Kinetic changes in activity of HR-peroxidase, induced by very low doses of phenol

The allosteric protein of horseradish peroxidase (HRP) shows two main types of activity, peroxidase and oxidase, depending on the kind of low molecular effectors. The effects of very low doses of phenol, prepared by successive dilutions in water or in 75% ethanol, on initial HRP activity in oxidation of o-dianisidine or luminol were tested in a systematic manner by colorimetric and luminometric methods. Results showed that phenol dilutions, including those below Avogadro’s number, could activate or inhibit HRP in peroxidase and oxidase type reactions with a sinusoidal pattern. Km values for the studied substrates changed parallel to HRP peroxidase/oxidase activity and the maximum activity in the peroxidase reaction corresponded to the minimum activity in the oxidase reaction and vice versa. The effect also depended on the type of dilutor. The observations of the peroxidase/oxidase oscillations in the sinusoidal pattern of HRP activity, dependent on the rate of phenol dissolution and the time of preincubation, point out to the conclusion that HRP might be a good model for high dilutions research. The experiments provide strong evidence that horseradish peroxidase (HRP) is a very sensitive detector of subtle changes in the concentration of phenol used as a cofactor in the peroxidase/oxidase reaction. Keywords: HR-peroxidase, peroxidase-oxidase, phenol, hormesis, homeopathy, high dilutions.  Mudanças cinéticas na atividade da HR-peroxidade induzidas por doses muito baixas de fenol Resumo A proteína alostérica da peroxidase do rabano (HRP) mostra dois tipos principais de atividade, peroxidase e oxidase, de acordo com o tipo de efetores de baixa molecularidade. Os efeitos de doses muito baixas de fenol, preparadas através de diluições sucessivas em água ou etanol 75% na atividade inicial da HRP sobre a oxidação da o-dianisidina ou luminol for testados de modo sistemático através de métodos colorimétricos e luminométricos. Os resultados mostram que as diluições de fenol, incluindo aquelas por baixo do número de Avogadro, foram capazes de ativar ou inibir a HRP em reações de tipo peroxidade e oxidase com um padrão sinusoidal. os valores Km dos substratos estudados variaram paralelamente àatividade peroxidase/oxidase da HRP; a atividade máxima da reação peroxidase correspondeu àatividade mínima na reação oxidase e vice-versa. O efeito também se mostrou dependente do tipo do solvente. A observação das oscilações sinusoidais na atividade da HRP, dependentes da taxa de dissolução do fenol e do tempo de pré-incubação, permitem concluir que a HRP pode ser um bom modelo na pesquisa das altas diluições. Os experimentos oferecem fortes evidéncias a favor da HRP como detector muito sensível de mudanças mínimas na concentração do fenol, utilizado como cofator na reação peroxidase/oxigenase. Palavras-chave: HR-peroxidase, peroxidase-oxidase, fenol, hormese, homeopatia, altas diluições.  Cambios cinéticos en la actividad de la HR-peroxidasa inducidos por dosis muy bajas de fenol Resumen La proteína alostérica de la peroxidasa del rábano (HRP) muestra dos tipos principales de actividad, peroxidasa y oxidasa, dependiendo del tipo de efectores de baja molecularidade. Los efectos de doses muy bajas de fenol, preparadas mediante diluciones sucesivas en agua o etanol al 75% sobre la actividad inicial de la HRP sobre la oxidación de o-dianisidina o luminol fueron testados de modo sistemático mediante métodos colorimétricos y luminométricos. Los resultados muestran que las diluciones de fenol, incluyendo aquellas abajo del número de Avogadro, pudieron activar o inhibir la HRP en reacciones de tipo peroxidasa y oxidasa con un patrón sinusoidal. Los valores Km de los sustratos estudiados variaron paralelamente a la actividad peroxidasa/oxidasa de la HRP; la actividad máxima de la reacción peroxidasa correspondió a la actividad mínima en la reacción oxidasa y viceversa. El efecto también se mostró dependiente del tipo de solvente. La observación de las oscilaciones sinusoidales en la actividad de la HRP, dependientes de la tasa de disolución del fenol y del tiempo de preincubación, llevan a concluir que la HRP puede ser un buen modelo para la investigación de las altas diluciones. Los experimentos ofrecen fuertes evidencias a favor de la HRP como detector muy sensible de cambios mínimos en la concentración de fenol, utilizado como cofactor en la reacción peroxidasa/oxigenasa. Palabras-clave: HR-peroxidasa, oxidasa-peroxidasa, fenol, hormesis, homeopatía, altas diluciones.  Correspondence author: Elzbieta Malarczyk, [email protected] How to cite this article: Malarczyk E. Kinetic changes in the activity of HR-peroxidase induced by very low doses of phenol. Int J High Dilution Res [online]. 2008 [cited YYYY Mmm DD]; 7(23): 48-55. Available from: http://journal.giri-society.org/index.php/ijhdr/article/view/37/349. ÂÂÂ

Retrieval of Daily Mean VIIRS SST Products in China Seas

Sea surface temperature (SST) is one of the most important factors in regulating air-sea heat flux and, thus, climate change. Most of current global daily SST products are derived from one or two transient measurements of polar-orbiting satellites, which are not the same to daily mean SST values. In this study, high-temporal-resolution SST measurements (32–40 snapshots per day) from a geostationary satellite, FengYun-4A (FY–4A), are used to analyze the diurnal variation of SST in China seas. The results present a sinusoidal pattern of the diurnal variability in SST, with the maximum value at 13:00–15:00 CST and the minimum at 06:00–08:00 CST. Based on the diurnal variation of SST, a retrieval method for daily mean SST products from polar-orbiting satellites is established and applied to 7716 visible infrared imaging radiometer (VIIRS) data in China seas. The results suggest that it is feasible and practical for the retrieval of daily mean SST with an average RMSE of 0.133 °C. This retrieval method can also be utilized to other polar-orbiting satellites and obtain more daily mean satellite SST products, which will contribute to more accurate estimation and prediction between atmosphere and ocean in the future.

The Clustering of Orbital Poles Induced by the LMC: Hints for the Origin of Planes of Satellites

A significant fraction of Milky Way (MW) satellites exhibit phase-space properties consistent with a coherent orbital plane. Using tailored N-body simulations of a spherical MW halo that recently captured a massive (1.8 × 1011 M ⊙) LMC-like satellite, we identify the physical mechanisms that may enhance the clustering of orbital poles of objects orbiting the MW. The LMC deviates the orbital poles of MW dark matter particles from the present-day random distribution. Instead, the orbital poles of particles beyond R ≈ 50 kpc cluster near the present-day orbital pole of the LMC along a sinusoidal pattern across the sky. The density of orbital poles is enhanced near the LMC by a factor δ ρ max = 30% (50%) with respect to underdense regions and δ ρ iso = 15% (30%) relative to the isolated MW simulation (no LMC) between 50 and 150 kpc (150–300 kpc). The clustering appears after the LMC’s pericenter (≈50 Myr ago, 49 kpc) and lasts for at least 1 Gyr. Clustering occurs because of three effects: (1) the LMC shifts the velocity and position of the central density of the MW’s halo and disk; (2) the dark matter dynamical friction wake and collective response induced by the LMC change the kinematics of particles; (3) observations of particles selected within spatial planes suffer from a bias, such that measuring orbital poles in a great circle in the sky enhances the probability of their orbital poles being clustered. This scenario should be ubiquitous in hosts that recently captured a massive satellite (at least ≈1:10 mass ratio), causing the clustering of orbital poles of halo tracers.

Non-Uniform Circumferential Expansion of Cylindrical Li-Ion Cells—The Potato Effect

This paper presents the non-uniform change in cell thickness of cylindrical Lithium (Li)-ion cells due to the change of State of Charge (SoC). Using optical measurement methods, with the aid of a laser light band micrometer, the expansion and contraction are determined over a complete charge and discharge cycle. The cell is rotated around its own axis by an angle of α=10° in each step, so that the different positions can be compared with each other over the circumference. The experimental data show that, contrary to the assumption based on the physical properties of electrode growth due to lithium intercalation in the graphite, the cell does not expand uniformly. Depending on the position and orientation of the cell coil, there are different zones of expansion and contraction. In order to confirm the non-uniform expansion around the circumference of the cell in 3D, X-ray computed tomography (CT) scans of the cells are performed at low and at high SoC. Comparison of the high resolution 3D reconstructed volumes clearly visualizes a sinusoidal pattern for non-uniform expansion. From the 3D volume, it can be confirmed that the thickness variation does not vary significantly over the height of the battery cell due to the observed mechanisms. However, a slight decrease in the volume change towards the poles of the battery cells due to the higher stiffness can be monitored.

Single-cell intracellular pH measurements reveal cell-cycle linked pH dynamics

Transient changes in intracellular pH (pHi) have been shown to regulate normal cell behaviors like migration and cell-cycle progression, while dysregulated pHi dynamics are a hallmark of cancer. However, little is known about how pHi heterogeneity and dynamics influence population-level measurements or single-cell behaviors. Here, we present and characterize single-cell pHi heterogeneity distributions in both normal and cancer cells and measure dynamic pHi increases in single cells in response to growth factor signaling. Next, we measure pHi dynamics in single cells during cell cycle progression. We determined that single-cell pHi is significantly decreased at the G1/S boundary, increases from S phase to the G2/M transition, rapidly acidifies during mitosis, and recovers in daughter cells. This sinusoidal pattern of pHi dynamics was linked to cell cycle timing regardless of synchronization method. This work confirms prior work at the population level and reveals distinct advantages of single-cell pHi measurements in capturing pHi heterogeneity across a population and dynamics within single cells.

Lithospheric mantle beneath the Vogelsberg volcanic field (Central Germany)

<p>Vogelsberg is a Cenozoic volcanic field situated at the northern tip of the Upper Rhine Graben. It stretches over two major Variscan basement units: the Rheno-Hercynian Zone in the NW and the Saxo-Thuringian Zone in the SE. We studied peridotite xenoliths from Breitenborn, Nidda and Dreihausen (SE, central and NW part of Vogelsberg, respectively) in order to reveal the evolution of the subcontinental lithospheric mantle (SCLM) rejuvenated during a Cenozoic rifting episode.</p><p>The Vogelsberg xenoliths are spinel harzburgites and clinopyroxene-poor spinel lherzolites. Most samples show grain size reduction leading to serial or porphyroclastic texture, or slight to well-defined foliation. All studied sites have similar major elements chemistry: olivine Fo 89.3-91.7%; orthopyroxene (opx) Mg# 0.89-0.92 and 0.06-0.25 atoms of Al pfu (per formula unit); clinopyroxene (cpx) Mg# 0.89-0.93 and 0.10-0.33 atoms of Al pfu. Spinel Cr# is highly variable: 0.18-0.45 for Breitenborn, 0.14-0.57 for Nidda and 0.11-0.61 for Dreihausen.</p><p>Vogelsberg peridotites exhibit a diversity of REE patterns:</p><p>(1) opx with a sinusoidal pattern, no cpx (Nidda, Dreihausen);</p><p>(2) cpx with flat patterns; coexisting opx with strong LREE-depletion, (La/Lu)<sub>N</sub> ~0.02 (Nidda, Dreihausen)</p><p>(3) cpx with flat, spoon-shaped patterns with La-Ce-enrichment (La/Pr)<sub>N</sub> ~4.3; opx similar to (2) but partly spoon-like, (Nd/Lu)<sub>N</sub> ~0.02 (Nidda, Breitenborn)</p><p>(4) cpx with different degree of LREE-enrichment, (La/Lu)<sub>N</sub>­ of 4-21.4; coexisting opx with mild LREE-depletion, (La/Lu)<sub>N</sub> of 0.1-0.3 (Breitenborn, Nidda, Dreihausen)</p><p>(5) cpx with flat HREE pattern and strongly LREE-depleted, (La/Eu)<sub>N</sub> ~0.03; coexisting opx similar to (2) but with (Ce/Lu)<sub>N</sub> ~0.001 (Breitenborn)</p><p>Temperatures calculated using REE content (T<sub>REE</sub>) [1] for the Breitenborn peridotites exhibit two ranges: 930-990°C and 1050-1130°C, for the Nidda ones: 880-930°C, 1000-1050°C and 1110-1150°C and for Dreihausen ones: 1140-1190°C. Temperatures calculated on the basis of pyroxene major element contents (T<sub>BKN</sub>) [2] are 40-90°C lower than T<sub>REE</sub> in Breitenborn and Nidda and lower by 10-55°C in Dreihausen.</p><p>The most common pyroxene REE patterns (type 4) are products of two-phase metasomatism: by Vogelsberg alkali basalt followed by a highly LREE-rich melt that further increased LREE contents in cpx, up to observed abundances. Strongly LREE-depleted opx (types 2, 3, 5) and cpx (type 5) patterns could be residues after partial melting of a fertile protolith, or products of metasomatism by melts derived from depleted MORB mantle. Cpx patterns of type 2 and 3 might have been once similar to type 5 but were later affected by the second phase of metasomatism: highly LREE-rich melt that increased chromatographically their LREE contents to variable degrees. The diversity of REE patterns and calculated temperatures shows that the SCLM beneath Vogelsberg is highly heterogeneous, probably due to spatial variability of deformation and percolation of hot melts connected with Cenozoic rifting.</p><p> </p><p>This study was funded by Polish National Science Centre to MZ (UMO-2018/29/N/ST10/00259) and JP (UMO-2014/15/B/ST10/00095). EPMA analyses were done thanks to the Polish-Austrian projects WTZ PL/16 and WTZ PL 08/2018. MZ acknowledges the DAAD fellowship at Goethe University Frankfurt.</p><p>References</p><p>[1] Liang Y. et al. (2013). GeochimCosmochimActa 102, 246–260.</p><p>[2] Brey G. & Köhler T. (1990). JPetrol 31, 1353–1378.</p>

Analysis of wave scattering in pipes with non-axisymmetric and inclined angle defects using finite element modeling

In this paper, elastic wave scattering in hollow pipes with non-axisymmetric and inclined angle defects is studied using finite element (FE) simulations. A comb array transducer is employed in the FE code to excite the pipe in its first longitudinal mode using a 10-cycle sine modulated excitation signal at 120[Formula: see text]kHz central frequency. Defects with variations in geometrical shapes such as depths, axial and circumferential lengths, and inclined angles are investigated to provide detailed analysis of wave propagation patterns and mode conversions in a 12-in diameter pipe. The influence of each geometrical parameter and also possible newborn modes is studied both in time and wavenumber-frequency domain via circumferential order identification approach and dispersion curves. Results show that the depth of a non-axisymmetric circumferential defect has the minimum influence on the propagating mode while crack’s width can influence the measured longitudinal mode in a sinusoidal pattern which is a function of excitation signal’s wavelength. Further, the propagating mode can exhibit higher contribution of either axisymmetric or non-axisymmetric modes based on the reflection patterns, depending on its angle and axial length.

Thermohydraulic characteristics and entropy analysis of a novel clockwise and anti-clockwise twisted sinusoidal wavy micro-channel under pulsating inlet condition

Heat transfer performance of microchannel are becoming an important area of research with the current fast growing scenario of high speed computing and miniaturized electronic devices. These devices pile up large amount of heat accompanied by smaller surface area to release it. The current work examines unsteady, laminar flow heat transfer inside a novel twisted sinusoidal wavy microchannel. The channel with square cross section is wavy in nature as well as twisted. The first half portion of the channel is twisted clockwise, whereas the twist in the remaining part is having counterclockwise twist. The novel geometry promotes mixing of fluid layers leading to transport augmentation. The inlet pulsation follows sinusoidal pattern in time. The thermal performance parameter of the proposed novel geometry was assessed within a Reynolds number range of 1–100. Both the pulsation amplitude and Strouhal number are varied during the course of this study. To solve the governing equations, a finite volume based method was utilized. The Nusselt number data shows significant enhancement for the sinusoidal inlet velocity as compared to that of the steady case, i.e. without inlet flow pulsation. The performance enhancement criterion combining heat transfer and pressure drop shows significant improvement over steady flow case as well as for one-way twisted tube. Entropy generation, which is the measure of dissipated energy, is also reported in the present work.

Effect of Geometric Uncertainty on a One Stage Transonic Compressor of an Industrial Gas Turbine

The geometrical uncertainties can result in flow asymmetry around the annulus of compressor which in turn can detrimentally affect on the compressor stability and performance. Typically these uncertainties arise as a consequence of in-service degradation and/or manufacturing tolerance, both of which have been dealt with in this paper. The paper deals with effects of leading edge damage and tip gap on rotor blades. It was found that the chord-wise damage is more critical than radial damage. It was found that a zigzag pattern of arranging the damaged rotor blades (i.e. most damaged blades between two least damaged blades) would give the best possible performance and stability when performing maintenance and overhauling while a sinusoidal pattern of arrangement had the worst performance and stability. This behaviour of zigzag arrangement of random damaged blades is consonant with the behaviour of zigzag arrangement in random tip gaps. It is also shown in this work that the level of damage has a bigger impact on the compressor performance and stability than the number of damaged blades.