Nuclear quantum effects on the vibrational dynamics of the water-air interface.

We have applied path-integral molecular dynamics simulations to investigate the impact of nuclear quantum effects on the vibrational dynamics of water molecules at the water-air interface. The instantaneous fluctuations in the frequencies of the O-H stretch modes are calculated using the wavelet method of time series analysis, while the time scales of vibrational spectral diffusion are determined from frequency-time correlation functions and joint probability distributions. We find that the inclusion of nuclear quantum effects leads not only to a redshift in the vibrational frequency distribution by about 120 cm-1 for both the bulk and interfacial water molecules but also to an acceleration of the vibrational dynamics at the water-air interface by as much as 35%.

Kinetics of the invasion of a non-phagocytic fish cell line, RTG-2 by Yersinia ruckeri serotype O1 biotype 1.

Yersiniosis, caused by the fish pathogen Yersinia ruckeri, is a serious bacterial septicaemia affecting mainly salmonids worldwide. The acute infection may result in high mortality without apparent external disease signs, while the chronic one causes moderate to considerable mortality. Survivors of yersiniosis outbreaks become carriers.

One Metre Plus (1M+): A Multifunctional Open-Source Sensor for Bicycles Based on Raspberry Pi.

During the last decade, bicycles equipped with sensors became an essential tool for research, particularly for studies analyzing the lateral passing distance between motorized vehicles and bicycles. The objective of this article is to describe a low-cost open-source sensor called (1m+) capable of measuring lateral passing distance, registering the geographical position of the cyclist, and video-recording the trip. The plans, codes, and schematic design are open and therefore easily accessible for the scientific community.

On the Different Faces of the Supercritical Phase of Water at a Near-Critical Temperature: Pressure-Induced Structural Transitions Ranging from a Gaslike Fluid to a Plastic Crystal Polymorph.

The present study reports a systematic analysis of a wide variety of structural, thermodynamic, and dynamic properties of supercritical water along the near-critical isotherm of = 1.03 and up to extreme pressures, using molecular dynamics and Monte Carlo simulations. The methodology employed provides solid evidence about the existence of a structural transition from a liquidlike fluid to a compressed, tightly packed liquid, in the density and pressure region around 3.

Structure and dynamics of water plastic crystals from computer simulations.

Water has a rich phase diagram with several crystals, as confirmed by experiments. High-pressure and high-temperature water is of interest for Earth's mantle and exoplanetary investigations. It is in this region of the phase diagram of water that new plastic crystal phases of water have been revealed via computer simulations by both classical forcefields and ab initio calculations.

On the microscopic origin of the cryoprotective effect in lysine solutions.

The amino acid lysine has been shown to prevent water crystallization at low temperatures in saturated aqueous solutions [S. Cerveny and J. Swenson, Phys.

Skin Picking Disorder in a Woman with Polyarteritis Nodosa. Case Report.

Introduction: Excoriation (skin picking) disorder is included in the DSM-5 in the obsessive compulsive and related disorders category. It is defined as the recurrent urge to touch, scratch, scrape, scrub, rub, squeeze, bite or dig in the skin, leading to skin lesions. It is a rare disorder (1.

Accuracy of mammography and clinical breast examination in the implementation of breast cancer screening programs in Colombia.

Most evidence on breast cancer screening accuracy derives from high income countries. We evaluated screening accuracy and factors related to program implementation in Bogota, Colombia. Between 2008 and 2012 participants underwent clinical breast examination (CBE) and mammography.

Nuclear quantum effects on the vibrational dynamics of liquid water.

Based on quantum-mechanical path-integral molecular dynamics simulations, the impact of nuclear quantum effects on the vibrational and hydrogen bond dynamics in liquid water is investigated. The instantaneous fluctuations in the frequencies of the O-H stretch modes are calculated using the wavelet method of time-series analysis, while the time scales of the vibrational spectral diffusion are determined from frequency-time correlation functions, joint probability distributions, and the slope of three-pulse photon echo. We find that the inclusion of nuclear quantum effects leads not only to a redshift of the vibrational frequency distribution by around 130 cm but also to an acceleration of the vibrational dynamics by as much as 30%.

On the positional and orientational order of water and methanol around indole: a study on the microscopic origin of solubility.

Although they are both highly polar liquids, there are a number of compounds, such as many pharmaceuticals, which show vastly different solubilities in methanol compared with water. From theories of the hydrophobic effect, it might be predicted that this enhanced solubility is due to association between drugs and the less polar -CH3 groups on methanol. In this work, detailed analysis on the atomic structural interactions between water, methanol and the small molecule indole - which is a precursor to many drugs and is sparingly soluble in water yet highly soluble in methanol - reveal that indole preferentially interacts with both water and methanol via electrostatic interactions rather than with direction interactions to the -CH3 groups.

The structure of liquid water beyond the first hydration shell.

To date there is a general consensus on the structure of the first coordination shells of liquid water, namely tetrahedral short range order of molecules. In contrast, little is known about the structure at longer distances and the influence of the tetrahedral molecular arrangement of the first shells on the order at these length scales. An expansion of the distance dependent excess entropy is used in this contribution to find out which molecular arrangements are important at each distance range.