57 research outputs found

    Demands and opportunities for sustainable growth.

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    The promotion of sustained economic growth and the generation of decent work, central points of SDG 8, are directly related. Economic growth occurs due to an increase in the total volume of goods and services produced in an economy, through a positive variation of productive capacity, in order to meet human needs. In turn, one of the main variables that characterize the economic growth process is the employment level. Sustainable economic growth is associated with caring for social and environmental issues for current and future generations. Thus, for economic growth to occur in a sustainable way, it is necessary to create conditions that allow people to have quality jobs and stimulate the economy, without damaging the environmen

    Interobserver agreement on definition of the target volume in stereotactic radiotherapy for pancreatic adenocarcinoma using different imaging modalities

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    PURPOSE The aim of this study was to evaluate interobserver agreement (IOA) on target volume definition for pancreatic cancer (PACA) within the Radiosurgery and Stereotactic Radiotherapy Working Group of the German Society of Radiation Oncology (DEGRO) and to identify the influence of imaging modalities on the definition of the target volumes. METHODS Two cases of locally advanced PACA and one local recurrence were selected from a large SBRT database. Delineation was based on either a planning 4D CT with or without (w/wo) IV contrast, w/wo PET/CT, and w/wo diagnostic MRI. Novel compared to other studies, a combination of four metrics was used to integrate several aspects of target volume segmentation: the Dice coefficient (DSC), the Hausdorff distance (HD), the probabilistic distance (PBD), and the volumetric similarity (VS). RESULTS For all three GTVs, the median DSC was 0.75 (range 0.17-0.95), the median HD 15 (range 3.22-67.11) mm, the median PBD 0.33 (range 0.06-4.86), and the median VS was 0.88 (range 0.31-1). For ITVs and PTVs the results were similar. When comparing the imaging modalities for delineation, the best agreement for the GTV was achieved using PET/CT, and for the ITV and PTV using 4D PET/CT, in treatment position with abdominal compression. CONCLUSION Overall, there was good GTV agreement (DSC). Combined metrics appeared to allow a more valid detection of interobserver variation. For SBRT, either 4D PET/CT or 3D PET/CT in treatment position with abdominal compression leads to better agreement and should be considered as a very useful imaging modality for the definition of treatment volumes in pancreatic SBRT. Contouring does not appear to be the weakest link in the treatment planning chain of SBRT for PACA

    The essential mycobacterial genes, fabG1 and fabG4, encode 3-oxoacyl-thioester reductases that are functional in yeast mitochondrial fatty acid synthase type 2

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    Mycobacterium tuberculosis represents a severe threat to human health worldwide. Therefore, it is important to expand our knowledge of vital mycobacterial processes, such as that effected by fatty acid synthase type 2 (FASII), as well as to uncover novel ones. Mycobacterial FASII undertakes mycolic acid biosynthesis, which relies on a set of essential enzymes, including 3-oxoacyl-AcpM reductase FabG1/Rv1483. However, the M. tuberculosis genome encodes four additional FabG homologs, designated FabG2–FabG5, whose functions have hitherto not been characterized in detail. Of the four candidates, FabG4/Rv0242c was recently shown to be essential for the survival of M. bovis BCG. The present work was initiated by assessing the suitability of yeast oar1Δ mutant cells lacking mitochondrial 3-oxoacyl-ACP reductase activity to act as a surrogate system for expressing FabG1/MabA directed to the mitochondria. Mutant yeast cells producing this targeted FabG1 variant were essentially wild type for all of the chronicled phenotype characteristics, including respiratory growth on glycerol medium, cytochrome assembly and lipoid acid production. This indicated that within the framework of de novo fatty acid biosynthesis in yeast mitochondria, FabG1 was able to act on shorter (C4) acyl substrates than was previously proposed (C8–20) during mycolic acid biosynthesis in M. tuberculosis. Thereafter, FabG2–FabG5 were expressed as mitochondrial proteins in the oar1Δ strain, and FabG4 was found to complement the mutant phenotype and contain high levels of 3-oxoacyl-thioester reductase activity. Hence, like FabG1, FabG4 is also an essential, physiologically functional 3-oxoacyl-thioester reductase, albeit the latter’s involvement in mycobacterial FASII remains to be explored

    Local Cooperativity in an Amyloidogenic State of Human Lysozyme Observed at Atomic Resolution

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    The partial unfolding of human lysozyme underlies its conversion from the soluble state into amyloid fibrils observed in a fatal hereditary form of systemic amyloidosis. To understand the molecular origins of the disease, it is critical to characterize the structural and physicochemical properties of the amyloidogenic states of the protein. Here we provide a high-resolution view of the unfolding process at low pH for three different lysozyme variants, the wild-type protein and the mutants I56T and I59T, which show variable stabilities and propensities to aggregate in vitro. Using a range of biophysical techniques that includes differential scanning calorimetry and nuclear magnetic resonance spectroscopy, we demonstrate that thermal unfolding under amyloidogenic solution conditions involves a cooperative loss of native tertiary structure, followed by progressive unfolding of a compact, molten globule-like denatured state ensemble as the temperature is increased. The width of the temperature window over which the denatured ensemble progressively unfolds correlates with the relative amyloidogenicity and stability of these variants, and the region of lysozyme that unfolds first maps to that which forms the core of the amyloid fibrils formed under similar conditions. Together, these results present a coherent picture at atomic resolution of the initial events underlying amyloid formation by a globular protein

    Mechanical plasticity of cells

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    The origin of traveling waves in an emperor penguin huddle

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    Emperor penguins breed during the Antarctic winter and have to endure temperatures as low as −50 °C and wind speeds of up to 200 km h−1. To conserve energy, they form densely packed huddles with a triangular lattice structure. Video recordings from previous studies revealed coordinated movements in regular wave-like patterns within these huddles. It is thought that these waves are triggered by individual penguins that locally disturb the huddle structure, and that the traveling wave serves to remove the lattice defects and restore order. The mechanisms that govern wave propagation are currently unknown, however. Moreover, it is unknown if the waves are always triggered by the same penguin in a huddle. Here, we present a model in which the observed wave patterns emerge from simple rules involving only the interactions between directly neighboring individuals, similar to the interaction rules found in other jammed systems, e.g. between cars in a traffic jam. Our model predicts that a traveling wave can be triggered by a forward step of any individual penguin located within a densely packed huddle. This prediction is confirmed by optical flow velocimetry of the video recordings of emperor penguins in their natural habitat

    Ustekinumab and Vedolizumab Are Equally Safe and Effective in Elderly Crohn's Disease Patients.

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    BACKGROUND: Anti-tumour necrosis factor (anti-TNF) agents are associated with increased infection risk among elderly inflammatory bowel disease (IBD) patients, and thus, alternative biologics may be preferable. However, little comparative data exist on the safety and efficacy of vedolizumab and ustekinumab in elderly IBD patients. AIMS: To compare the safety and effectiveness of ustekinumab and vedolizumab in elderly Crohn's disease patients. METHODS: Patients ≄ 60 years old who commenced ustekinumab or vedolizumab for Crohn's disease (CD) were included. Primary outcome was serious infections, defined as requiring hospitalisation. Efficacy was assessed by treatment persistence and clinical response rates. We appropriately adjusted for confounders using propensity score-matched analysis weighted by the inverse predicted probability of treatment weighing and performed a logistic regression analysis to assess factors associated with serious infections and treatment persistence. RESULTS: Eighty-three patients commencing ustekinumab and 42 commencing vedolizumab therapy were included. In a propensity adjusted cohort, the rate of serious infection and treatment persistence were comparable between ustekinumab and vedolizumab. There was a significant reduction in HBI at 6 and 12 months compared to baseline in both groups. Male gender was positively associated with serious infection risk at 12 months, and penetrating disease behaviour was positively associated with 12-month treatment persistence. Baseline HBI score was negatively associated with 12-month treatment persistence. Cox regression analysis showed no overall difference in treatment discontinuation-free and serious infection-free survival by 12 months. CONCLUSIONS: We observed comparable safety and effectiveness for ustekinumab and vedolizumab in treating elderly CD patients

    Population of nonnative States of lysozyme variants drives amyloid fibril formation.

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    The propensity of protein molecules to self-assemble into highly ordered, fibrillar aggregates lies at the heart of understanding many disorders ranging from Alzheimer's disease to systemic lysozyme amyloidosis. In this paper we use highly accurate kinetic measurements of amyloid fibril growth in combination with spectroscopic tools to quantify the effect of modifications in solution conditions and in the amino acid sequence of human lysozyme on its propensity to form amyloid fibrils under acidic conditions. We elucidate and quantify the correlation between the rate of amyloid growth and the population of nonnative states, and we show that changes in amyloidogenicity are almost entirely due to alterations in the stability of the native state, while other regions of the global free-energy surface remain largely unmodified. These results provide insight into the complex dynamics of a macromolecule on a multidimensional energy landscape and point the way for a better understanding of amyloid diseases
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