383 research outputs found
Post-traumatic brachial plexus MRI in practice
AbstractInjuries are separated into spinal nerve root avulsions (pre-ganglionic lesions) and more distal rupture (post-ganglionic lesions). The lesions may be associated with different nerve root levels. Spinal MRI is used to diagnose pre-ganglionic lesions, which may be present in the absence of pseudomeningoceles. The other sequences described are used to diagnose post-ganglionic lesions, regardless of the type of lesion. Knowledge that a graftable C5 nerve root is present is important in the treatment strategy. Contrast enhancement in the scalene triangle does not predict the quality of the nerve root (continuous injury with response to peroperative stimulation or division of the root needing grafting). Understanding post-traumatic neuronal injuries to the brachial plexus. Knowing how to look for spinal MRI abnormalities and post-ganglionic abnormalities
An experimental and numerical study of high-frequency Raman scattering in argon gas
International audienc
The microscopic structure of cold aqueous methanol mixtures
The evolution of the micro-segregated structure of aqueous methanol mixtures, in the temperature range 300 K-120 K, is studied with computer simulations, from the static structural point of view. The structural heterogeneity of water is reinforced at lower temperatures, as witnessed by a pre-peak in the oxygen-oxygen structure factor. Water tends to form predominantly chain-like clusters at lower temperatures and smaller concentrations. Methanol domains have essentially the same chain-like cluster structure as the pure liquid at high concentrations and becomes mono- meric at smaller ones. Concentration uctuations decrease with temperature, leading to quasi-ideal Kirkwood-Bu integrals, despite the enhanced molecular interactions, which we interpret as the signature of non-interacting segregated water and methanol clusters. This study throws a new light on the nature of the micro-heterogeneous structure of this mixture: the domain segregation is essentially based on the appearance of linear water clusters, unlike other alcohol aqueous mixtures, such as with propanol or butanol, where the water domains are more bulky.
Moving from a Product-Based Economy to a Service-Based Economy for a More Sustainable Future
Traditionally, economic growth and prosperity have been linked with the availability, production and distribution of tangible goods as well as the ability of consumers to acquire such goods. Early evidence regarding this connection dates back to Adam Smith's Wealth of Nations (1776), in which any activity not resulting in the production of a tangible good is characterized as unproductive of any value." Since then, this coupling of economic value and material production has been prevalent in both developed and developing economies throughout the world. One unintended consequence of this coupling has been the exponential increase in the amount of solid waste being generated. The reason is that any production and consumption of material goods eventually generates the equivalent amount of (or even more) waste. Exacerbating this problem is the fact that, with today's manufacturing and supply chain management technologies, it has become cheaper to dispose and replace most products rather than to repair and reuse them. This has given rise to what some call a disposable society." To put things in perspective: In 2012 households in the U.K. generated approximately 22 thousand tons of waste, which amounted to 411 kg of waste generated per person (Department for Environment, Food & Rural Affairs, 2015). During the same time period, households in the U.S. generated 251 million tons of waste, which is equivalent to a person generating approximately 2 kg of waste every day (U.S. Environmental Protection Agency, 2012). Out of these 251 million tons of total waste generated, approximately 20% of the discarded items were categorized as durable goods. The disposal of durable goods is particularly worrisome because they are typically produced using material from non- renewable resources such as iron, minerals, and petroleum-based raw materials
Early goal-directed therapy using a physiological holistic view: the ANDROMEDA-SHOCKâa randomized controlled trial
Septic shock is a highly lethal condition. Early recognition of tissue hypoperfusion and its reversion
are key factors for limiting progression to multiple organ dysfunction and death. Lactateâtargeted resuscitation is the goldâstandard under current guidelines, although it has several pitfalls including that nonâhypoxic sources of lactate might predominate in an unknown proportion of patients. Peripheral perfusionâtargeted resuscitation might provide a realâtime response to increases in ow that could lead to a more timely decision to stop resuscitation, thus avoiding uid overload and the risks of overâresuscitation. This article reports the rationale, study design and analysis plan of the ANDROMEDAâSHOCK Study.
Methods: ANDROMEDAâSHOCK is a randomized controlled trial which aims to determine if a peripheral perfusionâ targeted resuscitation is associated with lower 28âday mortality compared to a lactateâtargeted resuscitation in patients with septic shock with less than 4 h of diagnosis. Both groups will be treated with the same sequential approach during the 8âhour study period pursuing normalization of capillary re ll time versus normalization or a decrease of more than 20% of lactate every 2 h. The common protocol starts with uid responsiveness assessment and uid loading in responders, followed by a vasopressor and an inodilator test if necessary. The primary outcome
is 28âday mortality, and the secondary outcomes are: free days of mechanical ventilation, renal replacement therapy and vasopressor support during the rst 28 days after randomization; multiple organ dysfunction during the rst 72 h after randomization; intensive care unit and hospital lengths of stay; and allâcause mortality at 90âday. A sample size of 422 patients was calculated to detect a 15% absolute reduction in mortality in the peripheral perfusion group with 90% power and twoâtailed type I error of 5%. All analysis will follow the intentionâtoâtreat principle.
Conclusions: If peripheral perfusionâtargeted resuscitation improves 28âday mortality, this could lead to simpli ed algorithms, assessing almost in realâtime the reperfusion process, and pursuing more physiologically sound objecâ tives. At the end, it might prevent the risk of overâresuscitation and lead to a better utilization of intensive care unit resources
Importing genetically altered animals : ensuring quality
The reproducibility of research using laboratory animals requires reliable management of their quality, in particular of their genetics, health and environment, all of which contribute to their phenotypes. The point at which these biological materials are transferred between researchers is particularly sensitive, as it may result in a loss of integrity of the animals and/or their documentation. Here, we describe the various aspects of laboratory animal quality that should be confirmed when sharing rodent research models. We also discuss how repositories of biological materials support the scientific community to ensure the continuity of the quality of laboratory animals. Both the concept of quality and the role of repositories themselves extend to all exchanges of biological materials and all networks that support the sharing of these reagents.Peer reviewe
Aneuploidy screening of embryonic stem cell clones by metaphase karyotyping and droplet digital polymerase chain reaction
DNA input in ddPCR reaction. The figure shows copy number of Chr 8 (crosses) and Y (squares) measured by ddPCR with various input quantities of genomic DNA template. Vertical bars are Standard Errors. The experiment demonstrates linearity across the range of concentrations relevant to the DNA preparations assayed. This is a key point for the robustness of the screen, as gDNA preparations are challenging to standardize due to the disparity of growth rates between ES cell clones. (PDF 26 kb
Conformational and Structural Relaxations of Poly(ethylene oxide) and Poly(propylene oxide) Melts: Molecular Dynamics Study of Spatial Heterogeneity, Cooperativity, and Correlated Forward-Backward Motion
Performing molecular dynamics simulations for all-atom models, we
characterize the conformational and structural relaxations of poly(ethylene
oxide) and poly(propylene oxide) melts. The temperature dependence of these
relaxation processes deviates from an Arrhenius law for both polymers. We
demonstrate that mode-coupling theory captures some aspects of the glassy
slowdown, but it does not enable a complete explanation of the dynamical
behavior. When the temperature is decreased, spatially heterogeneous and
cooperative translational dynamics are found to become more important for the
structural relaxation. Moreover, the transitions between the conformational
states cease to obey Poisson statistics. In particular, we show that, at
sufficiently low temperatures, correlated forward-backward motion is an
important aspect of the conformational relaxation, leading to strongly
nonexponential distributions for the waiting times of the dihedrals in the
various conformational statesComment: 13 pages, 13 figure
Consensus on circulatory shock and hemodynamic monitoring. Task force of the European Society of Intensive Care Medicine.
OBJECTIVE: Circulatory shock is a life-threatening syndrome resulting in multiorgan failure and a high mortality rate. The aim of this consensus is to provide support to the bedside clinician regarding the diagnosis, management and monitoring of shock.
METHODS: The European Society of Intensive Care Medicine invited 12 experts to form a Task Force to update a previous consensus (Antonelli et al.: Intensive Care Med 33:575-590, 2007). The same five questions addressed in the earlier consensus were used as the outline for the literature search and review, with the aim of the Task Force to produce statements based on the available literature and evidence. These questions were: (1) What are the epidemiologic and pathophysiologic features of shock in the intensive care unit ? (2) Should we monitor preload and fluid responsiveness in shock ? (3) How and when should we monitor stroke volume or cardiac output in shock ? (4) What markers of the regional and microcirculation can be monitored, and how can cellular function be assessed in shock ? (5) What is the evidence for using hemodynamic monitoring to direct therapy in shock ? Four types of statements were used: definition, recommendation, best practice and statement of fact.
RESULTS: Forty-four statements were made. The main new statements include: (1) statements on individualizing blood pressure targets; (2) statements on the assessment and prediction of fluid responsiveness; (3) statements on the use of echocardiography and hemodynamic monitoring.
CONCLUSIONS: This consensus provides 44 statements that can be used at the bedside to diagnose, treat and monitor patients with shock
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