Coarse-grained lattice kinetic Monte Carlo simulation of systems of strongly interacting particles

A general approach is presented for spatially coarse-graining lattice kinetic Monte Carlo (LKMC) simulations of systems containing strongly interacting particles. While previous work has relied on approximations that are valid in the limit of weak interactions, here we show that it is possible to compute coarse-grained transition rates for strongly interacting systems without a large computational burden. A two-dimensional square lattice is employed on which a collection of (supersaturated) strongly interacting particles is allowed to reversibly evolve into clusters. A detailed analysis is presented of the various approximations applied in LKMC coarse graining, and a number of numerical closure rules are contrasted and compared. In each case, the overall cluster size distribution and individual cluster structures are used to assess the accuracy of the coarse-graining approach. The resulting closure approach is shown to provide an excellent coarse-grained representation of the systems considered in this study

Coarse-Grained Lattice Monte Carlo Simulations with Continuous Interaction Potentials

A coarse-grained lattice Metropolis Monte Carlo (CG-MMC) method is presented for simulating fluid systems described by standard molecular force fields. First, a thermodynamically consistent coarse-grained interaction potential is obtained numerically and automatically from a continuous force field such as Lennard-Jones. The coarse-grained potential then is used to driveCG-MMC simulations of vapor-liquid equilibrium in Lennard-Jones, square-well, and simple point chargewater systems. The CG-MMC predicts vapor-liquid phase envelopes, as well as the particle density distributions in both the liquid and vapor phases, in excellent agreement with full-resolution Monte Carlo simulations, at a fraction of the computational cost

On-lattice kinetic Monte Carlo simulations of point defect aggregation in entropically influenced crystalline systems

An on-lattice kinetic Monte Carlo model of vacancy aggregation in crystalline silicon is parametrized using direct regression to evolution data from nonequilibrium molecular dynamics simulations. The approach bypasses the need to manually compute an energy barrier for each possible transition and leads to an excellent, robust representation of the molecular dynamics data. We show that the resulting lattice kinetic Monte Carlo model correctly captures the behavior of the real, continuous space system by properly accounting for continuous space entropic effects, which are often neglected in lattice-based models of atomistic processes. These contributions are particularly important at the high temperatures relevant to many steps in semiconductor materials processing

Eight years later, are we still hurting newborn infants?

Objective: To study whether new pharmacological and nonpharmacological guidelines lowered numbers of painful procedures in neonates and changed the amount and frequency of analgesic therapy as compared to the results of our previous study in 2001. Design: A prospective observational study. Setting: Level III NICU of the Erasmus MC-Sophia Children's Hospital, Rotterdam. Participants: Neonates admitted at postnatal ages less than 3 days with length of stay at least 72 h. Main Outcome Measures: Number of all potentially painful procedures and analgesic therapy recorded at the bedside during the first 14 days of NICU stay. Results: A total number of 21,076 procedures were performed in the 175 neonates studied during 1,730 patient-days (mean 12.2). The mean number of painful procedures per neonate per day was 11.4 (SD 5.7), significantly lower than the number of 14.3 (SD 4.0) in 2001 (p < 0.001). The use of analgesics was 36.6% compared to 60.3% in 2001. Sixty-three percent of all peripheral arterial line insertions failed versus 37.5% in 2001 and 9.1% venipunctures failed versus 21% in 2001. Conclusions: The mean number of painful procedures per NICU patient per day declined. Nonpharmacological pain- or stress-reducing strategies like NIDCAP and sucrose were fully embedded in our pain management. As further reduction of the number of painful procedures is unlikely, we should apply more nonpharmacological interventions and explore newer pharmacological agents

Magnetic resonance imaging landmarks for preoperative localization of inferior medial genicular artery: a proof of concept analysis

The joint line is a useful landmark to identify IMGAcourse during knee surgery. The IMGA course is closerto the joint line and to the border of the medial tibialplateau in females than in males. Although the interindi-vidual variability these results should be taken into ac-count when performing all surgical procedures involvingthe medial aspect of the knee. Similar interindividualdistances were observed between IMGA and semimem-branosus tendon insertion regardless of gender. How-ever, the proximity to this tendon should be consideredespecially during specific cases of ligamentous balancingin TKA procedure

Can body mass index influence the fracture zone in the fifth metatarsal base? A retrospective review

Fifth metatarsal base fracture are common in routine orthopaedic practice [1–6]. Lawrence and Botte [7] pro- posed a classification based upon the position of the fracture line (zone 1: tuberosity, zone 2: meta-diaphyseal junction, zone 3: proximal diaphysis). Pathomechani- cally, injury patterns develop in different ways: in zone 1, a traction injury caused by peroneus brevis tendon and the lateral band of the plantar fascia determine an avul- sion fracture of the tuberosity, also called “pseudo-Jones’ “fracture; in zone 2, forced foot adduction and excessive plantar flexion determine a fracture in the metaphyseal- diaphyseal junction, also called Jones’ fracture [8, 9]; in zone 3, acute over-bearing onto the area or chronic overload determine a fracture in the proximal portion of the diaphysis, distal to the intermetatarsal joint [10, 11]. To the best of the Authors’ knowledge, no study has been published to date on the relationship between the value of Body Mass Index (BMI) and the prevalence of fractures in a specific portion of the fifth metatarsal base. The aim of this study was to define the impact of BMI on fifth metatarsal base fractures location according to Lawrence and Botte classification [7]

Poisoning by non-edible squash: retrospective series of 353 patients from French Poison Control Centers

CONTEXT: Among the numerous varieties of squash that exist, some are edible while other bitter-tasting ones are not fit for human consumption. Cases of confusion seem to be multiplying and are characterized by digestive problems (diarrhea, vomiting, and abdominal pain). METHODS: This is a descriptive retrospective study of cases of exposure reported to French Poison Control Centers between 1 January 2012 and 12 December 2016. RESULTS: 353 patients were included, with 71.7% belonging to collective cases of poisoning. The male to female sex ratio was 0.75 for an average age of 38.2 ± 23.6 years. The circumstances of exposure were dietary for 337 patients (95.5%). The majority of the squash consumed was purchased at a store (55.8%) but some also came from the garden (25.5%). 204 patients (57.8%) mostly presented with diarrhea, vomiting, abdominal pain, sometimes with the consequent dehydration, hypotension, tachycardia, headaches, or vertigo. There were no deaths or severe (Poisoning Severity Score (PSS) 3) cases, but there were 14 patients (4.0%) of moderate severity, 190 patients (53.8%) of minor severity (PSS 1), and 149 patients (42.2%) without severity (PSS 0) but among which we include the bitter taste of the squash. The average age of PSS 2 patients was significantly (p = .003) older than that of the PSS &lt;2 patients. CONCLUSION: As the first consequential series in Europe, our study shows that exposure to non-edible squash is frequent. Usually benign, poisoning could be the consequence of the irritating effect of certain cucurbits, the molecules responsible for the taste and toxicity of the fruits. In terms of prevention therefore, we recommend disposing of any squash with a bitter taste

Randomized controlled trial comparing different single doses of intravenous paracetamol for placement of peripherally inserted central catheters in preterm infants

__Background:__ The availability of a safe and effective pharmacological therapy to reduce procedural pain in preterm infants is limited. The effective analgesic single dose of intravenous paracetamol in preterm infants is unknown. Comparative studies on efficacy of different paracetamol doses in preterm infants are lacking. __Objectives:__ To determine the analgesic effects of different single intravenous paracetamol doses on pain from peripherally inserted central catheter (PICC) placement in preterm infants. __Methods:__ In a blinded randomized controlled trial, the an