Self-assembly of magnetic biofunctional nanoparticles

Spherical, ferromagnetic FePt nanoparticles with a particle size of 3 nm were prepared by the simultaneous polyol reduction of Fe(acac)3Fe(acac)3 and Pt(acac)2Pt(acac)2 in phenyl ether in the presence of oleic acid and oleylamine. The oleic acid ligands can be replaced with 11-mercaptoundecanoic acid, giving particles that can be dispersed in water. Both x-ray diffraction and transmission electron microscopy indicated that FePt particles were not affected by ligands replacement. Dispersions of the FePt particles with 11-mercaptoundecanoic acid ligands and ammonium counter ions gave self-assembled films consisting of highly ordered hexagonal arrays of particles.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87511/2/10Q901_1.pd

Emergency medicine physicians infrequently perform pediatric critical procedures: a national perspective

Objective To our knowledge, this is the first comprehensive study using a nationally representative database to estimate the frequency of critical procedures (endotracheal tube intubation [ETI], cardiopulmonary resuscitation [CPR], and central line insertion [CLI]) in children and adults. Methods The study was based on the secondary analysis of the 2010-2014 National Hospital Ambulatory Medical Care Survey. We included adult and pediatric patients undergoing critical procedures in the emergency department. We extracted demographic and clinical information, including the performance of critical procedures. For frequent procedures (≥1 per year), we estimated the annual number of critical procedures per emergency physician (EP) by dividing the total number of annual critical procedures by the total number of EPs (estimated at 40,000). For infrequent procedures, we calculated the average interval between procedures. We summarized the data with descriptive statistics and 95% confidence intervals (CIs). Results There were an estimated 668 million total emergency department visits (24% pediatric). On average, a single EP performed 8.6 (95% CI, 5.5 to 11.7) CLIs, 3.7 (95% CI, 2.4 to 5.0) CPRs, and 6.3 (95% CI, 5.3 to 7.4) ETIs per year in adults. In comparison, a single EP performed one pediatric CLI, CPR, and ETI every 3.2 (95% CI, 1.9 to 9.8), 5.2 (95% CI, 2.8 to 33.5), and 2.8 (95% CI, 1.6 to 8.9) years, respectively. Conclusion Our nationwide findings confirm those of previous smaller studies that critical procedures are significantly fewer in children than adults. We suggest that methods to retain skills in pediatric critical procedures should be developed for general EPs to ensure that they deliver the highest level of care across the entire age spectrum

Estado actual de la investigación arqueometalúrgica prehistórica en la provincia de Málaga

The lack of data on prehistoric metallurgical activities in Málaga made local prehistorians think that all the metal artefacts recovered in the province were of non-local origin. As a result of a project funded by the Junta de Andalucía, new data have been collected and we can begin to outline the development and socioeconomic importance that metal technologies have in different parts of Málaga throughout prehistory.La práctica inexistencia de datos sobre actividades metalúrgicas prehistóricas en Málaga y el vacío investigador que sobre este aspecto existía en la provincia habían creado un estado de opinión entre los prehistoriadores locales tendente a considerar como de origen extraprovincial la totalidad de los artefactos metálicos prehistóricos recuperados. Como resultado de un proyecto subvencionado por la Junta de Andalucía, estos datos que faltaban comienzan ahora a ser recuperados, y se puede empezar a trazar un esbozo general del desarrollo e importancia socieconómica que este grupo de tecnologías tuvieron en los diversos ambientes geográficos de la provincia de Málaga durante la prehistoria

Three-dimensional beam pattern of regular sperm whale clicks confirms bent-horn hypothesis

Author Posting. © Acoustical Society of America, 2005. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 117 (2005): 1473-1485, doi:10.1121/1.1828501.The three-dimensional beam pattern of a sperm whale (Physeter macrocephalus) tagged in the Ligurian Sea was derived using data on regular clicks from the tag and from hydrophones towed behind a ship circling the tagged whale. The tag defined the orientation of the whale, while sightings and beamformer data were used to locate the whale with respect to the ship. The existence of a narrow, forward-directed P1 beam with source levels exceeding 210 dBpeak re: 1 µPa at 1 m is confirmed. A modeled forward-beam pattern, that matches clicks >20° off-axis, predicts a directivity index of 26.7 dB and source levels of up to 229 dBpeak re: 1 µPa at 1 m. A broader backward-directed beam is produced by the P0 pulse with source levels near 200 dBpeak re: 1 µPa at 1 m and a directivity index of 7.4 dB. A low-frequency component with source levels near 190 dBpeak re: 1 µPa at 1 m is generated at the onset of the P0 pulse by air resonance. The results support the bent-horn model of sound production in sperm whales. While the sperm whale nose appears primarily adapted to produce an intense forward-directed sonar signal, less-directional click components convey information to conspecifics, and give rise to echoes from the seafloor and the surface, which may be useful for orientation during dives.This work was funded by grants from the Office of Naval Research Grants N00014-99-1-0819 and N00014-01-1-0705, and the Packard Foundation

Inverse chemical modeling and radiocarbon dating of palaeogroundwaters: The Tertiairy Ledo-paniselian aquifer in Flanders, Belgium.

Groundwater samples from the Ledo-Paniselian aquifer have been interpreted for chemical reaction patterns

Diversity in sound pressure levels and estimated active space of resident killer whale vocalizations

Author Posting. © The Author, 2005. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Journal of Comparative Physiology A: Sensory, Neural, and Behavioral Physiology 192 (2006): 449-459, doi:10.1007/s00359-005-0085-2.Signal source intensity and detection range, which integrates source intensity with propagation loss, background noise and receiver hearing abilities, are important characteristics of communication signals. Apparent source levels were calculated for 819 pulsed calls and 24 whistles produced by free-ranging resident killer whales by triangulating the angles-of-arrival of sounds on two beamforming arrays towed in series. Levels in the 1-20 kHz band ranged from 131-168 dB re 1μPa @1m, with differences in the means of different sound classes (whistles: 140.2 ± 4.1 dB; variable calls: 146.6 ± 6.6 dB; stereotyped calls: 152.6 ± 5.9 dB), and among stereotyped call types. Repertoire diversity carried through to estimates of active space, with “long-range” stereotyped calls all containing overlapping, independently-modulated high-frequency components (mean estimated active space of 10-16km in sea state zero) and “short-range” sounds (5-9 km) included all stereotyped calls without a high-frequency component, whistles, and variable calls. Short-range sounds are reported to be more common during social and resting behaviors, while long-range stereotyped calls predominate in dispersed travel and foraging behaviors. These results suggest that variability in sound pressure levels may reflect diverse social and ecological functions of the acoustic repertoire of killer whales.Funding was provided by WHOI’s Ocean Ventures Fund and Rinehart Coastal Research Center and a Royal Society fellowship

Ceramic Microbial Fuel Cells Stack: Power generation in standard and supercapacitive mode

© 2018 The Author(s). In this work, a microbial fuel cell (MFC) stack containing 28 ceramic MFCs was tested in both standard and supercapacitive modes. The MFCs consisted of carbon veil anodes wrapped around the ceramic separator and air-breathing cathodes based on activated carbon catalyst pressed on a stainless steel mesh. The anodes and cathodes were connected in parallel. The electrolytes utilized had different solution conductivities ranging from 2.0 mScm-1 to 40.1 mScm-1, simulating diverse wastewaters. Polarization curves of MFCs showed a general enhancement in performance with the increase of the electrolyte solution conductivity. The maximum stationary power density was 3.2 mW (3.2 Wm-3) at 2.0 mScm-1 that increased to 10.6 mW (10.6 Wm-3) at the highest solution conductivity (40.1 mScm-1). For the first time, MFCs stack with 1 L operating volume was also tested in supercapacitive mode, where full galvanostatic discharges are presented. Also in the latter case, performance once again improved with the increase in solution conductivity. Particularly, the increase in solution conductivity decreased dramatically the ohmic resistance and therefore the time for complete discharge was elongated, with a resultant increase in power. Maximum power achieved varied between 7.6 mW (7.6 Wm-3) at 2.0 mScm-1 and 27.4 mW (27.4 Wm-3) at 40.1 mScm-1