Cerebral monitoring in surgical ICU patients

PURPOSE OF REVIEW: To give an overview of cerebral monitoring techniques for surgical ICU patients. RECENT FINDINGS: As the burden of postsurgical neurological and neurocognitive complications becomes increasingly recognized, cerebral monitoring in the surgical ICU might gain a relevant role in detecting and possibly preventing adverse outcomes. However, identifying neurological alterations in surgical ICU patients, who are often sedated and mechanically ventilated, can be challenging. Various noninvasive and invasive techniques are available for cerebral monitoring, providing an assessment of cortical electrical activity, cerebral oxygenation, blood flow autoregulation, intracranial pressure, and cerebral metabolism. These techniques can be used for the diagnosis of subclinical seizures, the assessment of sedation depth and delirium, the detection of an impaired cerebral blood flow, and the diagnosis of neurosurgical complications. SUMMARY: Cerebral monitoring can be a valuable tool in the early detection of adverse outcomes in surgical ICU patients, but the evidence is limited, and clear clinical indications are still lacking

Variable stars in Terzan 5: additional evidence of multi-age and multi-iron stellar populations

Terzan 5 is a complex stellar system in the Galactic bulge, harboring stellar populations with very different iron content ({\Delta}[Fe/H] ~1 dex) and with ages differing by several Gyrs. Here we present an investigation of its variable stars. We report on the discovery and characterization of three RR Lyrae stars. For these newly discovered RR Lyrae and for six Miras of known periods we provide radial velocity and chemical abundances from spectra acquired with X-SHOOTER at the VLT. We find that the three RR Lyrae and the three short period Miras (P<300 d) have radial velocity consistent with being Terzan 5 members. They have sub-solar iron abundances and enhanced [{\alpha}/Fe], well matching the age and abundance patterns of the 12 Gyr metal-poor stellar populations of Terzan 5. Only one, out of the three long period (P>300 d) Miras analyzed in this study, has a radial velocity consistent with being Terzan 5 member. Its super-solar iron abundance and solar-scaled [{\alpha}/Fe] nicely match the chemical properties of the metal rich stellar population of Terzan 5 and its derived mass nicely agrees with being several Gyrs younger than the short period Miras. This young variable is an additional proof of the surprising young sub-population discovered in Terzan 5.Comment: 20 pages, 4 figures, in press on the Ap

High-performance sustainable active packaging from poly(hexamethylene furanoate) and bark extracts

The development of sustainable high-performance polymeric formulations, possibly showing multifunctional characteristics, is of key importance to produce materials in line with the circular economy agenda. This work focuses on the preparation of fully biomass-derived blends from furan-based polyester and natural extracts to yield an innovative packaging system. Terpenoids and suberin monomers are isolated from largely available waste biomass, namely, birch bark, through simple and straightforward methodologies and mixed with poly(hexamethylene furanoate) (PHF). The physicomechanical properties of the blends evidence a modulation of the surface hydrophobicity together with a significant increase in flexibility and toughness owing to the dual function exerted by the extracts, which act both as plasticizing agents and cross-linking molecules due to the formation of weak interactions, such as hydrogen bonding, with the macromolecular chains of PHF. The evaluation of the functional properties highlights that the excellent gas barrier characteristics of PHF are not just preserved; rather, a substantial increase of the CO2/O-2 permselectivity ratio is measured because of the presence of an increased concentration of disclinations that favor the diffusion of CO2. Lastly, the addition of natural extracts allows for the implementation of antioxidant and antibacterial features otherwise absent in the pristine polymer

Methodological Issues in the Clinical Validation of Biomarkers for Alzheimer&apos;s Disease : The Paradigmatic Example of CSF

The use of biomarkers is profoundly transforming medical research and practice. Their adoption has triggered major advancements in the field of Alzheimer's disease (AD) over the past years. For instance, the analysis of the cerebrospinal fluid (CSF) and neuroimaging changes indicative of neuronal loss and amyloid deposition has led to the understanding that AD is characterized by a long preclinical phase. It is also supporting the transition towards a biology-grounded framework and definition of the disease. Nevertheless, though sufficient evidence exists about the analytical validity (i.e., accuracy, reliability, and reproducibility) of the candidate AD biomarkers, their clinical validity (i.e., how well the test measures the clinical features, and the disease or treatment outcomes) and clinical utility (i.e., if and how the test improves the patient's outcomes, confirms/changes the diagnosis, identifies at-risk individuals, influences therapeutic choices) have not been fully proven. In the present review, some of the methodological issues and challenges that should be addressed in order to better appreciate the potential benefits and limitations of AD biomarkers are discussed. The ultimate goal is to stimulate a constructive discussion aimed at filling the existing gaps and more precisely defining the directions of future research. Specifically, four main aspects of the clinical validation process are addressed and applied to the most relevant CSF biomarkers: (1) the definition of reference values; (2) the identification of reference standards for the disease of interest (i.e., AD); (3) the inclusion within the diagnostic process; and (4) the statistical process supporting the whole framework

What is new in microcirculation and tissue oxygenation monitoring?

Ensuring and maintaining adequate tissue oxygenation at the microcirculatory level might be considered the holy grail of optimal hemodynamic patient management. However, in clinical practice we usually focus on macro-hemodynamic variables such as blood pressure, heart rate, and sometimes cardiac output. Other macro-hemodynamic variables like pulse pressure or stroke volume variation are additionally used as markers of fluid responsiveness. In recent years, an increasing number of technological devices assessing tissue oxygenation or microcirculatory blood flow have been developed and validated, and some of them have already been incorporated into clinical practice. In this review, we will summarize recent research findings on this topic as published in the last 2 years in the Journal of Clinical Monitoring and Computing (JCMC). While some techniques are already currently used as routine monitoring (e.g. cerebral oxygenation using near-infrared spectroscopy (NIRS)), others still have to find their way into clinical practice. Therefore, further research is needed, particularly regarding outcome measures and cost-effectiveness, since introducing new technology is always expensive and should be balanced by downstream savings. The JCMC is glad to provide a platform for such research

comparative ease of use of a diagrammatic vs an iconic query language

Abstract The importance of designing query systems which are effective and easy to use has been widelyrecognized in the database area. Also, it is well known that the adequacy of a system should be testedagainst actual users in a well monitored experiment. However, very few such experiments have beenconducted. The objective of our study is to measure and understand the comparative ease with whichsubjects can construct queries in two kinds of visual languages, one diagrammatic and the other iconic.More specifically, we are interested in determining if there is significant interaction between: 1) the queryclass and the query language type; and 2) the type of query language and the experience of the user.Experimental results indicate that the effectiveness of a diagrammatic or an iconic query language variesdepending on the classes of queries and the kinds of users. This supports the opinion that an interfaceoffering to the user various visual representations and query modalities is the most appropriate for a wide setof users and applications.Keywords: Human-Computer Interaction; Query Languages; Visual Interfaces; Usability; Experiment

Bacterial porin disrupts mitochondrial membrane potential and sensitizes host cells to apoptosis

The bacterial PorB porin, an ATP-binding beta-barrel protein of pathogenic Neisseria gonorrhoeae, triggers host cell apoptosis by an unknown mechanism. PorB is targeted to and imported by host cell mitochondria, causing the breakdown of the mitochondrial membrane potential (delta psi m). Here, we show that PorB induces the condensation of the mitochondrial matrix and the loss of cristae structures, sensitizing cells to the induction of apoptosis via signaling pathways activated by BH3-only proteins. PorB is imported into mitochondria through the general translocase TOM but, unexpectedly, is not recognized by the SAM sorting machinery, usually required for the assembly of beta-barrel proteins in the mitochondrial outer membrane. PorB integrates into the mitochondrial inner membrane, leading to the breakdown of delta psi m. The PorB channel is regulated by nucleotides and an isogenic PorB mutant defective in ATP-binding failed to induce delta psi m loss and apoptosis, demonstrating that dissipation of delta psi m is a requirement for cell death caused by neisserial infection