Ab-Initio Molecular Dynamics

Computer simulation methods, such as Monte Carlo or Molecular Dynamics, are very powerful computational techniques that provide detailed and essentially exact information on classical many-body problems. With the advent of ab-initio molecular dynamics, where the forces are computed on-the-fly by accurate electronic structure calculations, the scope of either method has been greatly extended. This new approach, which unifies Newton's and Schr\"odinger's equations, allows for complex simulations without relying on any adjustable parameter. This review is intended to outline the basic principles as well as a survey of the field. Beginning with the derivation of Born-Oppenheimer molecular dynamics, the Car-Parrinello method and the recently devised efficient and accurate Car-Parrinello-like approach to Born-Oppenheimer molecular dynamics, which unifies best of both schemes are discussed. The predictive power of this novel second-generation Car-Parrinello approach is demonstrated by a series of applications ranging from liquid metals, to semiconductors and water. This development allows for ab-initio molecular dynamics simulations on much larger length and time scales than previously thought feasible.Comment: 13 pages, 3 figure

Expert Consensus Guidelines for Stocking of Antidotes in Hospitals That Provide Emergency Care

We provide recommendations for stocking of antidotes used in emergency departments (EDs). An expert panel representing diverse perspectives (clinical pharmacology, medical toxicology, critical care medicine, hematology/oncology, hospital pharmacy, emergency medicine, emergency medical services, pediatric emergency medicine, pediatric critical care medicine, poison centers, hospital administration, and public health) was formed to create recommendations for antidote stocking. Using a standardized summary of the medical literature, the primary reviewer for each antidote proposed guidelines for antidote stocking to the full panel. The panel used a formal iterative process to reach their recommendation for both the quantity of antidote that should be stocked and the acceptable timeframe for its delivery. The panel recommended consideration of 45 antidotes; 44 were recommended for stocking, of which 23 should be immediately available. In most hospitals, this timeframe requires that the antidote be stocked in a location that allows immediate availability. Another 14 antidotes were recommended for availability within 1 hour of the decision to administer, allowing the antidote to be stocked in the hospital pharmacy if the hospital has a mechanism for prompt delivery of antidotes. The panel recommended that each hospital perform a formal antidote hazard vulnerability assessment to determine its specific need for antidote stocking. Antidote administration is an important part of emergency care. These expert recommendations provide a tool for hospitals that offer emergency care to provide appropriate care of poisoned patients

When It Comes to Snakebites, Kids Are Little Adults: a Comparison of Adults and Children with Rattlesnake Bites.

BACKGROUND: Rattlesnake envenomations are a significant cause of morbidity in the USA. While pediatric rattlesnake envenomations are relatively common, data comparing adult and pediatric patients with rattlesnake envenomations remain limited. METHODS: This multi-center retrospective study used the North American Snakebite Registry (NASBR), a sub-registry of the Toxicology Investigator\u27s Consortium (ToxIC). All cases of rattlesnake envenomations between January 1, 2013, and December 31, 2017, which were entered into the NASBR, were reviewed. Clinical and laboratory parameters, as well as treatment and outcome measurements, were compared between adult and pediatric patients. RESULTS: A total of 420 unique cases were identified, including 94 pediatric patients. Adult patients were more likely to be male (76% vs. 62%; OR 1.98) and sustain upper extremity envenomations (57% vs. 25%; OR 4.4). After adjusting for bite location, adults were more likely to exhibit edema compared with pediatric patients. After controlling for envenomation location, there was no difference in rates of necrosis between adult and pediatric patients. Adults exhibited early hematologic toxicity less frequently than pediatric patients, but there was no difference in the rates of late hematologic toxicity. There were no differences in the rates of hypotension or intubation. CONCLUSION: While adult and pediatric patients have some differences in envenomation characteristics and laboratory parameters, adults and pediatric patients had similar rates of systemic toxicity, severity, length of stay, and late hematologic toxicity

Local structure correlations in plastic cyclohexane-a reverse Monte Carlo study

Two solid phases of cyclohexane have been investigated over a temperature range spanning 13-266 K on a powdered, perdeuterated sample using neutron total scattering. Phase II has an ordered structure (C2/c) that forms below 186 K. Between 186 and 280 K it exists as a plastic solid-phase I (Fm3m), where the molecules are rotationally disordered about the lattice points of the face-centred cubic cell. Data-dependent atomistic configurations that represent the 'instantaneous' crystal structure have been generated from the total scattering data using reverse Monte Carlo refinement. Analysis of the local structure reveals that instantaneous distortions in phase I resemble the average structure of phase II

Catalysing sustainable fuel and chemical synthesis

Concerns over the economics of proven fossil fuel reserves, in concert with government and public acceptance of the anthropogenic origin of rising CO2 emissions and associated climate change from such combustible carbon, are driving academic and commercial research into new sustainable routes to fuel and chemicals. The quest for such sustainable resources to meet the demands of a rapidly rising global population represents one of this century’s grand challenges. Here, we discuss catalytic solutions to the clean synthesis of biodiesel, the most readily implemented and low cost, alternative source of transportation fuels, and oxygenated organic molecules for the manufacture of fine and speciality chemicals to meet future societal demands

Update of position papers on gastrointestinal decontamination for acute overdose

International audienc