; Barrio, María; Tamarit, Josep Ll; Mondieig, Denise

2014-08-14

The polymorphism of two 2-X-adamantane derivatives, X = Cl, X = Br, has been studied by X-ray powder diffraction and normal- and high-pressure (up to 300 MPa) differential scanning calorimetry. 2-Br-adamantane displays a low-temperature orthorhombic phase (space group P212121, Z = 4) and a high-temperature plastic phase (Fm3̅m, Z = 4) from 277.9 ± 1.0 K to the melting point at 413.4 ± 1.0 K. 2-Cl-adamantane presents a richer polymorphic behavior through the temperature range studied. At low temperature it displays a triclinic phase (P1̅, Z = 2), which transforms to a monoclinic phase (C2/c, Z = 8) at 224.4 ± 1.0 K, both phases being ordered. Two high-temperature orientationally disordered are found for this compound, one hexagonal (P63/mcm, Z = 6) at ca. 241 K and the highest one, cubic (Fm3̅m, Z = 4), being stable from 244 ± 1.0 K up to the melting point at 467.5 ± 1.0 K. No additional phase appears due to the increase in pressure within the studied range. The intermolecular interactions are found to be weak, especially for the 2-Br-adamantane compound for which the Br···Br as well as C-Br···H distances are larger than the addition of the van der Waals radii, thus confirming the availability of this compound for building up diamondoid blocks.

Phase Equilibria in the ZnO-"FeO"-SiO2 System in Reducing Atmosphere and in the ZnO-"FeO"-SiO2-"Cu2O" System in Equilibrium with Liquid Copper Metal at 1250 °C (1523 K)

NASA Astrophysics Data System (ADS)

Hidayat, Taufiq; Hayes, Peter C.; Jak, Evgueni

2018-05-01

Recent experimental studies in the ZnO-"FeO"-SiO2 system in reducing atmosphere demonstrated significant discrepancies with the current FactSage thermodynamic model developed using previous experimental data in this system in equilibrium with metallic iron and air. The present experimental study on phase equilibria in the ZnO-"FeO"-SiO2-"Cu2O" system in equilibrium with liquid copper at 1250 °C (1523 K) at low copper oxide concentrations in slag was initiated and undertaken to resolve these discrepancies. A high-temperature equilibration-rapid quenching-electron-probe X-ray microanalysis (EPMA) technique using a primary phase substrate support and closed system approach with Cu metal introduced to determine effective equilibrium oxygen partial pressure from the Cumetal/Cu2Oslag equilibria was applied to provide accurate information on the liquidus and corresponding solid compositions in the spinel, willemite, and tridymite primary phase fields. The present results confirmed the accuracy of the FactSage model, resolved discrepancies, and demonstrated significant uncertainties in the recent studies by other authors on the system in the open reducing atmosphere. The present study shows how this closed system approach can be used to obtain key thermodynamic data on phase equilibria in systems containing volatile metal species, overcoming the limitations and uncertainties encountered in conventional open gas/condensed phase equilibration with these systems. The study highlights the importance of the focus on obtaining accurate experimental data and the risks of misleading information from inadequate experimental control and analysis. The study also demonstrates that continuing in-depth critical review and analysis of the elemental reactions taking place in complex systems is an essential step in phase equilibrium research.

Synthesis and Study on Ionic Conductive (Bi1−x,Vx)O1.5−δ Materials with a Dual-Phase Microstructure

PubMed Central

Lai, Yu-Wei; Wei, Wen-Cheng J.

2016-01-01

Homogeneous Bi2O3-V2O5 powder mixtures with different amounts of V2O5 content (≤15 mol%) were prepared by colloidal dispersion and sintering to high density. The sintered and annealed samples were studied by thermal analysis, quantitative X-ray diffraction and scanning electron microscopy. The electrical and ionic conductivities of the conductors were also measured by a four-probe direct current (DC) method. The results of the samples prepared at 600–800 °C and annealed for as long as 100 h show that the sintered samples consisting of a pure γ phase or δ + γ binary phase perform differently in conductivity. The highly conductive δ phase in the composition of Bi0.92V0.08O1.5−δ enhances the electric conductivity 10-times better than that of the pure γ-sample (Bi0.94V0.06O1.5−δ) between 400 and 600 °C. The compatible regions of the γ phase with the α- or δ phase are also reported and discussed, so a part of the previously published Bi2O3-V2O5 phase diagram below 800 °C is revised. PMID:28773981

Nitrogen fixation in the activated sludge treatment of thermomechanical pulping wastewater: effect of dissolved oxygen.

PubMed

Slade, A H; Anderson, S M; Evans, B G

2003-01-01

N-ViroTech, a novel technology which selects for nitrogen-fixing bacteria as the bacteria primarily responsible for carbon removal, has been developed to treat nutrient limited wastewaters to a high quality without the addition of nitrogen, and only minimal addition of phosphorus. Selection of the operating dissolved oxygen level to maximise nitrogen fixation forms a key component of the technology. Pilot scale activated sludge treatment of a thermomechanical pulping wastewater was carried out in nitrogen-fixing mode over a 15 month period. The effect of dissolved oxygen was studied at three levels: 14% (Phase 1), 5% (Phase 2) and 30% (Phase 3). The plant was operated at an organic loading of 0.7-1.1 kg BOD5/m3/d, a solids retention time of approximately 10 d, a hydraulic retention time of 1.4 d and a F:M ratio of 0.17-0.23 mg BOD5/mg VSS/d. Treatment performance was very stable over the three dissolved oxygen operating levels. The plant achieved 94-96% BOD removal, 82-87% total COD removal, 79-87% soluble COD removal, and >99% total extractives removal. The lowest organic carbon removals were observed during operation at 30% DO but were more likely to be due to phosphorus limitation than operation at high dissolved oxygen, as there was a significant decrease in phosphorus entering the plant during Phase 3. Discharge of dissolved nitrogen, ammonium and oxidised nitrogen were consistently low (1.1-1.6 mg/L DKN, 0.1-0.2 mg/L NH4+-N and 0.0 mg/L oxidised nitrogen). Discharge of dissolved phosphorus was 2.8 mg/L, 0.1 mg/L and 0.6 mg/L DRP in Phases 1, 2 and 3 respectively. It was postulated that a population of polyphosphate accumulating bacteria developed during Phase 1. Operation at low dissolved oxygen during Phase 2 appeared to promote biological phosphorus uptake which may have been affected by raising the dissolved oxygen to 30% in Phase 3. Total nitrogen and phosphorus discharge was dependent on efficient secondary clarification, and improved over the course of the study as suspended solids discharge improved. Nitrogen fixation was demonstrated throughout the study using an acetylene reduction assay. Based on nitrogen balances around the plant, there was a 55, 354 and 98% increase in nitrogen during Phases 1, 2 and 3 respectively. There was a significant decrease in phosphorus between Phases 1 and 2, and Phase 3 of the study, as well as a significant increase in nitrogen between Phases 2 and 3 which masked the effect of changing the dissolved oxygen. Operation at low dissolved oxygen appeared to confer a competitive advantage to the nitrogen-fixing bacteria.

21 CFR 312.47 - Meetings.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Phase 3 plan and protocols and the adequacy of current studies and plans to assess pediatric safety and...) “End-of-Phase 2” meetings and meetings held before submission of a marketing application. At specific... and evaluation process. In particular, FDA has found that meetings at the end of Phase 2 of an...

High-pressure sapphire cell for phase equilibria measurements of CO2/organic/water systems.

PubMed

Pollet, Pamela; Ethier, Amy L; Senter, James C; Eckert, Charles A; Liotta, Charles L

2014-01-24

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. Specifically, the sapphire cell enables visual data collection from multiple loadings to solve a set of material balances to precisely determine phase composition. Ternary phase diagrams can then be established to determine the proportion of each component in each phase at a given condition. In principle, any ternary system can be studied although ternary systems (gas-liquid-liquid) are the specific examples discussed herein. For instance, the ternary THF-Water-CO2 system was studied at 25 and 40 °C and is described herein. Of key importance, this technique does not require sampling. Circumventing the possible disturbance of the system equilibrium upon sampling, inherent measurement errors, and technical difficulties of physically sampling under pressure is a significant benefit of this technique. Perhaps as important, the sapphire cell also enables the direct visual observation of the phase behavior. In fact, as the CO2 pressure is increased, the homogeneous THF-Water solution phase splits at about 2 MPa. With this technique, it was possible to easily and clearly observe the cloud point and determine the composition of the newly formed phases as a function of pressure. The data acquired with the sapphire cell technique can be used for many applications. In our case, we measured swelling and composition for tunable solvents, like gas-expanded liquids, gas-expanded ionic liquids and Organic Aqueous Tunable Systems (OATS)(1-4). For the latest system, OATS, the high-pressure sapphire cell enabled the study of (1) phase behavior as a function of pressure and temperature, (2) composition of each phase (gas-liquid-liquid) as a function of pressure and temperature and (3) catalyst partitioning in the two liquid phases as a function of pressure and composition. Finally, the sapphire cell is an especially effective tool to gather accurate and reproducible measurements in a timely fashion.

Al-, Y-, and La-doping effects favoring intrinsic and field induced ferroelectricity in HfO2: A first principles study

NASA Astrophysics Data System (ADS)

Materlik, Robin; Künneth, Christopher; Falkowski, Max; Mikolajick, Thomas; Kersch, Alfred

2018-04-01

III-valent dopants have shown to be most effective in stabilizing the ferroelectric, crystalline phase in atomic layer deposited, polycrystalline HfO2 thin films. On the other hand, such dopants are commonly used for tetragonal and cubic phase stabilization in ceramic HfO2. This difference in the impact has not been elucidated so far. The prospect is a suitable doping to produce ferroelectric HfO2 ceramics with a technological impact. In this paper, we investigate the impact of Al, Y, and La doping, which have experimentally proven to stabilize the ferroelectric Pca21 phase in HfO2, in a comprehensive first-principles study. Density functional theory calculations reveal the structure, formation energy, and total energy of various defects in HfO2. Most relevant are substitutional electronically compensated defects without oxygen vacancy, substitutional mixed compensated defects paired with a vacancy, and ionically compensated defect complexes containing two substitutional dopants paired with a vacancy. The ferroelectric phase is strongly favored with La and Y in the substitutional defect. The mixed compensated defect favors the ferroelectric phase as well, but the strongly favored cubic phase limits the concentration range for ferroelectricity. We conclude that a reduction of oxygen vacancies should significantly enhance this range in Y doped HfO2 thin films. With Al, the substitutional defect hardly favors the ferroelectric phase before the tetragonal phase becomes strongly favored with the increasing concentration. This could explain the observed field induced ferroelectricity in Al-doped HfO2. Further Al defects are investigated, but do not favor the f-phase such that the current explanation remains incomplete for Al doping. According to the simulation, doping alone shows clear trends, but is insufficient to replace the monoclinic phase as the ground state. To explain this fact, some other mechanism is needed.

Dynamic electronic correlation effects in NbO 2 as compared to VO 2

DOE PAGES

Brito, W. H.; Aguiar, M. C. O.; Haule, K.; ...

2017-11-01

In this study we present a comparative investigation of the electronic structures of NbO 2 and VO 2 obtained within a combination of density functional theory and cluster-dynamical mean-field theory calculations. We investigate the role of dynamic electronic correlations on the electronic structure of the metallic and insulating phases of NbO 2 and VO 2, with a focus on the mechanism responsible for the gap opening in the insulating phases. For the rutile metallic phases of both oxides, we obtain that electronic correlations lead to a strong renormalization of the t 2g subbands, as well as the emergence of incoherentmore » Hubbard subbands, signaling that electronic correlations are also important in the metallic phase of NbO 2. Interestingly, we find that nonlocal dynamic correlations do play a role in the gap formation of the [body-centered-tetragonal (bct)] insulating phase of NbO 2, by a similar physical mechanism as that recently proposed by us in the case of the monoclinic (M 1) dimerized phase of VO 2. Finally, although the effect of nonlocal dynamic correlations in the gap opening of bct phase is less important than in the (M 1 and M 2) monoclinic phases of VO 2, their presence indicates that the former is not a purely Peierls-type insulator, as it was recently proposed.« less

A theoretical evaluation of aluminum gel propellant two-phase flow losses on vehicle performance

NASA Technical Reports Server (NTRS)

Mueller, Donn C.; Turns, Stephen R.

1993-01-01

A one-dimensional model of a hydrocarbon/Al/O2(gaseous) fueled rocket combustion chamber was developed to study secondary atomization effects on propellant combustion. This chamber model was coupled with a two dimensional, two-phase flow nozzle code to estimate the two-phase flow losses associated with solid combustion products. Results indicate that moderate secondary atomization significantly reduces propellant burnout distance and Al2O3 particle size; however, secondary atomization provides only moderate decreases in two-phase flow induced I(sub sp) losses. Despite these two-phase flow losses, a simple mission study indicates that aluminum gel propellants may permit a greater maximum payload than the hydrocarbon/O2 bi-propellant combination for a vehicle of fixed propellant volume. Secondary atomization was also found to reduce radiation losses from the solid combustion products to the chamber walls, primarily through reductions in propellant burnout distance.

Magnetisation studies of phase co-existence in Gd{sub 1-x}Ca{sub x}BaCo{sub 2}O{sub 5.5}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thirumurugan, N.; Bharathi, A., E-mail: bharathi@igcar.gov.in; Arulraj, A.

2012-04-15

Highlights: Black-Right-Pointing-Pointer The series Gd{sub 1-x}Ca{sub x}BaCo{sub 2}O{sub 5.5} was synthesised by solid state reaction. Black-Right-Pointing-Pointer Magnetisation studies were carried out in the 4-300 K temperature range in magnetic fields upto 16 Tesla. Black-Right-Pointing-Pointer Results were used to formulate the T versus Ca fraction, phase diagram. Black-Right-Pointing-Pointer Evidence for Magnet-electronic phase separation is shown for the first time in the compound. -- Abstract: Magnetic properties of hole doped, oxygen deficient double perovskite compounds, Gd{sub 1-x}Ca{sub x}BaCo{sub 2}O{sub 5.5}, have been investigated. Ferromagnetic transition temperatures increase and the anti-ferromagnetic transition temperatures decrease with Ca substitution leading to stabilisation of ferromagnetisim formore » x {>=} 0.05. A detailed study of the ferromagnetic phase indicates the presence of double hysterisis loops for Ca fractions, 0.05 {<=} x {<=} 0.2 in the 50-200 K temperature range, suggestive of the co-existence of two ferromagnetic phases with different co-ercivities. Based on the magnetisation and transport measurements a phase diagram is proposed for Ca doped GdBaCo{sub 2}O{sub 5.5}.« less

Investigating Li 2NiO 2–Li 2CuO 2 Solid Solutions as High-Capacity Cathode Materials for Li-Ion Batteries

DOE PAGES

Xu, Jing; Renfrew, Sara; Marcus, Matthew A.; ...

2017-05-11

Li 2Ni 1–xCu xO 2 solid solutions were prepared by a solid-state method to study the correlation between composition and electrochemical performance. Cu incorporation improved the phase purity of Li 2Ni 1–xCu xO 2 with orthorhombic Immm structure, resulting in enhanced capacity. However, the electrochemical profiles suggested Cu incorporation did not prevent irreversible phase transformation during the electrochemical process, instead, it likely influenced the phase transformation upon lithium removal. By combining ex situ X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and differential electrochemical mass spectrometry (DEMS) measurements, this study elucidates the relevant phase transformation (e.g., crystal structure, local environment, andmore » charge compensation) and participation of electrons from lattice oxygen during the first cycle in these complex oxides.« less

A facile way to control phase of tin selenide flakes by chemical vapor deposition

NASA Astrophysics Data System (ADS)

Wang, Zhigang; Pang, Fei

2018-06-01

Although two-dimensional (2D) tin selenides are attracting intense attentions, studies on its phase transition are still relatively few. Here we report a facile way to control the phase growth of tin selenide flakes on mica and SiO2/Si by only adjusting nominal Sn:Se ratio, which refers to the amount of loaded SnO2 and Se precursors. High normal Sn:Se ratio induced SnSe flakes, conversely SnSe2 flakes formed. It could be used as a practical guide to selectively synthesize pure phase of single crystalline 2D layered chalcogenide materials similar to tin selenides.

Fluid inclusions in minerals from the geothermal fields of Tuscany, Italy

USGS Publications Warehouse

Belkin, H.; de Vivo, B.; Gianelli, G.; Lattanzi, P.

1985-01-01

A reconnaissance study on fluid inclusions from the geothermal fields of Tuscany indicates that the hydrothermal minerals were formed by fluids which were, at least in part, boiling. Four types of aqueous inclusions were recognized: (A) two-phase (liquid + vapor) liquid rich, (B) two-phase (vapor + liquid) vapor rich, (C) polyphase hypersaline liquid rich and (D) three phase-H2O liquid + CO2 liquid + CO2-rich vapor. Freezing and heating microthermometric determinations are reported for 230 inclusions from samples from six wells. It is suggested that boiling of an originally homogeneous, moderately saline, CO2-bearing liquid phase produced a residual hypersaline brine and a CO2-rich vapor phase. There are indications of a temperature decrease in the geothermal field of Larderello, especially in its peripheral zones. ?? 1985.

Hydrothermal Synthesis of Dicalcium Silicate Based Cement

NASA Astrophysics Data System (ADS)

Dutta, N.; Chatterjee, A.

2017-06-01

It is imperative to develop low energy alternative binders considering the large amounts of energy consumed as well as carbon dioxide emissions involved in the manufacturing of ordinary Portland cement. This study is on the synthesis of a dicalcium silicate based binder using a low temperature hydrothermal route.The process consists of synthesizing an intermediate product consisting of a calcium silicate hydrate phase with a Ca:Si ratio of 2:1 and further thermal treatment to produce the β-Ca2SiO4 (C2S) phase.Effect of various synthesis parameters like water to solid ratio, dwell time and temperature on the formation of the desired calcium silicate hydrate phase is reported along with effect of heating conditions for formation of the β-C2S phase. Around 77.45% of β-C2S phase was synthesized by thermal treatment of the intermediate phase at 820°C.

Phase Transitions in Tetramethylammonium Hexachlorometalate Compounds (TMA) 2MCl 6 (M = U, Np, Pt, Sn, Hf, Zr)

DOE PAGES

Autillo, Matthieu; Wilson, Richard E.

2017-09-22

A study of the phase transitions occurring in tetramethylammonium hexachlorometalate compounds with M = U IV, Np IV, Zr IV, Sn IV, Hf IV and Pt IV were performed using single-crystal X-ray diffraction across the temperature range 120 - 400K. When the crystals were cooled, movement of the octahedral [MCl 6] 2- anions induces a phase transition from Fm3m to Fd3c with a doubling of the unit cell. For the actinide compounds, no correlation between the f-electron configuration and the transition temperature was observed, instead, a correlation between the transition temperatures and both the [MCl 6] 2- anion and themore » TMA cation size is highlighted. Two phase transitions were observed and characterized. The first phase transition occurs with the ordering of the TMA cation and the second from a rotation of the [MCl 6] 2- octahedra. A third phase transition was observed at lower temperatures and was ascribed to a tetragonal distortion of the [MCl 6] 2- anions. Synthesis and study of their deuterated compounds did not show a significant isotope effect. As a result, Raman spectra performed on the protonated and deuterated compounds indicate only weak hydrogen bonding interactions between the TMA cations and the [MCl 6] 2- octahedra.« less

In-situ high-pressure x-ray diffraction study of zinc ferrite nanoparticles

DOE PAGES

Ferrari, S.; Kumar, R. S.; Grinblat, F.; ...

2016-04-23

We have studied the high-pressure structural behavior of zinc ferrite (ZnFe 2O 4) nanoparticles by powder X-ray diffraction measurements up to 47 GPa. We found that the cubic spinel structure of ZnFe 2O 4 remains up to 33 GPa and a phase transition is induced beyond this pressure. The high-pressure phase is indexed to an orthorhombic CaMn 2O 4-type structure. Upon decompression the low- and high-pressure phases coexist. The compressibility of both structures was also investigated. We have observed that the lattice parameters of the high-pressure phase behave anisotropically upon compression. Further, we predict possible phase transition around 55 GPa.more » For comparison, we also studied the compression behavior of magnetite (Fe 3O 4) nanoparticles by X-ray diffraction up to 23 GPa. Spinel-type ZnFe 2O 4 and Fe 3O 4 nanoparticles have a bulk modulus of 172 (20) GPa and 152 (9) GPa, respectively. Lastly, this indicates that in both cases the nanoparticles do not undergo a Hall-Petch strengthening.« less

In-situ high-pressure x-ray diffraction study of zinc ferrite nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ferrari, S.; Kumar, R. S.; Grinblat, F.

We have studied the high-pressure structural behavior of zinc ferrite (ZnFe 2O 4) nanoparticles by powder X-ray diffraction measurements up to 47 GPa. We found that the cubic spinel structure of ZnFe 2O 4 remains up to 33 GPa and a phase transition is induced beyond this pressure. The high-pressure phase is indexed to an orthorhombic CaMn 2O 4-type structure. Upon decompression the low- and high-pressure phases coexist. The compressibility of both structures was also investigated. We have observed that the lattice parameters of the high-pressure phase behave anisotropically upon compression. Further, we predict possible phase transition around 55 GPa.more » For comparison, we also studied the compression behavior of magnetite (Fe 3O 4) nanoparticles by X-ray diffraction up to 23 GPa. Spinel-type ZnFe 2O 4 and Fe 3O 4 nanoparticles have a bulk modulus of 172 (20) GPa and 152 (9) GPa, respectively. Lastly, this indicates that in both cases the nanoparticles do not undergo a Hall-Petch strengthening.« less

The Co-Sb-Ga System: Isoplethal Section and Thermodynamic Modeling

NASA Astrophysics Data System (ADS)

Gierlotka, Wojciech; Chen, Sinn-wen; Chen, Wei-an; Chang, Jui-shen; Snyder, G. Jeffrey; Tang, Yinglu

2015-04-01

The Co-Sb-Ga ternary system is an important thermoelectric material system, and its phase equilibria are in need of further understanding. The CoSb3-GaSb isoplethal section is experimentally determined in this study. Phase equilibria of the ternary Co-Sb-Ga system are assessed, and the system's thermodynamic models are developed. In addition to the terminal phases and liquid phase, there are six binary intermediate phases and a ternary Co3Sb2Ga4 phase. The Ga solution in the CoSb3 compound is described by a dual-site occupation (GaVF) x Co4Sb12- x/2(GaSb) x/2 model. Phase diagrams are calculated using the developed thermodynamic models, and a reaction scheme is proposed based on the calculation results. The calculated results are in good agreement with the experimentally determined phase diagrams, including the CoSb3-GaSb isoplethal section, the liquidus projection, and an isothermal section at 923 K (650 °C). The dual-site occupation (GaVF) x Co4Sb12- x/2(GaSb) x/2 model gives good descriptions of both phase equilibria and thermoelectric properties of the CoSb3 phase with Ga doping.

The extracellular matrix locally regulates asynchronous concurrent lactation in tammar wallaby (Macropus eugenii).

PubMed

Wanyonyi, Stephen S; Lefevre, Christophe; Sharp, Julie A; Nicholas, Kevin R

2013-08-08

Asynchronous concurrent lactation (ACL) is an extreme lactation strategy in macropod marsupials including the tammar wallaby, that may hold the key to understanding local control of mammary epithelial cell function. Marsupials have a short gestation and a long lactation consisting of three phases; P2A, P2B and P3, representing early, mid and late lactation respectively and characterised by profound changes in milk composition. A lactating tammar is able to concurrently produce phase 2A and 3 milk from adjacent glands in order to feed a young newborn and an older sibling at heel. Physiological effectors of ACL remain unknown and in this study the extracellular matrix (ECM) is investigated for its role in switching mammary phenotypes between phases of tammar wallaby lactation. Using the level of expression of the genes for the phase specific markers tELP, tWAP, and tLLP-B representing phases 2A, 2B and 3 respectively we show for the first time that tammar wallaby mammary epithelial cells (WallMECs) extracted from P2B acquire P3 phenotype when cultured on P3 ECM. Similarly P2A cells acquire P2B phenotype when cultured on P2B ECM. We further demonstrate that changes in phase phenotype correlate with phase-specific changes in ECM composition. This study shows that progressive changes in ECM composition in individual mammary glands provide a local regulatory mechanism for milk protein gene expression thereby enabling the mammary glands to lactate independently. Copyright © 2013. Published by Elsevier B.V.

Instrument development and validation of a quality scale for historical research papers (QSHRP): a pilot study.

PubMed

Kelly, Jacinta; Watson, Roger

2014-12-01

To report a pilot study for the development and validation of an instrument to measure quality in historical research papers. There are no set criteria to assess historical papers published in nursing journals. A three phase mixed method sequential confirmatory design. In 2012, we used a three-phase approach to item generation and content evaluation. In phase 1, we consulted nursing historians using an online survey comprising three open-ended questions and revised the items. In phase 2, we evaluated the revised items for relevance with expert historians using a 4-point Likert scale and Content Validity Index calculation. In phase 3, we conducted reliability testing of the instrument using a 3-point Likert scale. In phase 1, 121 responses were generated via the online survey and revised to 40 interrogatively phrased items. In phase 2, five items with an Item Content Validity Index score of ≥0·7 remained. In phase 3, responses from historians resulted in 100% agreement to questions 1, 2 and 4 and 89% and 78%, respectively, to questions 3 and 5. Items for the QSHRP have been identified, content validated and reliability tested. This scale improves on previous scales, which over-emphasized source criticism. However, a full-scale study is needed with nursing historians to increase its robustness. © 2014 John Wiley & Sons Ltd.

Phase 1 and 2 studies demonstrate the safety and efficacy of intraprostatic injection of PRX302 for the targeted treatment of lower urinary tract symptoms secondary to benign prostatic hyperplasia.

PubMed

Denmeade, Samuel R; Egerdie, Blair; Steinhoff, Gary; Merchant, Rosemina; Abi-Habib, Ralph; Pommerville, Peter

2011-05-01

PRX302 is a prostate specific antigen (PSA)-activated pore-forming protein toxin under development as a targeted approach for improving lower urinary tract symptoms (LUTS) caused by benign prostatic hyperplasia (BPH) without affecting sexual function. To evaluate the safety and efficacy of PRX302 in men with moderate to severe BPH. Eligible subjects were refractory, intolerant, or unwilling to undergo medical therapies for BPH and had International Prostate Symptom Score (IPSS) ≥12, a quality of life (QoL) score ≥3, and prostate volumes between 30 and 80 g. Fifteen patients were enrolled in phase 1 studies, and 18 patients entered phase 2 studies. Subjects received intraprostatic injection of PRX302 into the right and left transition zone via a transperineal approach in an office-based setting. Phase 1 subjects received increasing concentrations of PRX302 at a fixed volume; phase 2 subjects received increasing volumes per deposit at a fixed concentration. IPSS, QoL, prostate volume, maximum flow rate (Q(max)), International Index of Erectile Function, serum PSA levels, pharmacokinetics, and adverse events were recorded at 30, 60, 90, 180, 270, and 360 d after treatment with PRX302. Sixty percent of men in the phase 1 study and 64% of men in the phase 2 study treated with PRX302 had ≥30% improvement compared to baseline in IPSS out to day 360. Patients also experienced improvement in QoL and reduction in prostate volume out to day 360. Patients receiving ≥1 ml of PRX302 per deposit had the best response overall. PRX302 had no deleterious effect on erectile function. Adverse events were mild to moderate and transient in nature. The major study limitation was the small sample size. The promising safety profile and evidence of efficacy in the majority of treated subjects in these phase 1 and 2 studies supports further development of PRX302 as a minimally invasive, targeted treatment for BPH. Copyright © 2010 European Association of Urology. Published by Elsevier B.V. All rights reserved.

Phase correction, phase resetting, and phase shifts after subliminal timing perturbations in sensorimotor synchronization.

PubMed

Repp, B H

2001-06-01

Recent studies of synchronized finger tapping have shown that perceptually subliminal phase shifts in an auditory sequence are rapidly compensated for in the motor activity (B. H. Repp, 2000a). Experiment 1 used a continuation-tapping task to confirm that this compensation is indeed a phase correction, not an adjustment of the central timekeeper period. Experiments 2-5 revealed that this phase correction occurs even when there is no ordinary sensorimotor asynchrony--when the finger taps are in antiphase or arbitrary phase relative to the auditory sequence (Experiments 2 and 3) or when the tap coinciding with the sequence phase shift is withheld (Experiments 4 and 5). The phase correction observed in the latter conditions was instantaneous, which suggests that phase resetting occurs when the motor activity is discontinuous. A prolonged phase shift suggestive of overcompensation was observed in some conditions, which poses a challenge to pure phase correction models.

Pharmacotherapy Relapse Prevention in Body Dysmorphic Disorder: A Double-Blind Placebo-Controlled Trial

PubMed Central

Phillips, Katharine A.; Keshaviah, Aparna; Dougherty, Darin; Stout, Robert L.; Menard, William; Wilhelm, Sabine

2016-01-01

Objective Body dysmorphic disorder (BDD) is common, distressing, and often severely impairing. Serotonin-reuptake inhibitors (SRIs) appear efficacious for BDD, but the few existing pharmacotherapy studies were short-term (≤4 months), and no relapse prevention studies or continuation phase studies have been conducted. We report results from the first BDD relapse prevention study. Method Adults (N=100) with DSM-IV BDD received open-label escitalopram for 14 weeks (Phase 1); 58 responders were then randomized to double-blind continuation treatment with escitalopram versus switch to placebo for six months (Phase 2). Reliable and valid outcome measures were utilized. Results Phase 1: Overall, 67.0% of treated subjects and 81.1% of completers were escitalopram responders (p’s<0.0001). BDD severity, BDD-related insight, depressive symptoms, psychosocial functioning, and quality of life significantly improved from baseline to end of Phase 1 (all p's<0.0001). Phase 2: Time to relapse was significantly longer for subjects receiving escitalopram than those receiving placebo (hazard ratio=2.72, 95% CI [1.01, 8.57], p=0.049). Phase 2 relapse proportions were 18% for escitalopram versus 40% for placebo. In escitalopram-treated subjects, BDD severity significantly decreased over time during the continuation treatment phase (p=0.036); further improvement occurred in 35.7% of the escitalopram group. There were no significant group differences in BDD severity, insight, depressive symptoms, psychosocial functioning, or quality of life. Conclusions Continuation-phase escitalopram delayed time to relapse, and fewer escitalopram-treated subjects relapsed compared with placebo-treated subjects. BDD severity significantly further improved during six additional months of escitalopram treatment following acute response; more than one-third of escitalopram-treated subjects had further improvement during continuation phase treatment. PMID:27056606

Pharmacotherapy Relapse Prevention in Body Dysmorphic Disorder: A Double-Blind, Placebo-Controlled Trial.

PubMed

Phillips, Katharine A; Keshaviah, Aparna; Dougherty, Darin D; Stout, Robert L; Menard, William; Wilhelm, Sabine

2016-09-01

Body dysmorphic disorder is common, distressing, and often severely impairing. Serotonin reuptake inhibitors appear efficacious, but the few existing pharmacotherapy studies were short term (≤4 months), and no relapse prevention studies or continuation phase studies have been conducted to the authors' knowledge. The authors report results from the first relapse prevention study in body dysmorphic disorder. Adults (N=100) with DSM-IV body dysmorphic disorder received open-label escitalopram for 14 weeks (phase 1); 58 responders were then randomized to double-blind continuation treatment with escitalopram versus switch to placebo for 6 months (phase 2). Reliable and valid outcome measures were utilized. In phase 1, 67.0% of treated subjects and 81.1% of subjects who completed phase 1 responded to escitalopram. Body dysmorphic disorder severity (in both the intent-to-treat and the completer groups) and insight, depressive symptoms, psychosocial functioning, and quality of life significantly improved from baseline to end of phase 1. In phase 2, time to relapse was significantly longer with escitalopram than with placebo treatment (hazard ratio=2.72, 95% CI=1.01-8.57). Phase 2 relapse proportions were 18% for escitalopram and 40% for placebo. Among escitalopram-treated subjects, body dysmorphic disorder severity significantly decreased over time during the continuation phase, with 35.7% of subjects showing further improvement. There were no significant group differences in body dysmorphic disorder severity or insight, depressive symptoms, psychosocial functioning, or quality of life. Continuation-phase escitalopram delayed time to relapse, and fewer escitalopram-treated subjects relapsed than did placebo-treated subjects. Body dysmorphic disorder severity significantly improved during 6 additional months of escitalopram treatment following acute response; more than one-third of escitalopram-treated subjects experienced further improvement.

Effect of thermal annealing on the phase evolution of silver tungstate in Ag/WO₃ films.

PubMed

Bose, R Jolly; Sreedharan, R Sreeja; Krishnan, R Resmi; Reddy, V R; Gupta, Mukul; Ganesan, V; Sudheer, S K; Pillai, V P Mahadevan

2015-06-15

Silver/tungsten oxide multi-layer films are deposited over quartz substrates by RF magnetron sputtering technique and the films are annealed at temperatures 200, 400 and 600°C. The effect of thermal annealing on the phase evolution of silver tungstate phase in Ag/WO3 films is studied extensively using techniques like X-ray diffraction, micro-Raman analysis, atomic force microscopy and photoluminescence studies. The XRD pattern of the as-deposited film shows only the peaks of cubic phase of silver. The film annealed at 200°C shows the presence of XRD peaks corresponding to orthorhombic phase of Ag2WO4 and peaks corresponding to cubic phase of silver with reduced intensity. It is found that, as annealing temperature increases, the volume fraction of Ag decreases and that of Ag2WO4 phase increases and becomes highest at a temperature of 400°C. When the temperature increases beyond 400°C, the volume fraction of Ag2WO4 decreases, due to its decomposition into silver and oxygen deficient phase Ag2W4O13. The micro-Raman spectra of the annealed films show the characteristic bands of tungstate phase which is in agreement with XRD analysis. The surface morphology of the films studied by atomic force microscopy reveals that the particle size and r.m.s roughness are highest for the sample annealed at 400°C. In the photoluminescence study, the films with silver tungstate phase show an emission peak in blue region centered around the wavelength 441 nm (excitation wavelength 256 nm). Copyright © 2015 Elsevier B.V. All rights reserved.

High temperature ferroic phase transitions and evidence of paraelectric cubic phase in the multiferroic 0.8BiFeO3-0.2BaTiO3

NASA Astrophysics Data System (ADS)

Singh, Anar; Patel, Jay Prakash; Pandey, Dhananjai

2009-10-01

We present here results of a powder x-ray diffraction study on the multiferroic 0.8BiFeO3-0.2BaTiO3 in the temperature range of 300-925 K. Our results provide unambiguous evidence for paraelectric cubic phase. We do not find any evidence for intermediate β-phase in our studies. The rhombohedral to cubic phase transition is shown to be of first order as revealed by the coexistence of cubic and rhombohedral phases over 100 K range and a discontinuous change in the unit cell volume. An anomaly in the unit cell volume at the magnetic transition temperature indicative of the magnetoelastic coupling is also reported.

ESP: Economics of Shipyard Painting, Bid Estimating Transfer Study

DTIC Science & Technology

1993-11-10

Estimating Transfer Study Final Report i EXECUTIVE SUMMARY During Phase I of the “Economics of Shipyard Painting” project, it became evident that detail...an SP-3 panel directive to establish a 2nd phase of the “Economics of Shipyard Painting” focussed on applying the detailed data collected in Phase I to...bid-stage estimating. During Phase II, a program was developed that worked in tandem with the detailed data collection effort laid out in Phase I

Rectal Microbicide Development

PubMed Central

Dezzutti, Charlene

2014-01-01

The last few years have seen important progress in demonstrating the efficacy of oral pre-exposure prophylaxis, vaginal microbicides, and treatment as prevention as effective strategies for reducing the risk of acquiring or transmitting HIV infection. There has also been significant progress in the development of rectal microbicides. Preclinical non-human primate studies have demonstrated that antiretroviral microbicides can provide significant protection from rectal challenge with SIV or SHIV. Recent Phase 1 rectal microbicide studies have characterized the safety, acceptability, compartmental pharmacokinetics (PK), and pharmaco-dynamics (PD) of both UC781 and tenofovir gels. The tenofovir gel formulation used in vaginal studies was not well tolerated in the rectum and newer rectal-specific formulations have been developed and evaluated in Phase 1 studies. The PK/PD data generated in these Phase 1 studies may reduce the risk of advancing ineffective candidate rectal microbicides into late stage development. Tenofovir gel is currently poised to move into Phase 2 evaluation and it is possible that a Phase 2B/3 effectiveness study with this product could be initiated in the next 2–3 years. PMID:23612991

Study of Ti 4+ substitution in ZrW 2O 8 negative thermal expansion materials

NASA Astrophysics Data System (ADS)

De Buysser, Klaartje; Van Driessche, Isabel; Putte, Bart Vande; Schaubroeck, Joseph; Hoste, Serge

2007-08-01

Powder XRD-analysis and thermo-mechanical analysis on sintered TiO 2-WO 3-ZrO 2 mixtures revealed the formation of Zr 1-xTi xW 2O 8 solid solutions. A noticeable decrease in unit cell parameter ' a' and in the order-disorder transition temperature could be seen in the case of Zr 1-xTi xW 2O 8 solid solutions. Studies performed on other ZrW 2O 8 solid solutions have attributed an increase in phase transition temperature to a decrease in free lattice volume, whereas a decrease in phase transition temperature was suggested to be due to the presence of a more disordered state. Our studies indicate that the phase transition temperature in our materials is strongly influenced by the bond dissociation energy of the substituting ion-oxygen bond. A decrease in bond strength may compensate for the effect of a decrease in lattice free volume, lowering the phase transition temperature as the degree of substitution by Ti 4+ increases. This hypothesis is proved by differential scanning calorimetry.

27Al-NMR studies of the structural phase transition in LaPd2Al2

NASA Astrophysics Data System (ADS)

Aoyama, Taisuke; Kobayashi, Fumiaki; Kotegawa, Hisashi; Tou, Hideki; Doležal, Petr; Kriegner, Dominik; Javorský, Pavel; Uhlířová, Klára

2018-05-01

We performed 27Al-NMR measurements for the CaBe2Ge2 type single crystalline LaPd2Al2 in the temperature range from 100 K to 5 K to investigate the origin of the structural phase transition. We found that the line profile of the 27Al-NMR spectrum does not change entirely on passing through the structural phase transition at Tst. Meanwhile, the peak position of the central line slightly change (≈ 30 ppm) below 70 K, suggesting the orbital shift changes below Tst. The present 27Al-NMR studies evidence that the local electronic state at Al site is hardly affected by the structural phase transition.

Gradient enhanced-fluidity liquid hydrophilic interaction chromatography of ribonucleic acid nucleosides and nucleotides: A "green" technique.

PubMed

Beilke, Michael C; Beres, Martin J; Olesik, Susan V

2016-03-04

A "green" hydrophilic interaction liquid chromatography (HILIC) technique for separating the components of mixtures with a broad range of polarities is illustrated using enhanced-fluidity liquid mobile phases. Enhanced-fluidity liquid chromatography (EFLC) involves the addition of liquid CO2 to conventional liquid mobile phases. Decreased mobile phase viscosity and increased analyte diffusivity results when a liquefied gas is dissolved in common liquid mobile phases. The impact of CO2 addition to a methanol:water (MeOH:H2O) mobile phase was studied to optimize HILIC gradient conditions. For the first time a fast separation of 16 ribonucleic acid (RNA) nucleosides/nucleotides was achieved (16min) with greater than 1.3 resolution for all analyte pairs. By using a gradient, the analysis time was reduced by over 100% compared to similar separations conducted under isocratic conditions. The optimal separation using MeOH:H2O:CO2 mobile phases was compared to MeOH:H2O and acetonitrile:water (ACN:H2O) mobile phases. Based on chromatographic performance parameters (efficiency, resolution and speed of analysis) and an assessment of the environmental impact of the mobile phase mixtures, MeOH:H2O:CO2 mixtures are preferred over ACN:H2O or MeOH:H2O mobile phases for the separation of mixtures of RNA nucleosides and nucleotides. Copyright © 2016 Elsevier B.V. All rights reserved.

Self-reports of induced abortion: an empathetic setting can improve the quality of data.

PubMed Central

Rasch, V; Muhammad, H; Urassa, E; Bergström, S

2000-01-01

OBJECTIVES: This study estimated the proportion of incomplete abortions that are induced in hospital-based settings in Tanzania. METHODS: A cross-sectional questionnaire study was conducted in 2 phases at 3 hospitals in Tanzania. Phase 1 included 302 patients with a diagnosis of incomplete abortion, and phase 2 included 823 such patients. RESULTS: In phase 1, in which cases were classified by clinical criteria and information from the patient, 3.9% to 16.1% of the cases were classified as induced abortion. In phase 2, in which the structured interview was changed to an empathetic dialogue and previously used clinical criteria were omitted, 30.9% to 60.0% of the cases were classified as induced abortion. CONCLUSIONS: An empathetic dialogue improves the quality of data collected among women with induced abortion. PMID:10897196

Evaluation of a Two-Phase Experimental Study of a Small Group ("MultiLit") Reading Intervention for Older Low-Progress Readers

ERIC Educational Resources Information Center

Buckingham, Jennifer; Beaman-Wheldall, Robyn; Wheldall, Kevin

2014-01-01

The study reported here examined the efficacy of a small group (Tier 2 in a three-tier Response to Intervention model) literacy intervention for older low-progress readers (in Years 3-6). This article focuses on the second phase of a two-phase, crossover randomized control trial involving 26 students. In Phase 1, the experimental group (E1)…

Low-moment ferrimagnetic phase of the Heusler compound Cr2CoAl

NASA Astrophysics Data System (ADS)

Jamer, Michelle E.; Marshall, Luke G.; Sterbinsky, George E.; Lewis, Laura H.; Heiman, Don

2015-11-01

Synthesizing half-metallic fully compensated ferrimagnets that form in the inverse Heusler phase could lead to superior spintronic devices. These materials would have high spin polarization at room temperature with very little fringing magnetic fields. Previous theoretical studies indicated that Cr2CoAl should form in a stable inverse Heusler lattice due to its low activation energy. Here, stoichiometric Cr2CoAl samples were arc-melted and annealed at varying temperatures, followed by studies of their structural and magnetic properties. High-resolution synchrotron X-ray diffraction revealed a chemically ordered Heusler phase in addition to CoAl and Cr phases. Soft X-ray magnetic circular dichroism revealed that the Cr and Co magnetic moments are antiferromagnetically oriented leading to the observed low magnetic moment in Cr2CoAl.

Structural and vibrational properties of single crystals of Scandia, Sc{sub 2}O{sub 3} under high pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ovsyannikov, Sergey V., E-mail: sergey.ovsyannikov@uni-bayreuth.de, E-mail: sergey2503@gmail.com; Wenz, Michelle D.; Pakhomova, Anna S.

2015-10-28

We report the results of single-crystal X-ray diffraction and Raman spectroscopy studies of scandium oxide, Sc{sub 2}O{sub 3}, at ambient temperature under high pressure up to 55 and 28 GPa, respectively. Both X-ray diffraction and Raman studies indicated a phase transition from the cubic bixbyite phase (so-called C-Res phase) to a monoclinic C2/m phase (so-called B-Res phase) at pressures around 25–28 GPa. The transition was accompanied by a significant volumetric drop by ∼6.7%. In addition, the Raman spectroscopy detected a minor crossover around 10–12 GPa, which manifested in the appearance of new and disappearance of some Raman modes, as well as in softeningmore » of one Raman mode. We found the bulk modulus values of the both C-Res and B-Res phases as B{sub 0} = 198.2(3) and 171.2(1) GPa (for fixed B′ = 4), respectively. Thus, the denser high-pressure lattice of Sc{sub 2}O{sub 3} is much softer than the original lattice. We discuss possible mechanisms that might be responsible for the pronounced elastic softening in the monoclinic high-pressure phase in this “simple” oxide with an ultra-wide band gap.« less

Synthesis of TiO2 Nanoparticle and its phase Transition

NASA Astrophysics Data System (ADS)

Mangrola, M. H.; Joshi, V. G.; Parmar, B. H.

2011-12-01

Here we report the synthesis of titanium dioxide (TiO2) nanoparticles and study of its phase transition from anataze to rutile. Titanium dioxide (TiO2) nanoparticles have been prepared by hydrolysis of Titanium isopropoxide an aqueous solution with constant value of pH 2 and peptizing the resultant suspension gel(white-Blue) and calcinate gel at different temperature. Structures of synthetic samples of TiO2 have been examined by X-ray diffraction (XRD) and scanning electron microscope (SEM). The anatase-rutile transition has been a popular topic due to its interest to scientific and engineering fields. . Here we have seen that the 100 °C calcinate powder consist of anatase fine crystalline phase with a particle size 14 to 15 nm. The prepared TiO2 nanoparticles have uniform size and morphology, and the phase transformation kinetics of obtained material was studied by interpretation of the X-ray diffraction patterns peaks. The phase transform occurred from anatase to rutile at calcinate temperature up to 600 °C. A very fine network texture made from uniform nanoparticles was revealed by scanning electron microscopy (SEM) analyses.

Post-Effect of Air Quality Improvement on Biomarkers for Systemic Inflammation and Microparticles in Asthma Patients After the 2008 Beijing Olympic Games: a Pilot Study.

PubMed

Gao, Jinming; Xu, Xiaohua; Ying, Zhekang; Jiang, Lei; Zhong, Mianhua; Wang, Aixia; Chen, Lung-Chi; Lu, Bo; Sun, Qinghua

2017-08-01

This study's aim was to investigate the post-effect of an air quality improvement on systemic inflammation and circulating microparticles in asthmatic patients during, and 2 months after, the Beijing Olympics 2008. We measured the levels of circulating inflammatory cytokines and microparticles in the peripheral blood from asthma patients and healthy controls during (phase 1), and 2 months after (phase 2) the Beijing 2008 Olympic Games. The concentrations of circulating cytokines (including TNFα, IL-6, IL-8, and IL-10) were still seen reduced in phase 2 when compared with those in phase 1. The number of circulating endothelial cell-derived microparticles was significantly lower during the phase 2 than that during phase 1 in asthma patients. The level of plasma lipopolysaccharide-binding protein (LBP) was significantly decreased in asthmatics in phase 2. The level of norepinephrine was significantly higher in phase 2 than that in phase 1 in plasma from both asthma patients and healthy subjects. There were no significant differences in the gene profile for the toll-like receptor (TLR) signaling from peripheral blood mononuclear cells. In vitro, microvesicles from patients with asthma impaired the relaxation to bradykinin and contraction to acetylcholine, whereas microparticles from healthy subjects did not. These data suggested that reduction in systemic pro-inflammatory responses and circulating LBP and increased level of norepinephrine in asthma patients persisted even after 2 months of the air pollution intervention. These changes were independent of the TLR signaling pathway. Circulating microparticles might be associated with airway smooth muscle dysfunction.

Metal-insulator-superconductor transition of spin-3/2 atoms on optical lattices

NASA Astrophysics Data System (ADS)

De Silva, Theja N.

2018-01-01

We use a slave-rotor approach within a mean-field theory to study the competition of metallic, Mott-insulating, and superconducting phases of spin-3/2 fermions subjected to a periodic optical lattice potential. In addition to the metallic, the Mott-insulating, and the superconducting phases that are associated with the gauge symmetry breaking of the spinon field, we identify an emerging superconducting phase that breaks both roton and spinon field gauge symmetries. This superconducting phase emerges as a result of the competition between spin-0 singlet and spin-2 quintet interaction channels naturally available for spin-3/2 systems. The two superconducting phases can be distinguished from each other by quasiparticle weight. We further discuss the properties of these phases for both two-dimensional square and three-dimensional cubic lattices at zero and finite temperatures.

In situ probing of doping- and stress-mediated phase transitions in a single-crystalline VO2 nanobeam by spatially resolved Raman spectroscopy

NASA Astrophysics Data System (ADS)

Chang, Sung-Jin; Park, Jong Bae; Lee, Gaehang; Kim, Hae Jin; Lee, Jin-Bae; Bae, Tae-Sung; Han, Young-Kyu; Park, Tae Jung; Huh, Yun Suk; Hong, Woong-Ki

2014-06-01

We demonstrate an experimental in situ observation of the temperature-dependent evolution of doping- and stress-mediated structural phase transitions in an individual single-crystalline VO2 nanobeam on a Au-coated substrate under exposure to hydrogen gas using spatially resolved Raman spectroscopy. The nucleation temperature of the rutile R structural phase in the VO2 nanobeam upon heating under hydrogen gas was lower than that under air. The spatial structural phase evolution behavior along the length of the VO2 nanobeam under hydrogen gas upon heating was much more inhomogeneous than that along the length of the same nanobeam under air. The triclinic T phase of the VO2 nanobeam upon heating under hydrogen gas transformed to the R phase and this R phase was stabilized even at room temperature in air after sample cooling. In particular, after the VO2 nanobeam with the R phase was annealed at approximately 250 °C in air, it exhibited the monoclinic M1 phase (not the T phase) at room temperature during heating and cooling cycles. These results were attributed to the interplay between hydrogen doping and stress associated with nanobeam-substrate interactions. Our study has important implications for engineering metal-insulator transition properties and developing functional devices based on VO2 nanostructures through doping and stress.We demonstrate an experimental in situ observation of the temperature-dependent evolution of doping- and stress-mediated structural phase transitions in an individual single-crystalline VO2 nanobeam on a Au-coated substrate under exposure to hydrogen gas using spatially resolved Raman spectroscopy. The nucleation temperature of the rutile R structural phase in the VO2 nanobeam upon heating under hydrogen gas was lower than that under air. The spatial structural phase evolution behavior along the length of the VO2 nanobeam under hydrogen gas upon heating was much more inhomogeneous than that along the length of the same nanobeam under air. The triclinic T phase of the VO2 nanobeam upon heating under hydrogen gas transformed to the R phase and this R phase was stabilized even at room temperature in air after sample cooling. In particular, after the VO2 nanobeam with the R phase was annealed at approximately 250 °C in air, it exhibited the monoclinic M1 phase (not the T phase) at room temperature during heating and cooling cycles. These results were attributed to the interplay between hydrogen doping and stress associated with nanobeam-substrate interactions. Our study has important implications for engineering metal-insulator transition properties and developing functional devices based on VO2 nanostructures through doping and stress. Electronic supplementary information (ESI) available: Illustration, photograph, Raman data, and EDX spectra. See DOI: 10.1039/c4nr01118j

Influences of W Content on the Phase Transformation Properties and the Associated Stress Change in Thin Film Substrate Combinations Studied by Fabrication and Characterization of Thin Film V1- xW xO2 Materials Libraries.

PubMed

Wang, Xiao; Rogalla, Detlef; Ludwig, Alfred

2018-04-09

The mechanical stress change of VO 2 film substrate combinations during their reversible phase transformation makes them promising for applications in micro/nanoactuators. V 1- x W x O 2 thin film libraries were fabricated by reactive combinatorial cosputtering to investigate the effects of the addition of W on mechanical and other transformation properties. High-throughput characterization methods were used to systematically determine the composition spread, crystalline structure, surface topography, as well as the temperature-dependent phase transformation properties, that is, the hysteresis curves of the resistance and stress change. The study indicates that as x in V 1- x W x O 2 increases from 0.007 to 0.044 the crystalline structure gradually shifts from the VO 2 (M) phase to the VO 2 (R) phase. The transformation temperature decreases by 15 K/at. % and the resistance change is reduced to 1 order of magnitude, accompanied by a wider transition range and a narrower hysteresis with a minimal value of 1.8 K. A V 1- x W x O 2 library deposited on a Si 3 N 4 /SiO 2 -coated Si cantilever array wafer was used to study simultaneously the temperature-dependent stress change σ( T) of films with different W content through the phase transformation. Compared with σ( T) of ∼700 MPa of a VO 2 film, σ( T) in V 1- x W x O 2 films decreases to ∼250 MPa. Meanwhile, σ( T) becomes less abrupt and occurs over a wider temperature range with decreased transformation temperatures.

Semiconductor-to-metal phase change in MoTe2 layers (Conference Presentation)

NASA Astrophysics Data System (ADS)

Davydov, Albert V.; Krylyuk, Sergiy; Kalish, Irina; Meshi, Louisa; Beams, Ryan; Kalanyan, Berc; Sharma, Deepak K.; Beck, Megan; Bergeron, Hadallia; Hersam, Mark C.

2016-09-01

Molybdenum ditelluride (MoTe2), which can exist in a semiconducting prismatic hexagonal (2H) or a metallic distorted octahedral (1T') phases, is one of the very few materials that exhibit metal-semiconductor transition. Temperature-driven 2H - 1T' phase transition in bulk MoTe2 occurs at high temperatures (above 900 °C) and it is usually accompanied by Te loss. The latter can exacerbate the control over reversibility of the phase transition. Here, we study effects of high-temperature annealing on phase transition in MoTe2 single crystals. First, MoTe2 were grown in sealed evacuated quartz ampoules from polycrystalline MoTe2 powder in an iodine-assisted chemical vapor transport process at 1000 °C. The 2H and 1T' phases were stabilized by controlling the cooling rate after the growth. In particular, slow cooling at 10 °C/h rate yielded the 2H phase whereas the 1T' phase was stabilized by ice-water quenching. Next, the phase conversion was achieved by annealing MoTe2 single crystals in vacuum-sealed ampoules at 1000 °C with or without additional poly-MoTe2 powder followed by fast or slow cooling. Similarly to the CVT growth, slow cooling and quenching consistently produced 2H and 1T' phases, respectively, regardless of the initial MoTe2 crystal structure. We will discuss structural and optical properties of the as-grown and phase-converted MoTe2 single crystals using TEM, SEM/EDS, XRD, XPS and Raman. Electrical characteristics of two-terminal devices made from metallic 1T' and bottom-gated FETs made from 2H exfoliated crystals will also be presented.

Properties of the correlated metal phase induced by electrolyte gating of insulating vanadium dioxide nanobeams

NASA Astrophysics Data System (ADS)

Singh, Sujay; Horrocks, Gregory; Marley, Peter; Banerjee, Sarbajit; Sambandamurthy, G.

2014-03-01

Vanadium oxide (VO2) undergoes a first order metal to insulator transition (MIT) and a structural phase transition (monoclinic insulator to rutile metal) near 340 K. Over the past few years, several attempts are made to trigger the MIT in VO2 using ionic liquids (IL). Parkin's group has recently showed that IL gating leads to the creation of oxygen vacancies in VO2 and stabilizes the metallic phase. Our goal is to study the electronic properties, changes in the stoichiometry and structure of this metallic phase created by oxygen vacancies. Electrical transport measurements on single crystal nanobeams show that the metallic phase has a higher resistance while IL gating is applied and results from Raman spectroscopy studies on any structural change during IL gating will be presented. The role of substitutional dopants (such as W, Mo) on the creation of oxygen vacancies and subsequent stabilization of metallic phase in IL gated experiments will also be discussed. The work is supported by NSF DMR 0847324 and 0847169.

Nanotwin and phase transformation in tetragonal Pb(Fe1/2Nb1/2)1-xTixO3 single crystal

NASA Astrophysics Data System (ADS)

Tu, C.-S.; Tseng, C.-T.; Chien, R. R.; Schmidt, V. Hugo; Hsieh, C.-M.

2008-09-01

This work is a study of phase transformation in (001)-cut Pb(Fe1/2Nb1/2)1-xTixO3 (x =48%) single crystals by means of dielectric permittivity, domain structure, and in situ x-ray diffraction. A first-order T(TNT)-C(TNT) phase transition was observed at the Curie temperature TC≅518 K upon zero-field heating. T, TNT, and C are tetragonal, tetragonal nanotwin, and cubic phases, respectively. T(TNT) and C(TNT) indicate that minor TNT domains reside in the T and C matrices. Nanotwins, which can cause broad diffraction peak, remain above TC≅518 K and give an average microscopic cubic symmetry in the polarizing microscopy. Colossal dielectric permittivity (>104) was observed above room temperature with strong frequency dispersion. This study suggests that nanotwins can play an important role in relaxor ferroelectric crystals while phase transition takes place. The Fe ion is a potential candidate as a B-site dopant for enhancing dielectric permittivity.

Magnetotransport properties of microstructured AlCu2Mn Heusler alloy thin films in the amorphous and crystalline phase

NASA Astrophysics Data System (ADS)

Barzola-Quiquia, José; Stiller, Markus; Esquinazi, Pablo D.; Quispe-Marcatoma, Justiniano; Häussler, Peter

2018-06-01

We have studied the resistance, magnetoresistance and Hall effect of AlCu2Mn Heusler alloy thin films prepared by flash evaporation on substrates cooled at 4He liquid temperature. The as-prepared samples were amorphous and were annealed stepwise to induce the transformation to the crystalline phase. The amorphous phase is metastable up to above room temperature and the transition to the crystalline phase was observed by means of resistance measurements. Using transmission electron microscopy, we have determined the structure factor S (K) and the pair correlation function g (r) , both results indicate that amorphous AlCu2Mn is an electronic stabilized phase. The X-ray diffraction of the crystallized film shows peaks corresponding to the well ordered L21 phase. The resistance shows a negative temperature coefficient in both phases. The magnetoresistance (MR) is negative in both phases, yet larger in the crystalline state compared to the amorphous one. The magnetic properties were studied further by anomalous Hall effect measurements, which were present in both phases. In the amorphous state, the anomalous Hall effect disappears at temperatures below 175 K and is present up to above room temperature in the case of crystalline AlCu2Mn.

Phase transition in the (Li 0.5-( x/2) K 0.5-( x/2) Cs x) 2SO 4 system

NASA Astrophysics Data System (ADS)

Hamed, A. E.; El-Aziz, Y. M. Abd.; Madi, N. K.; Kassem, M. E.

1995-12-01

Phase transition in the (Li 0.5-( x/2) K 0.5-( x/2) Cs x) 2SO 4 system was studied by measuring the specific heat at constant pressure, C p, as a function of temperature in the temperature range 300-800 K. For non-zero values of X ( X = 0.2%, 0.5%, 1% and 2%) the critical behaviour of the phase transition was found to change considerably compared with that of X = 0 or pure LiKSO 4. The observed change in the phase transition with increase of Cs 2SO 4 content ( X) was accompanied by a decrease in the thermodynamic parameters: the value of the specific heat at the transition point (Δ C P) max, the transition temperature, T1, and the value of the energy of ordering. The results were interpreted within the Landau thermodynamic theory of the phase transition.

Phase I study of 6-diazo-5-oxo-L-norleucine (DON).

PubMed

Sklaroff, R B; Casper, E S; Magill, G B; Young, C W

1980-01-01

We conducted a phase I study of 6-diazo-5-oxo-L-norleucine given iv on a twice weekly schedule. Twenty-six evaluable patients received 31 courses of the drug. Doses ranged from 100 to 500 mg/m2. Nausea with vomiting was the dose-limiting toxic effect, transient thrombocytopenia was seen frequently, and mucositis occurred in 39% of the patients. No definite therapeutic responses were observed in 18 patients with measurable lesions. The recommended dose for phase II studies is 200-300 mg/m2 iv twice weekly.

HIV/AIDS Clinical Trials

MedlinePlus

... Participants Studies with Female Participants What's this? Age Group: What's this? Child (birth-17) Adult (18-65) Senior (66+) Phase: What's this? Early Phase 1 Phase 1 Phase 2 Phase 3 Phase 4 Funded By: What's this? NIH Other U.S. Federal ...

Benefits of smart pumps for automated changeovers of vasoactive drug infusion pumps: a quasi-experimental study.

PubMed

Cour, M; Hernu, R; Bénet, T; Robert, J M; Regad, D; Chabert, B; Malatray, A; Conrozier, S; Serra, P; Lassaigne, M; Vanhems, P; Argaud, L

2013-11-01

Manual changeover of vasoactive drug infusion pumps (CVIP) frequently lead to haemodynamic instability. Some of the newest smart pumps allow automated CVIP. The aim of this study was to compare automated CVIP with manual 'Quick Change' relays. We performed a prospective, quasi-experimental study, in a university-affiliated intensive care unit (ICU). All adult patients receiving continuous i.v. infusion of vasoactive drugs were included. CVIP were successively performed manually (Phase 1) and automatically (Phase 2) during two 6-month periods. The primary endpoint was the frequency of haemodynamic incidents related to the relays, which were defined as variations of mean arterial pressure >15 mm Hg or heart rate >15 bpm. The secondary endpoints were the nursing time dedicated to relays and the number of interruptions in care because of CVIP. A multivariate mixed effects logistic regression was fitted for analytic analysis. We studied 1329 relays (Phase 1: 681, Phase 2: 648) from 133 patients (Phase 1: 63, Phase 2: 70). Incidents related to CVIP decreased from 137 (20%) in Phase 1 to 73 (11%) in Phase 2 (P<0.001). Automated relays were independently associated with a 49% risk reduction of CVIP-induced incidents (adjusted OR=0.51, 95% confidence interval 0.34-0.77, P=0.001). Time dedicated to the relays and the number of interruptions in care to manage CVIP were also significantly reduced with automated relays vs manual relays (P=0.001). These results demonstrate the benefits of automated CVIP using smart pumps in limiting the frequency of haemodynamic incidents related to relays and in reducing the nursing workload.

Phase transformations in the reaction cell of TiNi-based sintered systems

NASA Astrophysics Data System (ADS)

Artyukhova, Nadezhda; Anikeev, Sergey; Yasenchuk, Yuriy; Chekalkin, Timofey; Gunther, Victor; Kaftaranova, Maria; Kang, Ji-Hoon; Kim, Ji-Soon

2018-05-01

The present work addresses the structural-phase state changes of porous TiNi-based compounds fabricated by reaction sintering (RS) of Ti and Ni powders with Co, Mo, and no additives introduced. The study also emphasizes the features of a reaction cell (RC) during the transition from the solid- to liquid-phase sintering. Mechanisms of phase transformations occurring in the solid phase, involving the low-melting Ti2Ni phase within the RC, have been highlighted. Also, the intermediate Ti2Ni phase had a crucial role to provide both the required RS behavior and modified phase composition of RS samples, and besides, it is found to be responsible for the near-equiatomic TiNi saturation of the melt. Both cobalt and molybdenum additives are shown to cause additional structuring of the transition zone (TZ) at the Ti2Ni‑TiNi interface and broadening of this zone. The impact of Co and Mo on the Ti2Ni phase is evident through fissuring of this phase layer, which is referred to solidified stresses increased in the layer due to post-alloying defects in the structure.

A study of the phase transition behaviour of [(NH4)0.63Li0.37]2TeBr6

NASA Astrophysics Data System (ADS)

Karray, R.; Linda, D.; Van Der Lee, A.; Ben Salah, A.; Kabadou, A.

2012-02-01

The mixed hexabromotellurate [(NH4)0.63Li0.37]2TeBr6, presenting at room temperature a K2PtCl6-type structure with space group Fm bar 3 m, exhibits three anomalies at 195, 395 and 498 K in the differential scanning calorimetry diagram. Different techniques: dielectric investigation, High-temperature X-ray powder diffraction and infrared spectroscopic study, in the range temperature (300-470) K are applied to explore the phase transition around 395 K. Combining XRD, dielectric and differential scanning calorimetry (DSC) results, no phase transition leading to a super-ionic conductivity phase is found. At high temperature, [(NH4)0.63Li0.37]2TeBr6 is characterized by a medium conductivity σ453≈ 10-4 Ω-1m-1.

Train stimulation of parallel fibre to Purkinje cell inputs reveals two populations of synaptic responses with different receptor signatures

PubMed Central

Devi, Suma Priya Sudarsana; Howe, James R.

2016-01-01

Key points Purkinje cells of the cerebellum receive ∼180,000 parallel fibre synapses, which have often been viewed as a homogeneous synaptic population and studied using single action potentials.Many parallel fibre synapses might be silent, however, and granule cells in vivo fire in bursts. Here, we used trains of stimuli to study parallel fibre inputs to Purkinje cells in rat cerebellar slices.Analysis of train EPSCs revealed two synaptic components, phase 1 and 2. Phase 1 is initially large and saturates rapidly, whereas phase 2 is initially small and facilitates throughout the train. The two components have a heterogeneous distribution at dendritic sites and different pharmacological profiles.The differential sensitivity of phase 1 and phase 2 to inhibition by pentobarbital and NBQX mirrors the differential sensitivity of AMPA receptors associated with the transmembrane AMPA receptor regulatory protein, γ‐2, gating in the low‐ and high‐open probability modes, respectively. Abstract Cerebellar granule cells fire in bursts, and their parallel fibre axons (PFs) form ∼180,000 excitatory synapses onto the dendritic tree of a Purkinje cell. As many as 85% of these synapses have been proposed to be silent, but most are labelled for AMPA receptors. Here, we studied PF to Purkinje cell synapses using trains of 100 Hz stimulation in rat cerebellar slices. The PF train EPSC consisted of two components that were present in variable proportions at different dendritic sites: one, with large initial EPSC amplitude, saturated after three stimuli and dominated the early phase of the train EPSC; and the other, with small initial amplitude, increased steadily throughout the train of 10 stimuli and dominated the late phase of the train EPSC. The two phases also displayed different pharmacological profiles. Phase 2 was less sensitive to inhibition by NBQX but more sensitive to block by pentobarbital than phase 1. Comparison of synaptic results with fast glutamate applications to recombinant receptors suggests that the high‐open‐probability gating mode of AMPA receptors containing the auxiliary subunit transmembrane AMPA receptor regulatory protein γ‐2 makes a substantial contribution to phase 2. We argue that the two synaptic components arise from AMPA receptors with different functional signatures and synaptic distributions. Comparisons of voltage‐ and current‐clamp responses obtained from the same Purkinje cells indicate that phase 1 of the EPSC arises from synapses ideally suited to transmit short bursts of action potentials, whereas phase 2 is likely to arise from low‐release‐probability or ‘silent’ synapses that are recruited during longer bursts. PMID:27094216

Influence of the choice of gas-phase mechanism on predictions of key gaseous pollutants during the AQMEII phase-2 intercomparison

EPA Science Inventory

The formulations of tropospheric gas-phase chemistry (“mechanisms”)used in the regional-scale chemistry-transport models participating in theAir Quality Modelling Evaluation International Initiative (AQMEII) Phase2 are intercompared by the means of box model studies. Simulations ...

The association between lunar phase and intracranial aneurysm rupture: Myth or reality? Own data and systematic review.

PubMed

Bunevicius, Adomas; Gendvilaite, Agne; Deltuva, Vytenis Pranas; Tamasauskas, Arimantas

2017-05-19

It is a common belief in medical community that lunar phases have an impact on human health. A growing body of evidence indicates that lunar phases can predict the risk to develop acute neurological and vascular disorders. The goal of present report was to present our institution data and to perform systematic review of studies examining the association of intracranial aneurysm rupture with moon phases. We identified all patients admitted to our department for ruptured intracranial aneurysms in a period between November, 2011 and December, 2014. Patients with a known aneurysm rupture date were included. Lunar phases were determined by dividing lunar month (29.5 days) into eight equal parts, i.e., new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter and waning crescent. A systematic literature review was undertaken to identify studies that evaluated the association of lunar phases with the incident of intracranial aneurysm rupture. One hundred and eighty-six patients (62 men and 124 women, median age 56 years) were admitted to our department for treatment of ruptured intracranial aneurysms. The rate of intracranial aneurysm rupture was equally distributed across all phases of the lunar cycle (X 2 [7; 185] = 12.280, p = 0.092). We identified three studies that evaluated the association between incident intracranial aneurysm rupture and lunar phases with a total of 1483 patients. One study from Lebanon found that the incidence rate of intracranial aneurysm rupture was statistically significantly greater during the new moon phase (25% cases), relative to the other seven lunar phases (p < 0.001). Two subsequent studies from Austria and Germany in larger patient samples (n = 717 and n = 655, respectively) did not find an association between lunar phases and intracranial aneurysm rupture (p-values of 0.84 and 0.97, respectively). When analyzing all four studies together, we did not find an association between lunar phases and incidence of intracranial aneurysm rupture (X 2 [1668; 7] = 2.080, p = 0.955). Moon phases are not associated with incidence of intracranial aneurysm rupture. Studies investigating the association of intracranial aneurysm rupture with lunar illumination defined using more sensitive approaches are encouraged.

Changes in School Food Preparation Methods Result in Healthier Cafeteria Lunches in Elementary Schools.

PubMed

Behrens, Timothy K; Liebert, Mina L; Peterson, Hannah J; Howard Smith, Jennifer; Sutliffe, Jay T; Day, Aubrey; Mack, Jodi

2018-05-01

The purpose of this study is to examine the impact of a districtwide food best practices and preparation changes in elementary schools lunches, implemented as part of the LiveWell@School childhood obesity program, funded by LiveWell Colorado/Kaiser Permanente Community Health Initiative. Longitudinal study examining how school changes in best practices for food preparation impacted the types of side items offered from 2009 to 2015 in elementary school cafeterias in a high-need school district in southern Colorado. Specifically, this study examined changes in side items (fruits, vegetables, potatoes, breads, and desserts). In Phase 1 (2009-2010), baseline data were collected. During Phase 2 (2010-2011), breaded and processed foods (e.g., frozen nuggets, pre-packaged pizza) were removed and school chefs were trained on scratch cooking methods. Phase 3 (2011-2012) saw an increased use of fresh/frozen fruits and vegetables after a new commodity order. During Phase 4 (2013-2015), chef consulting and training took place. The frequency of side offerings was tracked across phases. Analyses were completed in Fall 2016. Because of limited sample sizes, data from Phases 2 to 4 (intervention phases) were combined for potatoes and desserts. Descriptive statistics were calculated. After adjusting for length of time for each phase, Pearson chi-square tests were conducted to examine changes in offerings of side items by phase. Fresh fruit offerings increased and canned fruit decreased in Phases 1-4 (p=0.001). A significant difference was observed for vegetables (p=0.001), with raw and steamed vegetables increasing and canned vegetables decreasing from Phase 1 to 4. Fresh potatoes (low in sodium) increased and fried potatoes (high in sodium) decreased from Phase 1 to Phases 2-4 (p=0.001). Breads were eliminated entirely in Phase 2, and dessert changes were not significant (p=0.927). This approach to promoting healthier lunch sides is a promising paradigm for improving elementary cafeteria food offerings. This article is part of a supplement entitled Building Thriving Communities Through Comprehensive Community Health Initiatives, which is sponsored by Kaiser Permanente, Community Health. Copyright © 2018 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Phase transition in lithium garnet oxide ionic conductors Li7La3Zr2O12: The role of Ta substitution and H2O/CO2 exposure

NASA Astrophysics Data System (ADS)

Wang, Yuxing; Lai, Wei

2015-02-01

High Li-content lithium garnet oxides are promising solid electrolyte materials for lithium batteries. Being the highest Li-content lithium garnet oxides, Li7La3Zr2O12 has been reported to crystallize in either the tetragonal or cubic phase with no consensus on the exact conditions under which these two phases are formed, which may be due to unintentional Al contamination and air exposure. In this work, the effects of Ta substitution and H2O/CO2 exposure have been studied under Al-contamination free conditions with minimal air exposure. We showed that 1) the Ta-substitution induced phase transition occurred through a two-phase mechanism and a minimum 0.6 mol of Ta substitution to Zr is needed to stabilize the cubic phase; 2) H2O and CO2 can individually induce the tetragonal-cubic phase transition in Li7La3Zr2O12 through proton exchange and Li extraction, respectively, which can have great influence on the transport properties of Li7La3Zr2O12.

Antinociceptive effects of imidazoline I2 receptor agonists in the formalin test in rats

PubMed Central

Thorn, David A; Qiu, Yanyan; Zhang, Yanan; Li, Jun-Xu

2015-01-01

The imidazoline I2 receptor is an emerging drug target for analgesics. This study extended previous studies by examining the antinociceptive effects of three I2 receptor agonists (2-BFI, BU224 and CR4056) in the formalin test. The receptor mechanisms and anatomical mediation of I2 receptor agonist-induced antinociception were also examined. Formalin-induced flinching responses (2%, 50µl) were quantified after treatment with I2 receptor agonists alone or in combination with the I2 receptor antagonist idazoxan. Anatomical mediation was studied by locally administering 2-BFI into the plantar surface or into the right lateral ventricle via cannulae (i.c.v). The locomotor activity was also examined after central (i.c.v.) administration of 2-BFI. 2-BFI (1–10 mg/kg, i.p.) and BU224 (1–10 mg/kg, i.p.) attenuated the spontaneous flinching response observed during 10 min (phase 1) and 20–60 min (phase 2) following formalin treatment, while CR4056 (1–32 mg/kg, i.p.) only decreased phase 2 flinching response. The I2 receptor antagonist idazoxan attenuated the antinociceptive effects of 2-BFI and BU224 during phase 1, but not phase 2. Peripheral administration of 2-BFI (1–10 mg/kg, i.pl) to the hindpaw of rats had no antinociceptive effects. In contrast, centrally delivered 2-BFI (10–100 µg, i.c.v.) dose-dependently attenuated phase 1 and phase 2 flinching at doses that did not reduce the locomotor activity. Together, these data revealed the differential antinociceptive effects of I2 receptor agonists and the differential antagonism profiles by idazoxan, suggesting the involvement of different I2 receptor subtypes in reducing different phases of formalin-induced pain-like behaviors. In addition, the results also suggest the central mediation of I2 receptor agonist-induced antinociceptive actions. PMID:26599907

Impact of Pharmacy Practice Model Expansion on Pharmacokinetic Services: Optimization of Vancomycin Dosing and Improved Patient Safety.

PubMed

Han, Zhe; Pettit, Natasha N; Landon, Emily M; Brielmaier, Benjamin D

2017-04-01

Background: The impact of pharmacy interventions on optimizing vancomycin therapy has been described, however interventions vary among studies and the most optimal pharmacy practice model (PPM) for pharmacokinetic (PK) services has not been established. Objective: The purpose of this study is to demonstrate the value of 24 hours a day, 7 days a week (24/7) PK services. Methods: New PK services were implemented in 2 phases with institutional PPM expansion. Phase 1 included universal monitoring by pharmacists with recommendations made to prescribers during business hours. Phase 2 expanded clinical pharmacists' coverage to 24/7 and provided an optional 24/7 pharmacist-managed PK consult service. We compared vancomycin therapeutic trough attainment, dosing, and clinical and safety outcomes between phases 1 and 2 in adult inpatients receiving therapeutic intravenous vancomycin. Results. One hundred and fifty patients were included in each phase. Phase 2 had a greater proportion of vancomycin courses with therapeutic initial trough concentrations (27.5% vs 46.1%; p = 0.002), higher initial trough concentrations (10.9 mcg/mL vs 16.4 mcg/mL; p < 0.001), and optimized initial vancomycin dosing (13.5 mg/kg vs 16.2 mg/kg; p < 0.001). Phase 2 also saw significant reduction in the incidence of vancomycin-associated nephrotoxicity (21.1% vs 11.7%; p = 0.038). Dose optimization and improvement in initial target trough attainment were most notable among intensive care unit (ICU) patients. Conclusions. Our study demonstrated that 24/7 PK services implemented with institutional PPM expansion optimized vancomycin target trough attainment and improved patient safety.

Function of the Pyruvate Oxidase-Lactate Oxidase Cascade in Interspecies Competition between Streptococcus oligofermentans and Streptococcus mutans

PubMed Central

Liu, Lei

2012-01-01

Complex interspecies interactions occur constantly between oral commensals and the opportunistic pathogen Streptococcus mutans in dental plaque. Previously, we showed that oral commensal Streptococcus oligofermentans possesses multiple enzymes for H2O2 production, especially lactate oxidase (Lox), allowing it to out-compete S. mutans. In this study, through extensive biochemical and genetic studies, we identified a pyruvate oxidase (pox) gene in S. oligofermentans. A pox deletion mutant completely lost Pox activity, while ectopically expressed pox restored activity. Pox was determined to produce most of the H2O2 in the earlier growth phase and log phase, while Lox mainly contributed to H2O2 production in stationary phase. Both pox and lox were expressed throughout the growth phase, while expression of the lox gene increased by about 2.5-fold when cells entered stationary phase. Since lactate accumulation occurred to a large degree in stationary phase, the differential Pox- and Lox-generated H2O2 can be attributed to differential gene expression and substrate availability. Interestingly, inactivation of pox causes a dramatic reduction in H2O2 production from lactate, suggesting a synergistic action of the two oxidases in converting lactate into H2O2. In an in vitro two-species biofilm experiment, the pox mutant of S. oligofermentans failed to inhibit S. mutans even though lox was active. In summary, S. oligofermentans develops a Pox-Lox synergy strategy to maximize its H2O2 formation so as to win the interspecies competition. PMID:22287002

Low Temperature X-Ray Diffraction Study on CaFe2As2

NASA Astrophysics Data System (ADS)

Huyan, Shuyuan; Deng, Liangzi; Wu, Zheng; Zhao, Kui; Lv, Bing; Xue, Yiyu; Chu, Ching-Wu; B. Lv Collaboration; HPLT (Paul C. W. Chu) Team

For undoped CaFe2As2 single crystals, we observed that utilizing thermal treatments could stabilize two pure tetragonal phases PI and PII. Both phases are non-superconducting, while the superconductivity with a Tc up to 25 K can be induced through proper thermal treatment. Room temperature X-ray studies suggest that the origin of superconductivity arises from the interface of the mesoscopically stacked layers of PI and PII. To further investigate, a systematic low temperature X-ray study was conducted over a series of thermal treated CaFe2As2 single crystals. From which, we observed the phase aggregation of PI and PII upon cooling, more importantly, an ordered stacking structure exists at low temperature, which closely related to superconducting volume fraction and the ratio of PI and PII. These results further support the proposal of interface-enhanced superconductivity in undoped CaFe2As2. UT Dallas

Effect of the magnetic field on the supramolecular structure of chiral smectic C phases: (2)H NMR studies.

PubMed

Domenici, Valentina; Marini, Alberto; Veracini, Carlo Alberto; Zhang, Jing; Dong, Ronald Y

2007-12-21

We present a theoretical and experimental (2)H NMR study of the effect of external magnetic fields on the supramolecular organization of chiral smectic liquid-crystalline mesophases, such as SmC* and re-entrant SmC*. Three experimental cases in which the supramolecular helical structure of the smectic C* phase is unwound by a magnetic field (H), parallel to the helical axes of this phase, are discussed in detail. Unwinding of the helical structure is described by using a theoretical model based on the Landau-de Gennes theory, which allows us to explain the transition temperatures among the SmA, SmC*, and uSmC* phases. The energy-density behavior in the vicinity of the transitions and the value of the critical magnetic field H(C) for unwinding the helical structure are discussed by applying this model to three ferroelectric smectogens (MBHB, 11EB1M7, ZLL7/*), which are studied by (2)H NMR spectroscopy at different magnetic fields (from 2.4 to 9.4 Tesla). Furthermore, the tilt angle of the three smectogens in the SmC* phase has been directly evaluated, for the first time, by comparing the quadrupolar splittings at different magnetic fields. In one case, (2)H NMR angular measurements are used to obtain the tilt angle in the re-entrant smectic C phase.

Study of nickel hydroxide electrodes. 2: Oxidation products of nickel (2) hydroxides

NASA Technical Reports Server (NTRS)

Bode, H.; Demelt, K.; White, J.

1986-01-01

Pure phases of some oxidized Ni oxides were prepared galvanimetrically with the Ni(2) hydroxide electrode of an alkaline battery. The crystallographic data of these phases, their chemical behavior, and conditions of transition were studied.

Study of the thermodynamic phase of hydrometeors in convective clouds in the Amazon Basin

NASA Astrophysics Data System (ADS)

Ferreira, W. C.; Correia, A. L.; Martins, J.

2012-12-01

Aerosol-cloud interactions are responsible for large uncertainties in climatic models. One key fator when studying clouds perturbed by aerosols is determining the thermodynamic phase of hydrometeors as a function of temperature or height in the cloud. Conventional remote sensing can provide information on the thermodynamic phase of clouds over large areas, but it lacks the precision needed to understand how a single, real cloud evolves. Here we present mappings of the thermodynamic phase of droplets and ice particles in individual convective clouds in the Amazon Basin, by analyzing the emerging infrared radiance on cloud sides (Martins et al., 2011). In flights over the Amazon Basin with a research aircraft Martins et al. (2011) used imaging radiometers with spectral filters to record the emerging radiance on cloud sides at the wavelengths of 2.10 and 2.25 μm. Due to differential absorption and scattering of these wavelengths by hydrometeors in liquid or solid phases, the intensity ratio between images recorded at the two wavelengths can be used as proxy to the thermodynamic phase of these hydrometeors. In order to analyze the acquired dataset we used the MATLAB tools package, developing scripts to handle data files and derive the thermodynamic phase. In some cases parallax effects due to aircraft movement required additional data processing before calculating ratios. Only well illuminated scenes were considered, i.e. images acquired as close as possible to the backscatter vector from the incident solar radiation. It's important to notice that the intensity ratio values corresponding to a given thermodynamic phase can vary from cloud to cloud (Martins et al., 2011), however inside the same cloud the distinction between ice, water and mixed-phase is clear. Analyzing histograms of reflectance ratios 2.10/2.25 μm in selected cases, we found averages typically between 0.3 and 0.4 for ice phase hydrometeors, and between 0.5 and 0.7 for water phase droplets, consistent with the findings in Martins et al., (2011). Figure 1 shows an example of thermodynamic phase classification obtained with this technique. These experimental results can potentially be used in fast derivations of thermodynamic phase mappings in deep convective clouds, providing useful information for studies regarding aerosol-cloud interactions. Image of the ratio of reflectances at 2.10/2.25μm

Effect of Massage Therapy on Labor Pain Reduction in Primiparous Women: A Systematic Review and Meta-analysis of Randomized Controlled Clinical Trials in Iran.

PubMed

Ranjbaran, Mehdi; Khorsandi, Maahboobeh; Matourypour, Pegah; Shamsi, Mohsen

2017-01-01

Pain is a common experience for women during labor. Therefore, pain relief care for mothers during labor is very important. This meta-analysis was conducted to evaluate the efficacy of massage therapy on labor pain reduction in primiparous women. In this meta-analysis, the databases of Web of Knowledge, PubMed, Scopus, Cochrane, Iranmedex, Scientific Information Database (SID), and Magiran were searched for published articles in English and Persian language up to January 2016. Among the studies, with regard to the inclusion and exclusion criteria, 10 studies were selected. Data were analyzed by using Stata software version 11, and standard mean difference (SMD) of effects of massage therapy was calculated. The heterogeneity among studies was evaluated by the Chi-square based Q-test and I 2 statistics. The results of Chi-square based on Q-test and I 2 statistics showed heterogeneity among studies in the latent phase ( Q = 63.52, P value < 0.001 and I 2 = 87.4%), active phase ( Q = 26.42, P value < 0.001, and I 2 = 77.3%), and transitional phase ( Q = 104.84, P value <0.001, and I 2 = 95.2%). Results showed that massage therapy reduces labor pain in the latent phase (SMD = -1.23, 95% CI: -1.73 to -0.74), active phase (SMD = -1.59, 95% CI: -2.06 to -1.12), and transitional phase (SMD = -1.90, 95% CI: -3.09 to -0.71). This study provides valid evidence for the effect of massage therapy in Iran for labor pain relief. Therefore, the use of massage therapy can be recommended in the primiparous women.

Effect of Nb on magnetic and mechanical properties of TbDyFe alloys

NASA Astrophysics Data System (ADS)

Wang, Naijuan; Liu, Yuan; Zhang, Huawei; Chen, Xiang; Li, Yanxiang

2018-03-01

The intrinsic brittleness in giant magnetostrictive material TbDyFe alloy has devastating influence on the machinability and properties of the alloy, thus affecting its applications. The purpose of this paper is to study the mechanical properties of the TbDyFe alloy by alloying with Nb element. The samples (Tb0.3Dy0.7)xFe2xNby (y = 0, 0.01, 0.04, 0.07, 0.1; 3x + y = 1) were melted in an arc melting furnace under high purity argon atmosphere. The microstructure, magnetostrictive properties and mechanical performance of the alloys were studied systematically. The results showed that NbFe2 phases were observed in the alloys with the addition of Nb. Moreover, both the NbFe2 phases and rare earth (RE)-rich phases were increased with the increasing of Nb element. The mechanical properties results revealed that the fracture toughness of the alloy with the addition of Nb enhanced 1.5-5 times of the Nb-free alloy. Both the NbFe2 phase and the RE-rich phase had the ability to prevent crack propagation, so that they can strengthen the REFe2 body. However, NbFe2 phase is a paramagnetic phase, which can reduce the magnetostrictive properties of the alloy by excessive precipitation.

2D Larkin-Imry-Ma state of deformed ABM phase of superfluid 3He in ``ordered'' aerogel

NASA Astrophysics Data System (ADS)

Dmitriev, Vladimir; Senin, Andrey; Yudin, Alexey

2014-03-01

We report NMR studies of high temperature superfluid phase of 3He in so called ``ordered'' aerogel1 which strands are almost parallel to each other. Previously, it was found that the NMR properties of this phase depend on whether it is obtained on cooling from the normal phase or on warming from the low temperature phase2. These two types of high temperature phase (called as ESP1 and ESP2) correspond to Anderson-Brinkman-Morel (ABM) phase with large polar distortion and with orbital vector being in 2D Larkin-Imry-Ma (LIM) state. Here we present results which show that the observed difference in NMR signatures of the ESP1 and the ESP2 states is due to that the corresponding 2D LIM states can be anisotropic. In the ESP1 phase the anisotropy is absent or small, while in the ESP2 phase the anisotropy is large. NMR data have allowed us to estimate values of these anisotropies.

Electron-beam-irradiation-induced crystallization of amorphous solid phase change materials

NASA Astrophysics Data System (ADS)

Zhou, Dong; Wu, Liangcai; Wen, Lin; Ma, Liya; Zhang, Xingyao; Li, Yudong; Guo, Qi; Song, Zhitang

2018-04-01

The electron-beam-irradiation-induced crystallization of phase change materials in a nano sized area was studied by in situ transmission electron microscopy and selected area electron diffraction. Amorphous phase change materials changed to a polycrystalline state after being irradiated with a 200 kV electron beam for a long time. The results indicate that the crystallization temperature strongly depends on the difference in the heteronuclear bond enthalpy of the phase change materials. The selected area electron diffraction patterns reveal that Ge2Sb2Te5 is a nucleation-dominated material, when Si2Sb2Te3 and Ti0.5Sb2Te3 are growth-dominated materials.

X-ray diffraction and spectroscopy study of nano-Eu 2O 3 structural transformation under high pressure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Zhenhai; Wang, Qinglin; Ma, Yanzhang

Nanoscale materials exhibit properties that are quite distinct from those of bulk materials because of their size restricted nature. Here, we investigated the high-pressure structural stability of cubic (C-type) nano-Eu2O3 using in situ synchrotron X-ray diffraction (XRD), Raman and luminescence spectroscopy, and impedance spectra techniques. Our high-pressure XRD experimental results revealed a pressure-induced structural phase transition in nano-Eu2O3 from the C-type phase (space group: Ia-3) to a hexagonal phase (A-type, space group: P-3m1). Our reported transition pressure (9.3 GPa) in nano-Eu2O3 is higher than that of the corresponding bulk-Eu2O3 (5.0 GPa), which is contrary to the preceding reported experimental result.more » After pressure release, the A-type phase of Eu2O3 transforms into a new monoclinic phase (B-type, space group: C2/m). Compared with bulk-Eu2O3, C-type and A-type nano-Eu2O3 exhibits a larger bulk modulus. Our Raman and luminescence findings and XRD data provide consistent evidence of a pressure-induced structural phase transition in nano-Eu2O3. To our knowledge, we have performed the first high-pressure impedance spectra investigation on nano-Eu2O3 to examine the effect of the structural phase transition on its transport properties. We propose that the resistance inflection exhibited at ~12 GPa results from the phase boundary between the C-type and A-type phases. Besides, we summarized and discussed the structural evolution process by the phase diagram of lanthanide sesquioxides (Ln2O3) under high pressure.« less

Detection of Cu2Zn5SnSe8 and Cu2Zn6SnSe9 phases in co-evaporated Cu2ZnSnSe4 thin-films

NASA Astrophysics Data System (ADS)

Schwarz, Torsten; Marques, Miguel A. L.; Botti, Silvana; Mousel, Marina; Redinger, Alex; Siebentritt, Susanne; Cojocaru-Mirédin, Oana; Raabe, Dierk; Choi, Pyuck-Pa

2015-10-01

Cu2ZnSnSe4 thin-films for photovoltaic applications are investigated using combined atom probe tomography and ab initio density functional theory. The atom probe studies reveal nano-sized grains of Cu2Zn5SnSe8 and Cu2Zn6SnSe9 composition, which cannot be assigned to any known phase reported in the literature. Both phases are considered to be metastable, as density functional theory calculations yield positive energy differences with respect to the decomposition into Cu2ZnSnSe4 and ZnSe. Among the conceivable crystal structures for both phases, a distorted zinc-blende structure shows the lowest energy, which is a few tens of meV below the energy of a wurtzite structure. A band gap of 1.1 eV is calculated for both the Cu2Zn5SnSe8 and Cu2Zn6SnSe9 phases. Possible effects of these phases on solar cell performance are discussed.

Low-frequency phase diagram of irradiated graphene and a periodically driven spin-1/2 X Y chain

NASA Astrophysics Data System (ADS)

Mukherjee, Bhaskar; Mohan, Priyanka; Sen, Diptiman; Sengupta, K.

2018-05-01

We study the Floquet phase diagram of two-dimensional Dirac materials such as graphene and the one-dimensional (1D) spin-1/2 X Y model in a transverse field in the presence of periodic time-varying terms in their Hamiltonians in the low drive frequency (ω ) regime where standard 1 /ω perturbative expansions fail. For graphene, such periodic time-dependent terms are generated via the application of external radiation of amplitude A0 and time period T =2 π /ω , while for the 1D X Y model, they result from a two-rate drive protocol with a time-dependent magnetic field and nearest-neighbor couplings between the spins. Using the adiabatic-impulse method, whose predictions agree almost exactly with the corresponding numerical results in the low-frequency regime, we provide several semianalytic criteria for the occurrence of changes in the topology of the phase bands (eigenstates of the evolution operator U ) of such systems. For irradiated graphene, we point out the role of the symmetries of the instantaneous Hamiltonian H (t ) and the evolution operator U behind such topology changes. Our analysis reveals that at low frequencies, topology changes of irradiated graphene phase bands may also happen at t =T /3 and2 T /3 (apart from t =T ) showing the necessity of analyzing the phase bands of the system for obtaining its phase diagrams. We chart out the phase diagrams at t =T /3 ,2 T /3 ,and T , where such topology changes occur, as a function of A0 and T using exact numerics, and compare them with the prediction of the adiabatic-impulse method. We show that several characteristics of these phase diagrams can be analytically understood from results obtained using the adiabatic-impulse method and point out the crucial contribution of the high-symmetry points in the graphene Brillouin zone to these diagrams. We study the modes that can appear at the edges of a finite-width strip of graphene and show that the change in the number of such modes agrees with the change in the Chern number of bulk graphene as we go across a phase band crossing. Finally, we study the 1D X Y model with a two-rate driving protocol. After studying the symmetries of the system, we use the adiabatic-impulse method and exact numerics to study its phase band crossing which occurs at t =T /2 and k =π /2 . We also study the end modes generated by such a drive and show that there can be anomalous modes whose Floquet eigenvalues are not equal to ±1 . We suggest experiments to test our theory.

The optical gap in VO2 insulating phases is dominated by Coulomb repulsion

NASA Astrophysics Data System (ADS)

Hendriks, Christopher; Walter, Eric; Krakauer, Henry; Huffman, Tyler; Qazilbash, Mumtaz

Under doping, tensile strain or heating, vanadium dioxide (VO2) transforms from an insulating monoclinic (M1) to a metallic rutile (R) phase, progressing through intermediate insulating triclinic (T) and magnetic (M2) phases. Broadband optical spectroscopy data have been obtained on the T and M2 phases in the same sample. While only half the V atoms are dimerized in M2 compared to M1 and T, the measured optical gap is essentially unaltered by the first-order structural phase transition between them. Moreover, the optical interband features in the T and M2 phases are remarkably similar to those previously observed in the well-studied M1 phase. This shows that the electronic structure is insensitive to the lattice structure. Our ab-initio HSE optical conductivity calculations on the insulating phases of VO2 are in excellent agreement with the experimental measurements. We will discuss the choice of α, the fraction of exact exchange. As the energy gap is insensitive to the different lattice structures of the three insulating phases, we rule out Peierls effects as the dominant contributor to the opening of the gap. Rather, the energy gap arises from intra-atomic Coulomb correlations. Supported by ONR.

SH-2F LAMPS Instructional Systems Development: Phase II. Final Report.

ERIC Educational Resources Information Center

Gibbons, Andrew S.; Hymes, Jonah P.

This project was one of four aircrew training development projects in a continuing study of the methodology, effectiveness, and resource requirements of the Instructional Systems Development (ISD) process. This report covers the Phase II activities of a two-phase project for the development of aircrew training for SH-2F anti-submarine warfare…

A controlled trial of universal gloving versus contact precautions for preventing the transmission of multidrug-resistant organisms.

PubMed

Bearman, Gonzalo M L; Marra, Alexandre R; Sessler, Curtis N; Smith, Wally R; Rosato, Adriana; Laplante, Justin K; Wenzel, Richard P; Edmond, Michael B

2007-12-01

Contact precautions are recommended to reduce the transmission of multidrug-resistant organisms. However, the optimal method for control of multidrug-resistant organisms remains unclear. A controlled trial was conducted in a medical intensive care unit. Phase 1 was a 3-month period of standard practice in which patients were placed in contact precautions per Centers for Disease Control and Prevention guidelines. In the second 3 months, phase 2, gloves were required for all patient contact, and no patients were placed in contact precautions. Compliance with contact precautions in phase 1 versus universal gloving in phase 2 was 75.7% versus 87.0%, respectively (P < .001). Hand hygiene compliance before patient care was significantly higher in phase 1 when compared with phase 2 (18.7% vs 11.4%, respectively, P < .001). Hand hygiene compliance after patient care was 57.7% in phase 1 versus 52.5% in phase 2 (P = .011). Nosocomial infection rates per 1000 device-days in phase 1 versus phase 2 were as follows: bloodstream infection, 6.2 versus 14.1, respectively (P < .001); urinary tract infection, 4.3 versus 7.4, respectively (P < .001); and ventilator-associated pneumonia, 0 versus 2.3, respectively (P < .001). There were no differences in vancomycin-resistant enterococci or methicillin-resistant Staphylococcus aureus acquisition in the 2 study phases; however, in both phases, the majority of vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus conversions were clonal. Compliance with universal gloving was significantly greater than compliance with contact precautions. However, greater compliance with hand hygiene was observed in the contact precautions phase. Measures must be in place to both increase and sustain hand hygiene compliance so as to minimize the risk of nosocomial cross transmission before reevaluating the concept of replacing contact precautions with universal gloving.

High pressure studies of A2Mo3O12 negative thermal expansion materials (A2=Al2, Fe2, FeAl, AlGa)

NASA Astrophysics Data System (ADS)

Young, Lindsay; Gadient, Jennifer; Gao, Xiaodong; Lind, Cora

2016-05-01

High pressure powder X-ray diffraction studies of several A2Mo3O12 materials (A2=Al2, Fe2, FeAl, and AlGa) were conducted up to 6-7 GPa. All materials adopted a monoclinic structure under ambient conditions, and displayed similar phase transition behavior upon compression. The initial isotropic compressibility first became anisotropic, followed by a small but distinct drop in cell volume. These patterns could be described by a distorted variant of the ambient pressure polymorph. At higher pressures, a distinct high pressure phase formed. Indexing results confirmed that all materials adopted the same high pressure phase. All changes were reversible on decompression, although some hysteresis was observed. The similarity of the high pressure cells to previously reported Ga2Mo3O12 suggested that this material undergoes the same sequence of transitions as all materials investigated in this paper. It was found that the transition pressures for all phase changes increased with decreasing radius of the A-site cations.

Study of bulk Hafnium oxide (HfO2) under compression

NASA Astrophysics Data System (ADS)

Pathak, Santanu; Mandal, Guruprasad; Das, Parnika

2018-04-01

Hafnium oxide (HfO2) is a technologically important material. This material has K-value of 25 and band gap 5.8 eV. A k value of 25-30 is preferred for a gate dielectric [1]. As it shows good insulating and capacitive properties, HfO2 is being considered as a replacement to SiO2 in microelectronic devices as gate dielectrics. On the other hand because of toughening mechanism due to phase transformation induced by stress field observed in these oxides, HFO2 has been a material of investigations in various configurations for a very long time. However the controversies about phase transition of HfO2 under pressure still exists. High quality synchrotron radiation has been used to study the structural phase transition of HfO2 under pressure.

Mesoscopic structural phase progression in photo-excited VO 2 revealed by time-resolved x-ray diffraction microscopy

DOE PAGES

Zhu, Yi; Cai, Zhonghou; Chen, Pice; ...

2016-02-26

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase seperated regions. The ability to simultanousely track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of- the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO 2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation ismore » initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO 2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, which is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO 2. Lastly, the direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.« less

Mesoscopic structural phase progression in photo-excited VO2 revealed by time-resolved x-ray diffraction microscopy

NASA Astrophysics Data System (ADS)

Zhu, Yi; Cai, Zhonghou; Chen, Pice; Zhang, Qingteng; Highland, Matthew J.; Jung, Il Woong; Walko, Donald A.; Dufresne, Eric M.; Jeong, Jaewoo; Samant, Mahesh G.; Parkin, Stuart S. P.; Freeland, John W.; Evans, Paul G.; Wen, Haidan

2016-02-01

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase separated regions. The ability to simultaneously track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of-the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation is initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, and is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO2. The direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.

Mesoscopic structural phase progression in photo-excited VO2 revealed by time-resolved x-ray diffraction microscopy.

PubMed

Zhu, Yi; Cai, Zhonghou; Chen, Pice; Zhang, Qingteng; Highland, Matthew J; Jung, Il Woong; Walko, Donald A; Dufresne, Eric M; Jeong, Jaewoo; Samant, Mahesh G; Parkin, Stuart S P; Freeland, John W; Evans, Paul G; Wen, Haidan

2016-02-26

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase separated regions. The ability to simultaneously track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of-the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation is initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, and is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO2. The direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.

The structural phases and vibrational properties of Mo1-xWxTe2 alloys

NASA Astrophysics Data System (ADS)

Oliver, Sean M.; Beams, Ryan; Krylyuk, Sergiy; Kalish, Irina; Singh, Arunima K.; Bruma, Alina; Tavazza, Francesca; Joshi, Jaydeep; Stone, Iris R.; Stranick, Stephan J.; Davydov, Albert V.; Vora, Patrick M.

2017-12-01

The structural polymorphism in transition metal dichalcogenides (TMDs) provides exciting opportunities for developing advanced electronics. For example, MoTe2 crystallizes in the 2H semiconducting phase at ambient temperature and pressure, but transitions into the 1T‧ semimetallic phase at high temperatures. Alloying MoTe2 with WTe2 reduces the energy barrier between these two phases, while also allowing access to the T d Weyl semimetal phase. The \\text{M}{{\\text{o}}1-\\text{x}} WxTe2 alloy system is therefore promising for developing phase change memory technology. However, achieving this goal necessitates a detailed understanding of the phase composition in the MoTe2-WTe2 system. We combine polarization-resolved Raman spectroscopy with x-ray diffraction (XRD) and scanning transmission electron microscopy (STEM) to study bulk \\text{M}{{\\text{o}}1-\\text{x}} WxTe2 alloys over the full compositional range x from 0 to 1. We identify Raman and XRD signatures characteristic of the 2H, 1T‧, and T d structural phases that agree with density-functional theory (DFT) calculations, and use them to identify phase fields in the MoTe2-WTe2 system, including single-phase 2H, 1T‧, and T d regions, as well as a two-phase 1T‧  +  T d region. Disorder arising from compositional fluctuations in \\text{M}{{\\text{o}}1-\\text{x}} WxTe2 alloys breaks inversion and translational symmetry, leading to the activation of an infrared 1T‧-MoTe2 mode and the enhancement of a double-resonance Raman process in \\text{2H-M}{{\\text{o}}1-\\text{x}} WxTe2 alloys. Compositional fluctuations limit the phonon correlation length, which we estimate by fitting the observed asymmetric Raman lineshapes with a phonon confinement model. These observations reveal the important role of disorder in \\text{M}{{\\text{o}}1-\\text{x}} WxTe2 alloys, clarify the structural phase boundaries, and provide a foundation for future explorations of phase transitions and electronic phenomena in this system.

Large bond-dimension time-evolution block decimation study of the XXZ quantum spin chains of S = 1/2 and 1

NASA Astrophysics Data System (ADS)

Choi, Hwan Bin; Lee, Ji-Woo

2017-09-01

We study quantum phase transitions of a XXZ spin model with spin S = 1/2 and 1 in one dimension. The XXZ spin chain is one of basic models in understanding various one-dimensional magnetic materials. To study this model, we construct infinite-lattice matrix product state (iMPS), which is a tensor product form for a one-dimensional many-body quantum wave function. By using timeevolution- block-decimation method (TEBD) on iMPS, we obtain the ground states of the XXZ model at zero temperature. This method is very delicate in calculating ground states so that we developed a reliable method of finding the ground state with the dimension of entanglement coefficients up to 300, which is beyond the previous works. By analyzing ground-state energies, half-chain entanglement entropies, and entanglement spectrum, we found the signatures of quantum phase transitions between ferromagnetic phase, XY phase, Haldane phase, and antiferromagnetic phase.

Pressure induced structural phase transition of OsB 2: First-principles calculations

NASA Astrophysics Data System (ADS)

Ren, Fengzhu; Wang, Yuanxu; Lo, V. C.

2010-04-01

Orthorhombic OsB 2 was synthesized at 1000 °C and its compressibility was measured by using the high-pressure X-ray diffraction in a Diacell diamond anvil cell from ambient pressure to 32 GPa [R.W. Cumberland, et al. (2005)]. First-principles calculations were performed to study the possibility of the phase transition of OsB 2. An analysis of the calculated enthalpy shows that orthorhombic OsB 2 can transfer to the hexagonal phase at 10.8 GPa. The calculated results with the quasi-harmonic approximation indicate that this phase transition pressure is little affected by the thermal effect. The calculated phonon band structure shows that the hexagonal P 6 3/ mmc structure (high-pressure phase) is stable for OsB 2. We expect the phase transition can be further confirmed by the experimental work.

VO2 microcrystals as an advanced smart window material at semiconductor to metal transition

NASA Astrophysics Data System (ADS)

Basu, Raktima; Magudapathy, P.; Sardar, Manas; Pandian, Ramanathaswamy; Dhara, Sandip

2017-11-01

Textured VO2(0 1 1) microcrystals are grown in the monoclinic, M1 phase which undergoes a reversible first order semiconductor to metal transition (SMT) accompanied by a structural phase transition to rutile tetragonal, R phase. Around the phase transition, VO2 also experiences noticeable change in its optical and electrical properties. A change in color of the VO2 micro crystals from white to cyan around the transition temperature is observed, which is further understood by absorption of red light using temperature dependent ultraviolet-visible spectroscopic analysis and photoluminescence studies. The absorption of light in the red region is explained by the optical transition between Hubbard states, confirming the electronic correlation as the driving force for SMT in VO2. The thermochromism in VO2 has been studied for smart window applications so far in the IR region, which supports the opening of the band gap in semiconducting phase; whereas there is hardly any report in the management of visible light. The filtering of blue light along with reflection of infrared above the semiconductor to metal transition temperature make VO2 applicable as advanced smart windows for overall heat management of a closure.

Coherently coupled ZnO and VO2 interface studied by photoluminescence and electrical transport across a phase transition

NASA Astrophysics Data System (ADS)

Srivastava, Amar; Herng, T. S.; Saha, Surajit; Nina, Bao; Annadi, A.; Naomi, N.; Liu, Z. Q.; Dhar, S.; Ariando; Ding, J.; Venkatesan, T.

2012-06-01

We have investigated the photoluminescence and electrical properties of a coherently coupled interface consisting of a ZnO layer grown on top of an oriented VO2 layer on sapphire across the phase transition of VO2. The band edge and defect luminescence of the ZnO overlayer exhibit hysteresis in opposite directions induced by the phase transition of VO2. Concomitantly the phase transition of VO2 was seen to induce defects in the ZnO layer. Such coherently coupled interfaces could be of use in characterizing the stability of a variety of interfaces in situ and also for novel device application.

Electrical properties and Raman studies of phase transitions in ferroelectric [N(CH3)4]2CoCl2Br2

NASA Astrophysics Data System (ADS)

Ben Mohamed, C.; Karoui, K.; Bulou, A.; Ben Rhaiem, A.

2018-03-01

The present paper accounted for the synthesis, electric properties and vibrational spectroscopy of [N(CH3)4]2CoCl2Br2. The dielectric spectra were measured in the frequency range 10-1-105 Hz and temperature interval from 223 to 393 K. The dielectical properties confirm the ferroelectric-paraelectric phase transition at 290 K, which is reported by Abdallah Ben Rhaiem et al. (2013). The equivalent circuit based on the Z-View-software was proposed and the conduction mechanisms were determined. The obtained results have been discussed in terms of the correlated barrier hopping model (CBH) in phase I and non-overlapping small polaron tunneling model (NSPT) in phases II and III. Raman spectra as function temperature have been used to characterize the phase transitions and their nature, which indicates a change of the some peak near the transitions phase.

No effect on QT intervals of mipomersen, a 2'-O-methoxyethyl modified antisense oligonucleotide targeting ApoB-100 mRNA, in a phase I dose escalation placebo-controlled study, and confirmed by a thorough QT (tQT) study, in healthy subjects.

PubMed

Yu, Rosie Z; Gunawan, Rudy; Li, Zhaoyang; Mittleman, Robert S; Mahmood, Asif; Grundy, John S; Singleton, Walter; Geary, Richard; Wang, Yanfeng

2016-03-01

The aim of this study to evaluate the effect of mipomersen on QT intervals in a phase I dose escalation, placebo-controlled study, and a thorough QT (tQT) study in healthy subjects. In the initial phase I study, 29 healthy subjects received either single or multiple (for 4 weeks) ascending doses of mipomersen (50-400 mg) administered subcutaneously (SC) or via a 2-h intravenous (IV) infusion, and 7 subjects received placebo. In the confirmative tQT study, 58 healthy subjects received placebo, 400 mg IV moxifloxacin, 200 mg SC, or 200 mg IV of mipomersen in a double-blind, 4-way crossover design with a minimum 5-day washout between treatments. ECG measurements were performed at baseline and selected time points (including Tmax). The correlation between QTcF intervals corrected for baseline and time-matched placebo when available with PK plasma exposure was evaluated by linear regression analysis. In the phase I study, no positive correlation between the PK exposure and ∆QTcF or ∆∆QTcF was observed within the wide dose or exposure range tested. Similar results were observed in the tQT study, where the predicted ΔΔQTcF and its upper bound of the 90% CI at Cmax of therapeutic and supratherapeutic dose were approximately -1.7 and 2.9 ms, respectively. Mipomersen showed no effect on QT intervals in both the phase I dose escalation study and the tQT study. These results support the proposal that QT assessment can be made in a phase I dose escalation study, and no tQT study may be necessary if the phase I dose escalation study showed a negative QT effect.

The phases and magnetic properties of (Ti, Co), and Cr doped Zn 2Y-type hexagonal ferrite

NASA Astrophysics Data System (ADS)

Chang, Y. H.; Wang, C. C.; Chin, T. S.; Yen, F. S.

1988-04-01

The phases and magnetic properties of Y-type hexagonal ferrite, Ba 2Zn 2 (Ti, Co) yFe 12-2 yO 22 doped with two sets of ions, (Ti, Co) and Cr were studied. In (Ti, Co) - doped ferrites the second phase appears at y ⩾ 0.6, which is a spinel type with the formula of (Zn 1-ηCo η)(Fe 2-δCo δ)O 4. Two resonant peaks are observed in ESR studies at the fields of 1020 and 2430 Oe, respectively, at a frequency of 9.684 GHz. The linewidth increases with the addition of the dopants. In chromium doped ferrite, two phases are identified as the amount of chromium is up to 0.2: spinel type of Zn(Fe 2-ɛCr ɛ)O 4 and orthorhombic BaCr 2O 4. Although the amount of Cr used does not influence the resonant field of the unique peak of the derivative curves from ESR, it eventually enlarges the linewidth.

Low Temperature Phase Transformations in Copper-Quenched Ti-44.5Al-8Nb-2.5V Alloy

PubMed Central

Cao, Shouzhen; Xiao, Shulong; Chen, Yuyong; Xu, Lijuan; Wang, Xiaopeng; Han, Jianchao

2017-01-01

In this study, an easily controlled transformation similar to the β + α → β + α + γ and the analysis of metastable phases in a β solidifying Ti-44.5Al-8Nb-2.5V alloy were investigated. Therefore, a liquid alloy copper-quenching followed by annealing at an application temperature (850 °C) has been carried out. Following quenching, a microstructure composed of several supersaturated phases—the basket-weave β0 (βbv) phase, the plate-like α2 (αp) phase and the stripe-like γ (γs) phase—was obtained. In the annealing processes, phase transformations in the prior βbv and αp phases domain corresponded nicely to the β + α → β + α + γ transformation during solidification. Also, in the annealed γs phase, the kinetics of the phase transformations involving the metastable L12 phase was firstly detected by transmission electron microscopy (TEM). The L12 phase had a lattice structure similar to the γ phase, whereas the composition of the phase was similar to the α2 phase. The formation of the γ pre-twin phase with an anti-phase boundary (APB) was detected in the γs phase of the matrix. The orientation relationships between the γs and precipitated: γ (γp) phase are <101]γs//<114]γp, (101¯)γs//(1¯10)γp and (01¯0)γs//(221¯)γp. PMID:28772561

Growth and study of first order metal insulator transition in VO2 films

NASA Astrophysics Data System (ADS)

Rathore, Ajay K.; Kumar, Satish; Kumar, Dhirendra; Sathe, V. G.

2015-06-01

VO2 films have been grown on Si substrate using pulse laser deposition technique. The as-deposited film prepared by V2O3 target is found to possess signatures of V2O5 phase. Up on annealing at 780°C the film transforms to VO2 phase. The annealed film is found to be highly oriented along (011) and single phase in nature. The high temperature Raman spectroscopic measurements on the annealed film showed first order transition from monoclinic insulating phase to conductive tetragonal rutile phase around 65°C.

Outcome of depression and anxiety after war: a prospective epidemiologic study of children and adolescents.

PubMed

Karam, Elie G; Fayyad, John; Karam, Aimee N; Melhem, Nadine; Mneimneh, Zeina; Dimassi, Hani; Tabet, Caroline Cordahi

2014-04-01

Prospective studies of children exposed to war have not investigated disorders other than posttraumatic stress disorder (PTSD) and have methodological limitations. From a stratified random sample of 386 children and adolescents who had been interviewed 3 weeks after war exposure (Phase 1) a random subsample (N = 143) was interviewed a year later (Phase 2). PTSD, major depressive disorder (MDD), separation anxiety disorder (SAD), overanxious disorder (OAD), and psychosocial stressors were assessed using structured interviews administered to both children and adolescents and their parents. The prevalence of disorders among the 143 at Phase 1 was MDD 25.9%, SAD 16.1%, OAD 28.0%, and PTSD 26.0%, with 44.1% having any disorder. At Phase 2 the prevalence was MDD, 5.6%; SAD, 4.2%; OAD, 0%; and PTSD, 1.4%, with 9.2% having any disorder. Occurrence of disorders at Phase 1 was associated with older age, prewar disorders, financial problems, fear of being beaten, and witnessing any war event (ORs ranged from 2.5 to 28.6). Persistence of disorders to Phase 2 was associated with prewar disorders (OR = 6.0) and witnessing any war event (OR = 14.3). There are implications for detection of at-risk cases following wars by screening for adolescents exposed to family violence, those with prewar disorders, and those who directly witnessed war events to target them for specific interventions. Copyright © 2014 International Society for Traumatic Stress Studies.

Tuning the Phase and Microstructural Properties of TiO2 Films Through Pulsed Laser Deposition and Exploring Their Role as Buffer Layers for Conductive Films

NASA Astrophysics Data System (ADS)

Agarwal, S.; Haseman, M. S.; Leedy, K. D.; Winarski, D. J.; Saadatkia, P.; Doyle, E.; Zhang, L.; Dang, T.; Vasilyev, V. S.; Selim, F. A.

2018-04-01

Titanium oxide (TiO2) is a semiconducting oxide of increasing interest due to its chemical and thermal stability and broad applicability. In this study, thin films of TiO2 were deposited by pulsed laser deposition on sapphire and silicon substrates under various growth conditions, and characterized by x-ray diffraction (XRD), atomic force microscopy (AFM), optical absorption spectroscopy and Hall-effect measurements. XRD patterns revealed that a sapphire substrate is more suitable for the formation of the rutile phase in TiO2, while a silicon substrate yields a pure anatase phase, even at high-temperature growth. AFM images showed that the rutile TiO2 films grown at 805°C on a sapphire substrate have a smoother surface than anatase films grown at 620°C. Optical absorption spectra confirmed the band gap energy of 3.08 eV for the rutile phase and 3.29 eV for the anatase phase. All the deposited films exhibited the usual high resistivity of TiO2; however, when employed as a buffer layer, anatase TiO2 deposited on sapphire significantly improves the conductivity of indium gallium zinc oxide thin films. The study illustrates how to control the formation of TiO2 phases and reveals another interesting application for TiO2 as a buffer layer for transparent conducting oxides.

Numerical study of incommensurate and decoupled phases of spin-1/2 chains with isotropic exchange J 1, J 2 between first and second neighbors

NASA Astrophysics Data System (ADS)

Soos, Zoltán G.; Parvej, Aslam; Kumar, Manoranjan

2016-05-01

The spin-1/2 chain with isotropic exchange J 1, J 2  >  0 between first and second neighbors is frustrated for either sign of J 1 and has a singlet ground state (GS) for J 1/J 2  ⩾  -4. Its rich quantum phase diagram supports gapless, gapped, commensurate (C), incommensurate (IC) and other phases. Critical points J 1/J 2 are evaluated using exact diagonalization and density matrix renormalization group calculations. The wave vector q G of spin correlations is related to GS degeneracy and obtained as the peak of the spin structure factor S(q). Variable q G indicates IC phases in two J 1/J 2 intervals, [-4, -  1.24] and [0.44, 2], and a C-IC point at J 1/J 2  =  2. The decoupled C phase in [-1.24, 0.44] has constant q G  =  π/2, nondegenerate GS, and a lowest triplet state with broken spin density on sublattices of odd and even numbered sites. The lowest triplet and singlet excitations, E m and E σ , are degenerate in finite systems at specific frustration J 1/J 2. Level crossing extrapolates in the thermodynamic limit to the same critical points as q G. The S(q) peak diverges at q G  =  π in the gapless phase with J 1/J 2  >  4.148 and quasi-long-range order (QLRO(π)). S(q) diverges at  ±π/2 in the decoupled phase with QLRO(π/2), but is finite in gapped phases with finite-range correlations. Numerical results and field theory agree at small J 2/J 1 but disagree for the decoupled phase with weak exchange J 1 between sublattices. Two related models are summarized: one has an exact gapless decoupled phase with QLRO(π/2) and no IC phases; the other has a single IC phase without a decoupled phase in between.

The phototoxic and photoallergy potential of clindamycin phosphate 1.2%/ tretinoin 0.025% gel for facial acne: results of two single-center, evaluator-blinded, randomized, vehicle-controlled phase 1 studies in healthy volunteers.

PubMed

Murray, John; Potts, Aaron

2014-01-01

A fixed-dose combination of clindamycin phosphate 1.2% and tretinoin 0.025% gel (VELTIN® (clindamycin phosphate and tretinoin) 1.2%/0.025% Gel [VELTIN]) (clindamycin/tretinoin gel) is currently available for the once-daily topical treatment of acne. Two-phase I studies were conducted to evaluate the phototoxic and photoallergic potential of clindamycin/tretinoin gel. Study 1 (phototoxic) (n=37) and Study 2 (photoallergic) (n=58) were single-center, evaluator-blinded, randomized, vehicle-controlled, phase 1 studies conducted in healthy volunteers. In Study 1, clindamycin/tretinoin gel patches, vehicle gel patches and blank patches (no gel) were applied concurrently for 24 hours to naïve sites. After patch removal, sites were irradiated with 16 joules/cm2 of ultraviolet A light (UVA) then 0.75 minimal erythema dose (MED) of UVA/ultraviolet B light (UVB), the same irradiation protocol followed by 15 joules/cm2 of visible light (VIS), or served as non-irradiated controls. Study 2 examined the effect of repeated drug exposure and involved an induction period (6 repeat phases at the same body sites during which clindamycin/tretinoin gel and vehicle gel patches were applied for 24 hours, removed and sites irradiated with UVB +/- VIS), followed by a rest period (10 to 17 days), then a challenge period that used the protocol described for Study 1. In both studies, inflammatory responses and other cutaneous effects were evaluated at 1, 24, 48, and 72 hours after patch removal. No subject experienced any adverse events in Study 1 (phototoxic). One subject in Study 2 (photoallergic) experienced AEs (diffuse erythema; mild application site irritation at one each of UV/VIS-irradiated clindamycin/tretinoin gel and vehicle gel patch sites) considered definitely related to study product that resulted in discontinuation from the study. Data from Study 1 and the challenge phase from Study 2 showed most subjects had no visible inflammatory reaction to clindamycin/tretinoin gel after irradiation. Clindamycin/tretinoin gel has a favorable safety profile following UV/visible irradiation and a low potential for phototoxicity and photoallergenicity.

Cesium vacancy ordering in phase-separated C s x F e 2 - y S e 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taddei, K. M.; Sturza, M.; Chung, D. Y.

2015-09-01

By simultaneously displaying magnetism and superconductivity in a single phase, the iron based superconductors provide a model system for the study of magnetism’s role in superconductivity. The class of intercalated iron selenide superconductors is unique amongst these in having the additional property of phase separation and coexistence of two distinct phases - one majority phase with iron vacancy ordering and strong antiferromagnetism and the other a poorly understood minority microscopic phase with a contested structure. Adding to the intrigue, the majority phase has never been found to show superconductivity on its own while the minority phase has never been successfullymore » synthesized separate from the majority phase. In order to better understand this minority phase, a series of high quality CsxFe2-ySe2 single crystals with (0.8 ≤ x ≤ 1; 0 ≤ y ≤ 0.3) were grown and studied. Neutron and x-ray powder diffraction performed on ground crystals show the average structure of the minority phase to be I4/mmm, however, the temperature evolution of its lattice parameters shows it to be distinct from the high temperature I4/mmm parent structure. Neutron and x-ray diffraction experiments performed on single crystal samples reveal the presence of previously unobserved discrete superlattice reflections that remove the degeneracy of the Cs sites in both the majority and minority phases and reduce their structural symmetries from body-centered to primitive. Group theoretical analysis in conjunction with structural modeling shows that the observed superlattice reflections originate from a three-dimensional Cs vacancy ordering in the minority phase. This model predicts a 25% vacancy of the Cs site which is consistent with the site’s refined occupancy. Magnetization measurements performed in tandem with neutron single crystal diffraction provide evidence that the minority phase is the host of superconductivity. Our results also reveal a superconducting dome in which the superconducting transition temperature varies as a function of the valence of iron.« less

A Study on Phase Changes of Heterogeneous Composite Materials

NASA Astrophysics Data System (ADS)

Hirasawa, Yoshio; Saito, Akio; Takegoshi, Eisyun

In this study, a phase change process in heterogeneous composite materials which consist of water and coiled copper wires as conductive solid is investigated by four kinds of typical calculation models : 1) model-1 in which the effective thermal conductivity of the composite material is used, 2) model-2 in which a fin metal acts for many conductive solids, 3) model-3 in which the effective thermal conductivities between nodes are estimated and three-dimensional calculation is performed, 4) model-4 proposed by authors in the previous paper in which effective thermal conductivity is not needed. Consequently, model-1 showed the phase change rate considerably lower than the experimental results. Model-2 gave the larger amount of the phase change rate. Model-3 agreed well with the experiment in the case of small coil diameter and relatively large Vd. Model-4 showed a very well agreement with the experiment in the range of this study.

Structural phase transitions in the Ag{sub 2}Nb{sub 4}O{sub 11}-Na{sub 2}Nb{sub 4}O{sub 11} solid solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodward, David I., E-mail: d.i.woodward@warwick.ac.uk; Lees, Martin R.; Thomas, Pam A.

2012-08-15

The phase transitions between various structural modifications of the natrotantite-structured system xAg{sub 2}Nb{sub 4}O{sub 11}-(1-x)Na{sub 2}Nb{sub 4}O{sub 11} have been investigated and a phase diagram constructed as a function of temperature and composition. This shows three separate phase transition types: (1) paraelectric-ferroelectric, (2) rhombohedral-monoclinic and (3) a phase transition within the ferroelectric rhombohedral zone between space groups R3c and R3. The parent structure for the entire series has space group R3{sup Macron }c. Compositions with x>0.75 are rhombohedral at all temperatures whereas compositions with x<0.75 are all monoclinic at room temperature and below. At x=0.75, rhombohedral and monoclinic phases coexistmore » with the phase boundary below room temperature being virtually temperature-independent. The ferroelectric phase boundary extends into the monoclinic phase field. No evidence was found for the R3-R3c phase boundary extending into the monoclinic phase field and it is concluded that a triple point is formed. - Graphical abstract: Phase diagram for xAg{sub 2}Nb{sub 4}O{sub 11}-(1-x)Na{sub 2}Nb{sub 4}O{sub 11} solid solution showing changes in crystal symmetry as a function of temperature and composition. The crystal structure is depicted. Highlights: Black-Right-Pointing-Triangle Ferroelectric, rhombohedral Ag{sub 2}Nb{sub 4}O{sub 11} in solid solution with monoclinic Na{sub 2}Nb{sub 4}O{sub 11}. Black-Right-Pointing-Triangle Three phase boundaries were studied as a function of composition and temperature. Black-Right-Pointing-Triangle Both rhombohedral and monoclinic variants exhibit ferroelectricity. The parent phase of the series has space group R3{sup Macron }c.« less

Reproducibility of CT Perfusion Parameters in Liver Tumors and Normal Liver

PubMed Central

Ng, Chaan S.; Chandler, Adam G.; Wei, Wei; Herron, Delise H.; Anderson, Ella F.; Kurzrock, Razelle; Charnsangavej, Chusilp

2011-01-01

Purpose: To assess the reproducibility of computed tomographic (CT) perfusion measurements in liver tumors and normal liver and effects of motion and data acquisition time on parameters. Materials and Methods: Institutional review board approval and written informed consent were obtained for this prospective study. The study complied with HIPAA regulations. Two CT perfusion scans were obtained 2–7 days apart in seven patients with liver tumors with two scanning phases (phase 1: 30-second breath-hold cine; phase 2: six intermittent free-breathing cines) spanning 135 seconds. Blood flow (BF), blood volume (BV), mean transit time (MTT), and permeability–surface area product (PS) for tumors and normal liver were calculated from phase 1 with and without rigid registration and, for combined phases 1 and 2, with manually and rigid-registered phase 2 images, by using deconvolution modeling. Variability was assessed with within-patient coefficients of variation (CVs) and Bland-Altman analyses. Results: For tumors, BF, BV, MTT, and PS values and reproducibility varied by analytical method, the former by up to 11%, 23%, 21%, and 138%, respectively. Median PS values doubled with the addition of phase 2 data to phase 1 data. The best overall reproducibility was obtained with rigidly registered phase 1 and phase 2 images, with within-patient CVs for BF, BV, MTT, and PS of 11.2%, 14.4%, 5.5% and 12.1%, respectively. Normal liver evaluations were similar, except with marginally lower variability. Conclusion: Absolute values and reproducibility of CT perfusion parameters were markedly influenced by motion and data acquisition time. PS, in particular, probably requires data acquisition beyond a single breath hold, for which motion-correction techniques are likely necessary. © RSNA, 2011 Supplemental material: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.11110331/-/DC1 PMID:21788525

Potent Effects of Flavonoid Nobiletin on Amplitude, Period, and Phase of the Circadian Clock Rhythm in PER2::LUCIFERASE Mouse Embryonic Fibroblasts.

PubMed

Shinozaki, Ayako; Misawa, Kenichiro; Ikeda, Yuko; Haraguchi, Atsushi; Kamagata, Mayo; Tahara, Yu; Shibata, Shigenobu

2017-01-01

Flavonoids are natural polyphenols that are widely found in plants. The effects of flavonoids on obesity and numerous diseases such as cancer, diabetes, and Alzheimer's have been well studied. However, little is known about the relationships between flavonoids and the circadian clock. In this study, we show that continuous or transient application of flavonoids to the culture medium of embryonic fibroblasts from PER2::LUCIFERASE (PER2::LUC) mice induced various modifications in the circadian clock amplitude, period, and phase. Transient application of some of the tested flavonoids to cultured cells induced a phase delay of the PER2::LUC rhythm at the down slope phase. In addition, continuous application of the polymethoxy flavonoids nobiletin and tangeretin increased the amplitude and lengthened the period of the PER2::LUC rhythm. The nobiletin-induced phase delay was blocked by co-treatment with U0126, an ERK inhibitor. In summary, among the tested flavonoids, polymethoxy flavones increased the amplitude, lengthened the period, and delayed the phase of the PER2::LUC circadian rhythm. Therefore, foods that contain polymethoxy flavones may have beneficial effects on circadian rhythm disorders and jet lag.

Study of thermal stability of Cu{sub 2}Se thermoelectric material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bohra, Anil, E-mail: anilbohra786@gmail.com; Bhatt, Ranu; Bhattacharya, Shovit

2016-05-23

Sustainability of thermoelectric parameter in operating temperature range is a key consideration factor for fabricating thermoelectric generator or cooler. In present work, we have studied the stability of thermoelectric parameter of Cu{sub 2}Se within the temperature range of 50-800°C. Temperature dependent Seebeck coefficients and electrical resistivity measurement are performed under three continuous thermal cycles. X-ray diffraction pattern shows the presence of mixed cubic-monoclinic Cu{sub 2}Se phase in bare pellet which transforms to pure α-Cu{sub 2}Se phase with repeating thermal cycle. Significant enhancement in Seebeck coefficient and electrical resistivity is observed which may be attributed to (i) Se loss observed inmore » EDS and (ii) the phase transformation from mixed cubic-monoclinic structure to pure monoclinic α-Cu{sub 2}Se phase.« less

Effects of inhalational anaesthesia with low tidal volume ventilation on end-tidal sevoflurane and carbon dioxide concentrations: prospective randomized study.

PubMed

de la Matta-Martín, M; López-Herrera, D; Luis-Navarro, J C; López-Romero, J L

2014-02-01

We investigated how ventilation with low tidal volumes affects the pharmacokinetics of sevoflurane uptake during the first minutes of inhaled anaesthesia. Forty-eight patients scheduled for lung resection were randomly assigned to three groups. Patients in group 1, 2 and 3 received 3% sevoflurane for 3 min via face mask and controlled ventilation with a tidal volume of 2.2, 8 and 12 ml kg(-1), respectively (Phase 1). After tracheal intubation (Phase 2), 3% sevoflurane was supplied for 2 min using a tidal volume of 8 ml kg(-1) (Phase 3). End-tidal sevoflurane concentrations were significantly higher in group 1 at the end of phase 1 and lower at the end of phase 2 than in the other groups as follows: median of 2.5%, 2.2% and 2.3% in phase 1 for groups 1, 2 and 3, respectively (P<0.001); and 1.7%, 2.1% and 2.0% in phase 2, respectively (P<0.001). End-tidal carbon dioxide values in group 1 were significantly lower at the end of phase 1 and higher at the end of phase 2 than in the other groups as follows: median of 16.5, 31 and 29.5 mm Hg in phase 1 for groups 1, 2 and 3, respectively (P<0.001); and 46.2, 36 and 33.5 mm Hg in phase 2, respectively (P<0.001). When sevoflurane is administered with tidal volume approximating the airway dead space volume, end-tidal sevoflurane and end-tidal carbon dioxide may not correctly reflect the concentration of these gases in the alveoli, leading to misinterpretation of expired gas data. Copyright © 2013 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Published by Elsevier España. All rights reserved.

North Dakota Statewide Nursing Study, Phase III. Final Report and Recommendations.

ERIC Educational Resources Information Center

Clark, Neil; Smith, David

The process, outcomes, and recommendations resulting from a project to develop a statewide nursing resource planning system are examined. Phase 1 of the project investigated nursing manpower demands for 1984 and 1986, while phase 2 studied the current scope of nursing practice. In addition to summarizing the findings of these investigations,…

Dense Carbon Monoxide to 160 GPa: Stepwise Polymerization to Two-Dimensional Layered Solid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryu, Young-Jay; Kim, Minseob; Lim, Jinhyuk

Carbon monoxide (CO) is the first molecular system found to transform into a nonmolecular “polymeric” solid above 5.5 GPa, yet been studied beyond 10 GPa. Here, we show a series of pressure-induced phase transformations in CO to 160 GPa: from a molecular solid to a highly colored, low-density polymeric phase I to translucent, high-density phase II to transparent, layered phase III. The properties of these phases are consistent with those expected from recently predicted 1D P2 1/m, 3D I2 12 12 1, and 2D Cmcm structures, respectively. Thus, the present results advocate a stepwise polymerization of CO triple bonds tomore » ultimately a 2D singly bonded layer structure with an enhanced ionic character.« less

The microstructure and composition of equilibrium phases formed in hypoeutectic Te-In alloy during solidification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Baoguang

As a key tellurium atoms evaporation source for ultraviolet detection photocathode, the hypoeutectic Te{sub 75}In{sub 25} alloy was prepared by employing a slow solidification speed of about 10{sup −2} K/s. The microstructure and chemical composition of the equilibrium phases formed in the as-prepared alloy were studied in this research work. The experimental results show that the as-prepared Te-In alloy was constituted by primary In{sub 2}Te{sub 5} phase and eutectic In{sub 2}Te{sub 5}/Te phases. The eutectic In{sub 2}Te{sub 5}/Te phases are distributed in the grain boundaries of primary In{sub 2}Te{sub 5} phase. With the slow solidification speed, a pure eutectic Temore » phase without any excessive indium solute was obtained, where Te content of eutectic Te phase is 100 mass%. Moreover, it can be considered that the stress between the In{sub 2}Te{sub 5} and Te phases plays an important role in reducing the tellurium vapor pressure in Te{sub 75}In{sub 25} alloy. - Highlights: • The microstructure of Te-In alloy as an evaporation source was analyzed. • A pure eutectic Te phase was obtained by using a slow solidification speed method. • The relation between vapor pressure and inner-stress in the alloy was discussed.« less

Superfluid helium 2 liquid-vapor phase separation: Technology assessment

NASA Technical Reports Server (NTRS)

Lee, J. M.

1984-01-01

A literature survey of helium 2 liquid vapor phase separation is presented. Currently, two types of He 2 phase separators are being investigated: porous, sintered metal plugs and the active phase separator. The permeability K(P) shows consistency in porous plug geometric characterization. Both the heat and mass fluxes increase with K(P). Downstream pressure regulation to adjust for varying heat loads and both temperatures is possible. For large dynamic heat loads, the active phase separator shows a maximum heat rejection rate of up to 2 W and bath temperature stability of 0.1 mK. Porous plug phase separation performance should be investigated for application to SIRTF and, in particular, that plugs of from 10 to the minus ninth square centimeters to 10 to the minus eighth square centimeters in conjunction with downstream pressure regulation be studied.

Development of a KSC test and flight engineering oriented computer language, Phase 1

NASA Technical Reports Server (NTRS)

Case, C. W.; Kinney, E. L.; Gyure, J.

1970-01-01

Ten, primarily test oriented, computer languages reviewed during the phase 1 study effort are described. Fifty characteristics of ATOLL, ATLAS, and CLASP are compared. Unique characteristics of the other languages, including deficiencies, problems, safeguards, and checking provisions are identified. Programming aids related to these languages are reported, and the conclusions resulting from this phase of the study are discussed. A glossary and bibliography are included. For the reports on phase 2 of the study, see N71-35027 and N71-35029.

Does the method of expression of venous blood affect ischaemia/reperfusion damage in tourniquet use? An experimental study on rabbits.

PubMed

Iltar, Serkan; Kılınç, Cem Yalın; Alemdaroğlu, Kadir Bahadır; Ozcan, Selahattin; Aydoğan, Nevres Hürriyet; Sürer, Hatice; Kılınç, Aytün Şadan

2013-11-01

The aim of this study was to compare the ischaemia and reperfusion phases of two tourniquet application models (Group 1: expressing the blood by a sterile rubber bandage and Group 2: elevation of the limb for several minutes) using an analysis of ischaemia/reperfusion parameters and blood pH. Sixteen New Zealand rabbits were used. Muscle samples were extracted from the triceps surae; at phase A (baseline: just before tourniquet application), phase B (ischaemia: 3h after tourniquet inflation) and phase C (2h after tourniquet deflation). Nitrite, nitrate, reduced glutathione, myeloperoxidase, malondyaldehyde were measured in the samples. Blood pH was also measured at each phase. Group 2 had significantly decreased nitrite (p=0.007) and nitrate (p=0.01) levels compared to Group 1 while passing from phase A to phase B. The pH decrease through the phases was significant within Group 1 (p=0.006) and was not significant within Group 2 (p=0.052). Lower levels of NO metabolites nitrate and nitrite, result from tourniquet use with incomplete venous blood expression by elevation. Also, with this technique severe acidosis is less likely to occur than when a tourniquet is used with expression of the venous blood by rubber bandage. These findings may help in the decision of which tourniquet technique is to be used for potentially long operations which may exceed 2h. Copyright © 2013 Elsevier Ltd. All rights reserved.

Coherently Coupled ZnO and VO2 Interface studied by Photoluminescence and electrical transport across a phase transition

NASA Astrophysics Data System (ADS)

Srivastava, Amar; Saha, S.; Annadi, A.; Zhao, Y. L.; Gopinadhan, K.; Wang, X.; Naomi, N.; Liu, Z. Q.; Dhar, S.; Herng, T. S.; Nina, Bao; Ariando, -; Ding, Jun; Venkatesan, T.

2012-02-01

In this work we report a study of a coherently coupled interface consisting of a ZnO layer grown on top of an oriented VO2 layer on sapphire by photoluminescence and electrical transport measurements across the VO2 metal insulator phase transition (MIT). The photoluminescence of the ZnO layer showed a broad hysteresis induced by the phase transition of VO2 while the width of the electrical hysteresis was narrow and unaffected by the over layer. The enhanced width of the PL hysteresis was due to the formation of defects during the MIT as evidenced by a broad hysteresis in the opposite direction to that of the band edge PL in the defect luminescense. Unlike VO2 the defects in ZnO did not fully recover across the phase transition. From the defect luminescence data, oxygen interstitials were found to be the predominant defects in ZnO mediated by the strain from the VO2 phase transition. Such coherently coupled interfaces could be of use in characterizing the stability of a variety of interfaces and also for novel device application.

Phase Diagram of Quaternary System NaBr-KBr-CaBr2-H2O at 323 K

NASA Astrophysics Data System (ADS)

Cui, Rui-Zhi; Wang, Wei; Yang, Lei; Sang, Shi-Hua

2018-03-01

The phase equilibria in the system NaBr-KBr-CaBr2-H2O at 323 K were studied using the isothermal dissolution equilibrium method. Using the experimental solubilities of salts data, phase diagram was constructed. The phase diagram have two invariant points, five univariant curves, and four crystallization fields. The equilibrium solid phases in the system are NaBr, NaBr · 2H2O, KBr, and CaBr2 · 4H2O. The solubilities of salts in the system at 323 K were calculated by Pitzer's equation. There is shown that the calculated solubilities agree well with experimental data.

Investigating the effect of V2O5 addition on sodium barium borosilicate glasses

NASA Astrophysics Data System (ADS)

Halder, Rumu; Sengupta, Pranesh; Sudarsan, V.; Kaushik, C. P.; Dey, G. K.

2016-05-01

V2O5 doped sodium barium borosilicate glasses were characterized by photoluminescence spectroscopy and electron probe microanalyzer (EPMA). The glass remains homogeneous for lower concentration of V2O5 but a phase separation is observed when V2O5 doping is increased beyond 5 mol%. Detailed microanalysis reveals that the phase separated glass consists of a phase containing V, Ba and Si and a separate Si rich phase within the glass matrix. The luminescence study demonstrated that at low concentration the vanadium mainly interacts with the structural units of B/Si while at higher concentrations, V-O-V/ V-O- Na+/Ba2+ linkages are formed.

Is there a difference between active opening of the Eustachian tube in a hypobaric surrounding compared to a hyperbaric surrounding?

PubMed

Mikolajczak, Stefanie; Meyer, Moritz Friedo; Felsch, Moritz; Jumah, Masen Dirk; Hüttenbrink, Karl-Bernd; Grosheva, Maria; Luers, Jan-Christoffer; Beutner, Dirk

2015-01-01

The Eustachian tube (ET) is the key to pressure equalization between the middle ear and ambient pressure. To date, little is known about differences of the opening mechanisms under hyper- or hypobaric conditions. Aim of this study was to compare standard ET opening parameters during standardized hypo- and hyperbaric exposures. Thirty healthy participants were exposed to a standardized profile of decompression and compression (SPDC) in a hypo-/hyperbaric pressure chamber. Impedance, expressed as tympanic membrane compliance, was recorded at intervals during the excursions from 1 atmosphere absolute (atm abs) to 0.8 and 1.2 atm abs respectively. Parameters for tubal opening were obtained during SPDC: ET opening pressure (ETOP), ET opening duration (ETOD) and ET opening frequency (ETOF), hypobaric (Phase 1) and hyperbaric (Phase 2) data were compared. Mean value for Valsalva maneuver ETOP was 40.10 ± 19.02 mbar in Phase 2 vs. 42.82 ± 21.75 mbar in Phase 1. For ETOD it was 2.80 ± 2.09 seconds in Phase 2 vs. 2.51 ± 1.90 seconds in Phase 1. For swallowing, mean value for ETOP was 33.47 ± 14.50 mbar in Phase 2 vs. 28.44 ± 14.04 in Phase 1. ETOD was 0.82 ± 0.60 seconds in Phase 2 vs. 0.76 ± 0.55 seconds in Phase 1. There was no statistical significance for ETOP, ETOD and ETOF between the two phases. No statistical significant difference was evident for active pressure equalization (Valsalva and swallowing) between a hyperbaric setting (dive) and a hypobaric setting (flight) in healthy subjects.

Liquidus Projections of Bi-Se-Ga and Bi-Se-Te Ternary Systems

NASA Astrophysics Data System (ADS)

Lin, Po-han; Chen, Sinn-wen; Hwang, Jenn-dong; Chu, Hsu-shen

2016-12-01

This study determines the liquidus projections of both Bi-Se-Ga and Bi-Se-Te ternary systems which are constituent ternary systems of promising Bi-Se-Te-Ga thermoelectric materials. Ternary Bi-Se-Ga and Bi-Se-Te alloys are prepared. Their primary solidification phases are experimentally determined, and thermal analysis experiments are carried out. The liquidus projections are determined based on the ternary experimental results and phase diagrams of constituent binary systems. The Bi-Se-Ga system includes seven primary solidification phases, Bi, Ga, GaSe, Ga2Se3, Se, Bi2Se3, and (Bi2)n(Bi2Se3)m. In the Bi-Se-Te system, there are five primary solidification phases, Bi, (Bi2)n(Bi2Te3)m, Bi2(Se,Te)3, (Se,Te), and (Bi2)n(Bi2Se3)m. Both the (Bi2)n(Bi2Te3)m and (Bi2)n(Bi2Se3)m phases are not a single phase, but a collection of series undetermined phases. Large miscibility gaps are observed in the Bi-Se-Ga system. The temperatures of the invariant reactions, Liquid + Bi + GaSe = Ga and Liquid + Ga2Se3 = Bi + GaSe, are at 495 K (222 °C) and 533 K (260 °C), respectively.

Monoclinic Cc-phase stabilization in magnetically diluted lead free Na1/2Bi1/2TiO3—Evolution of spin glass like behavior with enhanced ferroelectric and dielectric properties

NASA Astrophysics Data System (ADS)

Thangavelu, Karthik; Asthana, Saket

2015-09-01

The effect of magnetic cation substitution on the phase stabilization, ferroelectric, dielectric and magnetic properties of a lead free Na0.5Bi0.5TiO3 (NBT) system prepared by O2 atmosphere solid state sintering were studied extensively. Cobalt (Co) was chosen as the magnetic cation to substitute at the Ti-site of NBT with optimized 2.5 mol%. Rietveld analysis of x-ray diffraction data favours the monoclinic Cc phase stabilization strongly rather than the parent R3c phase. FE-SEM micrograph supports the single phase characteristics without phase segregation at the grain boundaries. The stabilized Cc space group was explained based on the collective local distortion effects due to spin-orbit stabilization at Co3+ and Co2+ functional centres. The phonon mode changes as observed in the TiO6 octahedral modes also support the Cc phase stabilization. The major Co3+-ion presence was revealed from corresponding crystal field transitions observed through solid state diffuse reflectance spectroscopy. The enhanced spontaneous polarization (Ps) from ≅38 μC cm-2 to 45 μC cm-2 could be due to the easy rotation of polarization vector along the {(1\\bar{1}0)}{{pc}} in Cc phase. An increase in static dielectric response (ɛ) from ɛ ≅ 42 to 60 along with enhanced diffusivity from γ ≅ 1.53 to 1.75 was observed. Magneto-thermal irreversibility and their magnetic field dependent ZFC/FC curves suggest the possibility of a spin glass like behaviour below 50 K. The monoclinic Cc phase stabilization as confirmed from structural studies was well correlated with the observed ferroic properties in magnetically diluted NBT.

Assessment of Device-Related Thrombus and Associated Clinical Outcomes With the WATCHMAN Left Atrial Appendage Closure Device for Embolic Protection in Patients With Atrial Fibrillation (from the PROTECT-AF Trial).

PubMed

Main, Michael L; Fan, Dali; Reddy, Vivek Y; Holmes, David R; Gordon, Nicole T; Coggins, Tina R; House, John A; Liao, Lawrence; Rabineau, Dawn; Latus, George G; Huber, Kenneth C; Sievert, Horst; Wright, Richard F; Doshi, Shephal K; Douglas, Pamela S

2016-04-01

Left atrial appendage closure with the WATCHMAN device is an alternative to anticoagulation for stroke prevention in selected patients with atrial fibrillation (AF). LA device-related thrombus (DRT) is poorly defined and understood. We aimed to (1) develop consensus echocardiographic diagnostic criteria for DRT; (2) estimate the incidence of DRT; and (3) determine clinical event rates in patients with DRT. In phase 1 (training), a training manual was developed and reviewed by 3 echocardiographers with left atrial appendage closure device experience. All available transesophageal (TEE) studies in the WATCHMAN left atrial appendage system for embolic protection in patients with atrial fibrillation (PROTECT-AF) trial patients with suspected DRT were reviewed in 2 subsequent phases. In phase 2 (primary blind read), each reviewer independently scored each study for DRT, and final echo criteria were developed. Unanimously scored studies were considered adjudicated, whereas all others were reevaluated by all reviewers in phase 3 (group adjudication read). DRT was suspected in 35 of 485 patients by the site investigator, the echocardiography core laboratory, or both; 93 of the individual TEE studies were available for review. In phase 2, 3 readers agreed on 67 (72%) of time points. Based on phases 1 and 2, 5 DRT criteria were developed. In phase 3, studies without agreement in phase 2 were adjudicated using these criteria. Overall, at least 1 TEE was DRT positive in 27 (5.7%) PROTECT-AF patients. Stroke, peripheral embolism, or cardiac/unexplained death occurred in subjects with DRT at a rate of 3.4 per 100 patient-years follow-up. In conclusion, DRT were identified on at least 1 TEE in 27 PROTECT-AF patients, indicating a DRT incidence of 5.7%. Primary efficacy events in patients with DRT occurred at a rate of 3.4 per 100 patient-years follow-up, intermediate in frequency between event rates previously reported for the overall device and warfarin arms in PROTECT-AF. Copyright © 2016 Elsevier Inc. All rights reserved.

Brief report on the effect of providing single versus assorted brand name condoms to hospital patients: a descriptive study

PubMed Central

Williams, James L; Christensen, Carol J; Cagle, Henry H; Homan, Chriss E

2001-01-01

Objectives This study examined condom acquisition by persons in a hospital setting when single versus assorted brand name condoms were provided. Methods Condom receptacles were placed in exam rooms of two clinics. During Phase 1, a single brand name was provided; for Phase 2, assorted brand names were added. Number of condoms taken was recorded for each phase. Results For one clinic there was nearly a two-fold increase in number of condoms taken (Phase 1 to Phase 2); for the second clinic there was negligible difference in number of condoms taken. Conclusions The provision of assorted brand name condoms, over a single brand name, can serve to increase condom acquisition. Locations of condoms and target population characteristics are related factors. PMID:11446904

Correlates of posttraumatic epilepsy 35 years following combat brain injury(CME)

PubMed Central

Raymont, V.; Salazar, A.M.; Lipsky, R.; Goldman, D.; Tasick, G.; Grafman, J.

2010-01-01

Background: The Vietnam Head Injury Study (VHIS) is a prospective, longitudinal follow-up of 1,221 Vietnam War veterans with mostly penetrating head injuries (PHIs). The high prevalence (45%–53%) of posttraumatic epilepsy (PTE) in this unique cohort makes it valuable for study. Methods: A standardized multidisciplinary neurologic, cognitive, behavioral, and brain imaging evaluation was conducted on 199 VHIS veterans plus uninjured controls, some 30 to 35 years after injury, as part of phase 3 of this study. Results: The prevalence of seizures (87 patients, 43.7%) was similar to that found during phase 2 evaluations 20 years earlier, but 11 of 87 (12.6%) reported very late onset of PTE after phase 2 (more than 14 years after injury). Those patients were not different from patients with earlier-onset PTE in any of the measures studied. Within the phase 3 cohort, the most common seizure type last experienced was complex partial seizures (31.0%), with increasing frequency after injury. Of subjects with PTE, 88% were receiving anticonvulsants. Left parietal lobe lesions and retained ferric metal fragments were associated with PTE in a logistic regression model. Total brain volume loss predicted seizure frequency. Conclusions: Patients with PHI carry a high risk of PTE decades after their injury, and so require long-term medical follow-up. Lesion location, lesion size, and lesion type were predictors of PTE. GLOSSARY ABLe = Analysis of Brain Lesions; AFQT = Armed Forces Qualification Test; AIR = Automated Image Registration; CHI = closed head injury; GAD = glutamic acid decarboxylase; PH1 = phase 1; PH2 = phase 2; PH3 = phase 3; PHI = penetrating head injury; PTE = posttraumatic epilepsy; TBI = traumatic brain injury; VHIS = Vietnam Head Injury Study; WAIS = Wechsler Adult Intelligence Scale. PMID:20644150

Effects of intermittent fasting on health markers in those with type 2 diabetes: A pilot study.

PubMed

Arnason, Terra G; Bowen, Matthew W; Mansell, Kerry D

2017-04-15

To determine the short-term biochemical effects and clinical tolerability of intermittent fasting (IF) in adults with type 2 diabetes mellitus (T2DM). We describe a three-phase observational study (baseline 2 wk, intervention 2 wk, follow-up 2 wk) designed to determine the clinical, biochemical, and tolerability of IF in community-dwelling volunteer adults with T2DM. Biochemical, anthropometric, and physical activity measurements (using the Yale Physical Activity Survey) were taken at the end of each phase. Participants reported morning, afternoon and evening self-monitored blood glucose (SMBG) and fasting duration on a daily basis throughout all study stages, in addition to completing a remote food photography diary three times within each study phase. Fasting blood samples were collected on the final days of each study phase. At baseline, the ten participants had a confirmed diagnosis of T2DM and were all taking metformin, and on average were obese [mean body mass index (BMI) 36.90 kg/m 2 ]. We report here that a short-term period of IF in a small group of individuals with T2DM led to significant group decreases in weight (-1.395 kg, P = 0.009), BMI (-0.517, P = 0.013), and at-target morning glucose (SMBG). Although not a study requirement, all participants preferentially chose eating hours starting in the midafternoon. There was a significant increase ( P < 0.001) in daily hours fasted in the IF phase (+5.22 h), although few attained the 18-20 h fasting goal (mean 16.82 ± 1.18). The increased fasting duration improved at-goal (< 7.0 mmol/L) morning SMBG to 34.1%, from a baseline of 13.8%. Ordinal Logistic Regression models revealed a positive relationship between the increase in hours fasted and fasting glucose reaching target values ( χ 2 likelihood ratio = 8.36, P = 0.004) but not for afternoon or evening SMBG (all P > 0.1). Postprandial SMBGs were also improved during the IF phase, with 60.5% readings below 9.05 mmol/L, compared to 52.6% at baseline, and with less glucose variation. Neither insulin resistance (HOMA-IR), nor inflammatory markers (C-reactive protein) normalized during the IF phase. IF led to an overall spontaneous decrease in caloric intake as measured by food photography (Remote Food Photography Method). The data demonstrated discernable trends during IF for lower energy, carbohydrate, and fat intake when compared to baseline. Physical activity, collected by a standardized measurement tool (Yale Physical Activity Survey), increased during the intervention phase and subsequently decreased in the follow-up phase. IF was well tolerated in the majority of individuals with 6/10 participants stating they would continue with the IF regimen after the completion of the study, in a full or modified capacity ( i.e. , every other day or reduced fasting hours). The results from this pilot study indicate that short-term daily IF may be a safe, tolerable, dietary intervention in T2DM patients that may improve key outcomes including body weight, fasting glucose and postprandial variability. These findings should be viewed as exploratory, and a larger, longer study is necessary to corroborate these findings.

Effects of intermittent fasting on health markers in those with type 2 diabetes: A pilot study

PubMed Central

Arnason, Terra G; Bowen, Matthew W; Mansell, Kerry D

2017-01-01

AIM To determine the short-term biochemical effects and clinical tolerability of intermittent fasting (IF) in adults with type 2 diabetes mellitus (T2DM). METHODS We describe a three-phase observational study (baseline 2 wk, intervention 2 wk, follow-up 2 wk) designed to determine the clinical, biochemical, and tolerability of IF in community-dwelling volunteer adults with T2DM. Biochemical, anthropometric, and physical activity measurements (using the Yale Physical Activity Survey) were taken at the end of each phase. Participants reported morning, afternoon and evening self-monitored blood glucose (SMBG) and fasting duration on a daily basis throughout all study stages, in addition to completing a remote food photography diary three times within each study phase. Fasting blood samples were collected on the final days of each study phase. RESULTS At baseline, the ten participants had a confirmed diagnosis of T2DM and were all taking metformin, and on average were obese [mean body mass index (BMI) 36.90 kg/m2]. We report here that a short-term period of IF in a small group of individuals with T2DM led to significant group decreases in weight (-1.395 kg, P = 0.009), BMI (-0.517, P = 0.013), and at-target morning glucose (SMBG). Although not a study requirement, all participants preferentially chose eating hours starting in the midafternoon. There was a significant increase (P < 0.001) in daily hours fasted in the IF phase (+5.22 h), although few attained the 18-20 h fasting goal (mean 16.82 ± 1.18). The increased fasting duration improved at-goal (< 7.0 mmol/L) morning SMBG to 34.1%, from a baseline of 13.8%. Ordinal Logistic Regression models revealed a positive relationship between the increase in hours fasted and fasting glucose reaching target values (χ2 likelihood ratio = 8.36, P = 0.004) but not for afternoon or evening SMBG (all P > 0.1). Postprandial SMBGs were also improved during the IF phase, with 60.5% readings below 9.05 mmol/L, compared to 52.6% at baseline, and with less glucose variation. Neither insulin resistance (HOMA-IR), nor inflammatory markers (C-reactive protein) normalized during the IF phase. IF led to an overall spontaneous decrease in caloric intake as measured by food photography (Remote Food Photography Method). The data demonstrated discernable trends during IF for lower energy, carbohydrate, and fat intake when compared to baseline. Physical activity, collected by a standardized measurement tool (Yale Physical Activity Survey), increased during the intervention phase and subsequently decreased in the follow-up phase. IF was well tolerated in the majority of individuals with 6/10 participants stating they would continue with the IF regimen after the completion of the study, in a full or modified capacity (i.e., every other day or reduced fasting hours). CONCLUSION The results from this pilot study indicate that short-term daily IF may be a safe, tolerable, dietary intervention in T2DM patients that may improve key outcomes including body weight, fasting glucose and postprandial variability. These findings should be viewed as exploratory, and a larger, longer study is necessary to corroborate these findings. PMID:28465792

Phase I/II Study of Weekly Oraxol for the Second-Line Treatment of Patients With Metastatic or Recurrent Gastric Cancer

PubMed Central

Lee, Keun-Wook; Lee, Kyung Hee; Zang, Dae Young; Park, Young Iee; Shin, Dong Bok; Kim, Jin Won; Im, Seock-Ah; Koh, Sung Ae; Cho, Joo-Youn; Jung, Jin-A

2015-01-01

Lessons Learned Oraxol, a novel oral formulation of paclitaxel, displayed modest efficacy as second-line chemotherapy for gastric cancer. Considering its favorable toxicity profiles, further studies are warranted in various solid tumors including gastric cancer. Background. Oraxol consists of paclitaxel and HM30181A, a P-glycoprotein inhibitor, to increase the oral bioavailability of paclitaxel. This phase I/II study (HM-OXL-201) was conducted to determine the maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of Oraxol. In addition, we investigated the efficacy and safety of Oraxol as second-line chemotherapy for metastatic or recurrent gastric cancer (GC). Methods. In the phase I component, paclitaxel was orally administered at escalating doses (90, 120, or 150 mg/m2 per day) with a fixed dose (15 mg/day) of HM30181A. Oraxol was administrated 6 times per cycle (days 1, 2, 8, 9, 15, and 16) every 4 weeks. In the phase II component, the efficacy and safety of Oraxol were evaluated. Results. In the phase I component, the MTD could not be determined. Based on toxicity and pharmacokinetic data, the RP2D of oral paclitaxel was determined to be 150 mg/m2. In the phase II component, 4 of 43 patients (9.3%) achieved partial responses. Median progression-free survival and overall survival were 2.6 and 10.7 months, respectively. Toxicity profiles were favorable, and the most common drug-related adverse events (grade ≥3) were neutropenia and diarrhea. Conclusion. Oraxol exhibited modest efficacy and favorable toxicity profiles as second-line chemotherapy for GC. PMID:26112004

Performance deficits following failure: learned helplessness or self-esteem protection?

PubMed

Witkowski, T; Stiensmeier-Pelster, J

1998-03-01

We report two laboratory experiments which compare two competing explanations of performance deficits following failure: one based on Seligman's learned helplessness theory (LHT), and the other, on self-esteem protection theory (SEPT). In both studies, participants (Study 1: N = 40 pupils from secondary schools in Walbrzych, Poland; Study 2: N = 45 students from the University of Bielefeld, Germany) were confronted with either success or failure in a first phase of the experiment. Then, in the second phase of the experiment the participants had to work on a set of mathematical problems (Study 1) or a set of tasks taken from Raven's Progressive Matrices (Study 2) either privately or in public. In both studies failure in the first phase causes performance deficits in the second phase only if the participants had to solve the test tasks in public. These results were interpreted in line with SEPT and as incompatible with LHT.

The composition of secondary amorphous phases under different environmental conditions

NASA Astrophysics Data System (ADS)

Smith, R.; Rampe, E. B.; Horgan, B. H. N.; Dehouck, E.; Morris, R. V.

2017-12-01

X-ray diffraction (XRD) patterns measured by the CheMin instrument on the Mars Science Laboratory Curiosity rover demonstrate that amorphous phases are major components ( 15-60 wt%) of all rock and soil samples in Gale Crater. The nature of these phases is not well understood and could be any combination of primary (e.g., glass) and secondary (e.g., silica, ferrihydrite) phases. Secondary amorphous phases are frequently found as weathering products in soils on Earth, but these materials remain poorly characterized. Here we study a diverse suite of terrestrial samples including: sediments from recently de-glaciated volcanoes (Oregon), modern volcanic soils (Hawaii), and volcanic paleosols (Oregon) in order to determine how formation environment, climate, and diagenesis affect the abundance and composition of amorphous phases. We combine bulk XRD mineralogy with bulk chemical compositions (XRF) to calculate the abundance and bulk composition of the amorphous materials in our samples. We then utilize scanning transmission electron microscopy (STEM) and energy dispersive x-ray spectroscopy (EDS) to study the composition of individual amorphous phases at the micrometer scale. XRD analyses of 8 samples thus far indicate that the abundance of amorphous phases are: modern soils (20-80 %) > paleosols (15-40 %) > glacial samples (15-30 %). Initial calculations suggest that the amorphous components consist primarily of SiO2, Al2O3, TiO2, FeO and Fe2O3, with minor amounts of other oxides (e.g., MgO, CaO, Na2O). Compared to their respective crystalline counterparts, calculations indicate bulk amorphous components enriched in SiO2 for the glacial sample, and depleted in SiO2 for the modern soil and paleosol samples. STEM analyses reveal that the amorphous components consist of a number of different phases. Of the two samples analyzed using STEM thus far, the secondary amorphous phases have compositions with varying ratios of SiO2, Al2O3, TiO2, and Fe-oxides, consistent with mass balance calculation results, but inconsistent with well-known amorphous phase compositions (e.g., allophane, ferrihydrite). These results show that a number of secondary amorphous phases can form within a single soil environment. Continued analysis can help determine whether compositional trends can be linked to environmental factors.

Quantum phase diagram of distorted J 1 - J 2 Heisenberg S  =  1/2 antiferromagnet in honeycomb lattice: a modified spin wave study

NASA Astrophysics Data System (ADS)

Ghorbani, Elaheh; Shahbazi, Farhad; Mosadeq, Hamid

2016-10-01

Using the modified spin wave method, we study the {{J}1}-{{J}2} Heisenberg model with first and second neighbor antiferromagnetic exchange interactions. For a symmetric S  =  1/2 model, with the same couplings for all the equivalent neighbors, we find three phases in terms of the frustration parameter \\barα={{J}2}/{{J}1} : (1) a commensurate collinear ordering with staggered magnetization (Néel.I state) for 0≤slant \\barα≲ 0.207 , (2) a magnetically gapped disordered state for 0.207≲ \\barα≲ 0.369 , preserving all the symmetries of the Hamiltonian and lattice, which by definition is a quantum spin liquid (QSL) state and (3) a commensurate collinear ordering in which two out of the three nearest neighbor magnetizations are antiparallel and the remaining pair are parallel (Néel.II state), for 0.396≲ \\barα≤slant 1 . We also explore the phase diagram of a distorted {{J}1}-{{J}2} model with S  =  1/2. Distortion is introduced as an inequality of one nearest neighbor coupling with the other two. This yields a richer phase diagram by the appearance of a new gapped QSL, a gapless QSL and also a valence bond crystal phase in addition to the previous three phases found for the undistorted model.

Energy Conversion Alternatives Study (ECAS)

NASA Technical Reports Server (NTRS)

1977-01-01

ECAS compared various advanced energy conversion systems that can use coal or coal-derived fuels for baseload electric power generation. It was conducted in two phases. Phase 1 consisted of parametric studies. From these results, 11 concepts were selected for further study in Phase 2. For each of the Phase 2 systems and a common set of ground rules, performance, cost, environmental intrusion, and natural resource requirements were estimated. In addition, the contractors defined the state of the associated technology, identified the advances required, prepared preliminary research and development plans, and assessed other factors that would affect the implementation of each type of powerplant. The systems studied in Phase 2 include steam systems with atmospheric- and pressurized-fluidized-bed boilers; combined cycle gas turbine/steam systems with integrated gasifiers or fired by a semiclean, coal derived fuel; a potassium/steam system with a pressurized-fluidized-bed boiler; a closed-cycle gas turbine/organic system with a high-temperature, atmospheric-fluidized-bed furnace; a direct-coal-fired, open- cycle magnetohydrodynamic/steam system; and a molten-carbonate fuel cell/steam system with an integrated gasifier. The sensitivity of the results to changes in the ground rules and the impact of uncertainties in capital cost estimates were also examined.

Magnetic studies of nickel hydride nanoparticles embedded in chitosan matrix

NASA Astrophysics Data System (ADS)

Araújo-Barbosa, S.; Morales, M. A.

2017-11-01

In this work we present a method to produce NiH (β-NiH phase) nanoparticles from Ni-Cu solid solution. The reduction of Ni2+ and Cu2+ occurred at high temperatures and in presence of glutaraldehyde, citric acid and chitosan biopolymer. The samples are mainly composed of Ni and NiH phases with particles sizes ranging from 9 to 27 nm. DC magnetization studies reveal the presence of hydrogen-poor nickel hydride phase (α-NiH phase) which enhances the saturation magnetization at temperatures below 50 K. Stability of samples stored in air after 8 months was verified, and thermal treatment at 350 oC in presence of air transformed the samples to Ni and Cu oxides. Furthermore, we present a discussion regarding the mechanism of Ni2+ and Cu2+ chemical reduction.

Impacts of climate change and variability on transportation systems and infrastructure : Gulf Coast study, phase 2 : task 3.1 : screening for vulnerability.

DOT National Transportation Integrated Search

2014-06-01

As part of Gulf Coast Study Phase 2, the U.S. Department of Transportation (U.S. DOT) sought to improve its understanding of how a metropolitan transportation systemincluding highways, ports, airports, rail, transit, and pipelinescould be affec...

Enantiomeric separation of 2-arylpropionic acid nonsteroidal anti-inflammatory drugs by HPLC with hydroxypropyl-beta-cyclodextrin as chiral mobile phase additive.

PubMed

Ye, Jincui; Yu, Wenying; Chen, Guosheng; Shen, Zhengrong; Zeng, Su

2010-08-01

The enantio-separations of eight 2-arylpropionic acid nonsteroidal anti-inflammatory drugs (2-APA NSAIDs) were established using reversed-phase high-performance liquid chromatography with hydroxypropyl-beta-cyclodextrin (HP-beta-CD) as chiral mobile phase additive for studying the stereoselective skin permeation of suprofen, ketoprofen, naproxen, indoprofen, fenoprofen, furbiprofen, ibuprofen and carprofen. The effects of the mobile phase composition, concentration of HP-beta-CD and column temperature on retention and enantioselective separation were investigated. With 2-APA NSAIDs as acidic analytes, the retention times and resolutions of the enantiomers were strongly related to the pH of the mobile phase. In addition, both the concentration of HP-beta-CD and temperature had a great effect on retention time, but only a slight or almost no effect on resolutions of the analytes. Enantioseparations were achieved on a Shimpack CLC-ODS (150 x 4.6 mm i.d., 5 microm) column. The mobile phase was a mixture of methanol and phosphate buffer (pH 4.0-5.5, 20 mM) containing 25 mM HP-beta-CD. This method was flexible, simple and economically advantageous over the use of chiral stationary phase, and was successfully applied to the enantioselective determination of the racemic 2-APA NSAIDs in an enantioselective skin permeation study.

Local structure of the crystalline and amorphous states of Ga2Te3 phase-change alloy without resonant bonding: A combined x-ray absorption and ab initio study

NASA Astrophysics Data System (ADS)

Kolobov, A. V.; Fons, P.; Krbal, M.; Mitrofanov, K.; Tominaga, J.; Uruga, T.

2017-02-01

Phase-change memories are usually associated with GeTe-Sb2Te3 quasibinary alloys, where the large optical contrast between the crystalline and amorphous phases is attributed to the formation of resonant bonds in the crystalline phase, which has a rocksalt-like structure. The recent findings that tetrahedrally bonded Ga2Te3 possesses a similarly large property contrast and very low thermal conductivity in the crystalline phase and undergoes low-energy switching [H. Zhu et al., Appl. Phys. Lett. 97, 083504 (2010), 10.1063/1.3483762; K. Kurosaki et al., Appl. Phys. Lett. 93, 012101 (2008), 10.1063/1.2940591] challenge the existing paradigm. In this work we report on the local structure of the crystalline and amorphous phases of Ga2Te3 obtained from x-ray absorption measurements and ab initio simulations. Based on the obtained results, a model of phase change in Ga2Te3 is proposed. We argue that efficient switching in Ga2Te3 is due to the presence of primary and secondary bonding in the crystalline phase originating from the high concentration of Ga vacancies, whereas the structural stability of both phases is ensured by polyvalency of Te atoms due to the presence of lone-pair electrons and the formation of like-atom bonds in the amorphous phase.

Structural phase transitions of (Bi 1$-$xSb x ) 2(Te 1$-$y Se y) 3 compounds under high pressure and the influence of the atomic radius on the compression processes of tetradymites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Jinggeng; Yu, Zhenhai; Hu, Qingyang

Recently, A 2B 3-type tetradymites have developed into a hot topic in physical and material research fields, where the A and B atoms represent V and VI group elements, respectively. In this study, in situ angle-dispersive X-ray diffraction measurements were performed on Bi 2Te 2Se, BiSbTeSe 2, and Sb 2Te 2Se tetradymites under high pressure. Bi 2Te 2Se transforms from a layered rhombohedral structure (phase I) into 7-fold monoclinic (phase II) and body-centered tetragonal (phase IV) structures at about 8.0 and 14.3 GPa, respectively, without an 8-fold monoclinic structure (phase III) similar to that in Bi 2Te 3. Thus, themore » compression behavior of Bi 2Te 2Se is the same as that of Bi 2Se 3, which could also be obtained from first-principles calculations and in situ high-pressure electrical resistance measurements. Under high pressure, BiSbTeSe 2 and Sb 2Te 2Se undergo similar structural phase transitions to Bi 2Te 2Se, which indicates that the compression process of tellurides can be modulated by doping Se in Te sites. According to these high-pressure investigations of A 2B 3-type tetradymites, the decrease of the B-site atomic radius shrinks the stable pressure range of phase III and expands that of phase II, whereas the decrease of the A-site atomic radius induces a different effect, i.e. expanding the stable pressure range of phase III and shrinking that of phase II. Lastly, the influence of the atomic radius on the compression process of tetradymites is closely related to the chemical composition and the atom arrangement in the quintuple layer.« less

Structural phase transitions of (Bi 1$-$xSb x ) 2(Te 1$-$y Se y) 3 compounds under high pressure and the influence of the atomic radius on the compression processes of tetradymites

DOE PAGES

Zhao, Jinggeng; Yu, Zhenhai; Hu, Qingyang; ...

2016-12-14

Recently, A 2B 3-type tetradymites have developed into a hot topic in physical and material research fields, where the A and B atoms represent V and VI group elements, respectively. In this study, in situ angle-dispersive X-ray diffraction measurements were performed on Bi 2Te 2Se, BiSbTeSe 2, and Sb 2Te 2Se tetradymites under high pressure. Bi 2Te 2Se transforms from a layered rhombohedral structure (phase I) into 7-fold monoclinic (phase II) and body-centered tetragonal (phase IV) structures at about 8.0 and 14.3 GPa, respectively, without an 8-fold monoclinic structure (phase III) similar to that in Bi 2Te 3. Thus, themore » compression behavior of Bi 2Te 2Se is the same as that of Bi 2Se 3, which could also be obtained from first-principles calculations and in situ high-pressure electrical resistance measurements. Under high pressure, BiSbTeSe 2 and Sb 2Te 2Se undergo similar structural phase transitions to Bi 2Te 2Se, which indicates that the compression process of tellurides can be modulated by doping Se in Te sites. According to these high-pressure investigations of A 2B 3-type tetradymites, the decrease of the B-site atomic radius shrinks the stable pressure range of phase III and expands that of phase II, whereas the decrease of the A-site atomic radius induces a different effect, i.e. expanding the stable pressure range of phase III and shrinking that of phase II. Lastly, the influence of the atomic radius on the compression process of tetradymites is closely related to the chemical composition and the atom arrangement in the quintuple layer.« less

Assessment of a web-based Guided Self-Determination intervention for adults with type 2 diabetes in general practice: a study protocol

PubMed Central

Karlsen, Bjørg; Oftedal, Bjørg; Stangeland Lie, Silje; Rokne, Berit; Peyrot, Mark; Zoffmann, Vibeke; Graue, Marit

2016-01-01

Introduction Self-management is deemed the cornerstone in overall diabetes management. Web-based self-management interventions have potential to support adults with type 2 diabetes (T2DM) in managing their disease. Owing to somewhat ambiguous results of such interventions, interventions should be theory-based and incorporate well-defined counselling methods and techniques for behavioural change. This study is designed to assess the effectiveness of a theory-driven web-based Guided Self-Determination (GSD) intervention among adults with T2DM in general practice to improve diabetes self-management behaviours and glycosylated haemoglobin (HbA1c). Methods and analysis A complex intervention design based on the framework of the UK Medical Research Council is employed as a guide for developing the intervention, assessing its feasibility and evaluating its effectiveness. The study consists of three phases: (1) the modelling phase adapting the original GSD programme for adults with T2DM, using a qualitative design, (2) feasibility assessment of the adapted intervention on the web, employing qualitative and quantitative methods and (3) evaluating the effectiveness of the intervention on diabetes self-management behaviours and HbA1c, using a quasi-experimental design. The first phase, which is completed, and the second phase, which is underway, will provide important information about the development of the intervention and its acceptability, whereas the third phase will assess the effectiveness of this systematically developed intervention. Ethics and dissemination The Norwegian Regional Committee for Medical and Health Research Ethics (REK west number 2015/60) has approved the study design. Patients recruited in the different phases will fill out an informed consent form prior to inclusion and will be guaranteed anonymity and the right to withdraw from the study at any time. The results of the study will be published in peer-reviewed journals, electronically and in print, and presented at research conferences. Trial registration number: NCT02575599. PMID:27965253

Computational thermodynamics aided design of novel ferritic alloys

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Ying; Chen, Tianyi; Tan, Lizhen

With the aid of computational thermodynamics, Ni was identified to suppress the liquidus temperature of Fe 2Zr and four Fe-Cr-Ni-Zr alloys were designed to study the Ni effect on the phase stability of Fe 2Zr laves_phase. These alloys were fabricated through traditional arc-metling, followed by annealing at 1000 C for 336 hours and 700 C for 1275 hours. The microstructure were examined and characterized by SEM BSE image, EDS compositional mapping and point scan, XRD and TEM analysis. The major results were summarized below: 1)For investigated alloys with 12wt% Cr, 3~6wt% Zr and 3~9 wt%Ni, the phases in equilibrium withmore » the BCC phase are C15_Laves phase, Fe 23Zr 6 phase. The volume fraction of intermetallic phases increases with Ni and Zr contents. 2)Instead of (Fe,Cr) 2Zr C14_Laves phase, Ni stabilizes the C15_Laves structure in Fe-Cr-Ni-Zr alloys by substituting Fe and Cr atoms with Ni atoms in the first sublattice. 3)Fe 23Zr 6, that is metastable in the Fe-Cr-Zr ternary, is also stabilized by Ni addition. 4)Ni 7Zr 2 phase was observed in samples with high Ni/Zr ratio. Extensive solubility of Fe was identified in the phase. The microstructural and composition results obtained from this study will be incorportated into the the Fe-Cr-Ni-Zr database. The current samples will be subjected to ion irradiaition to be compared with those results for Fe-Cr-Zr alloys. Additional alloys will be designed to form (Fe,Cr,Ni) 2Zr nanoprecipitates for further studies.« less

Boron-tuning transition temperature of vanadium dioxide from rutile to monoclinic phase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, J. J.; He, H. Y.; Xie, Y.

2014-11-21

The effect of the doped boron on the phase transition temperature between the monoclinic phase and the rutile phase of VO{sub 2} has been studied by performing first-principles calculations. It is found that the phase transition temperature decreases linearly with increasing the doping level of B in each system, no matter where the B atom is in the crystal. More importantly, the descent of the transition temperature is predicted to be as large as 83 K/at. % B, indicating that the boron concentration of only 0.5% can cause the phase transition at room temperature. These findings provide a new routinemore » of modulating the phase transition of VO{sub 2} and pave a way for the practicality of VO{sub 2} as an energy-efficient green material.« less

High-pressure and high-temperature study of the phase transition in anhydrite

NASA Astrophysics Data System (ADS)

Ma, Y. M.; Zhou, Q.; He, Z.; Li, F. F.; Yang, K. F.; Cui, Q. L.; Zou, G. T.

2007-10-01

The high-pressure and high-temperature behaviors of anhydrite (CaSO4) are studied up to 53.5 GPa and 1800 K using double-sided laser heating Raman spectroscopy and x-ray diffraction in diamond anvil cells. The evidence of phase transition from an anhydrite structure to the monazite type was observed at about 2 GPa under cold compression. Another phase transition and a change in color of the sample from transparent to black have been also observed at a pressure of 33.2 GPa after laser heating. The new phase after laser heating persists to 53.5 GPa and 1800 K.

Western Wind and Solar Integration Study: Phase 2 (Presentation)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lew, D.; Brinkman, G.; Ibanez, E.

This presentation summarizes the scope and results of the Western Wind and Solar Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.

Solution of semi-flexible self-avoiding trails on a Husimi lattice built with squares

NASA Astrophysics Data System (ADS)

Oliveira, Tiago J.; Dantas, Wellington G.; Prellberg, Thomas; Stilck, Jürgen F.

2018-02-01

We study a model of semi-flexible self-avoiding trails, where the lattice paths are constrained to visit each lattice edge at most once, with configurations weighted by the number of collisions, crossings and bends, on a Husimi lattice built with squares. We find a rich phase diagram with five phases: a non-polymerised phase (NP), low density (P1) and high density (P2) polymerised phases, and, for sufficiently large stiffness, two additional anisotropic (nematic) (AN1 and AN2) polymerised phases within the P1 phase. Moreover, the AN1 phase which shows a broken symmetry with a preferential direction, is separated from the P1 phase by the other nematic AN2 phase. Although this scenario is similar to what was found in our previous calculation on the Bethe lattice, where the AN-P1 transition was discontinuous and critical, the presence of the additional nematic phase between them introduces a qualitative difference. Other details of the phase diagram are that a line of tri-critical points may separate the P1-P2 transition surface into a continuous and a discontinuous portion, and that the same may happen at the NP-P1 transition surface, details of which depend on whether crossings are allowed or forbidden. A critical end-point line is also found in the phase diagram.

A comparison study of the Born effective charges and dielectric properties of the cubic, tetragonal, monoclinic, ortho-I, ortho-II and ortho-III phases of zirconia

NASA Astrophysics Data System (ADS)

Zhang, Yan; Chen, Hua-Xin; Duan, Li; Fan, Ji-Bin; Ni, Lei; Ji, Vincent

2018-07-01

Using density-functional perturbation theory, we systematically investigate the Born effective charges and dielectric properties of cubic, tetragonal, monoclinic, ortho-I (Pbca), ortho-II (Pnma) and ortho-III (Pca21) phases of ZrO2. The magnitudes of the Born effective charges of the Zr and oxygen atoms are greater than their nominal ionic valences (+4 for Zr and -2 for oxygen), indicating a strong dynamic charge transfer from Zr atoms to O atoms and a mixed covalent-ionic bonding in six phases of ZrO2. For all six phases of ZrO2, the electronic contributions εij∞ to the static dielectric constant are rather small (range from 5 to 6.5) and neither strongly anisotropic nor strongly dependent on the structural phase, while the ionic contributions εijion to the static dielectric constant are large and not only anisotropic but also dependent on the structural phase. The average dielectric constant εbar0 of the six ZrO2 phases decreases in the sequence of tetragonal, cubic, ortho-II (Pnma), ortho-I (Pbca), ortho-III (Pca21) and monoclinic. So among six phases of ZrO2, the tetragonal and cubic phases are two suitable phases to replace SiO2 as the gate dielectric material in modern integrated-circuit technology. Furthermore, for the tetragonal ZrO2 the best orientation is [100].

75 FR 51328 - Agency Information Collection Activities: Request for Comments for a New Information Collection

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-19

... National Transportation Systems Center (Volpe Center) have designed the survey and will submit the survey... Phase 2 Implementation Study Survey. The Federal Register notice with a 60-day public comment period...-LU Section 6009 Phase 2 Implementation Study Survey. Background: Section 6009 of the Safe...

Iron Corrosion Observations: Pu(VI)-Fe Reduction Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reed, Donald T.; Swanson, Juliet S.; Richmann, Michael K.

Iron and Pu Reduction: (1) Very different appearances in iron reaction products were noted depending on pH, brine and initial iron phase; (2) Plutonium was associated with the Fe phases; (3) Green rust was often noted at the higher pH; (4) XANES established the green rust to be an Fe2/3 phase with a bromide center; and (5) This green rust phase was linked to Pu as Pu(IV).

Phase II study of docetaxel in combination with epirubicin and protracted venous infusion 5-fluorouracil (ETF) in patients with recurrent or metastatic breast cancer. A Yorkshire breast cancer research group study.

PubMed

Humphreys, A C; Dent, J; Rodwell, S; Crawford, S M; Joffe, J K; Bradley, C; Dodwell, D; Perren, T J

2004-06-01

This study was originally designed as a phase I/II study, with a dose escalation of docetaxel in combination with epirubicin 50 mg m(-2) and 5-fluorouracil (5-FU) 200 mg m(-2) day(-1). However, as dose escalation was not possible, the study is reported as a phase II study of the combination to assess response and toxicity. A total of 51 patients with locally advanced or metastatic breast cancer were treated on this phase II study, with doses of docetaxel 50 mg m(-2), epirubicin 50 mg m(-2) and infusional 5-FU 200 mg m(-2) day(-1) for 21 days. The main toxicity of this combination was neutropenia with 89% of patients having grade 3 and 4 neutropenia, and 39% of patients experiencing febrile neutropenia. Nonhaematological toxicity was mild. The overall response rate in the assessable patients was 64%, with median progression-free survival of 38 weeks, and median survival of 70 weeks. The ETF regimen was found to be toxic, and it was not possible to escalate the dose of docetaxel above the first dose level. This regimen has therefore not been taken any further, but as a development of this a new study is ongoing, combining 3-weekly epirubicin, weekly docetaxel and capecitabine, days 1-14.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stassi, D.; Ma, H.; Schmidt, T. G., E-mail: taly.gilat-schmidt@marquette.edu

Purpose: Reconstructing a low-motion cardiac phase is expected to improve coronary artery visualization in coronary computed tomography angiography (CCTA) exams. This study developed an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. The algorithm uses prospectively gated, single-beat, multiphase data made possible by wide cone-beam imaging. The proposed algorithm differs from previous approaches because the optimal phase is identified based on vessel image quality (IQ) directly, compared to previous approaches that included motion estimation and interphase processing. Because there is no processing of interphase information, the algorithm can be applied to any sampling of image phases, makingmore » it suited for prospectively gated studies where only a subset of phases are available. Methods: An automated algorithm was developed to select the optimal phase based on quantitative IQ metrics. For each reconstructed slice at each reconstructed phase, an image quality metric was calculated based on measures of circularity and edge strength of through-plane vessels. The image quality metric was aggregated across slices, while a metric of vessel-location consistency was used to ignore slices that did not contain through-plane vessels. The algorithm performance was evaluated using two observer studies. Fourteen single-beat cardiac CT exams (Revolution CT, GE Healthcare, Chalfont St. Giles, UK) reconstructed at 2% intervals were evaluated for best systolic (1), diastolic (6), or systolic and diastolic phases (7) by three readers and the algorithm. Pairwise inter-reader and reader-algorithm agreement was evaluated using the mean absolute difference (MAD) and concordance correlation coefficient (CCC) between the reader and algorithm-selected phases. A reader-consensus best phase was determined and compared to the algorithm selected phase. In cases where the algorithm and consensus best phases differed by more than 2%, IQ was scored by three readers using a five point Likert scale. Results: There was no statistically significant difference between inter-reader and reader-algorithm agreement for either MAD or CCC metrics (p > 0.1). The algorithm phase was within 2% of the consensus phase in 15/21 of cases. The average absolute difference between consensus and algorithm best phases was 2.29% ± 2.47%, with a maximum difference of 8%. Average image quality scores for the algorithm chosen best phase were 4.01 ± 0.65 overall, 3.33 ± 1.27 for right coronary artery (RCA), 4.50 ± 0.35 for left anterior descending (LAD) artery, and 4.50 ± 0.35 for left circumflex artery (LCX). Average image quality scores for the consensus best phase were 4.11 ± 0.54 overall, 3.44 ± 1.03 for RCA, 4.39 ± 0.39 for LAD, and 4.50 ± 0.18 for LCX. There was no statistically significant difference (p > 0.1) between the image quality scores of the algorithm phase and the consensus phase. Conclusions: The proposed algorithm was statistically equivalent to a reader in selecting an optimal cardiac phase for CCTA exams. When reader and algorithm phases differed by >2%, image quality as rated by blinded readers was statistically equivalent. By detecting the optimal phase for CCTA reconstruction, the proposed algorithm is expected to improve coronary artery visualization in CCTA exams.« less

Paclitaxel and carboplatin in early phase studies: Roswell Park Cancer Institute experience in the subset of patients with lung cancer.

PubMed

Creaven, P J; Raghavan, D; Pendyala, L; Loewen, G; Kindler, H L; Berghorn, E J

1997-08-01

The combination of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) given by 3-hour infusion followed by carboplatin infused over 30 minutes has been evaluated in a series of phase I studies and is currently being explored in a phase II study in patients with limited- and extensive-stage small cell lung cancer. Pharmacokinetic measurements were performed at all dose levels in the phase I studies, in which the use of granulocyte colony-stimulating factor in previously treated patients enabled more than twice the dose of paclitaxel to be given with low to moderate doses of carboplatin (dosed to a target area under the concentration-time curve of 4.0 mg x min x mL[-1]). Treatment-naive patients tolerated high paclitaxel doses (270 mg/m2) with carboplatin (dosed to a target area under the curve of 4.5 mg x min x mL[-1]) without granulocyte colony-stimulating factor support. Twenty-three patients (including previously treated and untreated) with non-small cell lung cancer were entered at a variety of paclitaxel doses in the phase I studies. At 100 to 205 mg/m2 paclitaxel, none of nine treated patients responded; at 230 to 290 mg/m2, four (29%) of 14 responded. In the phase II study of paclitaxel 250 mg/m2 in previously untreated patients with small cell lung cancer, two of five evaluable patients with extensive-stage disease have shown a partial response. In a preliminary analysis of the pharmacodynamics of paclitaxel in relation to neurotoxicity (dose limiting in two of three phase I studies), neurotoxicity correlated with the total dose of paclitaxel, the area under the curve, and the peak paclitaxel concentration, but not with the length of time plasma paclitaxel levels remained above 0.05 micromol/L. These correlations were not strong, however, and analysis of these data is ongoing.

Growth and characterization of α and β-phase tungsten films on various substrates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jeong-Seop; Cho, Jaehun; You, Chun-Yeol, E-mail: cyyou@inha.ac.kr

2016-03-15

The growth conditions of tungsten thin films were investigated using various substrates including Si, Si/SiO{sub 2}, GaAs, MgO, and Al{sub 2}O{sub 3}, and recipes were discovered for the optimal growth conditions of thick metastable β-phase tungsten films on Si, GaAs, and Al{sub 2}O{sub 3} substrates, which is an important material in spin orbit torque studies. For the Si/SiO{sub 2} substrate, the crystal phase of the tungsten films was different depending upon the tungsten film thickness, and the transport properties were found to dramatically change with the thickness owing to a change in phase from the α + β phase to the α-phase.more » It is shown that the crystal phase changes are associated with residual stress in the tungsten films and that the resistivity is closely related to the grain sizes.« less

Main reinforcement effects of precipitation phase Mg2Cu3Si, Mg2Si and MgCu2 on Mg-Cu-Si alloys by ab initio investigation

NASA Astrophysics Data System (ADS)

Shi, Xue-Feng; Wang, Hai-Chen; Tang, Ping-Ying; Tang, Bi-Yu

2017-09-01

To predict and compare the main reinforcement effects of the key precipitation phases Mg2Cu3Si, Mg2Si and MgCu2 in Mg-Cu-Si alloy, the structural, mechanical and electronic properties of these phases have been studied by ab initio calculations. The lowest formation enthalpy and cohesive energy indicate that Mg2Cu3Si has the strongest alloying ability and structural stability. The mechanical modulus indicates that Mg2Cu3Si has the strongest resistance to reversible shear/volume distortion and has maximum hardness. The characterization of brittle (ductile) behavior manifests that MgCu2 has favorable ductility. Meanwhile the evaluation of elastic anisotropy indicates that Mg2Si possesses elastic isotropy. Debye temperature prediction shows that Mg2Si and Mg2Cu3Si have better thermal stability. To achieve an unbiased interpretation on the phase stability and mechanical behavior of these precipitation phases, the density of states and differential charge densities are also analyzed. The current study deepens the comprehensive understanding of main reinforcement effects of these precipitation phases on Mg-Cu-Si alloys, and also benefits to optimize the overall performances of Mg-Cu-Si alloy from the hardness, ductility and thermal stability by controlling these second precipitation phases during the heat treatment process.

Impact of MMX® mesalamine on improvement and maintenance of health-related quality of life in patients with ulcerative colitis.

PubMed

Hodgkins, Paul; Yen, Linnette; Yarlas, Aaron; Karlstadt, Robyn; Solomon, Dory; Kane, Sunanda

2013-02-01

Ulcerative colitis (UC) substantially reduces patients' health-related quality of life (HRQoL). The current study examined the burden of disease and the impact of daily multimatrix (MMX®) mesalamine treatment on HRQoL for patients with active or quiescent mild-to-moderate UC. Data were from a two-phase, multicenter, open-label study with mild-to-moderate UC patients. In the acute phase, 132 patients with active disease received MMX mesalamine 2.4-4.8 g/day QD for 8 weeks. In the maintenance phase, 207 patients with quiescent disease received MMX mesalamine 2.4 g/day QD for 12 months. The Short Form-12 (version 2) (SF-12v2) measured HRQoL during each phase. Disease burden was examined by comparing acute-phase baseline scores with a U.S. general population sample. Repeated-measures analyses assessed change in SF-12v2 scores for each phase. Correspondence between HRQoL and disease activity was examined through correlations between SF-12v2 scores with patient-reported symptom measures. Baseline SF-12v2 scores for patients with UC were generally much lower than for the general population sample, indicating a broad disease burden. In the acute phase, significant improvement was observed for most SF-12v2 scores at week 8; a comparison with the matched norms showed a complete elimination of burden. No changes in SF-12v2 scores were observed during the maintenance phase. Changes in symptom measures and SF-12v2 scores were moderately correlated. The sizeable burden of active mild-to-moderate UC on HRQoL was eliminated following 8 weeks' treatment with MMX mesalamine 2.4-4.8 g/day. HRQoL remained stable over 12 months of maintenance treatment in patients with quiescent UC.

Electrical conductivity of MgH2 at multiple shock compression

NASA Astrophysics Data System (ADS)

Shakhray, Denis; Molodets, Alexander; Fortov, Vladimir

2011-06-01

The electrical conductivity of MgH2 has been studied under multishock compression. Earlier we had been experimentally studied metallization possibility of alane at high pressures in conditions quasiisentropic compression up to 100 GPa. A study of thermodynamic properties of MgH2 under multishock compression has been carried out also. High pressures and temperatures were obtained with an explosive device, which accelerates the metallic impactor up to 3 km/s. Identification of the hydride in experiments was made on the basis of calculations of phase trajectories loading a material in the area of existence of polymorphic phases including high-pressure phases of magnesium hydride (α and γ MgH2, hP1 and hP2). It is shown that occurrence of magnesium hydride electrical conductivity occurs in the field of existence of high-pressure hP2 phase This work was partially supported by the Presidium of the Russian Academy of Sciences within the Program of Basic Research ``Thermal Physics and Mechanics of Extreme Energy Effects and Physics of Strongly Compressed Matter and Russian Foundation for Basic Research Grant No. 10-02-01078.''

Low Dose High Energy X-ray In-Line Phase Sensitive Imaging Prototype: Investigation of Optimal Geometric Conditions and Design Parameters

PubMed Central

Ghani, Muhammad. U.; Yan, Aimin; Wong, Molly. D.; Li, Yuhua; Ren, Liqiang; Wu, Xizeng; Liu, Hong

2016-01-01

The objective of this study was to investigate the optimization of a high energy in-line phase sensitive x-ray imaging prototype under different geometric and operating conditions for mammography application. A phase retrieval algorithm based on phase attenuation duality (PAD) was applied to the phase contrast images acquired by the prototype. Imaging performance was investigated at four magnification values of 1.67, 2, 2.5 and 3 using an acrylic edge, an American College of Radiology (ACR) mammography phantom and contrast detail (CD) phantom with tube potentials of 100, 120 and 140 kVp. The ACR and CD images were acquired at the same mean glandular dose (MGD) of 1.29 mGy with a computed radiography (CR) detector of 43.75 µm pixel pitch at a fixed source to image distance (SID) of 170 cm. The x-ray tube focal spot size was kept constant as 7 µm while a 2.5 mm thick aluminum (Al) filter was used for beam hardening. The performance of phase contrast and phase retrieved images were compared with computer simulations based on the relative phase contrast factor (RPF) at high x-ray energies. The imaging results showed that the x-ray tube operated at 100 kVp under the magnification of 2.5 exhibits superior imaging performance which is in accordance to the computer simulations. As compared to the phase contrast images, the phase retrieved images of the ACR and CD phantoms demonstrated improved imaging contrast and target discrimination. We compared the CD phantom images acquired in conventional contact mode with and without the anti-scatter grid using the same prototype at 1.295 mGy and 2.59 mGy using 40 kVp, a 25 µm rhodium (Rh) filter. At the same radiation dose, the phase sensitive images provided improved detection capabilities for both the large and small discs, while compared to the double dose image acquired in conventional mode, the observer study also indicated that the phase sensitive images provided improved detection capabilities for the large discs. This study therefore validates the potential of using high energy phase contrast x-ray imaging to improve lesion detection and reduce radiation dose for clinical applications such as mammography. PMID:26756405

The effect of sesame and sunflower oils on the plasma disposition of ivermectin in goats.

PubMed

Gokbulut, C; Karademir, U; Boyacioglu, M; McKellar, Q A

2008-10-01

The effect of sesame oil (SSO) and sunflower oil (SFO) (the excipients) on the plasma disposition of ivermectin (IVM) following intravenous (i.v.) and subcutaneous (s.c.) administration at a dosage of 200 microg/kg was investigated in goats. Ten clinically healthy crossbred goats were used in the study. The animals were allocated by weight and sex into two groups of five animals each. Group 1 (n = 5) received the drug and excipient by the i.v. route only and group 2 received drug and excipient by the s.c. route only. The study was designed according to a two-phase crossover design protocol. In the first phase three animals in group 1 were i.v. administered IVM (0.2 mg/kg) + SSO (1 mL) and the other two animals received IVM (0.2 mg/kg) + SFO (1 mL). In the second phase animals were crossed over and received the alternate excipient with IVM at the same dosages. In group 2 during the first phase, three animals were s.c. administered IVM (0.2 mg/kg) + SSO (1 mL) and the other two animals were received IVM (0.2 mg/kg) + SFO (1 mL). In the second phase animals were crossed over and received the alternate excipient with IVM at the same dosages. A 4-week washout period was allowed between the two phases. In group 2 significantly increased dermal thickness was observed at the s.c. injection site of the all animals which received IVM during phase I regardless of the excipient. There was almost no change observed at the injection site of any animal during the second phase of the study following s.c. administration. In group 2 the plasma concentrations of IVM in the second phase for both excipient combinations were much higher than the plasma concentrations following first administration and appeared to be related with the dermal changes. The mean plasma disposition of IVM in combination with SSO or SFO was similar following i.v. administration. Longer terminal elimination half-lives and resultant longer mean resident time were observed after s.c. administration of the both combinations compared with i.v. administration.

Structural transformations and disordering in zirconolite (CaZrTi2O7) at high pressure.

PubMed

Salamat, Ashkan; McMillan, Paul F; Firth, Steven; Woodhead, Katherine; Hector, Andrew L; Garbarino, Gaston; Stennett, Martin C; Hyatt, Neil C

2013-02-04

There is interest in identifying novel materials for use in radioactive waste applications and studying their behavior under high pressure conditions. The mineral zirconolite (CaZrTi(2)O(7)) exists naturally in trace amounts in diamond-bearing deep-seated metamorphic/igneous environments, and it is also identified as a potential ceramic phase for radionuclide sequestration. However, it has been shown to undergo radiation-induced metamictization resulting in amorphous forms. In this study we probed the high pressure structural properties of this pyrochlore-like structure to study its phase transformations and possible amorphization behavior. Combined synchrotron X-ray diffraction and Raman spectroscopy studies reveal a series of high pressure phase transformations. Starting from the ambient pressure monoclinic structure, an intermediate phase with P2(1)/m symmetry is produced above 15.6 GPa via a first order transformation resulting in a wide coexistence range. Upon compression to above 56 GPa a disordered metastable phase III with a cotunnite-related structure appears that is recoverable to ambient conditions. We examine the similarity between the zirconolite behavior and the structural evolution of analogous pyrochlore systems under pressure.

Ethanol- and trifluoroethanol-induced changes in phase states of DPPC membranes. Prodan emission-excitation fluorescence spectroscopy supported by PARAFAC analysis

NASA Astrophysics Data System (ADS)

Horochowska, Martyna; Cieślik-Boczula, Katarzyna; Rospenk, Maria

2018-03-01

It has been shown that Prodan emission-excitation fluorescence spectroscopy supported by Parallel Factor (PARAFAC) analysis is a fast, simple and sensitive method used in the study of the phase transition from the noninterdigitated gel (Lβ‧) state to the interdigitated gel (LβI) phase, triggered by ethanol and 2,2,2-trifluoroethanol (TFE) molecules in dipalmitoylphosphatidylcholines (DPPC) membranes. The relative contribution of lipid phases with spectral characteristics of each pure phase component has been presented as a function of an increase in alcohol concentration. It has been stated that both alcohol molecules can induce a formation of the LβI phase, but TFE is over six times stronger inducer of the interdigitated phase in DPPC membranes than ethanol molecules. Moreover, in the TFE-mixed DPPC membranes, the transition from the Lβ‧ to LβI phase is accompanied by a formation of the fluid phase, which most probably serves as a boundary phase between the Lβ‧ and LβI regions. Contrary to the three phase-state model of TFE-mixed DPPC membranes, in ethanol-mixed DPPC membranes only the two phase-state model has been detected.

Bidirectional longitudinal relationship between leisure-time physical activity and psychotropic medication usage: A register linked follow-up study.

PubMed

Stubbs, Brendon; Vancampfort, Davy; Mänty, Minna; Svärd, Anna; Rahkonen, Ossi; Lahti, Jouni

2017-01-01

This study aimed to examine the bidirectional relationship between psychotropic medication use and changes in leisure-time physical activity (LTPA) among a population cohort study. Phase 1 data were collected by mail surveys in 2000-2002 among 40-60-year-old employees of the City of Helsinki, Finland, and phase 2 follow up survey was conducted in 2007. Based on self-report, the respondents were classified as inactive and active (≥14.75 MET-hours/week) at the phases 1 and 2. Hazard ratios (HR) were calculated for subsequent (2007-10) psychotropic medication purchasing according to changes in physical activity (phases 1-2). Odds ratios (OR) for physical inactivity at phase 2 were calculated according to the amount of psychotropic medication between phases 1-2. Overall, 5361 respondents were included (mean age 50 years, 80% women). Compared with the persistently active, the persistently inactive, those decreasing and adopting LTPA had an increased risk for psychotropic medication. Only the persistently inactive remained at increased risk for psychotropic medication use, following the adjustment for prior psychotropic medication use. Compared with those having no medication, the risk for physical inactivity increased as the psychotropic medication increased. Our data suggest that physical activity has an important role in maintaining wellbeing and reducing psychotropic medication usage. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Effect of shrinkage on isothermal drying behavior of 2-phase olive mill waste

USDA-ARS?s Scientific Manuscript database

The objective of this study was to determine the drying behavior of 2-phase olive mill waste (2POMW) under isothermal microwave-convection drying conditions. 2POMW samples were dried in a thin layer in a variable-power pilot microwave oven with impinging air, using a feedback controller to maintain...

Treatment of nonneovascular idiopathic macular telangiectasia type 2 with intravitreal ranibizumab: results of a phase II clinical trial.

PubMed

Toy, Brian C; Koo, Euna; Cukras, Catherine; Meyerle, Catherine B; Chew, Emily Y; Wong, Wai T

2012-05-01

To evaluate the safety and preliminary efficacy of intravitreal ranibizumab for nonneovascular idiopathic macular telangiectasia Type 2. Single-center, open-label Phase II clinical trial enrolling five participants with bilateral nonneovascular idiopathic macular telangiectasia Type 2. Intravitreal ranibizumab (0.5 mg) was administered every 4 weeks in the study eye for 12 months with the contralateral eye observed. Outcome measures included changes in best-corrected visual acuity, area of late-phase leakage on fluorescein angiography, and retinal thickness on optical coherence tomography. The study treatment was well tolerated and associated with few adverse events. Change in best-corrected visual acuity at 12 months was not significantly different between treated study eyes (0.0 ± 7.5 letters) and control fellow eyes (+2.2 ± 1.9 letters). However, decreases in the area of late-phase fluorescein angiography leakage (-33 ± 20% for study eyes, +1 ± 8% for fellow eyes) and in optical coherence tomography central subfield retinal thickness (-11.7 ± 7.0% for study eyes and -2.9 ± 3.5% for fellow eyes) were greater in study eyes compared with fellow eyes. Despite significant anatomical responses to treatment, functional improvement in visual acuity was not detected. Intravitreal ranibizumab administered monthly over a time course of 12 months is unlikely to provide a general and significant benefit to patients with nonneovascular idiopathic macular telangiectasia Type 2.

Magnetic phase transitions and ferromagnetic short-range correlations in single-crystal Tb5Si2.2Ge1.8

NASA Astrophysics Data System (ADS)

Zou, M.; Pecharsky, V. K.; Gschneidner, K. A., Jr.; Schlagel, D. L.; Lograsso, T. A.

2008-07-01

Magnetic phase transitions in a Tb5Si2.2Ge1.8 single crystal have been studied as a function of temperature and magnetic field. Magnetic-field dependencies of the critical temperatures are highly anisotropic for both the main magnetic ordering process occurring around 120 K and a spin reorientation transition at ˜70K . Magnetic-field-induced phase transitions occur with the magnetic field applied isothermally along the a and b axes (but not along the c axis) between 1.8 and 70 K in fields below 70 kOe. Strong anisotropic thermal irreversibility is observed in the Griffiths phase regime between 120 and 200 K with applied fields ranging from 10 to 1000 Oe. Our data (1) show that the magnetic and structural phase transitions around 120 K are narrowly decoupled; (2) uncover the anisotropy of ferromagnetic short-range order in the Griffiths phase; and (3) reveal some unusual magnetic domain effects in the long-range ordered state of the Tb5Si2.2Ge1.8 compound. The temperature-magnetic field phase diagrams with field applied along the three major crystallographic directions have been constructed.

In situ Studies of Phase Evolution in (Pr 1-x Nd x) 2 NiO 4 Electrodes with Various Interlayer Chemistries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dogdibegovic, Emir; Alabri, Nawf Saif; Wright, Christopher J.

The interest in Pr2NiO4 (PNO) electrode stems from the necessity to develop active and stable oxygen electrodes (1-6) for solid oxide fuel cells (SOFCs) (7-9). PNO is known for its highly active nature (7,8,10), originating from its superior oxygen ion diffusion, surface exchange coefficient (2,7,9-11) and structural flexibility over a wide temperature region (from 500 to 900oC) (3,12). PNO electrode, however, does undergo structural evolution to form a higher order phase (Pr3Ni2O7) and Pr6O11 (PrOx) (8). The structural change has been a major concern because it possibly links with the performance degradation over long-term operation (7,8) Conventional x-ray diffraction (XRD)more » has been extensively used to investigate the structural evolution in nickelates in the form of powders or planar electrodes (8,10). This method has two major limitations due to its low flux and low resolution: (1) it might overlook the presence of additional phases in the system, which is especially true for praseodymium nickelates where XRD diffraction patterns of higher order phase(s) (e.g. Pr3Ni2O7) may overlap with the parent PNO phase, making quantification challenging (8); and (2) the quantification of phase evolution in electrochemically operated PNO electrode may show major structural change with almost 100% of the parent phase transition from the conventional XRD analysis, while the transmission electron microscopy (TEM) studies clearly show the regions of preserved PNO phase (7).« less

In situ Studies of Phase Evolution in (Pr1-xNdx)2NiO4 Electrodes with Various Interlayer Chemistries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dogdibegovic, Emir; Alabri, Nawf S.; Wright, Christopher J.

2017-07-24

The interest in Pr2NiO4 (PNO) electrode stems from the necessity to develop active and stable oxygen electrodes (1-6) for solid oxide fuel cells (SOFCs) (7-9). PNO is known for its highly active nature (7,8,10), originating from its superior oxygen ion diffusion, surface exchange coefficient (2,7,9-11) and structural flexibility over a wide temperature region (from 500 to 900oC) (3,12). PNO electrode, however, does undergo structural evolution to form a higher order phase (Pr3Ni2O7) and Pr6O11 (PrOx) (8). The structural change has been a major concern because it possibly links with the performance degradation over long-term operation (7,8) Conventional x-ray diffraction (XRD)more » has been extensively used to investigate the structural evolution in nickelates in the form of powders or planar electrodes (8,10). This method has two major limitations due to its low flux and low resolution: (1) it might overlook the presence of additional phases in the system, which is especially true for praseodymium nickelates where XRD diffraction patterns of higher order phase(s) (e.g. Pr3Ni2O7) may overlap with the parent PNO phase, making quantification challenging (8); and (2) the quantification of phase evolution in electrochemically operated PNO electrode may show major structural change with almost 100% of the parent phase transition from the conventional XRD analysis, while the transmission electron microscopy (TEM) studies clearly show the regions of preserved PNO phase (7).« less

Preliminary evaluation of the role of K2S in MHD hot stream seed recovery

NASA Technical Reports Server (NTRS)

Bennett, J. E.; Kohl, F. J.

1979-01-01

Results are presented for recent analytical and experimental studies of the role of K2S in MHD hot stream seed recovery. The existing thermodynamic data base was found to contain large uncertainties and to be nonexistent for vapor phase K2S. Knudsen cell mass spectrometric experiments were undertaken to determine the vapor species in equilibrium with K2S(c). K atoms and S2 molecules ere found to be the major vapor phase species in vacuum, accounting for greater than 99 percent of the vapor phase. Combustion gas deposition studies using No. 2 Diesel fuel were also undertaken and revealed that condensed phase K2SO3 may potentially be an important compound in the MHD stream at near-stoichiometric combustion.

Raman spectra and phase transitions in Rb{sub 2}KInF{sub 6} elpasolite

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krylov, A. S.; Krylova, S. N., E-mail: slanky@iph.krasn.ru; Vtyurin, A. N.

2011-01-15

The Raman spectra of Rb{sub 2}KInF{sub 6} elpasolite crystal have been studied in a wide temperature range, including two phase transitions: from the cubic phase to the tetragonal phase and then to the monoclinic phase. Several anomalies of internal modes of InF{sub 6} octahedra and low-frequency lattice vibrations, which are related to the structural changes at the transition points, have been found and quantitatively analyzed. The results of a quantitative analysis of the temperature dependences of the parameters of spectral lines are in good agreement with the thermodynamic data on the phase transitions.

Structure, phase transitions, and isotope effects in [(CH3)4N]2PuCl6

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, Richard E.

2015-11-02

The single crystal X-ray diffraction structure of [(CH3)4N]2PuCl6 is presented for the first time, resolving long standing confusion and speculation regarding the structure of this compound in the literature. A temperature dependent study of this compound shows that the structure of [(CH3)4N]2PuCl6 undergoes no fewer than two phase transitions between 100 and 360 K. The phase of [(CH3)4N]2PuCl6 at room temperature is Fd-3c a = 26.012(3) Å. At 360 K, the structure is in space group Fm-3m with a = 13.088(1) Å. The plutonium octahedra and tetramethylammonium cations undergo a rotative displacement and the degree of rotation varies with temperature,more » giving rise to the phase transition from Fm-3m to Fd-3c as the crystal is cooled. Synthesis and structural studies of the deuterated salt [(CD3)4N]2PuCl6 suggest that there is an isotopic effect associated with this phase transition as revealed by a changing transition temperature in the deuterated versus protonated compound indicating that the donor-acceptor interactions between the tetramethylammonium cations and the hexachloroplutonate anions are driving the phase transformation.« less

Pressure-induced structural and semiconductor-semiconductor transitions in C o0.5M g0.5C r2O4

NASA Astrophysics Data System (ADS)

Rahman, S.; Saqib, Hajra; Zhang, Jinbo; Errandonea, D.; Menéndez, C.; Cazorla, C.; Samanta, Sudeshna; Li, Xiaodong; Lu, Junling; Wang, Lin

2018-05-01

The effect of pressure on the structural, vibrational, and electronic properties of Mg-doped Cr bearing spinel C o0.5M g0.5C r2O4 was studied up to 55 GPa at room-temperature using x-ray diffraction, Raman spectroscopy, electrical transport measurements, and ab initio calculations. We found that the ambient-pressure phase is cubic (spinel-type, F d 3 ¯m ) and underwent a pressure-induced structural transition to a tetragonal phase (space group I 4 ¯m 2 ) above 28 GPa. The ab initio calculation confirmed this first-order phase transition. The resistivity of the sample decreased at low pressures with the existence of a low-pressure (LP) phase and started to increase with the emergence of a high-pressure (HP) phase. The temperature dependent resistivity experiments at different pressures illustrated the wide band gap semiconducting nature of both the LP and HP phases with different activation energies, suggesting a semiconductor-semiconductor transition at HP. No evidence of chemical decomposition or a semiconductor-metal transition was observed in our studies.

Global phase diagram and quantum spin liquids in a spin- 1 2 triangular antiferromagnet

DOE PAGES

Gong, Shou-Shu; Zhu, Wei; Zhu, Jianxin; ...

2017-08-09

For this research, we study the spin-1/2 Heisenberg model on the triangular lattice with the nearest-neighbor J 1 > 0 , the next-nearest-neighobr J 2 > 0 Heisenberg interactions, and the additional scalar chiral interaction Jχ (more » $$\\vec{S}$$ i × $$\\vec{S}$$ j ) · $$\\vec{S}$$ k for the three spins in all the triangles using large-scale density matrix renormalization group calculation on cylinder geometry. With increasing J 2 (J 2 / J 1 ≤ 0.3 ) and Jχ (Jχ / J 1 ≤ 1.0 ) interactions, we establish a quantum phase diagram with the magnetically ordered 120°, stripe, and noncoplanar tetrahedral phase. In between these magnetic order phases, we find a chiral spin liquid (CSL) phase, which is identified as a ν = 1/2 bosonic fractional quantum Hall state with possible spontaneous rotational symmetry breaking. By switching on the chiral interaction, we find that the previously identified spin liquid in the J 1 - J 2 triangular model (0.08 ≲ J 2 / J 1 ≲ 0.15) shows a phase transition to the CSL phase at very small Jχ. We also compute the spin triplet gap in both spin liquid phases, and our finite-size results suggest a large gap in the odd topological sector but a small or vanishing gap in the even sector. Lastly, we discuss the implications of our results on the nature of the spin liquid phases.« less

An Innovative, No-cost, Evidence-Based Smartphone Platform for Resident Evaluation.

PubMed

Green, John M

Timely performance evaluation and feedback are critical to resident development. However, formulating and delivering this information disrupts physician workflow, leading to low participation. This study was designed to determine if a locally developed smartphone platform would integrate regular evaluation into daily processes and thus increase faculty participation in timely resident evaluation. Formal, documented resident operative and patient interaction evaluations were compiled over an 8-month study period. The study was divided into two 4-month phases. No changes to the existing evaluation methods were made during Phase 1. Phase 2 began after a washout period of 2 weeks and coincided with the launch of a smartphone-based platform. The platform uses a combination of Likert scale questions and the Dreyfus model of skill acquisition to describe competence levels in technical and nontechnical skills. The instrument inflicts minimal effect on surgeon workflow, with the aim of integrating resident evaluation into daily processes. The number of different faculty members performing evaluations, resident level (postgraduate year), type of interaction or procedure, and competency data were compiled. All evaluations were tracked by the program director as they were automatically uploaded into a database. Faculty members were introduced to the new platform at the beginning of Phase 2, and previous methods of evaluation continued to be encouraged and were considered valid throughout both phases of the study. Data were analyzed using Fisher exact test for specific PGY level, and chi-square test was used for overall program analysis. Statistical significance was set at p < 0.05. Total faculty engagement, that is, number of faculty members completing evaluations, increased from 13% (5/38) in Phase 1 to 53% (20/38) in Phase 2. During Phase 1, all evaluations consisted of online forms through the department's established system or e-mails to the program director. Evaluations were completed in 0.9% (15/1599) of cases residents completed in Phase 1 versus 12% (217/1812) of those in Phase 2. During Phase 2, evaluations were conducted exclusively using the new platform. This was done based on participant's choice. Total numbers of residents and core faculty members did not change between Phases 1 and 2. A smartphone-based platform can be created with existing technology at no cost. It is adaptable and can be updated in real-time and can employ validated scales to build an evaluation portfolio for learners assessing technical and nontechnical skills. Furthermore, and perhaps most importantly, it can be designed to integrate into existing workflow patterns to increase faculty participation. Copyright © 2016 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Hydrothermal synthesis and enhanced photocatalytic activity of mixed-phase TiO2 powders with controllable anatase/rutile ratio

NASA Astrophysics Data System (ADS)

Wang, Qi; Qiao, Zhi; Jiang, Peng; Kuang, Jianlei; Liu, Wenxiu; Cao, Wenbin

2018-03-01

In this study, mixed-phase TiO2 powders were novelly synthesized via a facile and mild hydrothermal method without any post-heat treatment. TiOSO4 and peroxide titanic acid (PTA) were used as inorganic titanium sources, while no special solvent or additive were introduced. The XRD and TEM results showed the mixed-phase TiO2 powders were composed of anatase and rutile phases, and the PTA sol played an important role on forming the rutile nucleus. The proportion of rutile in the mixed-phase TiO2 could be easily controlled in the range of 0%-70.5% by changing the amount of PTA sol used in the synthesis process. The UV-Visible absorption spectra indicated the prepared mixed-phase TiO2 showed enhanced visible light absorption with the increase of rutile ratio. The photodegradation experiments revealed the mixed-phase TiO2 exhibited the best photocatalytic activity at the rutile ratio of 41.5%, while a higher or lower rutile ratio both resulted in the decrease of photocatalytic activity.

Fullerene-like WS(2) nanoparticles and nanotubes by the vapor-phase synthesis of WCl(n) and H(2)S.

PubMed

Margolin, A; Deepak, F L; Popovitz-Biro, R; Bar-Sadan, M; Feldman, Y; Tenne, R

2008-03-05

Inorganic fullerene-like (IF) nanoparticles and nanotubes of WS(2) were synthesized by a gas phase reaction starting from WCl(n) (n = 4, 5, 6) and H(2)S. The effect of the various metal chloride precursors on the formation of the products was investigated during the course of the study. Various parameters have been studied to understand the growth and formation of the IF-WS(2) nanoparticles and nanotubes. The parameters that have been studied include flow rates of the various carrier gases, heating of the precursor metal chlorides and the temperature at which the reactions were carried out. The best set of conditions wherein maximum yields of the high quality pure-phase IF-WS(2) nanoparticles and nanotubes are obtained have been identified. A detailed growth mechanism has been outlined to understand the course of formation of the various products of WS(2).

Fullerene-like WS2 nanoparticles and nanotubes by the vapor-phase synthesis of WCln and H2S

NASA Astrophysics Data System (ADS)

Margolin, A.; Deepak, F. L.; Popovitz-Biro, R.; Bar-Sadan, M.; Feldman, Y.; Tenne, R.

2008-03-01

Inorganic fullerene-like (IF) nanoparticles and nanotubes of WS2 were synthesized by a gas phase reaction starting from WCln (n = 4, 5, 6) and H2S. The effect of the various metal chloride precursors on the formation of the products was investigated during the course of the study. Various parameters have been studied to understand the growth and formation of the IF-WS2 nanoparticles and nanotubes. The parameters that have been studied include flow rates of the various carrier gases, heating of the precursor metal chlorides and the temperature at which the reactions were carried out. The best set of conditions wherein maximum yields of the high quality pure-phase IF-WS2 nanoparticles and nanotubes are obtained have been identified. A detailed growth mechanism has been outlined to understand the course of formation of the various products of WS2.

Exploration of a Metastable Normal Spinel Phase Diagram for the Quaternary Li–Ni–Mn–Co–O System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kan, Wang Hay; Huq, Ashfia; Manthiram, Arumugam

2016-02-27

In an attempt to enlarge the normal spinel phase diagram for the quaternary Li-Ni-Mn-Co-O system, the transformation at moderate temperatures (150-210 °C) of layered Li 0.5(Ni 1-y-zMn yCo z)O 2 (Rmore » $$\\bar{3}$$m), which were obtained by an ambient-temperature extraction of lithium from Li 0.5(Ni 1-y-zMn yCo z)O 2, into normal spinel-like (Fd$$\\bar{3}$$m) Li(Ni 1-y-zMn yCo z) 2O 4 has been investigated. The phase-conversion mechanism has been studied by joint time-of-flight (TOF) neutron and X-ray diffractions, thermogravimetric analysis, and bond valence sum map. The ionic diffusion of lithium (3a, 6c) and nickel (3a, 3b) ions has been quantified as a function of temperature. The investigated spinel phases are metastable, and they are subject to change into rock-salt phases at higher temperatures. The phases have been characterized as cathodes in lithium-ion cells. Finally, the study may serve as a strategic model to access other metastable phases by low-temperature synthesis approaches.« less

Population differences in the rate of proliferation of international HapMap cell lines.

PubMed

Stark, Amy L; Zhang, Wei; Zhou, Tong; O'Donnell, Peter H; Beiswanger, Christine M; Huang, R Stephanie; Cox, Nancy J; Dolan, M Eileen

2010-12-10

The International HapMap Project is a resource for researchers containing genotype, sequencing, and expression information for EBV-transformed lymphoblastoid cell lines derived from populations across the world. The expansion of the HapMap beyond the four initial populations of Phase 2, referred to as Phase 3, has increased the sample number and ethnic diversity available for investigation. However, differences in the rate of cellular proliferation between the populations can serve as confounders in phenotype-genotype studies using these cell lines. Within the Phase 2 populations, the JPT and CHB cell lines grow faster (p < 0.0001) than the CEU or YRI cell lines. Phase 3 YRI cell lines grow significantly slower than Phase 2 YRI lines (p < 0.0001), with no widespread genetic differences based on common SNPs. In addition, we found significant growth differences between the cell lines in the Phase 2 ASN populations and the Han Chinese from the Denver metropolitan area panel in Phase 3 (p < 0.0001). Therefore, studies that separate HapMap panels into discovery and replication sets must take this into consideration. Copyright © 2010 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

Calculation of Phase Equilibria in the Y2O3-Yb2O3-ZrO2 System

NASA Technical Reports Server (NTRS)

Jacobson, Nathan S.; Liu, Zi-Kui; Kaufman, Larry; Zhang, Fan

2001-01-01

Rare earth oxide stabilized zirconias find a wide range of applications. An understanding of phase equilibria is essential to all applications. In this study, the available phase boundary data and thermodynamic data is collected and assessed. Calphad-type databases are developed to completely describe the Y2O3-ZrO2, Yb2O3-ZrO2, and Y2O3-Yb2O3 systems. The oxide units are treated as components and regular and subregular solution models are used. The resultant calculated phase diagrams show good agreement with the experimental data. Then the binaries are combined to form the database for the Y2O3-Yb2O3-ZrO2 psuedo-ternary.

Phase I/II Study of Weekly Oraxol for the Second-Line Treatment of Patients With Metastatic or Recurrent Gastric Cancer.

PubMed

Lee, Keun-Wook; Lee, Kyung Hee; Zang, Dae Young; Park, Young Iee; Shin, Dong Bok; Kim, Jin Won; Im, Seock-Ah; Koh, Sung Ae; Yu, Kyung-Sang; Cho, Joo-Youn; Jung, Jin-A; Bang, Yung-Jue

2015-08-01

Oraxol consists of paclitaxel and HM30181A, a P-glycoprotein inhibitor, to increase the oral bioavailability of paclitaxel. This phase I/II study (HM-OXL-201) was conducted to determine the maximum tolerated dose (MTD) and recommended phase II dose (RP2D) of Oraxol. In addition, we investigated the efficacy and safety of Oraxol as second-line chemotherapy for metastatic or recurrent gastric cancer (GC). In the phase I component, paclitaxel was orally administered at escalating doses (90, 120, or 150 mg/m(2) per day) with a fixed dose (15 mg/day) of HM30181A. Oraxol was administrated 6 times per cycle (days 1, 2, 8, 9, 15, and 16) every 4 weeks. In the phase II component, the efficacy and safety of Oraxol were evaluated. In the phase I component, the MTD could not be determined. Based on toxicity and pharmacokinetic data, the RP2D of oral paclitaxel was determined to be 150 mg/m(2). In the phase II component, 4 of 43 patients (9.3%) achieved partial responses. Median progression-free survival and overall survival were 2.6 and 10.7 months, respectively. Toxicity profiles were favorable, and the most common drug-related adverse events (grade ≥3) were neutropenia and diarrhea. Oraxol exhibited modest efficacy and favorable toxicity profiles as second-line chemotherapy for GC. ©AlphaMed Press; the data published online to support this summary is the property of the authors.

Organizational justice and sleeping problems: The Whitehall II study.

PubMed

Elovainio, Marko; Ferrie, Jane E; Gimeno, David; De Vogli, Roberto; Shipley, Martin; Brunner, Eric J; Kumari, Meena; Vahtera, Jussi; Marmot, Michael G; Kivimäki, Mika

2009-04-01

To test the hypothesis that organizational injustice contributes to sleeping problems. Poor sleep quality can be a marker of prolonged emotional stress and has been shown to have serious effects on the immune system and metabolism. Data were from the prospective Whitehall II study of white-collar British civil servants (3143 women and 6895 men, aged 35-55 years at baseline). Age, employment grade, health behaviors, and depressive symptoms were measured at Phase 1 (1985-1988) and baseline sleeping problems were assessed at Phase 2 (1989-1990). Organizational justice was assessed twice, at Phases 1 and 2. The outcome was mean of sleeping problems during Phases 5 (1997-1999) and 7 (2003-2004). In men, low organizational justice at Phase 1 and Phase 2 were associated with overall sleeping problems, sleep maintenance problems, sleep onset problems, and nonrefreshing sleep at Phases 5 and 7. In women, a significant association was observed between low organizational justice and overall sleeping problems and sleep onset problems. These associations were robust to adjustments for age, employment grade, health behaviors, job strain, depressive symptoms, and sleeping problems at baseline. This study shows that perceived unfair treatment at workplace is associated with increased risk of poor sleep quality in men and women, one potential mechanism through which justice at work may affect health.

Switching patients with erectile dysfunction from sildenafil citrate to tadalafil: results of a European multicenter, open-label study of patient preference.

PubMed

Ströberg, Peter; Murphy, Aileen; Costigan, Tim

2003-11-01

Three inhibitors of phosphodiesterase 5 (PDE5) are now available for the treatment of erectile dysfunction (ED): sildenafil citrate, vardenafil, and tadalafil. Pharmacologic differences between these compounds may result in patient preferences for one over another and may influence treatment decisions made by the physician and patient. Therefore, clinical research is needed to investigate whether individual properties of the PDE5 inhibitors play a role in shaping patient preference. The goal of this study was to determine what proportion of ED patients currently taking sildenafil would, after a period of treatment with tadalafil, elect to resume treatment with sildenafil at the customary dose and what proportion would elect a switch to tadalafil 20 mg for a longer period. The tolerability of both treatments was also investigated. This was a short-term, multicenter, open-label, 1-way crossover trial conducted in Sweden and Italy. Eligible patients included men aged >or=18 years with a minimum 3-month history of ED who had been taking sildenafil at stable fixed doses of 25, 50, or 100 mg as needed for at least 6 weeks and up to 24 weeks. The study consisted of 6 phases: a 1-week screening phase, a 3-week sildenafil assessment phase, a 1-week washout phase, a 6-week tadalafil initiation phase, a 3-week tadalafil assessment phase, and a 6-month extension phase, during which patients received their treatment of choice free of charge. The primary outcome measure was the proportion of patients electing to take sildenafil or tadalafil during the extension phase. Of 155 men enrolled, 147 (97.8%) completed the assessment phases of the trial. Of these 147 men, 133 (90.5%) elected to receive tadalafil in the 6-month extension phase and 14 (9.5%) elected to receive sildenafil (P < 0.001). The proportions preferring tadalafil to sildenafil were similar irrespective of age group (>or=50 years, 92%; <50 years, 90%), severity of ED (mild, 95%; moderate, 88%; severe, 96%), etiology of ED (psychogenic, 94%; organic, 91%; mixed, 87%), and sildenafil dose at study entry (50 mg, 90%; 100 mg, 89%). Both medications were well tolerated. The most common treatment-emergent adverse events occurring in >or=2% of patients during the tadalafil assessment phase included headache (4.8%), nasal congestion (4.1%), dyspepsia (3.4%), flushing (2.7%), back pain (2.0%), diarrhea (2.0%), and nausea (2.0%); the most common treatment-emergent adverse events during the sildenafil assessment phase were flusing (7.1%), nasal congestion (6.5%), headache (4.5%), and nasopharyngitis (3.2%). In this short-term, open-label study, patients who were currently taking sildenafil for ED and then received tadalafil preferred to continue oral therapy with tadalafil over sildenafil by a ratio of approximately 9:1. Although the study sought to mimic the experience of actual patients receiving treatment for ED, the results are subject to potential limitations due to the design of the study, which included differences in dosing instructions and dosages for sildenafil and tadalafil. Both sildenafil and tadalafil were well tolerated.

A fundamental study of gas formation and migration during leakage of stored carbon dioxide in subsurface formations

NASA Astrophysics Data System (ADS)

Sakaki, T.; Plampin, M. R.; Lassen, R. N.; Pawar, R. J.; Komatsu, M.; Jensen, K. H.; Illangasekare, T. H.

2011-12-01

Geologic sequestration of CO2 has received significant attention as a potential method for reducing the release of greenhouse gases into the atmosphere. Potential risk of leakage of the stored CO2 to the shallow zones of the subsurface is one of the critical issues that is needed to be addressed to design effective field storage systems. If a leak occurs, gaseous CO2 reaching shallow zones of the subsurface can potentially impact the surface and groundwater sources and vegetation. With a goal of developing models that can predict these impacts, a research study is underway to improve our understanding of the fundamental processes of gas-phase formation and multi-phase flow dynamics during CO2 migration in shallow porous media. The approach involves conducting a series of highly controlled experiments in soil columns and tanks to study the effects of soil properties, temperature, pressure gradients and heterogeneities on gas formation and migration. This paper presents the results from a set of column studies. A 3.6m long column was instrumented with 16 soil moisture sensors, 15 of which were capable of measuring electrical conductivity (EC) and temperature, eight water pressure, and two gas pressure sensors. The column was filled with test sands with known hydraulic and retention characteristics with predetermined packing configurations. Deionized water saturated with CO2 under ~0.3 kPa (roughly the same as the hydrostatic pressure at the bottom of the column) was injected at the bottom of the column using a peristaltic pump. Water and gas outflow at the top of the column were monitored continuously. The results, in general, showed that 1) gas phase formation can be triggered by multiple factors such as water pressure drop, temperature rise, and heterogeneity, 2) transition to gas phase tends to occur rather within a short period of time, 3) gas phase fraction was as high as ~40% so that gas flow was not via individual bubble movement but two-phase flow, 4) water outflow that was initially equal to the inflow rate increased when gas-phase started to form (i.e., water gets displaced), and 5) gas starts to flow upward after gas phase fraction stabilizes (i.e., buoyant force overcomes). These results suggest that the generation and migration processes of gas phase CO2 can be modelled as a traditional two-phase flow with source (when CO2 gas exsolved due to complex factors) as well as sink (when gas dissolved) terms. The experimental data will be used to develop and test the conceptual models that will guide the development of numerical simulators for applications involving CO2 storage and leakage.

Inelastic Neutron Scattering Study of the Specific Features of the Phase Transitions in (NH4)2WO2F4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smirnov, Lev S; Kolesnikov, Alexander I; Flerov, I. N.

2009-01-01

Oxyfluoride (NH4)2WO2F4 has been studied by the inelastic neutron scattering method over a wide temperature range 10 300 K at two initial neutron energies of 15 and 60 meV. The role of tetrahedral ammonium groups in the mechanism of sequential phase transitions at T1 = 201 K and T2 = 160 K has been discussed.

STM studies of topological phase transition in (Bi,In)2Se3

NASA Astrophysics Data System (ADS)

Zhang, Wenhan; Wang, Xueyun; Cheong, Sang-Wook; Wu, Weida; Weida Wu Team; Sang-Wook Cheong Collaboration

Topological insulators (TI) are a class of materials with insulating bulk and metallic surface state, which is the result of band inversion induced by strong spin-orbit coupling (SOC). The transition from topological phase to non-topological phase is of great significance. In theory, topological phase transition is realized by tuning SOC strength. It is characterized by the process of gap closing and reopening. Experimentally it was observed in two systems: TlBi(S1-xSex)2 and (Bi1-xInx)2 Se3 where the transition is realized by varying isovalent elements doping concentration. However, none of the previous studies addressed the impact of disorder, which is inevitable in doped systems. Here, we present a systematic scanning tunneling microscopy/spectroscopy study on (Bi1-xInx)2 Se3 single crystals with different In concentrations across the transition. Our results reveal an electronic inhomogeneity due to the random distribution of In defects which locally suppress the topological surface states. Our study provides a new angle of understanding the topological transition in the presence of strong disorders. This work is supported by NSF DMR-1506618.

Study of a structural phase transition by two dimensional Fourier transform NMR method

NASA Astrophysics Data System (ADS)

Trokiner, A.; Man, P. P.; Théveneau, H.; Papon, P.

1985-09-01

The fluoroperovskite RbCaF 3 undergoes a structural phase transition at 195.5 K, from a cubic phase where the 87Rb nuclei have no quadrupolar interaction ( ωQ= 0) to a tetragonal phase where ω Q ≠ O. The transition is weakly first-order. A two-dimensional FT NMR experiment has been performed on 87Rb ( I = {3}/{2}) in a single crystal in both phases and in the vicinity of the phase transition. Our results show the coexistence of the two phases at the phase transition.

Fractography of poly(methyl methacrylates).

PubMed

Kusy, R P; Turner, D T

1975-07-01

For convenience in clinical manipulation, it is the practice to fabricate PMMA protheses from mixtures of powder and monomer. When the monomer is subsequently polymerized an unusual 2-phase polymeric material results in which grains of PMMA are dispersed in a matrix of the same polymer. The mechanical properties of the 2-phase materials are inferior in certain respects relative to 1-phase polymers. The purpose of the present work is to evaluate the failure of 2-phase materials by microscopical examination of their fracture surfaces. A granular microstructure was clearly distinguishable and a distinction made between materials which fail exclusively by transgranular fracture and others which additionally exhibit intergranular fracture. In order to interpret markings observed on the fracture surfaces of the complex 2-phase systems a study was made of the influence of molecular weight on the fractography of 1-phase PMMA. Molecular weight was reduced by degradation of samples by exposure to gamma-rays. The spacing of periodic rib markings on fracture surfaces was found to decrease with molecular weight and this relationship used to provide an estimate of the molecular weight of polymer in the matrix of 2-phase materials.

Cesium vacancy ordering in phase-separated C s x F e 2 - y S e 2

DOE PAGES

Taddei, Keith M.; Sturza, M.; Chung, Duck -Yung; ...

2015-09-14

By simultaneously displaying magnetism and superconductivity in a single phase, the iron-based superconductors provide a model system for the study of magnetism's role in superconductivity. The class of intercalated iron selenide superconductors is unique among these in having the additional property of phase separation and coexistence of two distinct phases—one majority phase with iron vacancy ordering and strong antiferromagnetism, and the other a poorly understood minority microscopic phase with a contested structure. Adding to the intrigue, the majority phase has never been found to show superconductivity on its own while the minority phase has never been successfully synthesized separate frommore » the majority phase. In order to better understand this minority phase, a series of high-quality Cs xFe 2–ySe 2 single crystals with (0.8 ≤ x ≤ 1;0 ≤ y ≤ 0.3) were grown and studied. Neutron and x-ray powder diffraction performed on ground crystals show that the average I4/mmm structure of the minority phase is distinctly different from the high-temperature I4/mmm parent structure. Moreover, single-crystal diffraction reveals the presence of discrete superlattice reflections that remove the degeneracy of the Cs sites in both the majority and minority phases and reduce their structural symmetries from body centered to primitive. Group theoretical analysis in conjunction with structural modeling shows that the observed superlattice reflections originate from three-dimensional Cs vacancy ordering. This model predicts a 25% vacancy of the Cs site in the minority phase which is consistent with the site's refined occupancy. Magnetization measurements performed in tandem with neutron single-crystal diffraction provide evidence that the minority phase is the host of superconductivity. Lastly, our results also reveal a superconducting dome in which the superconducting transition temperature varies as a function of the nominal valence of iron.« less

Electronic Structure of CO2 at High Pressure

NASA Astrophysics Data System (ADS)

Shieh, S. R.; Jarrige, I.; Hiraoka, N.; Cai, Y.

2009-12-01

Carbon dioxide (CO2) is one of the important planetary materials that can be found in the Venus, Earth and Mars. Therefore, the behavior of CO2 under different pressure and temperature conditions is of great importance for understanding the evolution of these planets. Recent studies showed that there are six solid phases and one amorphous phase of CO2 found at various pressure and temperature conditions. This indicates that CO2 may exhibit different forms within planetary interiors. To better understand the behavior of CO2 polymorphs and their interactions with other materials it is necessary to study the electronic structures of CO2 polymorphs. Here we report the electronic structures of CO2-I and -III at high pressure and room temperature. The high-pressure inelastic scattering measurements of CO2 were conducted at beamline 12XU, SPring-8. A monochromatic beam with incident energy about 10 KeV was focused by a pair of KB mirrors to a size of 20 by 30 μm2. The inelastic x-ray scattering photons were collected at about 35 degrees and a solid state Si detector with resolution of about 1.4eV was used. Each spectrum was collected for 8-20 hours. Our results show that a strong pi bond, together with weak sigma bonds of oxygen K-edge were observed in CO2-I and -III phase. For the carbon K-edge of CO2-I, only a single pi bond was observed. This suggests that the molecular solid phase of CO2-I exhibits a gas-like phase instead of a crystal-like phase. Similar results were also observed form CO2-III.

Evolution of structure and superconductivity in Ba(Ni 1 -xCox)2As2

NASA Astrophysics Data System (ADS)

Eckberg, Chris; Wang, Limin; Hodovanets, Halyna; Kim, Hyunsoo; Campbell, Daniel J.; Zavalij, Peter; Piccoli, Philip; Paglione, Johnpierre

2018-06-01

The effects of Co substitution on Ba (Ni1-xCox) 2As2 (0 ≤x ≤0.251 ) single crystals grown out of Pb flux are investigated via transport, magnetic, and thermodynamic measurements. BaNi2As2 exhibits a first-order tetragonal to triclinic structural phase transition at Ts=137 K upon cooling, and enters a superconducting phase below Tc=0.7 K. The structural phase transition is sensitive to cobalt content and is suppressed completely by x ≥0.133 . The superconducting critical temperature, Tc, increases continuously with x , reaching a maximum of Tc=2.3 K at x =0.083 and then decreases monotonically until superconductivity is no longer observable well into the tetragonal phase. In contrast to similar BaNi2As2 substitutional studies, which show an abrupt change in Tc at the triclinic-tetragonal boundary that extends far into the tetragonal phase, Ba (Ni1-xCox) 2As2 exhibits a domelike phase diagram centered around the zero-temperature tetragonal-triclinic boundary. Together with an anomalously large heat capacity jump Δ Ce/γ T ˜2.2 near optimal doping, the smooth evolution of Tc in the Ba (Ni1-xCox) 2As2 system suggests a mechanism for pairing enhancement other than phonon softening.

Field-induced spin-density-wave phases in (TMTSF)2 Cl O4 at high magnetic field: Effect of anion ordering

NASA Astrophysics Data System (ADS)

Haddad, S.; Charfi-Kaddour, S.; Héritier, M.; Bennaceur, R.

2005-08-01

We study the high magnetic field-induced spin-density-wave (FISDW) phases of the relaxed (TMTSF)2ClO4 salt. Due to an orientational ordering of the ClO4 anions, a gap opens at the Fermi surface leading to a two band energy spectrum. We go through the different experimental and theoretical results related to the high field regime of the (TMTSF)2ClO4 phase diagram. We show that, in spite of intensive studies, this phase diagram is still the subject of controversies. We then tackle the issue of analyzing the exotic features of the high field spin-density-wave (SDW) phases. Based on a mean field theory and a renormalization group method, we study the consequences of anion ordering on the stability of the FISFW phases. We show that the presence of a two pairs of Fermi surface gives rise to two types of competing SDW phases. One is due to a single interband nesting process, as in a one band model, while the second originates from two intraband nesting vectors. The latter, for which we derive a generalized instability criterion, has the highest metal-SDW transition temperature and is described by two coexisting order parameters. As the temperature decreases, this coexistence puts at disadvantage the corresponding phase. Eventually, a first order transition takes place to a second SDW phase characterized by a single nesting vector and which appears inside the first one. Within the proposed model, we are able to label the different SDW phases with definite quantum numbers N related to the quantum Hall effect. We argue that the first SDW phase is nothing but the N=0 state whereas the inner phase is the N=1 state. The obtained results are consistent with recent experiments.

A molecular dynamics study of ambient and high pressure phases of silica: structure and enthalpy variation with molar volume.

PubMed

Rajappa, Chitra; Sringeri, S Bhuvaneshwari; Subramanian, Yashonath; Gopalakrishnan, J

2014-06-28

Extensive molecular dynamics studies of 13 different silica polymorphs are reported in the isothermal-isobaric ensemble with the Parrinello-Rahman variable shape simulation cell. The van Beest-Kramer-van Santen (BKS) potential is shown to predict lattice parameters for most phases within 2%-3% accuracy, as well as the relative stabilities of different polymorphs in agreement with experiment. Enthalpies of high-density polymorphs - CaCl2-type, α-PbO2-type, and pyrite-type - for which no experimental data are available as yet, are predicted here. Further, the calculated enthalpies exhibit two distinct regimes as a function of molar volume-for low and medium-density polymorphs, it is almost independent of volume, while for high-pressure phases a steep dependence is seen. A detailed analysis indicates that the increased short-range contributions to enthalpy in the high-density phases arise not only from an increased coordination number of silicon but also shorter Si-O bond lengths. Our results indicate that amorphous phases of silica exhibit better optimization of short-range interactions than crystalline phases at the same density while the magnitude of Coulombic contributions is lower in the amorphous phase.

Enhancing and sustaining empathy in medical students.

PubMed

Hojat, Mohammadreza; Axelrod, David; Spandorfer, John; Mangione, Salvatore

2013-12-01

Empathy is an important component of physician competence that needs to be enhanced. To test the hypotheses that medical students' empathy can be enhanced and sustained by targeted activities. This was a two-phase study in which 248 medical students participated. In Phase 1, students in the experimental group watched and discussed video clips of patient encounters meant to enhance empathic understanding; those in the control group watched a documentary film. Ten weeks later in Phase 2 of the study, students who were in the experimental group were divided into two groups. One group attended a lecture on empathy in patient care, and the other plus the control group watched a movie about racism. The Jefferson Scale of Empathy (JSE) was administered pre-post in Phase 1 and posttest in Phase 2. In Phase 1, the JSE mean score for the experimental group improved significantly (p < 0.01); no change in the JSE scores was observed in the control group. In Phase 2, the JSE mean score improvement was sustained in the group that attended the lecture, but not in the other group. No change in empathy was noticed in the control group. Research hypotheses were confirmed.

Effect of Niobium on Phase Transformations, Mechanical Properties and Corrosion of Supermartensitic Stainless Steel

NASA Astrophysics Data System (ADS)

de Oliveira, Mariana Perez; Calderón-Hernández, José Wilmar; Magnabosco, Rodrigo; Hincapie-Ladino, Duberney; Alonso-Falleiros, Neusa

2017-04-01

The influence of niobium addition in a supermartensitic stainless steel with 13Cr-5Ni-2Mo has been studied. The steel with Nb tempered at 600 °C for 2 h showed improved mechanical resistance properties and lower degree of sensitization, without compromising elongation and pitting corrosion resistance, when compared to the reference steel. In order to understand the Nb effect in such steel, mainly regarding phase transformation, different tempering time intervals have been studied. The better performance of the SM2MoNb is attributed to the hindering effect that Nb has in the kinetics of the phase transformations during tempering, delaying the precipitation start and coarsening stages of the present phases.

Dimethylalkoxygallane incorporating a donor-functionalised alkoxide: the monomeric gas-phase structure.

PubMed

Knapp, Caroline E; Carmalt, Claire J; McMillan, Paul F; Wann, Derek A; Robertson, Heather E; Rankin, David W H

2008-12-28

The structure of the vapour produced upon heating the dimethylalkoxygallane [Me(2)GaOCH(2)CH(2)NMe(2)](2) has been studied by gas-phase electron diffraction and ab initio molecular orbital calculations; only the monomeric form [Me(2)GaOCH(2)CH(2)NMe(2)] is observed in the vapour, with the nitrogen atom forming a dative bond with the metal centre.

Validation of the phase II feasibility study in a palliative care setting: gastrografin in malignant bowel obstruction.

PubMed

Lee, Cindy; Vather, Ryash; O'Callaghan, Anne; Robinson, Jackie; McLeod, Briar; Findlay, Michael; Bissett, Ian

2013-12-01

Malignant bowel obstruction (MBO) is common in patients with advanced cancer. To perform a phase II study to assess the feasibility of conducting a phase III trial investigating the therapeutic value of gastrografin in MBO. Randomized double-blinded placebo-controlled feasibility study. Participants received 100 mL of either gastrografin or placebo. Over 8 months, 57 patients were screened and 9 enrolled (15.8% recruitment rate). Of the 9 enrolled, 4 received gastrografin (with 2 completing assessment) and 5 received placebo (with 4 completing assessment). It is not feasible to conduct a phase III trial using the same study protocol. This study validates the use of the phase II feasibility study to assess protocol viability in a palliative population prior to embarking on a larger trial.

The National LUST Cleanup Backlog: A Study of Opportunities

EPA Pesticide Factsheets

To understand the makeup of UST releases remaining and why the pace of cleanups is slowing, EPA undertook a two-phase, data-driven analysis of the cleanups remaining as of 2006 (Phase 1) and 2009 (Phase 2).

Space Shuttle Range Safety Command Destruct System Analysis and Verification. Phase 1. Destruct System Analysis and Verification

DTIC Science & Technology

1981-03-01

overcome the shortcomings of this system. A phase III study develops the breakup model of the Space Shuttle clus’ter at various times into flight. The...2-1 ROCKET MODEL ..................................................... 2-5 COMBUSTION CHAMBER OPERATION ................................... 2-5...2-19 RESULTS .......................................................... 2-22 ROCKET MODEL

Liquid-liquid phase separation in dilute solutions of poly(styrene sulfonate) with multivalent cations: Phase diagrams, chain morphology, and impact of temperature

NASA Astrophysics Data System (ADS)

Hansch, Markus; Hämisch, Benjamin; Schweins, Ralf; Prévost, Sylvain; Huber, Klaus

2018-01-01

The dilute solution behavior of sodium poly(styrene sulfonate) is studied in the presence of trivalent Al3+ and bivalent Ba2+ cations at various levels of excess NaCl. The study evaluates the phase behavior and the morphology of the polyelectrolyte chains with increasing extent of decoration with the Al3+ and Ba2+ cations and analyses the effect of temperature on these decorated chains. The phase behavior is presented in the form of the cation concentration versus the respective poly(styrene sulfonate) concentration, recorded at the onset of precipitation. Whereas poly(styrene sulfonate) with Al3+ exhibits a linear phase boundary, denoted as the "threshold line," which increases with increasing poly(styrene sulfonate) concentration, Ba2+ cations show a threshold line which is independent of the poly(styrene sulfonate) concentration. An additional re-entrant phase, at considerably higher cation content than those of the threshold lines, is observed with Al3+ cations but not with Ba2+ cations. The threshold line and the re-entrant phase boundary form parts of the liquid-liquid phase boundary observed at the limit of low polymer concentration. The dimensions of the polyelectrolyte chains shrink considerably while approaching the respective threshold lines on increase of the Al3+ and Ba2+ cation content. However, subtle differences occur between the morphological transformation induced by Al3+ and Ba2+. Most strikingly, coils decorated with Al3+ respond very differently to temperature variations than coils decorated with Ba2+ do. As the temperature increases, the poly(styrene sulfonate) chains decrease their size in the presence of Al3+ cations but increase in size in the presence of Ba2+ cations.

Immediate and long-term effects of meditation on acute stress reactivity, cognitive functions, and intelligence.

PubMed

Singh, Yogesh; Sharma, Ratna; Talwar, Anjana

2012-01-01

With the current globalization of the world's economy and demands for enhanced performance, stress is present universally. Life's stressful events and daily stresses cause both deleterious and cumulative effects on the human body. The practice of meditation might offer a way to relieve that stress. The research team intended to study the effects of meditation on stress-induced changes in physiological parameters, cognitive functions, intelligence, and emotional quotients. The research team conducted the study in two phases, with a month between them. Each participant served as his own control, and the first phase served as the control for the second phase. In phase 1, the research team studied the effects of a stressor (10 minutes playing a computer game) on participants' stress levels. In phase 2, the research team examined the effects of meditation on stress levels. The research team conducted the study in a lab setting at the All India Institute of Medical Sciences (AIIMS), New Delhi, India. The participants were 34 healthy, male volunteers who were students. To study the effects of long-term meditation on stress levels, intelligence, emotional quotients, and cognitive functions participants meditated daily for 1 month, between phases 1 and 2. To study the immediate effects of meditation on stress levels, participants meditated for 15 minutes after playing a computer game to induce stress. The research team measured galvanic skin response (GSR), heart rate (HR), and salivary cortisol and administered tests for the intelligence and emotional quotients (IQ and EQ), acute and perceived stress (AS and PS), and cognitive functions (ie, the Sternberg memory test [short-term memory] and the Stroop test [cognitive flexibility]). Using a pre-post study design, the team performed this testing (1) prior to the start of the study (baseline); (2) in phase 1, after induced stress; (3) in part 1 of phase 2, after 1 month of daily meditation, and (4) in part 2 of phase 2, after induced stress, both before and after 15 minutes of meditation. Induced stress from the computer game resulted in a significant increase in physiological markers of stress such as GSR and HR. In the short term, meditation was associated with a physiological relaxation response (significant decrease in GSR) and an improvement in scores on the Stroop test of reaction times. In the long-term, meditation brought significant improvements in IQ and scores for cognitive functions, whereas participants' stress levels (GSR and AS) decreased. EQ, salivary cortisol, and HR showed no significant changes. The practice of meditation reduced psychological stress responses and improved cognitive functions, and the effects were pronounced with practice of meditation for a longer duration (1 month).

Structure-electrochemical evolution of a Mn-rich P2 Na 2/3Fe 0.2Mn 0.8O 2 Na-ion battery cathode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dose, Wesley M.; Sharma, Neeraj; Pramudita, James C.

The structural evolution of electrode materials directly influences the performance of sodium-ion batteries. In this work, in situ synchrotron X-ray diffraction is used to investigate the evolution of the crystal structure of a Mn-rich P2-phase Na 2/3Fe 0.2Mn 0.8O 2 cathode. A single-phase reaction takes place for the majority of the discharge–charge cycle at ~C/10, with only a short, subtle hexagonal P2 to hexagonal P2 two-phase region early in the first charge. Thus, a higher fraction of Mn compared to previous studies is demonstrated to stabilize the P2 structure at high and low potentials, with neither “Z”/OP4 phases in themore » charged state nor significant quantities of the P'2 phase in the discharged state between 1.5 and 4.2 V. Notably, sodium ions inserted during discharge are located on both available crystallographic sites, albeit with a preference for the site sharing edges with the MO 6 octahedral unit. The composition Na ~0.70Fe 0.2Mn 0.8O 2 prompts a reversible single-phase sodium redistribution between the two sites. Sodium ions vacate the site sharing faces (Naf), favoring the site sharing edges (Nae) to give a Nae/Naf site occupation of 4:1 in the discharged state. This site preference could be an intermediate state prior to the formation of the P'2 phase. Furthermore, this work shows how the Mn-rich Na 2/3Fe 0.2Mn 0.8O 2 composition and its sodium-ion distribution can minimize phase transitions during battery function, especially in the discharged state.« less

Structure-electrochemical evolution of a Mn-rich P2 Na 2/3Fe 0.2Mn 0.8O 2 Na-ion battery cathode

DOE PAGES

Dose, Wesley M.; Sharma, Neeraj; Pramudita, James C.; ...

2017-08-04

The structural evolution of electrode materials directly influences the performance of sodium-ion batteries. In this work, in situ synchrotron X-ray diffraction is used to investigate the evolution of the crystal structure of a Mn-rich P2-phase Na 2/3Fe 0.2Mn 0.8O 2 cathode. A single-phase reaction takes place for the majority of the discharge–charge cycle at ~C/10, with only a short, subtle hexagonal P2 to hexagonal P2 two-phase region early in the first charge. Thus, a higher fraction of Mn compared to previous studies is demonstrated to stabilize the P2 structure at high and low potentials, with neither “Z”/OP4 phases in themore » charged state nor significant quantities of the P'2 phase in the discharged state between 1.5 and 4.2 V. Notably, sodium ions inserted during discharge are located on both available crystallographic sites, albeit with a preference for the site sharing edges with the MO 6 octahedral unit. The composition Na ~0.70Fe 0.2Mn 0.8O 2 prompts a reversible single-phase sodium redistribution between the two sites. Sodium ions vacate the site sharing faces (Naf), favoring the site sharing edges (Nae) to give a Nae/Naf site occupation of 4:1 in the discharged state. This site preference could be an intermediate state prior to the formation of the P'2 phase. Furthermore, this work shows how the Mn-rich Na 2/3Fe 0.2Mn 0.8O 2 composition and its sodium-ion distribution can minimize phase transitions during battery function, especially in the discharged state.« less

Final Report of Tank 241-C-105 Dissolution, the Phase 2 Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meznarich, Huei K.; bolling, Stacey D.; Cooke, Gary A.

2016-10-01

Three clamshell grab samples were taken from Tank 241-C-105 in October 2015 in accordance with RPP-PLAN-60011. Analytical results of those samples were issued in the report RPP-RPT-59115 by Wastren Advantage, Inc., Hanford Laboratory. Solid phase characterization results were reported separately in LAB-RPT-15-00011 and in RPP-RPT-59147. The major solid phases reported to be present were dawsonite [NaAlCO 3(OH) 2], trona [Na 3(HCO 3)(CO 3)·2H 2O], cejkaite [Na 4(UO 2)(CO 3) 3], and an unidentified organic solid, with minor amounts of gibbsite [Al(OH) 3], natrophosphate [Na 7F(PO 4) 2·19H 2O], and traces of unidentified iron-rich and manganese-rich phases. Note that the presencemore » of dawsonite, trona, and cejkaite requires a relatively low pH, likely around pH 9 to 10. One aliquot of each grab sample was provided to 222-S Laboratory Process Chemistry for dissolution studies. Phase 1 of the dissolution testing followed the approved test plan, WRPS-1404813, Rev. 3, and examined the behavior of the Tank 241-C-105 solids treated with water, 19M sodium hydroxide, 2M nitric acid, and 0.5M oxalic acid/2M nitric acid. Phase 2 of the testing was conducted in accordance with instructions from the client and emphasized treatment with 19M sodium hydroxide followed by water washing. This is the report of the Phase 2 testing.« less

Evaluation of the phase properties of hydrating cement composite using simulated nanoindentation technique

NASA Astrophysics Data System (ADS)

Gautham, S.; Sindu, B. S.; Sasmal, Saptarshi

2017-10-01

Properties and distribution of the products formed during the hydration of cementitious composite at the microlevel are investigated using a nanoindentation technique. First, numerical nanoindentation using nonlinear contact mechanics is carried out on three different phase compositions of cement paste, viz. mono-phase Tri-calcium Silicate (C3S), Di-calcium Silicate (C2S) and Calcium-Silicate-Hydrate (CSH) individually), bi-phase (C3S-CSH, C2S-CSH) and multi-phase (more than 10 individual phases including water pores). To reflect the multi-phase characteristics of hydrating cement composite, a discretized multi-phase microstructural model of cement composite during the progression of hydration is developed. Further, a grid indentation technique for simulated nanoindentation is established, and employed to evaluate the mechanical characteristics of the hydrated multi-phase cement paste. The properties obtained from the numerical studies are compared with those obtained from experimental grid nanoindentation. The influence of composition and distribution of individual phase properties on the properties obtained from indentation are closely investigated. The study paves the way to establishing the procedure for simulated grid nanoindentation to evaluate the mechanical properties of heterogeneous composites, and facilitates the design of experimental nanoindentation.

Effects of dietary protein levels during rearing and dietary energy levels during lay on body composition and reproduction in broiler breeder females.

PubMed

van Emous, R A; Kwakkel, R P; van Krimpen, M M; Hendriks, W H

2015-05-01

A study with a 2 × 3 × 2 factorial arrangement was conducted to determine the effects of 2 dietary protein levels (high = CPh and low = CPl) during rearing, 3 dietary energy levels (3,000, MEh1; 2,800, MEs1; and 2,600, MEl1, kcal/kg AMEn, respectively) during the first phase of lay, and 2 dietary energy levels (2,800, MEs2; and 3,000, MEh2, kcal/kg AMEn, respectively) during the second phase of lay on body composition and reproduction in broiler breeders. No meaningful interactions for energy and protein treatments within the different phases of the study were found and, therefore, this paper focusses on the main effects. Pullets fed the CPl diet had a 12.8% higher feed intake, 14% lower breast muscle, and 97% higher abdominal fat pad portion at 22 wk age. The increased abdominal fat pad and decreased breast muscle of the CPl compared to the CPh birds increased hatchability during the first phase of lay, due to a decreased embryonic mortality between d 10 to 21 of incubation, and increased egg production during the second phase of lay. Feeding birds the MEh1 and MEl1 diets slightly decreased egg production compared to the MEs1 birds. Birds fed the MEh1 diet showed a higher mortality compared to the birds fed the MEs1 and MEl1 diets. Feeding birds the MEh2 diet did not affect egg production, increased hatchability of fertile eggs, decreased embryonic mortality between d 3 to 21 of incubation, and increased the number of first-grade chicks. It was concluded that a low-protein diet during rearing changed body composition with positive effects on incubation traits during the first phase of lay and improved egg production during the second phase of lay in broiler breeders. A high-energy or low-energy diet compared to a standard diet during the first phase of lay slightly decreased total and settable egg numbers while a high-energy diet during the second phase of lay increased hatchability and number of saleable chicks. © 2015 Poultry Science Association Inc.

First steps towards a gas-phase acidity ladder for derivatized fullerene dications

NASA Astrophysics Data System (ADS)

Petrie, Simon; Javahery, Gholamreza; Bohme, Diethard K.

1993-03-01

C2+60 can be derivatized by gas-phase ion/molecule reactions with polar hydrogen-bearing molecules. The adduct dications so produced may then undergo proton transfer to neutrals. The occurrence or absence of proton transfer as a secondary process gives information on the gas-phase acidity of the dicationic species C60·(XH)2+in. We have performed studies using a selected-ion flow tube at 294 ± 2 K and 0.35 ± 0.01 Torr, and have used observed reactivity of such dicationic fullerene adducts to determine upper or lower limits to their apparent and absolute gas-phase acidities. We present also a rationale for assessing the proton-transfer reactivity of dications via the apparent gas-phase acidity of these species, rather than the traditional use of gas-phase basicities or proton affinities. We propose that further studies of proton transfer from polycharged fullerene adducts may provide considerable useful information to model the reactivity of polyprotonated proteins and other large molecular polycatiions which can now be produced by techniques such as electrospray ionization.

A comprehensive study on the structural evolution of HfO 2 thin films doped with various dopants

DOE PAGES

Park, Min Hyuk; Schenk, Tony; Fancher, Christopher M.; ...

2017-04-19

The origin of the unexpected ferroelectricity in doped HfO 2 thin films is now considered to be the formation of a non-centrosymmetric Pca2 1 orthorhombic phase. Due to the polycrystalline nature of the films as well as their extremely small thickness (~10 nm) and mixed orientation and phase composition, structural analysis of doped HfO 2 thin films remains a challenging task. As a further complication, the structural similarities of the orthorhombic and tetragonal phase are difficult to distinguish by typical structural analysis techniques such as X-ray diffraction. To resolve this issue, the changes in the grazing incidence X-ray diffraction (GIXRD)more » patterns of HfO 2 films doped with Si, Al, and Gd are systematically examined. For all dopants, the shift of o111/ t101 diffraction peak is observed with increasing atomic layer deposition (ALD) cycle ratio, and this shift is thought to originate from the orthorhombic to P4 2/ nmc tetragonal phase transition with decreasing aspect ratio (2 a/(b + c) for orthorhombic and c/a for the tetragonal phase). For quantitative phase analysis, Rietveld refinement is applied to the GIXRD patterns. A progressive phase transition from P2 1/c monoclinic to orthorhombic to tetragonal is confirmed for all dopants, and a strong relationship between orthorhombic phase fraction and remanent polarization value is uniquely demonstrated. The concentration range for the ferroelectric properties was the narrowest for the Si-doped HfO 2 films. As a result, the dopant size is believed to strongly affect the concentration range for the ferroelectric phase stabilization, since small dopants can strongly decrease the free energy of the tetragonal phase due to their shorter metal–oxygen bonds.« less

A comprehensive study on the structural evolution of HfO 2 thin films doped with various dopants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Min Hyuk; Schenk, Tony; Fancher, Christopher M.

The origin of the unexpected ferroelectricity in doped HfO 2 thin films is now considered to be the formation of a non-centrosymmetric Pca2 1 orthorhombic phase. Due to the polycrystalline nature of the films as well as their extremely small thickness (~10 nm) and mixed orientation and phase composition, structural analysis of doped HfO 2 thin films remains a challenging task. As a further complication, the structural similarities of the orthorhombic and tetragonal phase are difficult to distinguish by typical structural analysis techniques such as X-ray diffraction. To resolve this issue, the changes in the grazing incidence X-ray diffraction (GIXRD)more » patterns of HfO 2 films doped with Si, Al, and Gd are systematically examined. For all dopants, the shift of o111/ t101 diffraction peak is observed with increasing atomic layer deposition (ALD) cycle ratio, and this shift is thought to originate from the orthorhombic to P4 2/ nmc tetragonal phase transition with decreasing aspect ratio (2 a/(b + c) for orthorhombic and c/a for the tetragonal phase). For quantitative phase analysis, Rietveld refinement is applied to the GIXRD patterns. A progressive phase transition from P2 1/c monoclinic to orthorhombic to tetragonal is confirmed for all dopants, and a strong relationship between orthorhombic phase fraction and remanent polarization value is uniquely demonstrated. The concentration range for the ferroelectric properties was the narrowest for the Si-doped HfO 2 films. As a result, the dopant size is believed to strongly affect the concentration range for the ferroelectric phase stabilization, since small dopants can strongly decrease the free energy of the tetragonal phase due to their shorter metal–oxygen bonds.« less

10.2 Thermal-Structural Testing

NASA Technical Reports Server (NTRS)

Hudson, Larry D.

2008-01-01

Objective: Test a C/SiC Ruddervator Subcomponent under relevant thermal, mechanical & dynamic loading a) Thermal-structural mission cycling for re-entry and hypersonic cruise conditions; b) High-temperature modal survey to study the effect of heating on mode shapes, natural frequencies and damping. Supports NASA ARMD Hypersonics Material & Structures Program. Partners: NASA Dryden / Langley / Glenn, Lockheed-Martin, Materials Research & Design, GE CCP Test Phases - Phase 1: Acoustic-Vibration Testing (LaRC) completed - Phase 2: Thermal-Mechanical Testing (DFRC) in assembly - Phase 3: Mechanical Testing (DFRC) in assembly

Electronic structure of carbon dioxide under pressure and insights into the molecular-to-nonmolecular transition

PubMed Central

Shieh, Sean R.; Jarrige, Ignace; Wu, Min; Hiraoka, Nozomu; Tse, John S.; Mi, Zhongying; Kaci, Linada; Jiang, Jian-Zhong; Cai, Yong Q.

2013-01-01

Knowledge of the high-pressure behavior of carbon dioxide (CO2), an important planetary material found in Venus, Earth, and Mars, is vital to the study of the evolution and dynamics of the planetary interiors as well as to the fundamental understanding of the C–O bonding and interaction between the molecules. Recent studies have revealed a number of crystalline polymorphs (CO2-I to -VII) and an amorphous phase under high pressure–temperature conditions. Nevertheless, the reported phase stability field and transition pressures at room temperature are poorly defined, especially for the amorphous phase. Here we shed light on the successive pressure-induced local structural changes and the molecular-to-nonmolecular transition of CO2 at room temperature by performing an in situ study of the local electronic structure using X-ray Raman scattering, aided by first-principle exciton calculations. We show that the transition from CO2-I to CO2-III was initiated at around 7.4 GPa, and completed at about 17 GPa. The present study also shows that at ∼37 GPa, molecular CO2 starts to polymerize to an extended structure with fourfold coordinated carbon and minor CO3 and CO-like species. The observed pressure is more than 10 GPa below previously reported. The disappearance of the minority species at 63(±3) GPa suggests that a previously unknown phase transition within the nonmolecular phase of CO2 has occurred. PMID:24167283

Remedial investigation/feasibility study for the Clinch River/Poplar Creek operable unit. Volume 5. Appendixes G, H, I, J

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-09-01

The Quality Assurance/Quality Control (QA/QC) Program for Phase 2 of the Clinch River Remedial Investigation (CRRI) was designed to comply with both Department of Energy (DOE) Order 5700.6C and Environmental Protection Agency (EPA) QAMS-005/80 (EPA 1980a) guidelines. QA requirements and the general QA objectives for Phase 2 data were defined in the Phase 2 Sampling and Analysis Plan (SAP)-Quality Assurance Project Plan, and scope changes noted in the Phase 2 Sampling and Analysis Plan Addendum. The QA objectives for Phase 2 data were the following: (1) Scientific data generated will withstand scientific and legal scrutiny. (2) Data will be gatheredmore » using appropriate procedures for sample collection, sample handling and security, chain of custody (COC), laboratory analyses, and data reporting. (3) Data will be of known precision and accuracy. (4) Data will meet data quality objectives (DQOs) defined in the Phase 2 SAP.« less

Systematic approaches to layered materials with strong electron correlations

NASA Astrophysics Data System (ADS)

Chung, Chung-Hou

I present systematic large-N approaches to study the ground state magnetic orderings and charge transport of layered materials with strong electron correlations, including the organic material kappa-(BEDT-TTF)2X, and the antiferromagnetic insulators Cs2CuCl4 and SrCu2(BO3) 2. I model the electronic properties of the organic materials kappa-(BEDT-TTF) 2X with a fermionic SU(N) Hubbard-Heisenberg model on an anisotropic triangular lattice. The ground state phase diagram shows a metal-insulator transition and a depression of the density of states in the metallic phase which are consistent with the experiments. The magnetic properties of kappa-(BEDT-TTF) 2X are modeled by a bosonic Sp(N) quantum Heisenberg antiferromagnet on the same lattice. The phase diagram consists of five different phases as a function of the size of the spin and the degree of frustration: the Neel ordered phase, a (pi, pi) short-range-order (SRO) phase, an incommensurate (q, q) long-range-order (LRO) phase, a (q, q) SRO phase, and a decoupled chain phase. I apply the same Sp(N) approach on the same triangular lattice to model the magnetic properties of Cs2CuCl 4 both with and without a magnetic field. At zero field, I find the ground state either exhibits incommensurate spin order, or is in a quantum disordered phase with deconfined spin-1/2 excitations and topological order. The Sp(N) calculation of spin excitation spectrum shows a large upward quantum renormalization consistent with that seen in experiments. For fields perpendicular to the plane of spin rotation, I find that the spins form an incommensurate "cone" of polarization up to a saturation field where all spins are fully polarized. There is a large quantum renormalization of the zero-field incommensuration. The results are in apparent agreement with neutron scattering experiments. Finally, the magnetic properties of the insulator SrCu2(BO 3)2 is modeled by the Sp(N) quantum antiferromagnet on the Shastry-Sutherland lattice. In addition to the familiar Neel and dimer phases, I find a confining phase with plaquette order, and a topologically ordered phase with deconfined S = 1/2 spinons and helical spin correlations. The deconfined phase is contiguous to the dimer phase, and in a regime of couplings close to those appropriate for the material.

[Establishment of regional active neonatal transport network].

PubMed

Kong, Xiang-yong; Gao, Xin; Yin, Xiao-juan; Hong, Xiao-yang; Fang, Huan-sheng; Wang, Zi-zhen; Li, Ai-hua; Luo, Fen-ping; Feng, Zhi-chun

2010-01-01

To evaluate the clinical function and significance of establishing a regional active neonatal transport network (ANTN) in Beijing. The authors retrospectively studied intensive care and the role of ANTN system in management of critically ill neonates and compared the outcome of newborn infants transported to our NICU before and after we established standardized NICU and ANTN system (phase 1: July 2004 to June 2006 vs phase 2: July 2006 to May 2008). The number of neonatal transport significantly increased from 587 during phase 1 to 2797 during phase 2. Success rate of transport and the total cure rate in phase 2 were 97.85% and 91.99% respectively, which were significantly higher than those in phase 1 (94.36% and 88.69%, respectively, P < 0.01). The neonatal mortality significantly decreased in phase 2 compared with that in phase 1 (2.29% vs 4.31%, P < 0.01). The capacity of our NICU was enlarged following the development of ANTN. There are 200 beds for level 3 infants in phase 2, but there were only 20 beds in phase 1. Significantly less patients in the phase 2 had hypothermia, acidosis and the blood glucose instability than those in phase 1 (P < 0.01, 0.05, 0.01 and 0.05, respectively). The proportion of preterm infants transported to our NICU were higher in phase 2 compared with that in phase 1, especially infants whose gestational age was below 32 weeks. The proportions of asphyxia and respiratory distress syndrome were lower in phase 2 than that in phase 1, but the total cure rates of these two diseases had no significant changes between the two phases. The most important finding was that the improvement of outcome of premature infants and those with asphyxia and aspiration syndrome was noted following the development of ANTN. Establishing regional ANTN for a tertiary hospital is very important to elevate the total level in management of critically ill newborn infants. It plays a very important role in reducing mortality and improving total outcomes of newborn infants. There are still some problems remained to solve after four years practice in order to optimize the ANTN to meet needs of the development of neonatology.

The Maximal Oxygen Uptake Verification Phase: a Light at the End of the Tunnel?

PubMed

Schaun, Gustavo Z

2017-12-08

Commonly performed during an incremental test to exhaustion, maximal oxygen uptake (V̇O 2max ) assessment has become a recurring practice in clinical and experimental settings. To validate the test, several criteria were proposed. In this context, the plateau in oxygen uptake (V̇O 2 ) is inconsistent in its frequency, reducing its usefulness as a robust method to determine "true" V̇O 2max . Moreover, secondary criteria previously suggested, such as expiratory exchange ratios or percentages of maximal heart rate, are highly dependent on protocol design and often are achieved at V̇O 2 percentages well below V̇O 2max . Thus, an alternative method termed verification phase was proposed. Currently, it is clear that the verification phase can be a practical and sensitive method to confirm V̇O 2max ; however, procedures to conduct it are not standardized across the literature and no previous research tried to summarize how it has been employed. Therefore, in this review the knowledge on the verification phase was updated, while suggestions on how it can be performed (e.g. intensity, duration, recovery) were provided according to population and protocol design. Future studies should focus to identify a verification protocol feasible for different populations and to compare square-wave and multistage verification phases. Additionally, studies assessing verification phases in different patient populations are still warranted.

Retinopathy of prematurity and serum level of insulin-like growth factor-1.

PubMed

Banjac, Lidija; Bokan, Vesna

2012-06-01

The aim of our study was to measure and compare serum insulin-like growth factor-1 (IGF-1) levels at postmenstrual age of 33 weeks between preterm infants with and without retinopathy of prematurity (ROP). ROP occurs in two phases. Low serum levels of IGF-1 during ROP phase 1 have been found to correlate with the severity of ROP. ROP phase 2 begins around postmenstrual week 33. We conducted a prospective cohort study to measure serum IGF-1 levels in premature infants at postmenstrual age of 33 weeks. The study included all premature infants (N = 74), gestational age < or = 33 weeks, hospitalized at Department of Neonatology, Clinical Center of Montenegro, from April 2008 to July 2009. The incidence of ROP in the study cohort was 50.7%. Infants with ROP had a significantly lower birth weight and significantly shorter gestational age. The mean level of IGF-1 at postmenstrual age of 33 weeks was 23.7 mcg/L. Study results showed that there was no significant difference in serum IGF-1 level between newborns with and without ROP at postmenstrual age of 33 weeks (in newborns with ROP, it was the beginning of ROP phase 2). A large controlled study with repeated measurement of IGF-1 level in the neonatal period is needed to confirm that restoration of IGF-I level occurs in ROP phase 2, i.e. that the low level of IGF-1 is only a feature of ROP phase 1.

Phase Equilibria Study in the TeO2-Na2O-SiO2 System in Air Between 723 K (500 °C) and 1473 K (1200 °C)

NASA Astrophysics Data System (ADS)

Santoso, Imam; Taskinen, Pekka

2016-08-01

Knowledge of phase equilibria in the TeO2-Na2O-SiO2 system at elevated temperatures is important for ceramic and glass industries and for improving the operation of the smelting process of tellurium-containing materials. A review of previous investigations has indicated, however, that there are omissions in the available datasets on the liquidus temperatures of the molten TeO2-Na2O-SiO2 mixtures. The employed experimental method included equilibration of mixtures made from high purity oxides, rapid quenching of the equilibrated samples in water and followed by compositional analysis of the phases using an electron probe X-ray microanalyzer. The liquidus and phase equilibria in the TeO2-SiO2, TeO2-Na2O, and SiO2-TeO2-Na2O systems have been studied for a wide range of compositions between 723 K (500 °C) and 1473 K (1200 °C) at TeO2, SiO2, and Na2SiO3 saturations. New data have been generated in the SiO2-TeO2-Na2O system at SiO2 saturation. The liquidus compositions in the TeO2-Na2O system at TeO2 saturation have been compared with the previous data and an assessed phase diagram.

Formation of Gas-Phase Formate in Thermal Reactions of Carbon Dioxide with Diatomic Iron Hydride Anions.

PubMed

Jiang, Li-Xue; Zhao, Chongyang; Li, Xiao-Na; Chen, Hui; He, Sheng-Gui

2017-04-03

The hydrogenation of carbon dioxide involves the activation of the thermodynamically very stable molecule CO 2 and formation of a C-H bond. Herein, we report that HCO 2 - and CO can be formed in the thermal reaction of CO 2 with a diatomic metal hydride species, FeH - . The FeH - anions were produced by laser ablation, and the reaction with CO 2 was analyzed by mass spectrometry and quantum-chemical calculations. Gas-phase HCO 2 - was observed directly as a product, and its formation was predicted to proceed by facile hydride transfer. The mechanism of CO 2 hydrogenation in this gas-phase study parallels similar behavior of a condensed-phase iron catalyst. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biweekly Carboplatin Plus Gemcitabine as First-Line Treatment of Elderly Patients With Advanced Squamous Non-Small-cell Lung Cancer: A Multicenter Phase I-II Trial by the Hellenic Oncology Research Group.

PubMed

Karampeazis, Athanasios; Vamvakas, Lambros; Kentepozidis, Nikolaos; Polyzos, Aris; Chandrinos, Vassilis; Rigas, Georgios; Christofyllakis, Charalambos; Kotsakis, Athanasios; Hatzidaki, Dora; Pallis, Athanasios G; Georgoulias, Vassilis

2016-11-01

The present study was a phase I/II study to determine the maximum tolerated doses (MTDs) and dose-limiting toxicities of the biweekly carboplatin/gemcitabine combination and evaluate its safety and efficacy in patients aged ≥ 70 years with advanced squamous non-small-cell lung cancer (NSCLC). Patients aged ≥ 70 years with advanced or metastatic squamous NSCLC received escalated doses of carboplatin (area under the curve [AUC] 2-2.5 intravenously) and gemcitabine (800-1100 mg/m 2 intravenously) every 2 weeks (phase I). In the phase II, the drugs were administered at their previously defined MTDs (carboplatin, AUC 2.5; gemcitabine, 1100 mg/m 2 ). The primary endpoint was the overall response rate. A total of 69 patients were enrolled (phase I, n = 15). The median age was 76 years (range, 70-84 years); 52 patients had stage IV disease, and 61 and 8 patients had Eastern Cooperative Oncology Group performance status of 0 to 1 and 2, respectively. The MTDs could not be reached at the predefined last dose levels. The dose-limiting toxicities were grade 5 renal toxicity and grade 3 thrombocytopenia. In the phase II study, the overall response rate was 35.8% (95% confidence interval [CI], 23.0%-48.8%). In the intention-to-treat analysis, the median progression-free survival was 6.7 months (95% CI, 4.2-8.8 months), and the median overall survival was 13.3 months (95% CI, 7.1-19.6 months). Grade 3 or 4 neutropenia was observed in 7 patients (12.3%), grade 3 or 4 thrombocytopenia in 4 patients (7.1%), and grade 2 or 3 fatigue in 10 patients (17.5%). One toxic death occurred in the phase I of the study. The biweekly regimen of gemcitabine and carboplatin showed satisfactory efficacy and a favorable toxicity profile in elderly patients with advanced or metastatic squamous cell NSCLC. Copyright © 2016 Elsevier Inc. All rights reserved.

Changes of trehalose content and expression of relative genes during the bioethanol fermentation by Saccharomyces cerevisiae.

PubMed

Yi, Chenfeng; Wang, Fenglian; Dong, Shijun; Li, Hao

2016-10-01

Traditionally, trehalose is considered as a protectant to improve the ethanol tolerance of Saccharomyces cerevisiae. In this study, to clarify the changes and roles of trehalose during the bioethanol fermentation, trehalose content and expression of related genes at lag, exponential, and stationary phases (i.e., 2, 8, and 16 h of batch fermentation process) were determined. Although yeast cells at exponential and stationary phase had higher trehalose content than cells at lag phase (P < 0.01), there was no significant difference in trehalose content between exponential and stationary phases (P > 0.05). Moreover, expression of the trehalose degradation-related genes NTH1 and NTH2 decreased at exponential phase in comparison with that at lag phase; compared with cells at lag phase, cells at stationary phase had higher expression of TPS1, ATH1, NTH1, and NTH2 but lower expression of TPS2. During the lag-exponential phase transition, downregulation of NTH1 and NTH2 promoted accumulation of trehalose, and to some extent, trehalose might confer ethanol tolerance to S. cerevisiae before stationary phase. During the exponential-stationary phase transition, upregulation of TPS1 contributed to accumulation of trehalose, and Tps1 protein might be indispensable in yeast cells to withstand ethanol stress at the stationary phase. Moreover, trehalose would be degraded to supply carbon source at stationary phase.

Temperature-dependent Raman and ultraviolet photoelectron spectroscopy studies on phase transition behavior of VO{sub 2} films with M1 and M2 phases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Okimura, Kunio, E-mail: okifn@keyaki.cc.u-tokai.ac.jp; Hanis Azhan, Nurul; Hajiri, Tetsuya

Structural and electronic phase transitions behavior of two polycrystalline VO{sub 2} films, one with pure M1 phase and the other with pure M2 phase at room temperature, were investigated by temperature-controlled Raman spectroscopy and ultraviolet photoelectron spectroscopy (UPS). We observed characteristic transient dynamics in which the Raman modes at 195 cm{sup −1} (V-V vibration) and 616 cm{sup −1} (V-O vibration) showed remarkable hardening along the temperature in M1 phase film, indicating the rearrangements of V-V pairs and VO{sub 6} octahedra. It was also shown that the M1 Raman mode frequency approached those of invariant M2 peaks before entering rutile phase. In UPSmore » spectra with high energy resolution of 0.03 eV for the M2 phase film, narrower V{sub 3d} band was observed together with smaller gap compared to those of M1 phase film, supporting the nature of Mott insulator of M2 phase even in the polycrystalline film. Cooperative behavior of lattice rearrangements and electronic phase transition was suggested for M1 phase film.« less

Tensor-entanglement-filtering renormalization approach and symmetry-protected topological order

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gu Zhengcheng; Wen Xiaogang

2009-10-15

We study the renormalization group flow of the Lagrangian for statistical and quantum systems by representing their path integral in terms of a tensor network. Using a tensor-entanglement-filtering renormalization approach that removes local entanglement and produces a coarse-grained lattice, we show that the resulting renormalization flow of the tensors in the tensor network has a nice fixed-point structure. The isolated fixed-point tensors T{sub inv} plus the symmetry group G{sub sym} of the tensors (i.e., the symmetry group of the Lagrangian) characterize various phases of the system. Such a characterization can describe both the symmetry breaking phases and topological phases, asmore » illustrated by two-dimensional (2D) statistical Ising model, 2D statistical loop-gas model, and 1+1D quantum spin-1/2 and spin-1 models. In particular, using such a (G{sub sym},T{sub inv}) characterization, we show that the Haldane phase for a spin-1 chain is a phase protected by the time-reversal, parity, and translation symmetries. Thus the Haldane phase is a symmetry-protected topological phase. The (G{sub sym},T{sub inv}) characterization is more general than the characterizations based on the boundary spins and string order parameters. The tensor renormalization approach also allows us to study continuous phase transitions between symmetry breaking phases and/or topological phases. The scaling dimensions and the central charges for the critical points that describe those continuous phase transitions can be calculated from the fixed-point tensors at those critical points.« less

The Pliocene Model Intercomparison Project (PlioMIP) Phase 2: scientific objectives and experimental design

NASA Astrophysics Data System (ADS)

Haywood, Alan M.; Dowsett, Harry J.; Dolan, Aisling M.; Rowley, David; Abe-Ouchi, Ayako; Otto-Bliesner, Bette; Chandler, Mark A.; Hunter, Stephen J.; Lunt, Daniel J.; Pound, Matthew; Salzmann, Ulrich

2016-03-01

The Pliocene Model Intercomparison Project (PlioMIP) is a co-ordinated international climate modelling initiative to study and understand climate and environments of the Late Pliocene, as well as their potential relevance in the context of future climate change. PlioMIP examines the consistency of model predictions in simulating Pliocene climate and their ability to reproduce climate signals preserved by geological climate archives. Here we provide a description of the aim and objectives of the next phase of the model intercomparison project (PlioMIP Phase 2), and we present the experimental design and boundary conditions that will be utilized for climate model experiments in Phase 2. Following on from PlioMIP Phase 1, Phase 2 will continue to be a mechanism for sampling structural uncertainty within climate models. However, Phase 1 demonstrated the requirement to better understand boundary condition uncertainties as well as uncertainty in the methodologies used for data-model comparison. Therefore, our strategy for Phase 2 is to utilize state-of-the-art boundary conditions that have emerged over the last 5 years. These include a new palaeogeographic reconstruction, detailing ocean bathymetry and land-ice surface topography. The ice surface topography is built upon the lessons learned from offline ice sheet modelling studies. Land surface cover has been enhanced by recent additions of Pliocene soils and lakes. Atmospheric reconstructions of palaeo-CO2 are emerging on orbital timescales, and these are also incorporated into PlioMIP Phase 2. New records of surface and sea surface temperature change are being produced that will be more temporally consistent with the boundary conditions and forcings used within models. Finally we have designed a suite of prioritized experiments that tackle issues surrounding the basic understanding of the Pliocene and its relevance in the context of future climate change in a discrete way.

The Pliocene Model Intercomparison Project (PlioMIP) Phase 2: Scientific Objectives and Experimental Design

NASA Technical Reports Server (NTRS)

Haywood, Alan M.; Dowsett, Harry J.; Dolan, Aisling M.; Rowley, David; Abe-Ouchi, Ayako; Otto-Bliesner, Bette; Chandler, Mark A.; Hunter, Stephen J.; Lunt, Daniel J.; Pound, Matthew;

Anomalous magnetoelastic behaviour near morphotropic phase boundary in ferromagnetic Tb 1-xNd xCo 2 system

DOE PAGES

Murtaza, Adil; Yang, Sen; Zhou, Chao; ...

2016-08-04

In this study, we report a morphotropic phase boundary (MPB) involved ferromagnetic system Tb 1-xNd xCo 2 and reveal the corresponding structural and magnetoelastic properties of this system. With high resolution synchrotron X-ray diffractometry, the crystal structure of the TbCo 2-rich side is detected to be rhombohedral and that of NdCo 2-rich side is tetragonal below their respective Curie temperatures TC. The MPB composition Tb 0.35Nd 0.65Co 2 corresponds to the coexistence of the rhombohedral phase (R-phase) and tetragonal phase ( T-phase). Contrary to previously reported MPB involved ferromagnetic systems, the MPB composition of Tb 0.35Nd 0.65Co 2 shows minimummore » magnetization which can be understood as compensation of sublattice moments between the R-phase and the T-phase. Furthermore, magnetostriction of Tb 1-xNd xCo 2 decreases with increasing Nd concentration until x = 0.8 and then increases in the negative direction with further increasing Nd concentration; the optimum point for magnetoelastic properties lies towards the rhombohedral phase. Finally, our work not only shows an anomalous type of ferromagnetic MPB but also provides an effective way to design functional materials.« less

General phase transition models for vehicular traffic with point constraints on the flow

NASA Astrophysics Data System (ADS)

Dal Santo, E.; Rosini, M. D.; Dymski, N.; Benyahia, M.

2017-12-01

We generalize the phase transition model studied in [R. Colombo. Hyperbolic phase transition in traffic flow.\\ SIAM J.\\ Appl.\\ Math., 63(2):708-721, 2002], that describes the evolution of vehicular traffic along a one-lane road. Two different phases are taken into account, according to whether the traffic is low or heavy. The model is given by a scalar conservation law in the \\emph{free-flow} phase and by a system of two conservation laws in the \\emph{congested} phase. In particular, we study the resulting Riemann problems in the case a local point constraint on the flux of the solutions is enforced.

Pressure Induced Phase Transformations of Silica Polymorphs and Glasses

NASA Astrophysics Data System (ADS)

Cagin, Tahir; Demiralp, Ersan; Goddard, William A., III

1998-03-01

Silica, SiO_2, is one of the most widely studied substance, and it has some complex and unusual properties. We have used a recently developed 2-body interaction force field (E. Demiralp, T. Cagin, W.A. Goddard, III, unpublished.) to study the structural phase transformations in silica under various pressure loading conditions. The specific transformations we studied are α-quartz to stishovite, coesite to stishovite and fused glass to stishovite-like dense, a dominantly six-coordinated glassy phase. Molecular dynamics simulations are performed under the constant loading rates ranging from 0.1 GPa/ps to 2.0 GPa/ps, pressures upto 100 GPa and at temperatures 300, 500, 700 and 900 K. We observe the crystal to crystal transformations to occur reconstructively, whereas it occurs in a smooth and displacive manner from glass to a stishovite-like phase confirming earlier conjectures. (E.M. Stolper and T.J. Ahrens, Geophys. Res. Let.) 14, 1231 (1987). To elucidate the shock loading experiments, we studied the dependence of transition pressure on the loading rate and the temperature. To assess the hysterisis effect we also studied the unloading behavior of each transformation.

Translational phases of evidence in a prognostic biomarker: a systematic review and meta-analysis of natriuretic peptides and the prognosis of stable coronary disease.

PubMed

Sutaria, Shailen; Philipson, Peter; Fitzpatrick, Natalie K; Abrams, Keith; Moreno, Santiago G; Timmis, Adam; Hingorani, Aroon D; Hemingway, Harry

2012-04-01

Translational phases of study are important in evaluating whether a prognostic biomarker is likely to have impact on clinical practice but systematic evaluations of such evidence are lacking. To systematically evaluate the clinical usefulness of the published literature on the association of natriuretic peptides (NP) and prognosis in stable coronary disease. MEDLINE and EMBASE until the end of July 2009, without restrictions. Prospective studies measuring NP in people with stable coronary disease who were followed-up for all cause mortality, coronary or cardiovascular events. Two independent reviewers categorised studies according to the American Heart Association phase of study, and extracted data according to the study reporting guidelines from the American Heart Association and REMARK. Systematic review of 19 studies found 17 which were phase 2, reporting an association between NP and events, two phase 3 studies, statistically examining the incremental prognostic value of NP, but no studies assessing whether NP predicted risk sufficiently to change management (phase 4), improve clinical outcomes (phase 5) or cost effectiveness (phase 6). No study referred to a statistical analytic protocol. Meta-analysis of 14 studies, reporting 18,841 patients and 1655 outcome events, found an RR for events of 3.28 (95% CI 2.45 to 4.38) comparing top versus bottom third of NP. This effect was 26% lower among the five studies which adjusted for a priori confounders (age, sex, renal function and left ventricular function) and 38% lower when adjusting for publication bias (Egger's p=0.001). The unbiased strength of association of NP with prognosis in stable coronary disease is unclear, and there is a lack of reports of clinically useful measures of prediction and discrimination or studies relating NP levels to clinical decision making. The available literature is confined to early phases and is of limited clinical usefulness.

First principles study of LiAlO2: new dense monoclinic phase under high pressure

NASA Astrophysics Data System (ADS)

Liu, Guangtao; Liu, Hanyu

2018-03-01

In this work, we have systematically explored the crystal structures of LiAlO2 at high pressures using crystal structure prediction method in combination with the density functional theory calculations. Besides the reported α, β, γ, δ and ɛ-phases, here we propose a new monoclinic ζ-LiAlO2 (C2/m) structure, which becomes thermodynamically and dynamically stable above 27 GPa. It is found that the cation coordination number increases from 4 to 6 under compression. Consisting of the compact {LiO6} and {AlO6} octahedrons, the newly-discovered ζ-phase possesses a very high density. Further electronic calculations show that LiAlO2 is still an insulator up to 60 GPa, and its bandgap increases upon compression. The present study advances our understanding on the crystal structures and high-pressure phase transitions of LiAlO2 that may trigger applications in multiple areas of industry and provoke more related basic science research.

Human responses to bright light of different durations.

PubMed

Chang, Anne-Marie; Santhi, Nayantara; St Hilaire, Melissa; Gronfier, Claude; Bradstreet, Dayna S; Duffy, Jeanne F; Lockley, Steven W; Kronauer, Richard E; Czeisler, Charles A

2012-07-01

Light exposure in the early night induces phase delays of the circadian rhythm in melatonin in humans. Previous studies have investigated the effect of timing, intensity, wavelength, history and pattern of light stimuli on the human circadian timing system. We present results from a study of the duration–response relationship to phase-delaying bright light. Thirty-nine young healthy participants (16 female; 22.18±3.62 years) completed a 9-day inpatient study. Following three baseline days, participants underwent an initial circadian phase assessment procedure in dim light (<3 lux), and were then randomized for exposure to a bright light pulse (∼10,000 lux) of 0.2 h, 1.0 h, 2.5 h or 4.0 h duration during a 4.5 h controlled-posture episode centred in a 16 h wake episode. After another 8 h sleep episode, participants completed a second circadian phase assessment. Phase shifts were calculated from the difference in the clock time of the dim light melatonin onset (DLMO) between the initial and final phase assessments. Exposure to varying durations of bright light reset the circadian pacemaker in a dose-dependent, non-linear manner. Per minute of exposure, the 0.2 h duration was over 5 times more effective at phase delaying the circadian pacemaker (1.07±0.36 h) as compared with the 4.0 h duration (2.65±0.24 h). Acute melatonin suppression and subjective sleepiness also had a dose-dependent response to light exposure duration. These results provide strong evidence for a non-linear resetting response of the human circadian pacemaker to light duration.

Safety and tolerability of rifaximin for the treatment of irritable bowel syndrome without constipation: a pooled analysis of randomised, double-blind, placebo-controlled trials.

PubMed

Schoenfeld, P; Pimentel, M; Chang, L; Lembo, A; Chey, W D; Yu, J; Paterson, C; Bortey, E; Forbes, W P

2014-05-01

The efficacy of rifaximin, a nonsystemic, gut-targeted antibiotic for reducing non-constipation-predominant irritable bowel syndrome (non-C IBS) symptoms, has been demonstrated in one phase 2b and two phase 3 randomised, double-blind, placebo-controlled trials, but detailed data about rifaximin safety and tolerability during treatment and subsequent follow-up periods are lacking. To assess and determine the frequency of rifaximin and placebo adverse events (AEs) in phase 2b and phase 3 non-C IBS trials. A post hoc pooled safety analysis of the phase 2b (rifaximin 275, 550, and 1100 mg twice daily for 2 weeks; 550 mg twice daily for 4 weeks) and phase 3 (rifaximin 550 mg three times daily for 2 weeks) studies was performed. Data on treatment and post-treatment AEs were collected. Patients were followed up for 12 weeks and 10 weeks post-treatment in the phase 2b and phase 3 trials, respectively. Patients receiving rifaximin (n = 1103) and placebo (n = 829) had a similar incidence of drug-related AEs (12.1% vs. 10.7%), serious AEs (1.5% vs. 2.2%), drug-related AEs resulting in study discontinuation (0.8% vs. 0.8%), gastrointestinal-associated AEs (12.2% vs. 12.2%) and infection-associated AEs (8.5% vs. 9.5%). There were no cases of Clostridium difficile colitis or deaths. The safety and tolerability profile of rifaximin during treatment and post-treatment was comparable to placebo. Future research should define the safety and tolerability profile, including risk of C. difficile colitis and microbial antibiotic resistance, with repeated courses of rifaximin in patients with non-constipation-predominant irritable bowel syndrome (ClinicalTrials.gov: NCT00269412, NCT00731679, and NCT00724126). © 2014 The Authors. Alimentary Pharmacology & Therapeutics published by John Wiley & Sons Ltd.

Crystallization studies and dielectric properties of (Ba0.7Sr0.3)TiO3 in bariumaluminosilicate glass

NASA Astrophysics Data System (ADS)

Divya, P. V.; Vignesh, G.; Kumar, V.

2007-12-01

Ferroelectric glass-ceramics with a basic composition (1 - y)(Ba0.70Sr0.30)TiO3 : y(BaO : Al2O3 : 2SiO2) have been synthesized by the sol-gel method. The major crystalline phase is the perovskite. The crystallization of the ferroelectric phase in the glass matrix have been studied using differential thermal analysis and x-ray diffraction and the kinetic parameters characterizing the crystallization have been determined using an Arrhenius model. Glass contents <= 5 mol% promoted liquid phase sintering, which reduced the sintering temperature to 1250 °C. The dielectric permittivity of the glass-ceramic samples decreased and the ferroelectric-paraelectric phase transition became more diffuse with increasing glass content. The dielectric connectivity of the ferroelectric phase in the composite have also been investigated and are reported.

Hygroscopic and phase separation properties of ammonium sulfate/organics/water ternary solutions

NASA Astrophysics Data System (ADS)

Zawadowicz, M. A.; Proud, S. R.; Seppalainen, S. S.; Cziczo, D. J.

2015-08-01

Atmospheric aerosol particles are often partially or completely composed of inorganic salts, such as ammonium sulfate and sodium chloride, and therefore exhibit hygroscopic properties. Many inorganic salts have well-defined deliquescence and efflorescence points at which they take up and lose water, respectively. Field measurements have shown that atmospheric aerosols are not typically pure inorganic salt, instead, they often also contain organic species. There is ample evidence from laboratory studies that suggests that mixed particles exist in a phase-separated state, with an aqueous inorganic core and organic shell. Although phase separation has not been measured in situ, there is no reason it would not also take place in the atmosphere. Here, we investigate the deliquescence and efflorescence points, phase separation and ability to exchange gas-phase components of mixed organic and inorganic aerosol using a flow tube coupled with FTIR (Fourier transform infrared) spectroscopy. Ammonium sulfate aerosol mixed with organic polyols with different O : C ratios, including 1,4-butanediol, glycerol, 1,2,6-hexanetriol, 1,2-hexanediol, and 1,5-pentanediol have been investigated. Those constituents correspond to materials found in the atmosphere in great abundance and, therefore, particles prepared in this study should mimic atmospheric mixed-phase aerosol particles. Some results of this study tend to be in agreement with previous microscopy experiments, but others, such as phase separation properties of 1,2,6-hexanetriol, do not agree with previous work. Because the particles studied in this experiment are of a smaller size than those used in microscopy studies, the discrepancies found could be a size-related effect.

Impact of 5-h phase advance on sleep architecture and physical performance in athletes.

PubMed

Petit, Elisabeth; Mougin, Fabienne; Bourdin, Hubert; Tio, Grégory; Haffen, Emmanuel

2014-11-01

Travel across time zones causes jet lag and is accompanied by deleterious effects on sleep and performance in athletes. These poor performances have been evaluated in field studies but not in laboratory conditions. The purpose of this study was to evaluate, in athletes, the impact of 5-h phase advance on the architecture of sleep and physical performances (Wingate test). In a sleep laboratory, 16 male athletes (age: 22.2 ± 1.7 years, height: 178.3 ± 5.6 cm, body mass: 73.6 ± 7.9 kg) spent 1 night in baseline condition and 2 nights, 1 week apart, in phase shift condition recorded by electroencephalography to calculate sleep architecture variables. For these last 2 nights, the clock was advanced by 5 h. Core body temperature rhythm was assessed continuously. The first night with phase advance decreased total sleep time, sleep efficiency, sleep onset latency, stage 2 of nonrapid eye movement (N2), and rapid eye movement (REM) sleep compared with baseline condition, whereas the second night decreased N2 and increased slow-wave sleep and REM, thus improving the quality of sleep. After phase advance, mean power improved, which resulted in higher lactatemia. Acrophase and bathyphase of temperature occurred earlier and amplitude decreased in phase advance but the period was not modified. These results suggest that a simulated phase shift contributed to the changes in sleep architecture, but did not significantly impair physical performances in relation with early phase adjustment of temperature to the new local time.

Psychopathological factors that can influence academic achievement in early adolescence: a three-year prospective study.

PubMed

Voltas, Núria; Hernández-Martínez, Carmen; Aparicio, Estefania; Arija, Victoria; Canals, Josefa

2014-12-30

This three-phase prospective study investigated psychosocial factors predicting or associated with academic achievement. An initial sample of 1,514 school-age children was assessed with screening tools for emotional problems (Screen for Childhood Anxiety and Related Emotional Disorders; Leyton Obsessional Inventory-Child Version; Children's Depression Inventory). The following year, 562 subjects (risk group/without risk group) were re-assessed and attention deficit/hyperactivity disorder (ADHD) was assessed. Two years later, 242 subjects were followed, and their parents informed about their academic achievement. Results showed that early depression (phase 1 B = -.130, p = .001; phase 1 + phase 2 B = -.187, p < .001), persistent anxiety symptoms (phase 1 + phase 2 B = -1.721, p = .018), and ADHD were predictors of lower academic achievement (phase 1 + phase 2 B = -3.415, p = .005). However, some anxiety symptoms can improve academic achievement (Social phobia B = .216, p = .018; Generalized anxiety B = .313, p < .001). Socio-economic status (SES) was positively related to academic achievement. We can conclude that in the transition period to adolescence, school-health professionals and teachers need to consider the emotional issues of students to avoid unwanted academic outcomes.

Metabolism of the tryptamine-derived new psychoactive substances 5-MeO-2-Me-DALT, 5-MeO-2-Me-ALCHT, and 5-MeO-2-Me-DIPT and their detectability in urine studied by GC-MS, LC-MSn , and LC-HR-MS/MS.

PubMed

Caspar, Achim T; Gaab, Jonas B; Michely, Julian A; Brandt, Simon D; Meyer, Markus R; Maurer, Hans H

2018-01-01

Many N,N-dialkylated tryptamines show psychoactive properties and were encountered as new psychoactive substances. The aims of the presented work were to study the phase I and II metabolism and the detectability in standard urine screening approaches (SUSA) of 5-methoxy-2-methyl-N,N-diallyltryptamine (5-MeO-2-Me-DALT), 5-methoxy-2-methyl-N-allyl-N-cyclohexyltryptamine (5-MeO-2-Me-ALCHT), and 5-methoxy-2-methyl-N,N-diisopropyltryptamine (5-MeO-2-Me-DIPT) using gas chromatography-mass spectrometry (GC-MS), liquid chromatography coupled with multistage accurate mass spectrometry (LC-MS n ), and liquid chromatography-high-resolution tandem mass spectrometry (LC-HR-MS/MS). For metabolism studies, urine was collected over a 24 h period after administration of the compounds to male Wistar rats at 20 mg/kg body weight (BW). Phase I and II metabolites were identified after urine precipitation with acetonitrile by LC-HR-MS/MS. 5-MeO-2-Me-DALT (24 phase I and 12 phase II metabolites), 5-MeO-2-Me-ALCHT (24 phase I and 14 phase II metabolites), and 5-MeO-2-Me-DIPT (20 phase I and 11 phase II metabolites) were mainly metabolized by O-demethylation, hydroxylation, N-dealkylation, and combinations of them as well as by glucuronidation and sulfation of phase I metabolites. Incubations with mixtures of pooled human liver microsomes and cytosols (pHLM and pHLC) confirmed that the main metabolic reactions in humans and rats might be identical. Furthermore, initial CYP activity screenings revealed that CYP1A2, CYP2C19, CYP2D6, and CYP3A4 were involved in hydroxylation, CYP2C19 and CYP2D6 in O-demethylation, and CYP2C19, CYP2D6, and CYP3A4 in N-dealkylation. For SUSAs, GC-MS, LC-MS n , and LC-HR-MS/MS were applied to rat urine samples after 1 or 0.1 mg/kg BW doses, respectively. In contrast to the GC-MS SUSA, both LC-MS SUSAs were able to detect an intake of 5-MeO-2-Me-ALCHT and 5-MeO-2-Me-DIPT via their metabolites following 1 mg/kg BW administrations and 5-MeO-2-Me-DALT following 0.1 mg/kg BW dosage. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

Energy management by enhanced glycolysis in G1-phase in human colon cancer cells in vitro and in vivo.

PubMed

Bao, Yan; Mukai, Kuniaki; Hishiki, Takako; Kubo, Akiko; Ohmura, Mitsuyo; Sugiura, Yuki; Matsuura, Tomomi; Nagahata, Yoshiko; Hayakawa, Noriyo; Yamamoto, Takehiro; Fukuda, Ryo; Saya, Hideyuki; Suematsu, Makoto; Minamishima, Yoji Andrew

2013-09-01

Activation of aerobic glycolysis in cancer cells is well known as the Warburg effect, although its relation to cell- cycle progression remains unknown. In this study, human colon cancer cells were labeled with a cell-cycle phase-dependent fluorescent marker Fucci to distinguish cells in G1-phase and those in S + G2/M phases. Fucci-labeled cells served as splenic xenograft transplants in super-immunodeficient NOG mice and exhibited multiple metastases in the livers, frozen sections of which were analyzed by semiquantitative microscopic imaging mass spectrometry. Results showed that cells in G1-phase exhibited higher concentrations of ATP, NADH, and UDP-N-acetylglucosamine than those in S and G2-M phases, suggesting accelerated glycolysis in G1-phase cells in vivo. Quantitative determination of metabolites in cells synchronized in S, G2-M, and G1 phases suggested that efflux of lactate was elevated significantly in G1-phase. By contrast, ATP production in G2-M was highly dependent on mitochondrial respiration, whereas cells in S-phase mostly exhibited an intermediary energy metabolism between G1 and G2-M phases. Isogenic cells carrying a p53-null mutation appeared more active in glycolysis throughout the cell cycle than wild-type cells. Thus, as the cell cycle progressed from G2-M to G1 phases, the dependency of energy production on glycolysis was increased while the mitochondrial energy production was reciprocally decreased. These results shed light on distinct features of the phase-specific phenotypes of metabolic systems in cancer cells. ©2013 AACR.

Insulating phases of vanadium dioxide are Mott-Hubbard insulators

DOE PAGES

Huffman, T. J.; Hendriks, C.; Walter, E. J.; ...

2017-02-15

Here, we present comprehensive broadband optical spectroscopy data on two insulating phases of vanadium dioxide (VO 2): monoclinic M 2 and triclinic. The main result of our work is that the energy gap and the electronic structure are essentially unaltered by the first-order structural phase transition between the M 2 and triclinic phases. Moreover, the optical interband features in the M 2 and triclinic phases are remarkably similar to those observed in the well-studied monoclinic M 1 insulating phase of VO 2. As the energy gap is insensitive to the different lattice structures of the three insulating phases, we rulemore » out vanadium-vanadium pairing (the Peierls component) as the dominant contributor to the opening of the gap. Rather, the energy gap arises primarily from intra-atomic Coulomb correlations.« less

Texture analysis of ultrahigh field T2*-weighted MR images of the brain: application to Huntington's disease.

PubMed

Doan, Nhat Trung; van den Bogaard, Simon J A; Dumas, Eve M; Webb, Andrew G; van Buchem, Mark A; Roos, Raymund A C; van der Grond, Jeroen; Reiber, Johan H C; Milles, Julien

2014-03-01

To develop a framework for quantitative detection of between-group textural differences in ultrahigh field T2*-weighted MR images of the brain. MR images were acquired using a three-dimensional (3D) T2*-weighted gradient echo sequence on a 7 Tesla MRI system. The phase images were high-pass filtered to remove phase wraps. Thirteen textural features were computed for both the magnitude and phase images of a region of interest based on 3D Gray-Level Co-occurrence Matrix, and subsequently evaluated to detect between-group differences using a Mann-Whitney U-test. We applied the framework to study textural differences in subcortical structures between premanifest Huntington's disease (HD), manifest HD patients, and controls. In premanifest HD, four phase-based features showed a difference in the caudate nucleus. In manifest HD, 7 magnitude-based features showed a difference in the pallidum, 6 phase-based features in the caudate nucleus, and 10 phase-based features in the putamen. After multiple comparison correction, significant differences were shown in the putamen in manifest HD by two phase-based features (both adjusted P values=0.04). This study provides the first evidence of textural heterogeneity of subcortical structures in HD. Texture analysis of ultrahigh field T2*-weighted MR images can be useful for noninvasive monitoring of neurodegenerative diseases. Copyright © 2013 Wiley Periodicals, Inc.

Treatment of Severe Edema in Children with Nephrotic Syndrome with Diuretics Alone — A Prospective Study

PubMed Central

Kapur, Gaurav; Valentini, Rudolph P.; Imam, Abubakr A.; Mattoo, Tej K.

2009-01-01

Background and objective: Severe edema in children with nephrotic syndrome (NS) may be associated with volume contraction (VC) or volume expansion (VE). Usually, severe edema in children is treated with intravenous (IV) albumin and diuretics, which is appropriate for VC patients. However, in VE patients, this can precipitate fluid overload. The objective of this study was to evaluate treatment of severe edema in NS with diuretics alone. Design, setting, participants, & measurements: Thirty NS patients with severe edema were enrolled in this prospective study in two phases. VC was diagnosed based on fractional excretion of sodium (FeNa) <1%. VC patients received IV albumin and furosemide. VE patients received IV furosemide and oral spironolactone. On the basis of phase 1 observations, FeNa <0.2% identified VC in 20 phase 2 patients. Results: All phase 1 patients had FeNa <1%. Phase 1 patients when reanalyzed based on a FeNa cutoff of 0.2%; it was noted that VC patients had higher BUN, BUN/creatinine ratio, urine osmolality, and lower FeNa and urine sodium compared with VE patients. Similar results were observed in phase 2. VC patients had significantly higher renin, aldosterone, and antidiuretic hormone levels. In phase 2, 11 VE patients received diuretics alone and 9 VC patients received albumin and furosemide. There was no difference in hospital stay and weight loss in VC and VE groups after treatment. Conclusions: FeNa is useful in distinguishing VC versus VE in NS children with severe edema. The use of diuretics alone in VE patients is safe and effective. PMID:19406963

Ground-state properties of Na2IrO3 determined from an ab initio Hamiltonian and its extensions containing Kitaev and extended Heisenberg interactions

NASA Astrophysics Data System (ADS)

Okubo, Tsuyoshi; Shinjo, Kazuya; Yamaji, Youhei; Kawashima, Naoki; Sota, Shigetoshi; Tohyama, Takami; Imada, Masatoshi

2017-08-01

We investigate the ground state properties of Na2IrO3 based on numerical calculations of the recently proposed ab initio Hamiltonian represented by Kitaev and extended Heisenberg interactions. To overcome the limitation posed by small tractable system sizes in the exact diagonalization study employed in a previous study [Y. Yamaji et al., Phys. Rev. Lett. 113, 107201 (2014), 10.1103/PhysRevLett.113.107201], we apply a two-dimensional density matrix renormalization group and an infinite-size tensor-network method. By calculating at much larger system sizes, we critically test the validity of the exact diagonalization results. The results consistently indicate that the ground state of Na2IrO3 is a magnetically ordered state with zigzag configuration in agreement with experimental observations and the previous diagonalization study. Applications of the two independent methods in addition to the exact diagonalization study further uncover a consistent and rich phase diagram near the zigzag phase beyond the accessibility of the exact diagonalization. For example, in the parameter space away from the ab initio value of Na2IrO3 controlled by the trigonal distortion, we find three phases: (i) an ordered phase with the magnetic moment aligned mutually in 120 degrees orientation on every third hexagon, (ii) a magnetically ordered phase with a 16-site unit cell, and (iii) an ordered phase with presumably incommensurate periodicity of the moment. It suggests that potentially rich magnetic structures may appear in A2IrO3 compounds for A other than Na. The present results also serve to establish the accuracy of the first-principles approach in reproducing the available experimental results thereby further contributing to finding a route to realize the Kitaev spin liquid.

[Treatment of severe intermittent claudication: ORACLE-PGE1 short term study. A randomised 40-week study. Evaluation of efficacy and costs].

PubMed

Cesarone, M R; Belcaro, G; Nicolaides, A N; Griffin, M; Geroulakos, G; Ramaswami, G; Cazaubon, M; Barsotti, A; Vasdekis, S; Christopoulos, D; Agus, G; Bavera, P; Mondani, P; Ippolito, E; Flenda, F

2002-12-01

The efficacy and cost of prostaglandin E1 (PGE1) in severe intermittent claudication was studied comparing a long-term protocol (LTP) with a short-term protocol (STP) in a randomised 40-week study. Phase 1 was a 2-week run-in phase (no treatment) for both protocols. In LTP, phase 2 was the main treatment phase. Treatment was performed with 2-hour infusions (60 micro g PGE1, 5 days each week for 4 weeks. In phase 3 (4-week interval period), PGE1 was administered twice a week (same dosage). In phase 4 (40 weeks), no PGE1 were used. In STP, phase 2 treatment was performed in two days by a 2-hour infusion (60 micro g PGE1 twice a day in 2 days). The same cycle was repeated every 4 weeks. A treadmill test was performed at inclusion, at the beginning of each phase and at the end of weeks 12, 16, 20 32 and 40. A progressive training plan (walking) and reduction in risk factors plan was used in both groups. Out of the 1276 included patients 1165 completed the study (606 in LTP group; 559 in the STP). Drop-outs were 111. The two groups were comparable in distribution, risk factors and smoking. Intention-to-treat analysis indicated an increase in pain free walking distance (PFWD). The absolute and percent increase in pain-free walking distance (PFWD) was comparable in both LTP and STP groups with a significative increase in TWD at 4 weeks. At 20 and 40 weeks increase was up to 219% in the LTP and 460% in the STP group (p<0.02). Comparable results concerning PFWD were obtained in the two groups. Both treatments were well tolerated. No side effect was observed. Local effects were observed in 8.5% of the treated subjects in the LTP and 4% in the STP. The average cost of the LTP protocol was 8786 Euro. For STP the costs was 946 (10.8% of LTP). For both protocols the cost of the infusion was 24% of the total for the LTP and 35% in the STP. Therefore 75% of the cost is not drug-related. In conclusion between-group-analysis favours STP considering walking distance and costs. Results indicate good efficacy and tolerability of PGE1 treatment particularly STP.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Yi; Cai, Zhonghou; Chen, Pice

Dynamical phase separation during a solid-solid phase transition poses a challenge for understanding the fundamental processes in correlated materials. Critical information underlying a phase transition, such as localized phase competition, is difficult to reveal by measurements that are spatially averaged over many phase seperated regions. The ability to simultanousely track the spatial and temporal evolution of such systems is essential to understanding mesoscopic processes during a phase transition. Using state-of- the-art time-resolved hard x-ray diffraction microscopy, we directly visualize the structural phase progression in a VO 2 film upon photoexcitation. Following a homogenous in-plane optical excitation, the phase transformation ismore » initiated at discrete sites and completed by the growth of one lattice structure into the other, instead of a simultaneous isotropic lattice symmetry change. The time-dependent x-ray diffraction spatial maps show that the in-plane phase progression in laser-superheated VO 2 is via a displacive lattice transformation as a result of relaxation from an excited monoclinic phase into a rutile phase. The speed of the phase front progression is quantitatively measured, which is faster than the process driven by in-plane thermal diffusion but slower than the sound speed in VO 2. Lastly, the direct visualization of localized structural changes in the time domain opens a new avenue to study mesoscopic processes in driven systems.« less

Crystal structures and high-temperature phase-transitions in SrNdMRuO{sub 6} (M=Zn,Co,Mg,Ni) new double perovskites studied by symmetry-mode analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iturbe-Zabalo, E., E-mail: iturbe@ill.fr; Fisika Aplikatua II Saila, Zientzia eta Teknologia Fakultatea, UPV/EHU, P.O. Box 644, 48080 Bilbao; Igartua, J.M.

2013-02-15

Crystal structures of SrNdZnRuO{sub 6}, SrNdCoRuO{sub 6}, SrNdMgRuO{sub 6} and SrNdNiRuO{sub 6} double perovskites have been studied by X-ray, synchrotron radiation and neutron powder diffraction method, at different temperatures, and using the symmetry-mode analysis. All compounds adopt the monoclinic space group P2{sub 1}/n at room-temperature, and contain a completely ordered array of the tilted MO{sub 6} and RuO{sub 6} octahedra, whereas Sr/Nd cations are completely disordered. The analysis of the structures in terms of symmetry-adapted modes of the parent phase allows the identification of the modes responsible for the phase-transition. The high-temperature study (300-1250 K) has shown that the compoundsmore » present a temperature induced structural phase-transition: P2{sub 1}/n{yields}P4{sub 2}/n{yields}Fm3{sup Macron }m. - Graphical abstract: Representation of the dominant distortion modes of the symmetry mode decomposition of the room-temperature (P2{sub 1}/n), intermediate (P4{sub 2}/n) and cubic (Fm-3m) phase SrNdMRuO{sub 6} (M=Zn,Co,Mg,Ni), with respect to the parent phase Fm-3m. The dominant distortion modes are: in the monoclinic phase-GM{sub 4}{sup +} (blue arrow), X{sub 3}{sup +} (green arrow) and X{sub 5}{sup +} acting on A-site cations (red arrow); in the tetragonal phase-GM{sub 4}{sup +} (pink arrow), X{sub 3}{sup +} (light blue arrow) and X{sub 5}{sup +} acting on A-site cations (brown arrow). Highlights: Black-Right-Pointing-Pointer Structural study of four ruthenate double perovskites. Black-Right-Pointing-Pointer Room-temperature structural determination using symmetry-mode procedure. Black-Right-Pointing-Pointer Determination of temperature induced structural phase-transitions. Black-Right-Pointing-Pointer Symmetry adapted-mode analysis.« less

Photoinduced discommensuration of the commensurate charge-density wave phase in 1 T -Ta S2

NASA Astrophysics Data System (ADS)

Tanimura, Katsumi

2018-06-01

The dynamics induced by femtosecond-laser excitation of the commensurate phase of the charge-density wave (CDW) in 1 T -Ta S2 have been studied using both time-resolved electron diffraction and the time-resolved spectroscopy of coherent-phonon dynamics. Electron diffraction results show that the commensurate CDW phase is transformed into a new phase with CDW order that is similar to the nearly commensurate phase with threshold-type transition rates; the threshold excitation density of 0.2 per 13 Ta atoms is evaluated. Coherent-phonon spectroscopy results show that, together with the amplitude mode of CDW with a frequency of 2.41 THz, two other modes with frequencies of 2.34 and 2.07 THz are excited in the photoexcited commensurate CDW phase over a timescale of several tens of picoseconds after excitation. Spectroscopic, temporal, and excitation-intensity dependent characteristics of the three coherent phonons reveal that a photoinduced decomposition of the commensurate CDW order into an ensemble of domains with different CDW orders is induced before the CDW-phase transition occurs. The physics underlying the photoinduced decomposition and evolution into discommensurations responsible for the CDW-order transformation are discussed.

Year-round high physical activity levels in agropastoralists of Bolivian Andes: Results from repeated measurements of DLW method in peak and slack seasons of agricultural activities

PubMed Central

Kashiwazaki, Hiroshi; Uenishi, Kazuhiro; Kobayashi, Toshio; Rivera, Jose Orias; Coward, William A; Wright, Antony

2009-01-01

By the repeated use of the doubly labeled water method (DLW), this study aimed to investigate (1) the extent of changes in energy expenditure and physical activity level (PAL) in response to increased agricultural work demands, and (2) whether the seasonal work demands induce the changes in the fairly equitable division of work and similarity of energy needs between men and women observed in our previous study (Phase 1 study; Kashiwazaki et al., 1995: Am J Clin Nutr 62: 901–910). In a rural small agropastoral community of the Bolivian Andes, we made the follow-up study (Phase 2, 14 adults; a time of high agricultural activity) of the Phase 1 study (12 adults; a time of low agricultural activity). In the Phase 2 study, both men and women showed very high PAL (mean±SD), but there was no significant difference by sex (men; 2.18 ± 0.23 (age; 64 ± 11 years, n = 7), women; 2.26 ± 0.25 (63 ± 10 years, n = 7)). The increase of PAL by 11% (P = 0.023) in the Phase 2 was equally occurred in both men and women. The factorial approach underestimated PAL significantly by ≈15% (P < 0.05). High PAL throughout the year ranging on average 2.0 and 2.2 was attributable to everyday tasks for subsistence and domestic works undertaking over 9–11 h (men spent 2.7 h on agricultural work and 4.7 h on animal herding, whereas women spent 7.3 h almost exclusively on animal herding). The seasonal increase in PAL was statistically significant, but it was smaller than those anticipated from published reports. A flexible division of labor played an important role in the equitable energetic increase in both men and women. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc. PMID:19127525

A crossover study of the combination therapy of metformin and exenatide or biphasic insulin aspart 30 in overweight or obese patients newly diagnosed with type 2 diabetes mellitus

PubMed Central

Quan, Huibiao; Zhang, Huachuan; Wei, Weiping; Fang, Tuanyu; Chen, Daoxiong; Chen, Kaining

2017-01-01

The aim of the present study was to explore the effects of various combinations of exenatide, metformin (MET) and biphasic insulin aspart 30 (BIA30) on type 2 diabetes mellitus (T2DM). Two hundred overweight or obese patients newly diagnosed with T2DM were evenly randomized into two groups: A (twice daily for all: Phase I, 5 µg exenatide + 0.5 g MET for 4 weeks, then 10 µg exenatide + 0.5 g MET for 8 weeks; Phase II, 0.5 g MET for 12 weeks; Phase III, 0.3–0.4 U/kg/day BIA30 + 0.5 g MET for 12 weeks) and B (Phases I, II, III matched the phases III, II and I in group A). In groups A and B a significant decrease and increase, respectively, in glycated hemoglobin (HbAlc) and body mass index (BMI) was noted during Phase I. A 3.2±0.4-kg decrease in body weight in group A and a 2.6±0.3-kg increase in group B was observed. In Phase II, HbAlc was significantly increased in both groups (P<0.05). In Phase III, the BMI was increased in group A and reduced in group B (P<0.05). There was a 3.8±0.4-kg weight decrease in group B and 4.2±0.5-kg increase in group A (P<0.05). The combination of exenatide and MET promoted weight loss, glycemic control, β-cell function index, C peptide and adiponectin levels. These results suggested that the combination of exenatide and MET is better than the combination of BIA and MET for the therapy of overweight or obese patients newly diagnosed with T2DM. PMID:28912879

Treatment of Non-neovascular Idiopathic Macular Telangiectasia Type 2 with Intravitreal Ranibizumab: Results of a Phase II Clinical Trial

PubMed Central

Toy, Brian C.; Koo, Euna; Cukras, Catherine; Meyerle, Catherine B.; Chew, Emily Y.; Wong, Wai T.

2015-01-01

Purpose To evaluate the safety and preliminary efficacy of intravitreal ranibizumab for non-neovascular idiopathic macular telangiectasia, type 2 (IMT2). Methods Single-center, open-label phase II clinical trial enrolling 5 participants with bilateral non-neovascular IMT2. Intravitreal ranibizumab (0.5mg) was administered every 4 weeks in the study eye for 12 months with the contralateral eye observed. Outcome measures included changes in: best corrected visual acuity (BCVA), area of late-phase leakage on fluorescein angiography (FA), and retinal thickness on optical coherence tomography (OCT). Results The study treatment was well-tolerated and associated with few adverse events. Change in BCVA at 12 months was not significantly different between treated study eyes (0.0±7.5 letters) and control fellow eyes (+2.2±1.9 letters). However, decreases in the area of late-phase FA leakage (−33±20% for study eyes, +1±8% for fellow eyes) and in OCT central subfield retinal thickness (−11.7±7.0% for study eyes and −2.9±3.5% for fellow eyes) were greater in study eyes compared to fellow eyes. Conclusions Despite significant anatomical responses to treatment, functional improvement in visual acuity was not detected. Intravitreal ranibizumab administered monthly over a time course of 12 months is unlikely to provide a general and significant benefit to patients with non-neovascular IMT2. PMID:22266930

Unconventional Topological Phase Transition in Two-Dimensional Systems with Space-Time Inversion Symmetry

NASA Astrophysics Data System (ADS)

Ahn, Junyeong; Yang, Bohm-Jung

2017-04-01

We study a topological phase transition between a normal insulator and a quantum spin Hall insulator in two-dimensional (2D) systems with time-reversal and twofold rotation symmetries. Contrary to the case of ordinary time-reversal invariant systems, where a direct transition between two insulators is generally predicted, we find that the topological phase transition in systems with an additional twofold rotation symmetry is mediated by an emergent stable 2D Weyl semimetal phase between two insulators. Here the central role is played by the so-called space-time inversion symmetry, the combination of time-reversal and twofold rotation symmetries, which guarantees the quantization of the Berry phase around a 2D Weyl point even in the presence of strong spin-orbit coupling. Pair creation and pair annihilation of Weyl points accompanying partner exchange between different pairs induces a jump of a 2D Z2 topological invariant leading to a topological phase transition. According to our theory, the topological phase transition in HgTe /CdTe quantum well structure is mediated by a stable 2D Weyl semimetal phase because the quantum well, lacking inversion symmetry intrinsically, has twofold rotation about the growth direction. Namely, the HgTe /CdTe quantum well can show 2D Weyl semimetallic behavior within a small but finite interval in the thickness of HgTe layers between a normal insulator and a quantum spin Hall insulator. We also propose that few-layer black phosphorus under perpendicular electric field is another candidate system to observe the unconventional topological phase transition mechanism accompanied by the emerging 2D Weyl semimetal phase protected by space-time inversion symmetry.

Fine Structure in Multi-Phase Zr8Ni21-Zr7Ni10-Zr2Ni7 Alloy Revealed by Transmission Electron Microscope

PubMed Central

Shen, Haoting; Bendersky, Leonid A.; Young, Kwo; Nei, Jean

2015-01-01

The microstructure of an annealed alloy with a Zr8Ni21 composition was studied by both scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The presence of three phases, Zr8Ni21, Zr2Ni7, and Zr7Ni10, was confirmed by SEM/X-ray energy dispersive spectroscopy compositional mapping and TEM electron diffraction. Distribution of the phases and their morphology can be linked to a multi-phase structure formed by a sequence of reactions: (1) L → Zr2Ni7 + L’; (2) peritectic Zr2Ni7 + L’ → Zr2Ni7 + Zr8Ni21 + L”; (3) eutectic L” → Zr8Ni21 + Zr7Ni10. The effect of annealing at 960 °C, which was intended to convert a cast structure into a single-phase Zr8Ni21 structure, was only moderate and the resulting alloy was still multi-phased. TEM and crystallographic analysis of the Zr2Ni7 phase show a high density of planar (001) defects that were explained as low-energy boundaries between rotational variants and stacking faults. The crystallographic features arise from the pseudo-hexagonal structure of Zr2Ni7. This highly defective Zr2Ni7 phase was identified as the source of the broad X-ray diffraction peaks at around 38.4° and 44.6° when a Cu-K was used as the radiation source. PMID:28793460

Pressure-induced structural transformations in lanthanide titanates: La{sub 2}TiO{sub 5} and Nd{sub 2}TiO{sub 5}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, F.X., E-mail: zhangfx@umich.ed; Wang, J.W.; Lang, M.

The structure of orthorhombic rare earth titanates of La{sub 2}TiO{sub 5} and Nd{sub 2}TiO{sub 5}, where Ti cations are in five-fold coordination with oxygen, has been studied at high pressures by X-ray diffraction (XRD), Raman scattering measurements, and quantum mechanical calculations. Both XRD and Raman results indicated two pressure-induced phase transitions during the process. An orthorhombic super cell (axbx2c) formed at a pressure between 6 and 10 GPa, and then transformed to a hexagonal high-pressure phase accompanied by partial decomposition. The hexagonal high-pressure phase is quenchable. Detailed structural analysis indicated that the five-coordinated TiO{sub 5} polyhedra remain during the formationmore » of super cell, but the orthorhombic-to-hexagonal phase transition at high pressures is a reconstructive process, and the five-fold Ti-O coordination increased to more than 6. This phase transition sequence was verified by quantum mechanical calculations. - Graphical abstract: At high pressures, La{sub 2}TiO{sub 5} and Nd{sub 2}TiO{sub 5} transform from the orthorhombic phase to an axbx2c superlattice of the orthorhombic structure and then to a hexagonal high-pressure phase. Display Omitted« less

Fundamental studies of gas phase ionic reactions by ion mobility spectrometry

NASA Technical Reports Server (NTRS)

Giles, K.; Knighton, W. B.; Sahlstrom, K. E.; Grimsrud, E. P.

1995-01-01

Ion mobility spectrometry (IMS) provides a promising approach to the study of gas phase ionic reactions in buffer gases at unusually high pressures. This point is illustrated here by studies of the Sn2 nucleophilic displacement reaction, Cl(-) + CH3Br yields Br + CH3Br, using IMS at atmospheric pressure. The equilibrium clustering reaction, Cl(-)(CHCI3)(n - 1) + CHCI3 yields Cl(-)(CHCI3)(n), where n = 1 and 2, and the effect of clustering on the Sn2 reaction with CH3Br have also been characterized by this IMS-based kinetic method. Present problems and anticipated improvements in the application of ion mobility spectrometry to studies of other gas phase ionic processes are discussed.

Effects of Primary Processing Techniques and Significance of Hall-Petch Strengthening on the Mechanical Response of Magnesium Matrix Composites Containing TiO2 Nanoparticulates

PubMed Central

Meenashisundaram, Ganesh Kumar; Nai, Mui Hoon; Gupta, Manoj

2015-01-01

In the present study, Mg (1.98 and 2.5) vol % TiO2 nanocomposites are primarily synthesized utilizing solid-phase blend-press-sinter powder metallurgy (PM) technique and liquid-phase disintegrated melt deposition technique (DMD) followed by hot extrusion. Microstructural characterization of the synthesized Mg-TiO2 nanocomposites indicated significant grain refinement with DMD synthesized Mg nanocomposites exhibiting as high as ~47% for 2.5 vol % TiO2 NPs addition. X-ray diffraction studies indicated that texture randomization of pure Mg depends not only on the critical amount of TiO2 NPs added to the Mg matrix but also on the adopted synthesis methodology. Irrespective of the processing technique, theoretically predicted tensile yield strength of Mg-TiO2 nanocomposites was found to be primarily governed by Hall-Petch mechanism. Among the synthesized Mg materials, solid-phase synthesized Mg 1.98 vol % TiO2 nanocomposite exhibited a maximum tensile fracture strain of ~14.5%. Further, the liquid-phase synthesized Mg-TiO2 nanocomposites exhibited higher tensile and compression properties than those primarily processed by solid-phase synthesis. The tensile-compression asymmetry values of the synthesized Mg-TiO2 nanocomposite was found to be lower than that of pure Mg with solid-phase synthesized Mg 1.98 vol % TiO2 nanocomposite exhibiting as low as 1.06. PMID:28347063

Nature of ferroelectric to paraelectric phase transition in multiferroic 0.8BiFeO3-0.2Pb(Fe1/2Nb1/2)O3 ceramics

NASA Astrophysics Data System (ADS)

Patel, Jay Prakash; Singh, Anar; Pandey, Dhananjai

2010-05-01

We present here the results of high temperature powder x-ray diffraction study on 0.8BiFeO3-0.2Pb(Fe1/2Nb1/2)O3, which is isostructural with the well known multiferroic BiFeO3 (BF). It is shown that the room temperature ferroelectric phase of 0.8BF-0.2PFN in the R3c space group transforms to the paraelectric/paraelastic cubic (Pm3¯m) phase directly without any intermediate "β" phase reported in the literature for pure BF. This transition is of first order type as confirmed by the coexistence of R3c and Pm3¯m phases over a 100 K range and discontinuous change in the unit cell volume.

Hierarchical mean-field approach to the J1-J2 Heisenberg model on a square lattice

NASA Astrophysics Data System (ADS)

Isaev, L.; Ortiz, G.; Dukelsky, J.

2009-01-01

We study the quantum phase diagram and excitation spectrum of the frustrated J1-J2 spin-1/2 Heisenberg Hamiltonian. A hierarchical mean-field approach, at the heart of which lies the idea of identifying relevant degrees of freedom, is developed. Thus, by performing educated, manifestly symmetry-preserving mean-field approximations, we unveil fundamental properties of the system. We then compare various coverings of the square lattice with plaquettes, dimers, and other degrees of freedom, and show that only the symmetric plaquette covering, which reproduces the original Bravais lattice, leads to the known phase diagram. The intermediate quantum paramagnetic phase is shown to be a (singlet) plaquette crystal, connected with the neighboring Néel phase by a continuous phase transition. We also introduce fluctuations around the hierarchical mean-field solutions, and demonstrate that in the paramagnetic phase the ground and first excited states are separated by a finite gap, which closes in the Néel and columnar phases. Our results suggest that the quantum phase transition between Néel and paramagnetic phases can be properly described within the Ginzburg-Landau-Wilson paradigm.

Hierarchical mean-field approach to the J1-J2 Heisenberg model on a square lattice

NASA Astrophysics Data System (ADS)

Isaev, Leonid; Ortiz, Gerardo; Dukelsky, Jorge

2009-03-01

We study the quantum phase diagram and excitation spectrum of the frustrated J1-J2 spin-1/2 Heisenberg Hamiltonian. A hierarchical mean-field approach, at the heart of which lies the idea of identifying relevant degrees of freedom, is developed. Thus, by performing educated, manifestly symmetry preserving mean-field approximations, we unveil fundamental properties of the system. We then compare various coverings of the square lattice with plaquettes, dimers and other degrees of freedom, and show that only the symmetric plaquette covering, which reproduces the original Bravais lattice, leads to the known phase diagram. The intermediate quantum paramagnetic phase is shown to be a (singlet) plaquette crystal, connected with the neighbouring N'eel phase by a continuous phase transition. We also introduce fluctuations around the hierarchical mean-field solutions, and demonstrate that in the paramagnetic phase the ground and first excited states are separated by a finite gap, which closes in the N'eel and columnar phases. Our results suggest that the quantum phase transition between N'eel and paramagnetic phases can be properly described within the Ginzburg-Landau-Wilson paradigm.

Band Alignment-Driven Oxidative Injury to the Skin by Anatase/Rutile Mixed-Phase Titanium Dioxide Nanoparticles under Sunlight Exposure.

PubMed

Sun, Xiujuan; Chang, Yun; Cheng, Yan; Feng, Yanlin; Zhang, Haiyuan

2018-04-12

Anatase/rutile mixed-phase titanium dioxide (TiO2) nanoparticles (NPs) have been found in cosmetics and cotton textiles. Once exposed to sunlight, mixed-phase TiO2 NPs are even more toxic to cells than pure phase NPs, however, the underlying mechanism remains unclear. Considering the unique anatase/rutile heterojunction structure existing in mixed-phase NPs, the potent toxicity of mixed-phase TiO2 NPs probably originates from the high reactive oxygen species (ROS) production because the anatase/rutile heterojunction is constituted by the staggered energy bands that facilitate the electron-hole separation at the interface due to the band alignment. In the present study, a library of mixed-phase TiO2 NPs with different anatase/rutile ratios was established to investigate the potential property-activity relationship and further clarify the underlying molecular mechanism. Under sunlight exposure, these mixed-phase TiO2 NPs could produce significant abiotic ROS and induce hierarchical oxidative stress to HaCaT skin cells and mice skin. The ROS magnitude and toxicity potential of these NPs were found to be proportional to their energy band bending (BB) levels. This means that the toxicity of mixed-phase TiO2 NPs can be correlated to their heterojunction density, and the toxicity potential of mixed-phase TiO2 NPs can be weighed by their BB levels.

Ultrafast diffraction conoscopy of the structural phase transition in VO2: Evidence of two lattice distortions

NASA Astrophysics Data System (ADS)

Kumar, Nardeep; Rúa, Armando; Fernández, Félix E.; Lysenko, Sergiy

2017-06-01

Photoinduced phase transitions in complex correlated systems occur very rapidly and involve the interplay between various electronic and lattice degrees of freedom. For these materials to be considered for practical applications, it is important to discover how their phase transitions take place. Here we use a novel ultrafast diffraction conoscopy technique to study the evolution of vanadium dioxide (VO2) from biaxial to uniaxial symmetry. A key finding in this study is an additional relaxation process through which the phase transition takes place. Our results show that the biaxial monoclinic crystal initially, within the first 100-300 fs, transforms to a transient biaxial crystal, and within the next 300-400 fs converts into a uniaxial rutile crystal. The characteristic times for these transitions depend on film morphology and are presumably altered by misfit strain. We take advantage of Landau phenomenology to describe the complex dynamics of VO2 phase transition in the femtosecond regime.

Phase behaviour, interactions, and structural studies of (amines+ionic liquids) binary mixtures.

PubMed

Jacquemin, Johan; Bendová, Magdalena; Sedláková, Zuzana; Blesic, Marijana; Holbrey, John D; Mullan, Claire L; Youngs, Tristan G A; Pison, Laure; Wagner, Zdeněk; Aim, Karel; Costa Gomes, Margarida F; Hardacre, Christopher

2012-05-14

We present a study on the phase equilibrium behaviour of binary mixtures containing two 1-alkyl-3-methylimidazolium bis{(trifluoromethyl)sulfonyl}imide-based ionic liquids, [C(n)mim] [NTf(2)] (n=2 and 4), mixed with diethylamine or triethylamine as a function of temperature and composition using different experimental techniques. Based on this work, two systems showing an LCST and one system with a possible hourglass shape are measured. Their phase behaviours are then correlated and predicted by using Flory-Huggins equations and the UNIQUAC method implemented in Aspen. The potential of the COSMO-RS methodology to predict the phase equilibria was also tested for the binary systems studied. However, this methodology is unable to predict the trends obtained experimentally, limiting its use for systems involving amines in ionic liquids. The liquid-state structure of the binary mixture ([C(2)mim] [NTf(2)]+diethylamine) is also investigated by molecular dynamics simulation and neutron diffraction. Finally, the absorption of gaseous ethane by the ([C(2)mim][NTf(2)]+diethylamine) binary mixture is determined and compared with that observed in the pure solvents. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improving the Quality of Radiographs in Neonatal Intensive Care Unit Utilizing Educational Interventions.

PubMed

Gupta, Ashish O; Rorke, Jeanne; Abubakar, Kabir

2015-08-01

We aimed to develop an educational tool to improve the radiograph quality, sustain this improvement overtime, and reduce the number of repeat radiographs. A three phase quality control study was conducted at a tertiary care NICU. A retrospective data collection (phase1) revealed suboptimal radiograph quality and led to an educational intervention and development of X-ray preparation checklist (primary intervention), followed by a prospective data collection for 4 months (phase 2). At the end of phase 2, interim analysis revealed a gradual decline in radiograph quality, which prompted a more comprehensive educational session with constructive feedback to the NICU staff (secondary intervention), followed by another data collection for 6 months (phase 3). There was a significant improvement in the quality of radiographs obtained after primary educational intervention (phase 2) compared with phase 1 (p < 0.001). During interim analysis after phase 2, radiograph quality declined but still remained significantly better than phase 1. Secondary intervention resulted in significant improvement in radiograph quality to > 95% in all domains of image quality. No radiographs were repeated in phase 3, compared with 5.8% (16/277) in phase 1. A structured, collaborated educational intervention successfully improves the radiograph quality and decreases the need for repeat radiographs and radiation exposure in the neonates. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Automated selection of the optimal cardiac phase for single-beat coronary CT angiography reconstruction.

PubMed

Stassi, D; Dutta, S; Ma, H; Soderman, A; Pazzani, D; Gros, E; Okerlund, D; Schmidt, T G

2016-01-01

Reconstructing a low-motion cardiac phase is expected to improve coronary artery visualization in coronary computed tomography angiography (CCTA) exams. This study developed an automated algorithm for selecting the optimal cardiac phase for CCTA reconstruction. The algorithm uses prospectively gated, single-beat, multiphase data made possible by wide cone-beam imaging. The proposed algorithm differs from previous approaches because the optimal phase is identified based on vessel image quality (IQ) directly, compared to previous approaches that included motion estimation and interphase processing. Because there is no processing of interphase information, the algorithm can be applied to any sampling of image phases, making it suited for prospectively gated studies where only a subset of phases are available. An automated algorithm was developed to select the optimal phase based on quantitative IQ metrics. For each reconstructed slice at each reconstructed phase, an image quality metric was calculated based on measures of circularity and edge strength of through-plane vessels. The image quality metric was aggregated across slices, while a metric of vessel-location consistency was used to ignore slices that did not contain through-plane vessels. The algorithm performance was evaluated using two observer studies. Fourteen single-beat cardiac CT exams (Revolution CT, GE Healthcare, Chalfont St. Giles, UK) reconstructed at 2% intervals were evaluated for best systolic (1), diastolic (6), or systolic and diastolic phases (7) by three readers and the algorithm. Pairwise inter-reader and reader-algorithm agreement was evaluated using the mean absolute difference (MAD) and concordance correlation coefficient (CCC) between the reader and algorithm-selected phases. A reader-consensus best phase was determined and compared to the algorithm selected phase. In cases where the algorithm and consensus best phases differed by more than 2%, IQ was scored by three readers using a five point Likert scale. There was no statistically significant difference between inter-reader and reader-algorithm agreement for either MAD or CCC metrics (p > 0.1). The algorithm phase was within 2% of the consensus phase in 15/21 of cases. The average absolute difference between consensus and algorithm best phases was 2.29% ± 2.47%, with a maximum difference of 8%. Average image quality scores for the algorithm chosen best phase were 4.01 ± 0.65 overall, 3.33 ± 1.27 for right coronary artery (RCA), 4.50 ± 0.35 for left anterior descending (LAD) artery, and 4.50 ± 0.35 for left circumflex artery (LCX). Average image quality scores for the consensus best phase were 4.11 ± 0.54 overall, 3.44 ± 1.03 for RCA, 4.39 ± 0.39 for LAD, and 4.50 ± 0.18 for LCX. There was no statistically significant difference (p > 0.1) between the image quality scores of the algorithm phase and the consensus phase. The proposed algorithm was statistically equivalent to a reader in selecting an optimal cardiac phase for CCTA exams. When reader and algorithm phases differed by >2%, image quality as rated by blinded readers was statistically equivalent. By detecting the optimal phase for CCTA reconstruction, the proposed algorithm is expected to improve coronary artery visualization in CCTA exams.

Characterization of the Solid-Phase Behavior of n-Nonylammonium Tetrachlorocuprate by Fourier Transform Infrared Spectroscopy

NASA Astrophysics Data System (ADS)

Ning, Guo

1995-06-01

The solid-phase behavior of [n-C9H19NH3]2CuCl4 was investigated by infrared spectroscopy. The nature of the three solid phases (phase I, phase II, and phase III) is discussed. A temperature-dependent study of infrared spectra provides evidence for the occurrence of structural phase transitions related to the dynamics of the alkyl chains and -NH3 polar heads. The phase transition at Tc1 (22°C) arises from variation in the interaction and packing structure of the chain. The phase transition at Tc2 (34°C) is related to variation in partial conformational order-disorder at the intramolecular level. The GTG or GTG‧ and small concentration of TG structures near the CH3 group are generated in phase III (above 38°C).

Quantifying phase synchronization using instances of Hilbert phase slips

NASA Astrophysics Data System (ADS)

Govindan, R. B.

2018-07-01

We propose to quantify phase synchronization between two signals, x(t) and y(t), by calculating variance in the Hilbert phase of y(t) at instances of phase slips exhibited by x(t). The proposed approach is tested on numerically simulated coupled chaotic Roessler systems and second order autoregressive processes. Furthermore we compare the performance of the proposed and original approaches using uterine electromyogram signals and show that both approaches yield consistent results A standard phase synchronization approach, which involves unwrapping the Hilbert phases (ϕ1(t) and ϕ2(t)) of the two signals and analyzing the variance in the | n ṡϕ1(t) - m ṡϕ2(t) | , mod 2 π, (n and m are integers), was used for comparison. The synchronization indexes obtained from the proposed approach and the standard approach agree reasonably well in all of the systems studied in this work. Our results indicate that the proposed approach, unlike the traditional approach, does not require the non-invertible transformations - unwrapping of the phases and calculation of mod 2 π and it can be used to reliably to quantify phase synchrony between two signals.

Entanglement convertibility by sweeping through the quantum phases of the alternating bonds XXZ chain

PubMed Central

Tzeng, Yu-Chin; Dai, Li; Chung, Ming-Chiang; Amico, Luigi; Kwek, Leong-Chuan

2016-01-01

We study the entanglement structure and the topological edge states of the ground state of the spin-1/2 XXZ model with bond alternation. We employ parity-density matrix renormalization group with periodic boundary conditions. The finite-size scaling of Rényi entropies S2 and S∞ are used to construct the phase diagram of the system. The phase diagram displays three possible phases: Haldane type (an example of symmetry protected topological ordered phases), Classical Dimer and Néel phases, the latter bounded by two continuous quantum phase transitions. The entanglement and non-locality in the ground state are studied and quantified by the entanglement convertibility. We found that, at small spatial scales, the ground state is not convertible within the topological Haldane dimer phase. The phenomenology we observe can be described in terms of correlations between edge states. We found that the entanglement spectrum also exhibits a distinctive response in the topological phase: the effective rank of the reduced density matrix displays a specifically large “susceptibility” in the topological phase. These findings support the idea that although the topological order in the ground state cannot be detected by local inspection, the ground state response at local scale can tell the topological phases apart from the non-topological phases. PMID:27216970

Entanglement convertibility by sweeping through the quantum phases of the alternating bonds XXZ chain.

PubMed

Tzeng, Yu-Chin; Dai, Li; Chung, Ming-Chiang; Amico, Luigi; Kwek, Leong-Chuan

2016-05-24

We study the entanglement structure and the topological edge states of the ground state of the spin-1/2 XXZ model with bond alternation. We employ parity-density matrix renormalization group with periodic boundary conditions. The finite-size scaling of Rényi entropies S2 and S∞ are used to construct the phase diagram of the system. The phase diagram displays three possible phases: Haldane type (an example of symmetry protected topological ordered phases), Classical Dimer and Néel phases, the latter bounded by two continuous quantum phase transitions. The entanglement and non-locality in the ground state are studied and quantified by the entanglement convertibility. We found that, at small spatial scales, the ground state is not convertible within the topological Haldane dimer phase. The phenomenology we observe can be described in terms of correlations between edge states. We found that the entanglement spectrum also exhibits a distinctive response in the topological phase: the effective rank of the reduced density matrix displays a specifically large "susceptibility" in the topological phase. These findings support the idea that although the topological order in the ground state cannot be detected by local inspection, the ground state response at local scale can tell the topological phases apart from the non-topological phases.

Activity of Simulated Human Dosage Regimens of Meropenem and Vaborbactam against Carbapenem-Resistant Enterobacteriaceae in an In Vitro Hollow-Fiber Model.

PubMed

Sabet, Mojgan; Tarazi, Ziad; Rubio-Aparicio, Debora; Nolan, Thomas G; Parkinson, Jonathan; Lomovskaya, Olga; Dudley, Michael N; Griffith, David C

2018-02-01

The objective of these studies was to evaluate the exposures of meropenem and vaborbactam that would produce antibacterial activity and prevent resistance development in carbapenem-resistant Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae strains when tested at an inoculum of 10 8 CFU/ml. Thirteen K. pneumoniae isolates, three Enterobacter cloacae isolates, and one Escherichia coli isolate were examined in an in vitro hollow-fiber model over 32 h. Simulated dosage regimens of 1 to 2 g of meropenem with 1 to 2 g of vaborbactam, with meropenem administered every 8 h by a 3-h infusion based on phase 1 or phase 3 patient pharmacokinetic data, were studied in the model. A dosage of 2 g of meropenem in combination with 2 g of vaborbactam was bactericidal against K. pneumoniae , E. cloacae , and E. coli strains, with meropenem-vaborbactam MICs of up to 8 mg/liter. When the vaborbactam exposure was adjusted to the levels observed in patients enrolled in phase 3 trials (24-h free AUC, ∼550 mg · h/liter, versus 320 mg · h/liter in the phase 1 studies), 2 g of meropenem with 2 g of vaborbactam was also bactericidal against strains with meropenem-vaborbactam MICs of 16 mg/liter. In addition, this level of vaborbactam also suppressed the development of resistance observed using phase 1 exposures. In this pharmacodynamic model, exposures similar to 2 g of meropenem in combination with 2 g of vaborbactam administered every 8 h by a 3-h infusion in phase 3 trials produced antibacterial activity and suppressed the development of resistance against carbapenem-resistant KPC-producing strains of Enterobacteriaceae . Copyright © 2018 American Society for Microbiology.

The Phase Transformation and Crystal Structure Studies of Strontium Substituted Barium Monoferrite

NASA Astrophysics Data System (ADS)

Mulyawan, A.; Adi, W. A.; Mustofa, S.; Fisli, A.

2017-03-01

Unlike other AFe2O4 ferrite materials, Barium Monoferrite (BaFe2O4) have an orthorhombic structure which is very interesting to further study the crystal structure and phase formation. In this study, Strontium substituted Barium Monoferrite in the form of Ba(1-x)Sr(x)Fe2O4 has successfully been synthesized through solid state reaction method which includes BaCO3, SrCO3, and Fe2O3 as starting materials. Ba(1-x)Sr(x)Fe2O4 was made by varying the dopant composition of Strontium (Sr2+) from x = 0, 0.1, 0.3, and 0.5. Each composition was assisted by ethanol and continued to the milling process for 5 hours then followed by sintering process at 900 °C for 5 hours. The phase transformation was studied by using X-ray diffractometer (XRD) and Rietveld refinement using General Structure Analysis System (GSAS) also 3D crystal visualization using VESTA. Referring to the refinement results, a single phase of BaFe2O4 was formed in x = 0 and 0.1. The composition has orthorhombic structure, space group B b21m, and lattice parameters of a = 19.0229, b = 5.3814 c = 8.4524 Å, α = β = γ = 90° and a = 18.9978, b = 5.3802 c = 8.4385 Å, α = β = γ = 90° respectively. In the composition of x = 0.3 it was found that the phase of BaSrFe4O8 begin to form due to the overload expansion of the Sr2+ occupancy which made the distortion of the initial lattice parameters and finally in the x = 0.5 composition the single phase of BaSrFe4O8 was clearly formed. Energy Dispersive Spectroscopy (EDS) was used to confirm the change of the material structure by measuring the elemental compound composition ratio. The result of EDS spectra clearly exhibited the dominant elements were Barium (Ba), Strontium (Sr), Iron (Fe), and Oxygen (O) with the compound ratio (Atomic percentage and mass percentage) correspond to the BaFe2O4 and BaSrFe4O8 phase.

Numerical Study of Quantum Hall Bilayers at Total Filling νT=1 : A New Phase at Intermediate Layer Distances

NASA Astrophysics Data System (ADS)

Zhu, Zheng; Fu, Liang; Sheng, D. N.

2017-10-01

We study the phase diagram of quantum Hall bilayer systems with total filing νT=1 /2 +1 /2 of the lowest Landau level as a function of layer distances d . Based on numerical exact diagonalization calculations, we obtain three distinct phases, including an exciton superfluid phase with spontaneous interlayer coherence at small d , a composite Fermi liquid at large d , and an intermediate phase for 1.1

Alternative Solvents/Technologies for Paint Stripping: Phase 1.

DTIC Science & Technology

1994-03-01

processes . Three phases of study are defined: Phase I, identify alternate solvents/strippers and screen them; Phase II, field test solvent/ strippers...Section Title Page 1 Metal Refinishing Process - Immersion Method ............... 8 2 Phase Summary Chart ........................ 12 3 The...of the following: (a) nontoxic chemical formulations, (b) new process development, and (c) new coating reformulations. This program consists of three

High Pressure Strength Study on NaCl

NASA Astrophysics Data System (ADS)

Mi, Z.; Shieh, S. R.; High Pressure Mineral Physics Group

2010-12-01

Yield strength is regarded as one important property related to rheological characteristics of minerals in the Earth’s interior. The strength study of NaCl, a popular pressure medium in static high pressure experiments, has been carried out under non-hydrostatic conditions in a diamond anvil cell up to 43 GPa at room temperature using radial energy dispersive X-ray diffraction technique. Phase transformation from B1 (rock salt structure) to B2 (CsCl structure) starts at 29.4 GPa, and is complete at 32.1 GPa. Bulk modulus obtained by third order Birch-Manurgham equation of state is 25.5 GPa with pressure derivative 4.6 for B1 phase, and 30.78 GPa with pressure derivative 4.32 GPa for B2 phase, which are in a good agreement with previous studies. The differential stress of NaCl B1 phase shows very gentle increase with pressure, which indicates that NaCl is a very good pressure-transmitting medium at pressure below 30 GPa. However, the differential stress increases more abruptly for B2 phase and this may imply that NaCl can no longer be regarded as a “soft” pressure medium at very high pressures. For B1 phase, (111) is the strongest plane and (200) is the weakest plane, while (200) becomes the strongest plane in B2 phase. Pure NaCl is weaker than mixture MgO and NaCl, which indicates that soft material become stronger when mixed with hard material. The yield strength of B2 obtained through energy dispersive X-ray diffraction technique increase linearly, while the value derived by pressure gradient method shows jagged trend.

Development of pharmaceutical clear gel based on Peceol®, lecithin, ethanol and water: Physicochemical characterization and stability study.

PubMed

Mouri, Abdelkader; Diat, Olivier; El Ghzaoui, Abdeslam; Ly, Isabelle; Dorandeu, Christophe; Maurel, Jean Claude; Devoisselle, Jean-Marie; Legrand, Philippe

2015-11-01

The phase behavior of the four-components Peceol®/lecithin/ethanol/water system has been studied in a part of the phase diagram poor in water and varying the lecithin/Peceol® ratio. Using several complementary techniques such as Karl Fischer titration, rheology, polarized microscopy and SAXS measurements several nanostructures of the complex systems were identified. W/O microemulsion (L2) as well as an inverted hexagonal (H2) liquid-crystal phase were studied. The analysis of the different phase transitions allows us to understand the effect of lecithin on the water solubilization efficiency of this clear gel and to show its pharmaceutical interest among lecithin organogels. Copyright © 2015 Elsevier Inc. All rights reserved.

BFV-BRST analysis of the classical and quantum q-deformations of the sl(2) algebra

NASA Astrophysics Data System (ADS)

Dayi, O. F.

1994-01-01

BFV--BRST charge for q-deformed algebras is not unique. Different constructions of it in the classical as well as in the quantum phase space for the $q$-deformed algebra sl_q(2) are discussed. Moreover, deformation of the phase space without deforming the generators of sl(2) is considered. $\\hbar$-q-deformation of the phase space is shown to yield the Witten's second deformation. To study the BFV--BRST cohomology problem when both the quantum phase space and the group are deformed, a two parameter deformation of sl(2) is proposed, and its BFV-BRST charge is given.

Electron backscatter diffraction studies of focused ion beam induced phase transformation in cobalt

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, H.G., E-mail: helen.jones@npl.co.uk

A focused ion beam microscope was used to induce cubic to hexagonal phase transformation in a cobalt alloy, of similar composition to that of the binder phase in a hardmetal, in a controlled manner at 0°, 45° and 80° ion incident angles. The cobalt had an average grain size of ~ 20 μm, allowing multiple orientations to be studied, exposed to a range of doses between 6 × 10{sup 7} and 2 × 10{sup 10} ions/μm{sup 2}. Electron backscatter diffraction (EBSD) was used to determine the original and induced phase orientations, and area fractions, before and after the ion beammore » exposure. On average, less phase transformation was observed at higher incident angles and after lower ion doses. However there was an orientation effect where grains with an orientation close to (111) planes were most susceptible to phase transformation, and (101) the least, where grains partially and fully transformed at varying ion doses. - Highlights: •Ion-induced phase change in FCC cobalt was observed at multiple incidence angles. •EBSD was used to study the relationship between grain orientation and transformation. •Custom software analysed ion dose and phase change with respect to grain orientation. •A predictive capability of ion-induced phase change in cobalt was enabled.« less

The properties of clusters in the gas phase. IV - Complexes of H2O and HNOx clustering on NOx/-/

NASA Technical Reports Server (NTRS)

Lee, N.; Castleman, A. W., Jr.; Keesee, R. G.

1980-01-01

Thermodynamic quantities for the gas-phase clustering equilibria of NO2(-) and NO3(-) were determined with high-pressure mass spectrometry. A comparison of values of the free energy of hydration derived from the data shows good agreement with formerly reported values at 296 K. New data for larger NO2(-) and NO3(-) hydrates as well as NO2(-)(HNO2)n were obtained in this study. To aid in understanding the bonding and stability of the hydrates of nitrite and nitrate ions, CNDO/2 calculations were performed, and the results are discussed. A correlation between the aqueous-phase total hydration enthalpy of a single ion and its gas-phase hydration enthalpy was obtained. Atmospheric implications of the data are also briefly discussed.

DEMONSTRATION OF FUEL CELLS TO RECOVER ENERGY FROM LANDFILL GAS - PHASE III. DEMONSTRATION TESTS - PHASE IV. GUIDELINES AND DEMONSTRATIONS - VOLUME 2. APPENDICES

EPA Science Inventory

The report summarizes the results of a four-phase program to demonstrate that fuel cell energy recovery using a commercial phosphoric acid fuel cell is both environmentally sound and commercially feasible. Phase I, a conceptual design and evaluation study, addressed the technical...

Thermal Stability of NaxCrO2 for Rechargeable Sodium Batteries; Studies by High-Temperature Synchrotron X-ray Diffraction.

PubMed

Yabuuchi, Naoaki; Ikeuchi, Issei; Kubota, Kei; Komaba, Shinichi

2016-11-30

Thermal stability and phase transition processes of NaCrO 2 and Na 0.5 CrO 2 are carefully examined by high-temperature synchrotron X-ray diffraction method. O3-type NaCrO 2 shows anisotropic thermal expansion on heating, which is a common character as layered materials, without phase transition in the temperature range of 27-527 °C. In contrast, for the desodiated phase, in-plane distorted P3-type layered oxide (P'3 Na 0.5 CrO 2 ), phase transition occurs in the following order. Monoclinic distortion associated with Na/vacancy ordering is gradually lost on heating, and its symmetry increases and changes to a rhombohedral lattice at 207 °C. On further heating, phase segregation to two P3 layered metastable phases, which have different interlayer distances (17.0 and 13.5 Å, presumably sodium-rich and sodium-free P3 phases, respectively) are observed on heating to 287-477 °C, but oxygen loss is not observed. Oxygen loss is observed at temperatures only above 500 °C, resulting in the formation of corundum-type Cr 2 O 3 and O3 NaCrO 2 as thermodynamically stable phases. From these results, possibility of Na x CrO 2 as a positive electrode material for safe rechargeable sodium batteries is also discussed.

Olaratumab and doxorubicin versus doxorubicin alone for treatment of soft-tissue sarcoma: an open-label phase 1b and randomised phase 2 trial.

PubMed

Tap, William D; Jones, Robin L; Van Tine, Brian A; Chmielowski, Bartosz; Elias, Anthony D; Adkins, Douglas; Agulnik, Mark; Cooney, Matthew M; Livingston, Michael B; Pennock, Gregory; Hameed, Meera R; Shah, Gaurav D; Qin, Amy; Shahir, Ashwin; Cronier, Damien M; Ilaria, Robert; Conti, Ilaria; Cosaert, Jan; Schwartz, Gary K

2016-07-30

Treatment with doxorubicin is a present standard of care for patients with metastatic soft-tissue sarcoma and median overall survival for those treated is 12-16 months, but few, if any, novel treatments or chemotherapy combinations have been able to improve these poor outcomes. Olaratumab is a human antiplatelet-derived growth factor receptor α monoclonal antibody that has antitumour activity in human sarcoma xenografts. We aimed to assess the efficacy of olaratumab plus doxorubicin in patients with advanced or metastatic soft-tissue sarcoma. We did an open-label phase 1b and randomised phase 2 study of doxorubicin plus olaratumab treatment in patients with unresectable or metastatic soft-tissue sarcoma at 16 clinical sites in the USA. For both the phase 1b and phase 2 parts of the study, eligible patients were aged 18 years or older and had a histologically confirmed diagnosis of locally advanced or metastatic soft-tissue sarcoma not previously treated with an anthracycline, an Eastern Cooperative Oncology Group (ECOG) performance status of 0-2, and available tumour tissue to determine PDGFRα expression by immunohistochemistry. In the phase 2 part of the study, patients were randomly assigned in a 1:1 ratio to receive either olaratumab (15 mg/kg) intravenously on day 1 and day 8 plus doxorubicin (75 mg/m(2)) or doxorubicin alone (75 mg/m(2)) on day 1 of each 21-day cycle for up to eight cycles. Randomisation was dynamic and used the minimisation randomisation technique. The phase 1b primary endpoint was safety and the phase 2 primary endpoint was progression-free survival using a two-sided α level of 0.2 and statistical power of 0.8. This study was registered with ClinicalTrials.gov, number NCT01185964. 15 patients were enrolled and treated with olaratumab plus doxorubicin in the phase 1b study, and 133 patients were randomised (66 to olaratumab plus doxorubicin; 67 to doxorubicin alone) in the phase 2 trial, 129 (97%) of whom received at least one dose of study treatment (64 received olaratumab plus doxorubicin, 65 received doxorubicin). Median progression-free survival in phase 2 was 6.6 months (95% CI 4.1-8.3) with olaratumab plus doxorubicin and 4.1 months (2.8-5.4) with doxorubicin (stratified hazard ratio [HR] 0.67; 0.44-1.02, p=0.0615). Median overall survival was 26.5 months (20.9-31.7) with olaratumab plus doxorubicin and 14.7 months (9.2-17.1) with doxorubicin (stratified HR 0.46, 0.30-0.71, p=0.0003). The objective response rate was 18.2% (9.8-29.6) with olaratumab plus doxorubicin and 11.9% (5.3-22.2) with doxorubicin (p=0.3421). Steady state olaratumab serum concentrations were reached during cycle 3 with mean maximum and trough concentrations ranging from 419 μg/mL (geometric coefficient of variation in percentage [CV%] 26.2) to 487 μg/mL (CV% 33.0) and from 123 μg/mL (CV% 31.2) to 156 μg/mL (CV% 38.0), respectively. Adverse events that were more frequent with olaratumab plus doxorubicin versus doxorubicin alone included neutropenia (37 [58%] vs 23 [35%]), mucositis (34 [53%] vs 23 [35%]), nausea (47 [73%] vs 34 [52%]), vomiting (29 [45%] vs 12 [18%]), and diarrhoea (22 [34%] vs 15 [23%]). Febrile neutropenia of grade 3 or higher was similar in both groups (olaratumab plus doxorubicin: eight [13%] of 64 patients vs doxorubicin: nine [14%] of 65 patients). This study of olaratumab with doxorubicin in patients with advanced soft-tissue sarcoma met its predefined primary endpoint for progression-free survival and achieved a highly significant improvement of 11.8 months in median overall survival, suggesting a potential shift in the treatment of soft-tissue sarcoma. Eli Lilly and Company. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cellulose tris-(3,5-dimethylphenylcarbamate)-based chiral stationary phase for the enantioseparation of drugs in supercritical fluid chromatography: comparison with HPLC.

PubMed

Kalíková, Květa; Martínková, Monika; Schmid, Martin G; Tesařová, Eva

2018-03-01

A cellulose tris-(3,5-dimethylphenylcarbamate)-based chiral stationary phase was studied as a tool for the enantioselective separation of 21 selected analytes with different pharmaceutical and physicochemical properties. The enantioseparations were performed using supercritical fluid chromatography. The effect of the mobile phase composition was studied. Four different additives (diethylamine, triethylamine, isopropylamine, and trifluoroacetic acid) and isopropylamine combined with trifluoroacetic acid were tested and their influence on enantioseparation was compared. The influence of two different mobile phase co-solvents (methanol and propan-2-ol) combined with all the additives was also evaluated. The best mobile phase compositions for the separation of the majority of enantiomers were CO 2 /methanol/isopropylamine 80:20:0.1 v/v/v or CO 2 /propan-2-ol/isopropylamine/trifluoroacetic acid 80:20:0.05:0.05 v/v/v/v. The best results were obtained from the group of basic β-blockers. A high-performance liquid chromatography separation system composed of the same stationary phase and mobile phase of similar properties prepared as a mixture of hexane/propan-2-ol/additive 80:20:0.1 v/v/v was considered for comparison. Supercritical fluid chromatography was found to yield better results, i.e. better enantioresolution for shorter analysis times than high-performance liquid chromatography. However, examples of enantiomers better resolved under the optimized conditions in high-performance liquid chromatography were also found. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Development of High Strength Ni-Cu-Zr-Ti-Si-Sn In-Situ Bulk Metallic Glass Composites Reinforced by Hard B2 Phase

NASA Astrophysics Data System (ADS)

Park, Hyo Jin; Hong, Sung Hwan; Park, Hae Jin; Kim, Young Seok; Kim, Jeong Tae; Na, Young Sang; Lim, Ka Ram; Wang, Wei-Min; Kim, Ki Buem

2018-03-01

In the present study, the influence of atomic ratio of Zr to Ti on the microstructure and mechanical properties of Ni-Cu-Zr-Ti-Si-Sn alloys is investigated. The alloys were designed by fine replacement of Ti for Zr from Ni39Cu20Zr36-xTixSi2Sn3. The increase of Ti content enhances glass forming ability of the alloy by suppression of formation of (Ni, Cu)10(Zr, Ti)7 phase during solidification. With further increasing Ti content up to 24 at.%, the B2 phase is introduced in the amorphous matrix with a small amount of B19' phase from alloy melt. The bulk metallic glass composite containing B2 phase with a volume fraction of 10 vol% exhibits higher fracture strength ( 2.5 GPa) than that of monolithic bulk metallic glass ( 2.3 GPa). This improvement is associated to the individual mechanical characteristics of the B2 phase and amorphous matrix. The B2 phase exhibits higher hardness and modulus than those of amorphous matrix as well as effective stress accommodation up to the higher stress level than the yield strength of amorphous matrix. The large stress accommodation capacity of the hard B2 phase plays an important factor to improve the mechanical properties of in situ Ni-based bulk metallic glass composites.

Competing order parameters in Fermi systems with engineered band dispersion

NASA Astrophysics Data System (ADS)

Wu, Chien-Te; Boyack, Rufus; Anderson, Brandon; Levin, K.

We explore a variety of competing phases in 2D and 3D Fermi gases in the presence of novel dispersion relations resulting from a shaken optical lattice. We incorporate spin imbalance along with attractive interactions. In 3D, at the mean field level we present phase diagrams reflecting the stability of alternative order parameters in the pairing (including LOFF) and charge density wave channels. We perform analogous studies in 2D, where we focus on the competition between different paired phases. Important in this regard is that our 2D studies are consistent with the Mermin Wagner theorem, so that, while there is competition, conventional superfluidity cannot occur

Sustainability of protocolized handover of pediatric cardiac surgery patients to the intensive care unit.

PubMed

Chenault, Kristin; Moga, Michael-Alice; Shin, Minah; Petersen, Emily; Backer, Carl; De Oliveira, Gildasio S; Suresh, Santhanam

2016-05-01

Transfer of patient care among clinicians (handovers) is a common source of medical errors. While the immediate efficacy of these initiatives is well documented, sustainability of practice changes that results in better processes of care is largely understudied. The objective of the current investigation was to evaluate the sustainability of a protocolized handover process in pediatric patients from the operating room after cardiac surgery to the intensive care unit. This was a prospective study with direct observation assessment of handover performance conducted in the cardiac ICU (CICU) of a free-standing, tertiary care children's hospital in the United States. Patient transitions from the operating room to the CICU, including the verbal handoff, were directly observed by a single independent observer in all phases of the study. A checklist of key elements identified errors classified as: (1) technical, (2) information omissions, and (3) realized errors. Total number of errors was compared across the different times of the study (preintervention, postintervention, and the current sustainability phase). A total of 119 handovers were studied: 41 preintervention, 38 postintervention, and 40 in the current sustainability phase. The median [Interquartile range (IQR)] number of technical errors was significantly reduced in the sustainability phase compared to the preintervention and postintervention phase, 2 (1-3), 6 (5-7), and 2.5 (2-4), respectively P = 0.0001. Similarly, the median (IQR) number of verbal information omissions was also significantly reduced in the sustainability phase compared to the preintervention and postintervention phases, 1 (1-1), 4 (3-5) and 2 (1-3), respectively. We demonstrate sustainability of an improved handover process using a checklist in children being transferred to the intensive care unit after cardiac surgery. Standardized handover processes can be a sustainable strategy to improve patient safety after pediatric cardiac surgery. © 2016 John Wiley & Sons Ltd.

Hexagonal OsB 2: Sintering, microstructure and mechanical properties

DOE PAGES

Xie, Zhilin; Lugovy, Mykola; Orlovskaya, Nina; ...

2015-02-07

In this study, the metastable high pressure ReB 2-type hexagonal OsB 2 bulk ceramics was produced by spark plasma sintering. The phase composition, microstructure, and mechanical behavior of the sintered OsB 2 were studied by X-ray diffraction, optical microscopy, TEM, SEM, EDS, and nanoindentation. The produced ceramics was rather porous and contained a mixture of hexagonal (~80 wt.%) and orthorhombic (~20 wt.%) phases as identified by X-ray diffraction and EBSD analysis. Two boron-rich phases, which do not contain Os, were also identified by TEM and SEM/EDS analysis. Nanoindentation measurements yielded a hardness of 31 ± 9 GPa and Young’s modulusmore » of 574 ± 112 GPa, indicating that the material is rather hard and very stiff; but, it is very prone to crack formation and propagation, which is indicative of a very brittle nature of this material. Improvements in the sintering regime are required in order to produce dense, homogeneous and single phase hexagonal OsB 2 bulk ceramics.« less

Enriched classification of parafermionic gapped phases with time-reversal symmetry

NASA Astrophysics Data System (ADS)

Xu, Wen-Tao; Zhang, Guang-Ming

2018-03-01

Based on the recently established parafermionic matrix product states, we study the classification of one-dimensional gapped phases of parafermions with time-reversal (TR) symmetry satisfying T2=1 . Without extra symmetry, it has been found that Zp parafermionic gapped phases can be classified as topological phases, spontaneous symmetry breaking (SSB) phases, and a trivial phase, which are uniquely labeled by the divisors n of p . In the presence of TR symmetry, however, the enriched classification is characterized by three indices n , κ , and μ , where κ ∈Z2 denotes the linear or projective TR actions on the edges, and μ ∈Z2 indicates the commutation relations between the TR and (fractionalized) charge operator. For the Zr-symmetric parafermionic ground states, where r =p for trivial or topological phases, and r =p /n for SSB phases, each original gapped phase with odd r is divided into two phases, while each phase with even r is further separated into four phases. The gapped parafermionic phases with the TR symmetry include the symmetry protected topological phases, symmetry enriched topological phases, and the SSB coexisting symmetry protected topological phases. From analyzing the structures and symmetries of their reduced density matrices of these resulting topological phases, we can obtain the topologically protected degeneracies of their entanglement spectra.

Effect of organic matters on CO2 hydrate phase equilibrium conditions in Na-montmorillonite clay

NASA Astrophysics Data System (ADS)

Park, T.; Kyung, D.; Lee, W.

2013-12-01

Formation of gas hydrates provides an attractive idea for storing greenhouse gases in a long-term stable geological formation. Since the phase equilibrium conditions of gas hydrates indicate the stability of hydrates, estimation of the phase equilibrium conditions of gas hydrates in marine geological conditions is necessary. In this study, we have identified the effects of organic matters (glycine, glucose, and urea) and solid surface (montmorillonite (MMT)) on the three-phase (liquid-hydrate-vapor) equilibrium conditions of CO2 hydrate. CO2 phase equilibrium experiments were conducted using 0.5mol% organic matter solutions with and without 10g soil mineral were experimentally conducted. Addition of organic matters shifted the phase equilibrium conditions of CO2 hydrate to the higher pressure or lower pressure region because of higher competition of water molecules due to the dissolved organic matters. Presence of MMT also leaded to the higher equilibrium pressure due to the interaction of cations with water molecules. By addition of organic matters to the clay suspension, the hydrate phase equilibrium conditions were less inhibited compared to those of MMT and organic matters independently. The diminished magnitudes by addition of organic matters to the clay suspension (MMT > MMT+urea > MMT+glycine > MMT+glucose > DIW) were different to the order of inhibition degree without MMT (Glucose > glycine > urea > DIW). X-ray diffraction (XRD), scanning electron microscope (SEM), and ion chromatography (IC) analysis were conducted to support the hypothesis that the organic matters interact with cations in MMT interlayer space, and leads to the less inhibition of phase equilibrium conditions. The present study provides basic information for the formation and dissociation of CO2 hydrates in the geological formation when sequestering CO2 as a form of CO2 hydrate.

From Macromolecular to Small-Molecular Triggers: Facile Method toward Photoinduced LCST Phase Behavior of Thermoresponsive Polymers in Mixed Ionic Liquids Containing an Azobenzene Moiety.

PubMed

Wang, Caihong; Ma, Xiaofeng; Kitazawa, Yuzo; Kobayashi, Yumi; Zhang, Shiguo; Kokubo, Hisashi; Watanabe, Masayoshi

2016-12-01

Instead of the reported photoinduced lower critical solution temperature (LCST) phase transition behavior in ionic liquids (ILs) achieved by photofunctional polymers, this study reports the facile photoinduced LCST phase behavior of nonfunctionalized polymers (poly(benzyl methacrylate) (PBnMA) and poly(2-phenylethyl methacrylate) (PPhEtMA)) in mixed ILs (1,3-dimethylimidazolium bis(trifluoromethanesulfonyl)amide; [C 1 mim][NTf 2 ] and a newly designed functionalized IL containing an azobenzene moiety (1-butyl-3-(4-phenylazobenzyl)imidazolium bis(trifluoromethanesulfonyl)amide; [Azo][NTf 2 ])) as a small-molecular photo trigger. Interestingly, the length of the alkyl spacer between the ester and aryl groups, which is the only structural difference between the two polymers, leads to two different photoresponsive LCST phase transition behaviors. On the basis of spectroscopic studies, the different phase transition behaviors of PBnMA and PPhEtMA may attribute to the different cooperative interactions between the polymers and [C 1 mim][NTf 2 ]. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Three-dimensional image authentication scheme using sparse phase information in double random phase encoded integral imaging.

PubMed

Yi, Faliu; Jeoung, Yousun; Moon, Inkyu

2017-05-20

In recent years, many studies have focused on authentication of two-dimensional (2D) images using double random phase encryption techniques. However, there has been little research on three-dimensional (3D) imaging systems, such as integral imaging, for 3D image authentication. We propose a 3D image authentication scheme based on a double random phase integral imaging method. All of the 2D elemental images captured through integral imaging are encrypted with a double random phase encoding algorithm and only partial phase information is reserved. All the amplitude and other miscellaneous phase information in the encrypted elemental images is discarded. Nevertheless, we demonstrate that 3D images from integral imaging can be authenticated at different depths using a nonlinear correlation method. The proposed 3D image authentication algorithm can provide enhanced information security because the decrypted 2D elemental images from the sparse phase cannot be easily observed by the naked eye. Additionally, using sparse phase images without any amplitude information can greatly reduce data storage costs and aid in image compression and data transmission.

Measurement of a True [Formula: see text]O2max during a Ramp Incremental Test Is Not Confirmed by a Verification Phase.

PubMed

Murias, Juan M; Pogliaghi, Silvia; Paterson, Donald H

2018-01-01

The accuracy of an exhaustive ramp incremental (RI) test to determine maximal oxygen uptake ([Formula: see text]O 2max ) was recently questioned and the utilization of a verification phase proposed as a gold standard. This study compared the oxygen uptake ([Formula: see text]O 2 ) during a RI test to that obtained during a verification phase aimed to confirm attainment of [Formula: see text]O 2max . Sixty-one healthy males [31 older (O) 65 ± 5 yrs; 30 younger (Y) 25 ± 4 yrs] performed a RI test (15-20 W/min for O and 25 W/min for Y). At the end of the RI test, a 5-min recovery period was followed by a verification phase of constant load cycling to fatigue at either 85% ( n = 16) or 105% ( n = 45) of the peak power output obtained from the RI test. The highest [Formula: see text]O 2 after the RI test (39.8 ± 11.5 mL·kg -1 ·min -1 ) and the verification phase (40.1 ± 11.2 mL·kg -1 ·min -1 ) were not different ( p = 0.33) and they were highly correlated ( r = 0.99; p < 0.01). This response was not affected by age or intensity of the verification phase. The Bland-Altman analysis revealed a very small absolute bias (-0.25 mL·kg -1 ·min -1 , not different from 0) and a precision of ±1.56 mL·kg -1 ·min -1 between measures. This study indicated that a verification phase does not highlight an under-estimation of [Formula: see text]O 2max derived from a RI test, in a large and heterogeneous group of healthy younger and older men naïve to laboratory testing procedures. Moreover, only minor within-individual differences were observed between the maximal [Formula: see text]O 2 elicited during the RI and the verification phase. Thus a verification phase does not add any validation of the determination of a [Formula: see text]O 2max . Therefore, the recommendation that a verification phase should become a gold standard procedure, although initially appealing, is not supported by the experimental data.

Partially collapsed cristobalite structure in the non molecular phase V in CO2

PubMed Central

Santoro, Mario; Gorelli, Federico A.; Bini, Roberto; Haines, Julien; Cambon, Olivier; Levelut, Claire; Montoya, Javier A.; Scandolo, Sandro

2012-01-01

Non molecular CO2 has been an important subject of study in high pressure physics and chemistry for the past decade opening up a unique area of carbon chemistry. The phase diagram of CO2 includes several non molecular phases above 30 GPa. Among these, the first discovered was CO2-V which appeared silica-like. Theoretical studies suggested that the structure of CO2-V is related to that of β-cristobalite with tetrahedral carbon coordination similar to silicon in SiO2, but reported experimental structural studies have been controversial. We have investigated CO2-V obtained from molecular CO2 at 40–50 GPa and T > 1500 K using synchrotron X-ray diffraction, optical spectroscopy, and computer simulations. The structure refined by the Rietveld method is a partially collapsed variant of SiO2 β-cristobalite, space group , in which the CO4 tetrahedra are tilted by 38.4° about the c-axis. The existence of CO4 tetrahedra (average O-C-O angle of 109.5°) is thus confirmed. The results add to the knowledge of carbon chemistry with mineral phases similar to SiO2 and potential implications for Earth and planetary interiors. PMID:22431594

Synthesis of TiO2 Nanoparticles from Ilmenite Through the Mechanism of Vapor-Phase Reaction Process by Thermal Plasma Technology

NASA Astrophysics Data System (ADS)

Samal, Sneha

2017-11-01

Synthesis of nanoparticles of TiO2 was carried out by non-transferred arc thermal plasma reactor using ilmenite as the precursor material. The powder ilmenite was vaporized at high temperature in plasma flame and converted to a gaseous state of ions in the metastable phase. On cooling, chamber condensation process takes place on recombination of ions for the formation of nanoparticles. The top-to-bottom approach induces the disintegration of complex ilmenite phases into simpler compounds of iron oxide and titanium dioxide phases. The vapor-phase reaction mechanism was carried out in thermal plasma zone for the synthesis of nanoparticles from ilmenite compound in a plasma reactor. The easy separation of iron particles from TiO2 was taken place in the plasma chamber with deposition of light TiO2 particles at the top of the cooling chamber and iron particles at the bottom. The dissociation and combination process of mechanism and synthesis are studied briefly in this article. The product TiO2 nanoparticle shows the purity with a major phase of rutile content. TiO2 nanoparticles produced in vapor-phase reaction process shows more photo-induced capacity.

Rectal Microbicide Development

PubMed Central

McGowan, Ian

2013-01-01

Purpose of review Individuals practicing unprotected receptive anal intercourse are at particularly high risk of HIV infection. Men who have sex with men (MSM) in the developed and developing world continue to have disproportionate and increasing levels of HIV infection. The last few years have seen important progress in demonstrating the efficacy of oral pre-exposure prophylaxis (PrEP), vaginal microbicides, and treatment as prevention but there has also been significant progress in the development of rectal microbicides (RM). The purpose of this review is to summarize the status of RM research and to identify opportunities, challenges, and future directions in this important field of HIV prevention. Recent findings Recent Phase 1 RM studies have characterized the safety, acceptability, compartmental pharmacokinetics (PK), and pharmacodynamics (PD) of both UC781 and tenofovir gels. The tenofovir gel formulation used in vaginal studies was not well tolerated in the rectum and newer rectal specific formulations have been developed and evaluated in Phase 1 studies. Summary Complex Phase 1 studies have provided important data on candidate RMs. Tenofovir gel is poised to move into Phase 2 evaluation and it is possible that a Phase 2B/3 effectiveness study could be initiated in the next 2–3 years. PMID:23032732

Rectal microbicide development.

PubMed

McGowan, Ian

2012-11-01

Individuals practicing unprotected receptive anal intercourse are at particularly high risk of HIV infection. Men who have sex with men (MSM) in the developed and developing world continue to have disproportionate and increasing levels of HIV infection. The past few years have seen important progress in demonstrating the efficacy of oral pre-exposure prophylaxis (PrEP), vaginal microbicides, and treatment as prevention, but there has also been significant progress in the development of rectal microbicides. The purpose of this review is to summarize the status of rectal microbicide research and to identify opportunities, challenges, and future directions in this important field of HIV prevention. Recent phase 1 rectal microbicide studies have characterized the safety, acceptability, compartmental pharmacokinetics, and pharmacodynamics of both UC781 and tenofovir gels. The tenofovir gel formulation used in vaginal studies was not well tolerated in the rectum and newer rectal-specific formulations have been developed and evaluated in phase 1 studies. Complex phase 1 studies have provided important data on candidate rectal microbicides. Tenofovir gel is poised to move into phase 2 evaluation and it is possible that a phase 2B/3 effectiveness study could be initiated in the next 2-3 years.

Individualized treatment with transcranial direct current stimulation in patients with chronic non-fluent aphasia due to stroke

PubMed Central

Shah-Basak, Priyanka P.; Norise, Catherine; Garcia, Gabriella; Torres, Jose; Faseyitan, Olufunsho; Hamilton, Roy H.

2015-01-01

While evidence suggests that transcranial direct current stimulation (tDCS) may facilitate language recovery in chronic post-stroke aphasia, individual variability in patient response to different patterns of stimulation remains largely unexplored. We sought to characterize this variability among chronic aphasic individuals, and to explore whether repeated stimulation with an individualized optimal montage could lead to persistent reduction of aphasia severity. In a two-phase study, we first stimulated patients with four active montages (left hemispheric anode or cathode; right hemispheric anode or cathode) and one sham montage (Phase 1). We examined changes in picture naming ability to address (1) variability in response to different montages among our patients, and (2) whether individual patients responded optimally to at least one montage. During Phase 2, subjects who responded in Phase 1 were randomized to receive either real-tDCS or to receive sham stimulation (10 days); patients who were randomized to receive sham stimulation first were then crossed over to receive real-tDCS (10 days). In both phases, 2 mA tDCS was administered for 20 min per real-tDCS sessions and patients performed a picture naming task during stimulation. Patients' language ability was re-tested after 2-weeks and 2-months following real and sham tDCS in Phase 2. In Phase 1, despite considerable individual variability, the greatest average improvement was observed after left-cathodal stimulation. Seven out of 12 subjects responded optimally to at least one montage as demonstrated by transient improvement in picture-naming. In Phase 2, aphasia severity improved at 2-weeks and 2-months following real-tDCS but not sham. Despite individual variability with respect to optimal tDCS approach, certain montages result in consistent transient improvement in persons with chronic post-stroke aphasia. This preliminary study supports the notion that individualized tDCS treatment may enhance aphasia recovery in a persistent manner. PMID:25954178

Long working hours and sleep disturbances: the Whitehall II prospective cohort study.

PubMed

Virtanen, Marianna; Ferrie, Jane E; Gimeno, David; Vahtera, Jussi; Elovainio, Marko; Singh-Manoux, Archana; Marmot, Michael G; Kivimäki, Mika

2009-06-01

To examine whether exposure to long working hours predicts various forms of sleep disturbance; short sleep, difficulty falling asleep, frequent waking, early waking and waking without feeling refreshed. Prospective study with 2 measurements of working hours (phase 3, 1991-1994 and phase 5, 1997-1999) and 2 measurements of subjective sleep disturbances (phase 5 and phase 7, 2002-2004). The Whitehall II study of British civil servants. Full time workers free of sleep disturbances at phase 5 and employed at phases 5 and 7 (n = 937-1594) or at phases 3, 5, and 7 (n = 886-1510). Working more than 55 hours a week, compared with working 35-40 hours a week, was related to incident sleep disturbances; demographics-adjusted odds ratio (95% CI) 1.98 (1.05, 3.76) for shortened sleeping hours, 3.68 (1.58, 8.58) for difficulty falling asleep; and 1.98 (1.04, 3.77) for waking without feeling refreshed. Repeat exposure to long working hours was associated with odds ratio 3.24 (1.45, 7.27) for shortened sleep, 6.66 (2.64, 16.83) for difficulty falling asleep, and 2.23 (1.16, 4.31) for early morning awakenings. Some associations were attenuated after adjustment for other risk factors. To a great extent, similar results were obtained using working hours as a continuous variable. Imputation of missing values supported the findings on shortened sleep and difficulty in falling asleep. Working long hours appears to be a risk factor for the development of shortened sleeping hours and difficulty falling asleep.

Calcium titanium silicate based glass-ceramic for nuclear waste immobilisation

NASA Astrophysics Data System (ADS)

Sharma, K.; Srivastav, A. P.; Goswami, M.; Krishnan, Madangopal

2018-04-01

Titanate based ceramics (synroc) have been studied for immobilisation of nuclear wastes due to their high radiation and thermal stability. The aim of this study is to synthesis glass-ceramic with stable phases from alumino silicate glass composition and study the loading behavior of actinides in glass-ceramics. The effects of CaO and TiO2 addition on phase evolution and structural properties of alumino silicate based glasses with nominal composition x(10CaO-9TiO2)-y(10Na2O-5 Al2O3-56SiO2-10B2O3); where z = x/y = 1.4-1.8 are reported. The glasses are prepared by melt-quench technique and characterized for thermal and structural properties using DTA and Raman Spectroscopy. Glass transition and peak crystallization temperatures decrease with increase of CaO and TiO2 content, which implies the weakening of glass network and increased tendency of glasses towards crystallization. Sphene (CaTiSiO5) and perovskite (CaTiO3) crystalline phases are confirmed from XRD which are well known stable phase for conditioning of actinides. The microsturcture and elemental analysis indicate the presence of actinide in stable crystalline phases.

High-fat diet with stress impaired islets' insulin secretion by reducing plasma estradiol and pancreatic GLUT2 protein levels in rats' proestrus phase.

PubMed

Salimi, M; Zardooz, H; Khodagholi, F; Rostamkhani, F; Shaerzadeh, F

2016-10-01

This study was conducted to determine whether two estrus phases (proestrus and diestrus) in female rats may influence the metabolic response to a high-fat diet and/or stress, focusing on pancreatic insulin secretion and content. Animals were divided into high-fat and normal diet groups, then each group was subdivided into stress and non-stress groups, and finally, each one of these was divided into proestrus and diestrus subgroups. At the end of high-fat diet treatment, foot-shock stress was applied to the animals. Then, blood samples were taken to measure plasma factors. Finally, the pancreas was removed for determination of glucose transporter 2 (GLUT2) protein levels and assessment of insulin content and secretion of the isolated islets. In the normal and high-fat diet groups, stress increased plasma corticosterone concentration in both phases. In both study phases, high-fat diet consumption decreased estradiol and increased leptin plasma levels. In the high-fat diet group in response to high glucose concentration, a reduction in insulin secretion was observed in the proestrus phase compared with the same phase in the normal diet group in the presence and absence of stress. Also, high-fat diet decreased the insulin content of islets in the proestrus phase compared with the normal diet. High-fat diet and/or stress caused a reduction in islet GLUT2 protein levels in both phases. In conclusion, it seems possible that high-fat diet alone or combined with foot-shock, predispose female rats to impaired insulin secretion, at least in part, by interfering with estradiol levels in the proestrus phase and decreasing pancreatic GLUT2 protein levels.

Pilot study assessing differentiation of steatosis hepatis, hepatic iron overload, and combined disease using two-point dixon MRI at 3 T: in vitro and in vivo results of a 2D decomposition technique.

PubMed

Boll, Daniel T; Marin, Daniele; Redmon, Grace M; Zink, Stephen I; Merkle, Elmar M

2010-04-01

The purpose of our study was to evaluate whether two-point Dixon MRI using a 2D decomposition technique facilitates metabolite differentiation between lipids and iron in standardized in vitro liver phantoms with in vivo patient validation and allows semiquantitative in vitro assessment of metabolites associated with steatosis, iron overload, and combined disease. The acrylamide-based phantoms were made to reproduce the T1- and T2-weighted MRI appearances of physiologic hepatic parenchyma and hepatic steatosis-iron overload by the admixture of triglycerides and ferumoxides. Combined disease was simulated using joint admixtures of triglycerides and ferumoxides at various concentrations. For phantom validation, 30 patients were included, of whom 10 had steatosis, 10 had iron overload, and 10 had no liver disease. For MRI an in-phase/opposed-phase T1-weighted sequence with TR/TE(opposed-phase)/TE(in-phase) of 4.19/1.25/2.46 was used. Fat/water series were obtained by Dixon-based algorithms. In-phase and opposed-phase and fat/water ratios were calculated. Statistical cluster analysis assessed ratio pairs of physiologic liver, steatosis, iron overload, and combined disease in 2D metabolite discrimination plots. Statistical assessment proved that metabolite decomposition in phantoms simulating steatosis (1.77|0.22; in-phase/opposed-phase|fat/water ratios), iron overload (0.75|0.21), and healthy control subjects (1.09|0.05) formed three clusters with distinct ratio pairs. Patient validation for hepatic steatosis (3.29|0.51), iron overload (0.56|0.41), and normal control subjects (0.99|0.05) confirmed this clustering (p < 0.001). One-dimensional analysis assessing in vitro combined disease only with in-phase/opposed-phase ratios would have failed to characterize metabolites. The 2D analysis plotting in-phase/opposed-phase and fat/water ratios (2.16|0.59) provided accurate semiquantitative metabolite decomposition (p < 0.001). MR Dixon imaging facilitates metabolite decomposition of intrahepatic lipids and iron using in vitro phantoms with in vivo patient validation. The proposed decomposition technique identified distinct in-phase/opposed-phase and fat/water ratios for in vitro steatosis, iron overload, and combined disease.

Communication: Two-dimensional gas-phase coherent anti-Stokes Raman spectroscopy (2D-CARS): Simultaneous planar imaging and multiplex spectroscopy in a single laser shot

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bohlin, Alexis; Kliewer, Christopher J.

2013-01-01

Coherent anti-Stokes Raman spectroscopy (CARS) has been widely used as a powerful tool for chemical sensing, molecular dynamics measurements, and rovibrational spectroscopy since its development over 30 years ago, finding use in fields of study as diverse as combustion diagnostics, cell biology, plasma physics, and the standoff detection of explosives. The capability for acquiring resolved CARS spectra in multiple spatial dimensions within a single laser shot has been a long-standing goal for the study of dynamical processes, but has proven elusive because of both phase-matching and detection considerations. Here, by combining new phase matching and detection schemes with the highmore » efficiency of femtosecond excitation of Raman coherences, we introduce a technique for single-shot two-dimensional (2D) spatial measurements of gas phase CARS spectra. We demonstrate a spectrometer enabling both 2D plane imaging and spectroscopy simultaneously, and present the instantaneous measurement of 15, 000 spatially correlated rotational CARS spectra in N 2 and air over a 2D field of 40 mm 2.« less

Tofacitinib, an oral Janus kinase inhibitor, for the treatment of Latin American patients with rheumatoid arthritis: Pooled efficacy and safety analyses of Phase 3 and long-term extension studies.

PubMed

Radominski, Sebastião Cezar; Cardiel, Mario Humberto; Citera, Gustavo; Goecke, Annelise; Jaller, Juan Jose; Lomonte, Andrea Barranjard Vannucci; Miranda, Pedro; Velez, Patricia; Xibillé, Daniel; Kwok, Kenneth; Rojo, Ricardo; García, Erika Gabriela

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis (RA). We assessed tofacitinib efficacy and safety in the Latin American (LA) subpopulation of global Phase 3 and long-term extension (LTE) studies. Data from LA patients with RA and inadequate response to disease-modifying antirheumatic drugs (DMARDs) were pooled across five Phase 3 studies. Phase 3 patients received tofacitinib 5 or 10mg twice daily (BID), adalimumab or placebo; patients in the single LTE study received tofacitinib 5 or 10mg BID; treatments were administered alone or with conventional synthetic DMARDs. Efficacy was reported up to 12 months (Phase 3) and 36 months (LTE) by American College of Rheumatology (ACR) 20/50/70 response rates, Disease Activity Score (DAS)28-4(erythrocyte sedimentation rate [ESR]) and Health Assessment Questionnaire-Disability Index (HAQ-DI). Incidence rates (IRs; patients with event/100 patient-years) of adverse events (AEs) of special interest were reported. The Phase 3 studies randomized 496 LA patients; the LTE study enrolled 756 LA patients from Phase 2 and Phase 3. In the Phase 3 studies, patients who received tofacitinib 5 and 10mg BID showed improvements vs placebo at Month 3 in ACR20 (68.9% and 75.7% vs 35.6%), ACR50 (45.8% and 49.7% vs 20.7%) and ACR70 (17.5% and 23.1% vs 6.9%) responses, mean change from baseline in HAQ-DI (-0.6 and -0.8 vs -0.3) and DAS28-4(ESR) score (-2.3 and -2.4 vs -1.4). The improvements were sustained up to Month 36 in the LTE study. In the Phase 3 studies, IRs with tofacitinib 5 and 10mg BID and placebo were 7.99, 6.57 and 9.84, respectively, for SAEs, and 3.87, 5.28 and 3.26 for discontinuation due to AEs. IRs of AEs of special interest in tofacitinib-treated LA patients were similar to the global population. In Phase 3 and LTE studies in LA patients with RA, tofacitinib demonstrated efficacy up to 36 months with a manageable safety profile up to 60 months, consistent with the overall tofacitinib study population. Copyright © 2016 Elsevier España, S.L.U. and Sociedad Española de Reumatología y Colegio Mexicano de Reumatología. All rights reserved.

[Study of the phase transformation of TiO2 with in-situ XRD in different gas].

PubMed

Ma, Li-Jing; Guo, Lie-Jin

2011-04-01

TiO2 sample was prepared by sol-gel method from chloride titanium. The phase transformation of the prepared TiO2 sample was studied by in-situ XRD and normal XRD in different gas. The experimental results showed that the phase transformation temperatures of TiO2 were different under in-situ or normal XRD in different kinds of gas. The transformation of amorphous TiO2 to anatase was controlled by kinetics before 500 degrees C. In-situ XRD showed that the growth of anatase was inhibited, but the transformation of anatase to rutile was accelerated under inactive nitrogen in contrast to air. Also better crystal was obtained under hydrogen than in argon. These all showed that external oxygen might accelerate the growth of TiO2, but reduced gas might partly counteract the negative influence of lack of external oxygen. The mechanism of phase transformation of TiO2 was studied by in-situ XRD in order to control the structure in situ.

Interlayer Communication in Aurivillius Vanadate to Enable Defect Structures and Charge Ordering.

PubMed

Zhang, Yaoqing; Yamamoto, Takafumi; Green, Mark A; Kageyama, Hiroshi; Ueda, Yutaka

2015-11-16

The fluorite-like [Bi2O2](2+) layer is a fundamental building unit in a great variety of layered compounds. Here in this contribution, we presented a comprehensive study on an unusual Aurivillius phase Bi3.6V2O10 with respect to its defect chemistry and polymorphism control as well as implications for fast oxide ion transport at lower temperatures. The bismuth oxide layer in Bi4V2O11 is found to tolerate a large number of Bi vacancies without breaking the high temperature prototype I4/mmm structure (γ-phase). On cooling, an orthorhombic distortion occurs to the γ-phase, giving rise to a different type of phase (B-phase) in the intermediate temperature region. Cooling to room temperature causes a further transition to an oxygen-vacancy ordered A-phase, which is accompanied by the charge ordering of V(4+) and V(5+) cations, providing magnetic (d(1)) and nonmagnetic (d(0)) chains along the a axis. This is a novel charge ordering transition in terms of the concomitant change of oxygen coordination. Interestingly, upon quenching, both the γ- and B-phase can be kinetically trapped, enabling the structural probing of the two phases at ambient temperature. Driven by the thermodynamic forces, the oxide anion in the γ-phase undergoes an interlayer diffusion process to reshuffle the compositions of both Bi-O and V-O layers.

TGBA and TGBC phases in some chiral tolan derivatives

NASA Astrophysics Data System (ADS)

Nguyen, H. T.; Bouchta, A.; Navailles, L.; Barois, P.; Isaert, N.; Twieg, R. J.; Maaroufi, A.; Destrade, C.

1992-10-01

Three chiral compounds (n=10, 11, 12) belonging to the optically active series : 3-fluoro-4-[(R) or (S)-1-methylheptyloxy]-4'-(4''-alkoxy-2'', 3''-difluorobenzoyloxy) tolans (nF{2}BTFO{1}M{7}) have been synthesized. The helical SA^{*} phase or TGBA phase is found in the decyloxy derivative. The most interesting compound is obtained with n=11. It displays, for the first time, two TGB phases (TGBA and TGBC phases). The nature of these helical smectic phases is confirmed by different studies : optical observation, DSC, contact method, mixtures, X-ray diffraction and helical pitch measurements. the electrooptical properties of the SC^{*} phase have also been studied. Trois produits (n=10, 11, 12) de la série chirale : 3-fluoro-4-[(R) ou (S)-1-methylheptyloxy]-4'-(4''-alcoxy-2'', 3''-difluorobenzoyloxy) tolanes (nF{2}BTFO{1}M{7}) ont été synthétisés. Les deux premiers produits présentent la phase SA^{*} hélicoïdale ou torse (TGBA). L'existence de la nouvelle phase TGBC, prédite par Renn et Lubensky, a été trouvée dans les deux derniers matériaux et prouvée par plusieurs études : observation microscopique, AED, méthode de contact, mélanges binaires, diffraction de rayons X et mesures du pas d'hélice. Le diagramme de phase réalisé entre ces trois matériaux est similaire à celui prédit par Renn. Les propriétés électrooptiques de la phase SC^{*} ferroélectrique ont aussi été étudiées.

Design of a Bayesian adaptive phase 2 proof-of-concept trial for BAN2401, a putative disease-modifying monoclonal antibody for the treatment of Alzheimer's disease.

PubMed

Satlin, Andrew; Wang, Jinping; Logovinsky, Veronika; Berry, Scott; Swanson, Chad; Dhadda, Shobha; Berry, Donald A

2016-01-01

Recent failures in phase 3 clinical trials in Alzheimer's disease (AD) suggest that novel approaches to drug development are urgently needed. Phase 3 risk can be mitigated by ensuring that clinical efficacy is established before initiating confirmatory trials, but traditional phase 2 trials in AD can be lengthy and costly. We designed a Bayesian adaptive phase 2, proof-of-concept trial with a clinical endpoint to evaluate BAN2401, a monoclonal antibody targeting amyloid protofibrils. The study design used dose response and longitudinal modeling. Simulations were used to refine study design features to achieve optimal operating characteristics. The study design includes five active treatment arms plus placebo, a clinical outcome, 12-month primary endpoint, and a maximum sample size of 800. The average overall probability of success is ≥80% when at least one dose shows a treatment effect that would be considered clinically meaningful. Using frequent interim analyses, the randomization ratios are adapted based on the clinical endpoint, and the trial can be stopped for success or futility before full enrollment. Bayesian statistics can enhance the efficiency of analyzing the study data. The adaptive randomization generates more data on doses that appear to be more efficacious, which can improve dose selection for phase 3. The interim analyses permit stopping as soon as a predefined signal is detected, which can accelerate decision making. Both features can reduce the size and duration of the trial. This study design can mitigate some of the risks associated with advancing to phase 3 in the absence of data demonstrating clinical efficacy. Limitations to the approach are discussed.

A possible answer to the mysterious non-detection of hydroxylamine in space: the thermal desorption mechanism

NASA Astrophysics Data System (ADS)

Jonusas, Mindaugas; Krim, Lahouari

2016-06-01

The presence of NH2OH, one of the main precursors in the formation of amino-acids, on dust grain mantles, may be the most obvious elucidation for the creation of large pre-biotic molecules in the interstellar medium. However, while many laboratory experimental studies, to simulate the icy grain chemistry in space, found that NH2OH molecules may be easily formed in solid phase with high abundances and then they should desorb, through a temperature-induced desorption into the gas phase, with the same high abundances; all the spatial observations conclude that NH2OH is not detected in gas phase within any of the explored astronomical sources. Such inconsistencies between laboratory experiment simulations and spatial observations lead our investigations towards this experimental study to see if there is any chemical transformation of NH2OH, occurring in the solid phase before the desorption processes of NH2OH from the mantle of interstellar icy grains. Our experimental results show that the heating of NH2OH-H2O ices lead to a decomposition of NH2OH into HNO, NH3 and O2, even before reaching its desorption temperature. We show through this work that the NH2OH non-detection from previous examined astronomical sources could mainly due to its high reactivity in solid phase on the icy interstellar grains.

The Effect of CaO on Gas/Slag/Matte/Tridymite Equilibria in Fayalite-Based Copper Smelting Slags at 1473 K (1200 °C) and P(SO2) = 0.25 Atm

NASA Astrophysics Data System (ADS)

Fallah-Mehrjardi, Ata; Hayes, Peter C.; Jak, Evgueni

2018-04-01

Fundamental experimental studies have been undertaken to determine the effect of CaO on the equilibria between the gas phase (CO/CO2/SO2/Ar) and slag/matte/tridymite phases in the Cu-Fe-O-S-Si-Ca system at 1473 K (1200 °C) and P(SO2) = 0.25 atm. The experimental methodology developed in the Pyrometallurgy Innovation Centre was used. New experimental data have been obtained for the four-phase equilibria system for fixed concentrations of CaO (up to 4 wt pct) in the slag phase as a function of copper concentration in matte, including the concentrations of dissolved sulfur and copper in slag, and Fe/SiO2 ratios in slag at tridymite saturation. The new data provided in the present study are of direct relevance to the pyrometallurgical processing of copper and will be used as an input to optimize the thermodynamic database for the copper-containing multi-component multi-phase system.

Phase 2 of CATALISE: A Multinational and Multidisciplinary Delphi Consensus Study of Problems with Language Development--Terminology

ERIC Educational Resources Information Center

Bishop, Dorothy V. M.; Snowling, Margaret J.; Thompson, Paul A.; Greenhalgh, Trisha

2017-01-01

Background: Lack of agreement about criteria and terminology for children's language problems affects access to services as well as hindering research and practice. We report the second phase of a study using an online Delphi method to address these issues. In the first phase, we focused on criteria for language disorder. Here we consider…