Discovering how organisms and their proteins adapt to extreme conditions is a complicated process. Every condition has its own set of adaptations that make it uniquely stable in its environment. The ...purpose of our review is to discuss what is known in the extremophilic community about protein adaptations. To simplify our mission, we broke the extremophiles into three broad categories: thermophiles, halophiles and psychrophiles. While there are crossover organisms- organisms that exist in two or more extremes, like heat plus acid or cold plus pressure, most of them have a primary adaptation that is within one of these categories which tends to be the most easily identifiable one. While the generally known adaptations are still accepted, like thermophilic proteins have increased ionic interactions and a hardier hydrophobic core, halophilic proteins have a large increase in acidic amino acids and amino acid/peptide insertions and psychrophiles have a much more open structure and reduced ionic interactions, some new information has come to light. Thermophilic stability can be improved by increased subunit-subunit or subunit-cofactor interactions. Halophilic proteins have reversible folding when in the presence of salt. Psychrophilic proteins have an increase in cavities that not only decrease the formation of ice, but also increase flexibility under low temperature conditions. In a proof of concept experiment, we applied what is currently known about adaptations to a well characterized protein, malate dehydrogenase (MDH). While this protein has been profiled in the literature, we are applying our adaptation predictions to its sequence and structure to see if the described adaptations apply. Our analysis demonstrates that thermophilic and halophilic adaptations fit the corresponding MDHs very well. However, because the number of psychrophiles MDH sequences and structures is low, our analysis on psychrophiles is inconclusive and needs more information. By discussing known extremophilic adaptations and applying them to a random, conserved protein, we have found that general adaptations are conserved and can be predicted in proposed extremophilic proteins. The present field of extremophile adaptations is discovering more and more ways organisms and their proteins have adapted. The more that is learned about protein adaptation, the closer we get to custom proteins, designed to fit any extreme and solve some of the world’s most pressing environmental problems.
Latex compounding technique is an economic and ecosustainable alternative to melt mixing for preparing nanocomposites in which fillers are directly mixed with natural rubber in the latex aqueous ...dispersion. Clay minerals are excellent potential fillers to be used in masterbatches prepared exploiting this technique, but their presence is associated to the occurrence of oxidative degradation phenomena of natural rubber. In this work, by exploiting a combination of high- and low-resolution 13C and 1H Solid State Nuclear Magnetic Resonance techniques, with the support of Fourier Transform Infrared spectroscopy and thermal analyses, we characterized for the first time the oxidation phenomena occurring in sepiolite/natural rubber masterbatches obtained by the latex compounding technique. Oxidized species were identified and quantified and the dynamic properties, molecular weight and thermal stability of the rubber were characterized. Moreover, the dependence of degradation phenomena on the filler treatment and on the masterbatch work-up procedure was assessed, identifying freeze-drying as the method able to effectively protect the rubber from oxidation.
OBJECTIVETo determine whether early and more frequent mobilization after stroke affects health-related quality of life.
METHODSA Very Early Rehabilitation Trial (AVERT) was an international, ...multicenter (56 sites), phase 3 randomized controlled trial, spanning 2006–2015. People were included if they were aged ≥18 years, presented within 24 hours of a first or recurrent stroke (ischemic or hemorrhagic), and satisfied preordained physiologic criteria. Participants were randomized to usual care alone or very early and more frequent mobilization in addition to usual care. Quality of life at 12 months was a prespecified secondary outcome, evaluated using the Assessment of Quality of Life 4D (AQoL-4D). This utility-weighted scale has scores ranging from −0.04 (worse than death) to 1 (perfect health). Participants who died were assigned an AQoL-4D score of 0.
RESULTSNo significant difference in quality of life at 12 months between intervention (median 0.47, interquartile range IQR 0.07–0.81) and usual care (median 0.49, IQR 0.08–0.81) groups was identified (p = 0.86), nor were there any group differences across the 4 AQoL-4D domains. The same lack of group difference in quality of life was observed at 3 months. When cohort data were analyzed (both groups together), quality of life was strongly associated with acute length of stay, independence in activities of daily living, cognitive function, depressive symptoms, and anxiety symptoms (all p < 0.001). Quality of life in AVERT participants was substantially lower than population norms, and the gap increased with age.
CONCLUSIONSEarlier and more frequent mobilization after stroke did not influence quality of life.
CLINICAL TRIAL REGISTRATIONanzctr.org.au; ACTRN12606000185561
CLASSIFICATION OF EVIDENCEThis study provides Class II evidence that for people with stroke, earlier and more frequent mobilization did not influence quality of life over the subsequent year.
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