3-D Structural Modeling of Humic Acids through Experimental Characterization, Computer Assisted Structure Elucidation and Atomistic Simulations. 1. Chelsea Soil Humic Acid

This paper describes an integrated experimental and computational framework for developing 3-D structural models for humic acids (HAs). This approach combines experimental characterization, computer assisted structure elucidation (CASE), and atomistic simulations to generate all 3-D structural models or a representative sample of these models consistent with the analytical data and bulk thermodynamic/structural properties of HAs. To illustrate this methodology, structural data derived from elemental analysis, diffuse reflectance FT-IR spectroscopy, 1-D/2-D ^1H and ^(13)C solution NMR spectroscopy, and electrospray ionization quadrupole time-of-flight mass spectrometry (ESI QqTOF MS) are employed as input to the CASE program SIGNATURE to generate all 3-D structural models for Chelsea soil humic acid (HA). These models are subsequently used as starting 3-D structures to carry out constant temperature-constant pressure molecular dynamics simulations to estimate their bulk densities and Hildebrand solubility parameters. Surprisingly, only a few model isomers are found to exhibit molecular compositions and bulk thermodynamic properties consistent with the experimental data. The simulated ^(13)C NMR spectrum of an equimolar mixture of these model isomers compares favorably with the measured spectrum of Chelsea soil HA

Models of Neolithisation of Northeastern Iberian

Altres ajuts: The archaeological excavation at La Draga and Coves del Fem was funded by the Departament de Cultura (Generalitat de Catalunya) CLT009/18/00026 and CLT009/18/.The goal of this article is to discuss the significance of the archaeological evidence from the sites of La Draga (Banyoles, Spain) and Coves del Fem (Ulldemolins, Spain), in the context of the neolithisation of Northeastern Iberia. The 14C dates have been analysed using Bayesian statistics. The stratigraphy of Coves del Fem covers the transition between the last hunter-gatherers of the region and the first farmers. The chronological sequence covers approximately 1,300 years, from 6065-5990 cal BC to 4700-4550 cal BC. The site of La Draga was occupied by the first farmers circa 5300-5230 cal BC when a wooden platform was constructed and first used. Subsequent repairs of the wooden piles have been dated as well. Another use of the wooden platform is documented around 5200-5085 cal BC, although until now new construction evidence has not been documented. La Draga site was reoccupied later, when several travertine structures dated in two moments between the years 5100-4900 cal BC and 4950-4700 cal BC were constructed and used. The radiocarbon dates of Coves del Fem and La Draga support the existence of two different models of neolithisation in Northeastern Iberia. In the southern part of the territory, Coves del Fem suggests that the Holocene hunter-gatherer populations remained in the area until the arrival of the first farmers, in a model similar to the one observed at the Ebro basin. On the contrary, the site of La Draga supports the hypothesis of the first farmers colonising a previously unoccupied territory

An Initial Assessment of the Utility of Validated Alcohol and Drug Screening Tools in Predicting 30-Day Readmission to Adult General Medicine Wards

Previous studies have identified drug and alcohol use as risk factors for readmission using claims data, but not by using substance use screening scores. This preliminary study tested the hypothesis that prevalence of 30-day readmission would be higher among patients screening positive on the 10-item Alcohol Use Disorders Identification Test (AUDIT-10) or the 10-item Drug Abuse Screening Test (DAST-10) tools at intake than among the general patient population. Social workers screened 4708 adult inpatients using prescreening questions followed by the AUDIT-10 and/or DAST-10. Patients with positive screens were followed for readmissions within 30 days of discharge. A positive screening score on the AUDIT-10 or DAST-10 instrument at intake was associated with higher risk of readmission to the general medicine wards within 30 days; this relationship appears complex and subject to mediation. Post hoc chart review found that the majority of readmissions among patients with positive screens were not immediately attributable to substance use. Further study is needed to verify these preliminary findings

Selection of bead-displayed, PNA-encoded chemicals

The lack of efficient identification and isolation methods for specific molecular binders has fundamentally limited drug discovery. Here, we have developed a method to select peptide nucleic acid (PNA) encoded molecules with specific functional properties from combinatorially generated libraries. This method consists of three essential stages: (1) creation of a Lab-on-Bead™ library, a one-bead, one-sequence library that, in turn, displays a library of candidate molecules, (2) fluorescence microscopy-aided identification of single target-bound beads and the extraction – wet or dry – of these beads and their attached candidate molecules by a micropipette manipulator, and (3) identification of the target-binding candidate molecules via amplification and sequencing. This novel integration of techniques harnesses the sensitivity of DNA detection methods and the multiplexed and miniaturized nature of molecule screening to efficiently select and identify target-binding molecules from large nucleic acid encoded chemical libraries. Beyond its potential to accelerate assays currently used for the discovery of new drug candidates, its simple bead-based design allows for easy screening over a variety of prepared surfaces that can extend this technique's application to the discovery of diagnostic reagents and disease markers