Specific effects of background electrolytes on the kinetics of step propagation during calcite growth

AbstactIn order to probe the possibility of simulating irradiation effects with swift ions and obtaining some insight about the production rate of freely migrating defects in iron, we studied the kinetics of copper precipitation in FeCu1.34at% irradiated at 300°C with 202 MeV O- ions and 2.5 MeV electrons. The precipitation kinetics are studied in situ (GANIL for O- ions and Van de Graaff for electrons) by measuring the electrical resistivity at 30°C to reduce the phonon component. We found that, in both cases, the resistivity versus fluence (in dpa) curves are identical. This would imply either that the relatively small cascades induced by 202 MeV O- ions (compared with those produced by neutrons) are very efficient in producing freely migrating point defects or that the energy deposition by electronic excitations plays an important role. We show that this latter possibility is not relevant for 202 MeV O18 ions.

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Oxidation of DL-penicillamine by chromium(VI). Kinetics of formation of the thioester intermediate

Canadian Journal of Chemistry ◽

10.1139/v94-206 ◽

1994 ◽

Vol 72 (7) ◽

pp. 1637-1644 ◽

Cited By ~ 7

Author(s):

Joaquin F. Perez-Benito ◽

Driss Lamrhari ◽

Conchita Arias

Keyword(s):

Reaction Rate ◽

Aqueous Media ◽

Bimolecular Reaction ◽

Spectrophotometric Detection ◽

State Behavior ◽

Chromium Vi ◽

Specific Effects ◽

Kinetics Of Formation ◽

Kinetics Of ◽

Catalytic Power

The kinetics of formation of the thioester involved as an intermediate in the reaction between chromium(VI) and DL-penicillamine in aqueous media (pH = 1–8) containing different buffers (acetate, citrate, and phosphate) has been studied by monitoring the disappearance of chromium(VI) at 370 nm and application of the initial-rates method. The initial rate is directly proportional to the initial concentrations of both oxidant and reductant, and the rate vs. pH plots show bell-shaped profiles. The reaction is catalyzed by the buffer present in the medium, the catalytic power of each buffer increasing in the order acetate < citrate < phosphate. This is explained in terms of a mechanism involving the formation of a complex between the acidic form of the buffer and HCrO4− previous to the formation of the thioester. Potassium chloride and sodium sulfate do not seem to have important specific effects on the reaction rate, their effect being that of an acceleration of the reaction as the ionic strength increases. On the contrary, the sulfates of magnesium, manganese(II), and zinc (the latter only in the presence of acetate buffer) have specific effects, indicating the probable formation of several complexes. The spectrophotometric detection of the thioester at 430 nm has allowed to confirm some of the conclusions extracted from the measurement of initial rates, and suggests that this intermediate might approach a steady-state behavior in the three buffers at pH > 6.25, and also that a bimolecular reaction with DL-penicillamine might be involved in its destruction.

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The Dynamics of Hole Transfer in DNA

Molecules ◽

10.3390/molecules24224044 ◽

2019 ◽

Vol 24 (22) ◽

pp. 4044 ◽

Cited By ~ 7

Author(s):

Andrea Peluso ◽

Tonino Caruso ◽

Alessandro Landi ◽

Amedeo Capobianco

Keyword(s):

High Energy ◽

Hole Transport ◽

Charge Hole ◽

Hole Transfer ◽

High Energy Radiation ◽

Specific Effects ◽

Redox Sensing ◽

Hole Migration ◽

Kinetics Of ◽

Disease Understanding

High-energy radiation and oxidizing agents can ionize DNA. One electron oxidation gives rise to a radical cation whose charge (hole) can migrate through DNA covering several hundreds of Å, eventually leading to irreversible oxidative damage and consequent disease. Understanding the thermodynamic, kinetic and chemical aspects of the hole transport in DNA is important not only for its biological consequences, but also for assessing the properties of DNA in redox sensing or labeling. Furthermore, due to hole migration, DNA could potentially play an important role in nanoelectronics, by acting as both a template and active component. Herein, we review our work on the dynamics of hole transfer in DNA carried out in the last decade. After retrieving the thermodynamic parameters needed to address the dynamics of hole transfer by voltammetric and spectroscopic experiments and quantum chemical computations, we develop a theoretical methodology which allows for a faithful interpretation of the kinetics of the hole transport in DNA and is also capable of taking into account sequence-specific effects.

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Measuring the complexity of cell cycle arrest and killing of drugs: Kinetics of phase-specific effects induced by Taxol

Cytometry ◽

10.1002/(sici)1097-0320(19991001)37:2<113::aid-cyto4>3.0.co;2-m ◽

1999 ◽

Vol 37 (2) ◽

pp. 113-124 ◽

Cited By ~ 29

Author(s):

Giovanni Sena ◽

Carlo Onado ◽

Paolo Cappella ◽

Francesco Montalenti ◽

Paolo Ubezio

Keyword(s):

Cell Cycle ◽

Cell Cycle Arrest ◽

Cycle Arrest ◽

Specific Effects ◽

Kinetics Of

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The Frequent Sampling of Wound Scratch Assay Reveals the “Opportunity” Window for Quantitative Evaluation of Cell Motility-Impeding Drugs

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.640972 ◽

2021 ◽

Vol 9 ◽

Author(s):

Sholpan Kauanova ◽

Arshat Urazbayev ◽

Ivan Vorobjev

Keyword(s):

Wound Healing ◽

Cell Motility ◽

Cell Lines ◽

Drug Testing ◽

Dynamic Instability ◽

Time Window ◽

Specific Cell ◽

Microtubule Inhibitors ◽

Specific Effects ◽

Kinetics Of

Wound healing assay performed with automated microscopy is widely used in drug testing, cancer cell analysis, and similar approaches. It is easy to perform, and the results are reproducible. However, it is usually used as a semi-quantitative approach because of inefficient image segmentation in transmitted light microscopy. Recently, several algorithms for wound healing quantification were suggested, but none of them was tested on a large dataset. In the current study, we develop a pipeline allowing to achieve correct segmentation of the wound edges in >95% of pictures and extended statistical data processing to eliminate errors of cell culture artifacts. Using this tool, we collected data on wound healing dynamics of 10 cell lines with 10 min time resolution. We determine that the overall kinetics of wound healing is non-linear; however, all cell lines demonstrate linear wound closure dynamics in a 6-h window between the fifth and 12th hours after scratching. We next analyzed microtubule-inhibiting drugs’, nocodazole, vinorelbine, and Taxol, action on the kinetics of wound healing in the drug concentration-dependent way. Within this time window, the measurements of velocity of the cell edge allow the detection of statistically significant data when changes did not exceed 10–15%. All cell lines show decrease in the wound healing velocity at millimolar concentrations of microtubule inhibitors. However, dose-dependent response was cell line specific and drug specific. Cell motility was completely inhibited (edge velocity decreased 100%), while in others, it decreased only slightly (not more than 50%). Nanomolar doses (10–100 nM) of microtubule inhibitors in some cases even elevated cell motility. We speculate that anti-microtubule drugs might have specific effects on cell motility not related to the inhibition of the dynamic instability of microtubules.

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Specific effects of ATP on the kinetics of reconstituted bovine heart cytochrome-c oxidase

FEBS Letters ◽

10.1016/0014-5793(86)80018-7 ◽

1986 ◽

Vol 207 (1) ◽

pp. 89-94 ◽

Cited By ~ 41

Author(s):

Fritz-Joachim Hüther ◽

Bernhard Kadenbach

Keyword(s):

Cytochrome C ◽

Cytochrome C Oxidase ◽

Bovine Heart ◽

Specific Effects ◽

Kinetics Of

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Sex-Specific Effects of Daily Tadalafil on Contraction Kinetics of the Diabetic Heart. The RECOGITO Randomized, Double-Blind, Placebo-Controlled Trial

SSRN Electronic Journal ◽

10.2139/ssrn.3745196 ◽

2020 ◽

Author(s):

Riccardo Pofi ◽

Elisa Giannetta ◽

Tiziana Feola ◽

Nicola Galea ◽

Federica Campolo ◽

...

Keyword(s):

Controlled Trial ◽

Diabetic Heart ◽

Double Blind ◽

Double Blind Placebo ◽

Specific Effects ◽

Kinetics Of ◽

Contraction Kinetics

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Spontaneous and Ion-Specific Formation of Inverted Bilayers at Air/Aqueous Interface

10.33774/chemrxiv-2021-pzxn9-v2 ◽

2021 ◽

Author(s):

Srikanth Nayak ◽

Raju R Kumal ◽

Ahmet Uysal

Keyword(s):

Rare Earths ◽

Energy Barrier ◽

Rare Earth Metals ◽

Chemical Separation ◽

Interfacial Structure ◽

Arrhenius Behavior ◽

Temperature Dependent ◽

Specific Effects ◽

Kinetics Of ◽

Conversion Temperature

Developing better separation technologies for rare earth metals is important for a sustainable economy. However, the chemical similarities between rare earths make their separations difficult. Identifying molecular scale interactions that amplify the subtle differences between the rare earths can be useful in developing new separation technologies. Here, we describe ion-dependent monolayer to inverted bilayer transformation of extractant molecules at the air/aqueous interface. The inverted bilayers form with Lu3+ ions but not with Nd3+. By introducing Lu3+ ions to preformed monolayers, we extract kinetic parameters corresponding to the monolayer to inverted bilayer conversion. Temperature-dependent studies show Arrhenius behavior with an energy barrier of 40 kcal/mol. The kinetics of monolayer to inverted bilayer conversion is also affected by the character of the background anion, although anions are expected to be repelled from the interface. Our results show the outsized importance of ion-specific effects on interfacial structure and kinetics, pointing to their role in chemical separation methods.

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