239 research outputs found

    Compound-specific amino acid isotopic proxies for detecting freshwater resource consumption

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    AbstractOf central importance to palaeodietary reconstruction is a clear understanding of relative contributions of different terrestrial (i.e., C3 vs. C4 plants) and aquatic (i.e., freshwater vs. marine) resources to human diet. There are, however, significant limitations associated with the ability to reconstruct palaeodiet using bulk collagen stable isotope compositions in regions where diverse dietary resources are available. Recent research has determined that carbon-isotope analysis of individual amino acids has considerable potential to elucidate dietary protein source where bulk isotopic compositions cannot. Using ή13CAA values for human and faunal remains from Zvejnieki, Latvia (8th – 3rd millennia BCE), we test several isotopic proxies focused on distinguishing freshwater protein consumption from both plant-derived and marine protein consumption. We determined that the Δ13CGly-Phe and Δ13CVal-Phe proxies can effectively discriminate between terrestrial and aquatic resource consumption, and the relationship between essential ή13CAA values and the Δ13CGly-Phe and Δ13CVal-Phe proxies can differentiate among the four protein consumption groups tested here. Compound-specific amino acid carbon-isotope dietary proxies thus enable an enhanced understanding of diet and resource exploitation in the past, and can elucidate complex dietary behaviour

    Integrating isotopes and documentary evidence : dietary patterns in a late medieval and early modern mining community, Sweden

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    We would like to thank the Archaeological Research Laboratory, Stockholm University, Sweden and the Tandem Laboratory (Ångström Laboratory), Uppsala University, Sweden, for undertaking the analyses of stable nitrogen and carbon isotopes in both human and animal collagen samples. Also, thanks to Elin Ahlin Sundman for providing the ÎŽ13C and ÎŽ15N values for animal references from VĂ€sterĂ„s. This research (BĂ€ckström’s PhD employment at Lund University, Sweden) was supported by the Berit Wallenberg Foundation (BWS 2010.0176) and Jakob and Johan Söderberg’s foundation. The ‘Sala project’ (excavations and analyses) has been funded by Riksens Clenodium, Jernkontoret, Birgit and Gad Rausing’s Foundation, SAU’s Research Foundation, the Royal Physiographic Society of Lund, Berit Wallenbergs Foundation, Åke Wibergs Foundation, Lars Hiertas Memory, Helge Ax:son Johnson’s Foundation and The Royal Swedish Academy of Sciences.Peer reviewedPublisher PD

    Using a Powered Bone Marrow Biopsy System Results in Shorter Procedures, Causes Less Residual Pain to Adult Patients, and Yields Larger Specimens

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    <p>Abstract</p> <p>Background</p> <p>In recent years, a battery-powered bone marrow biopsy system was developed and cleared by the U.S. Food and Drug Administration to allow health care providers to access the bone marrow space quickly and efficiently. A multicenter randomized clinical trial was designed for adult patients to determine if the powered device had advantages over traditional manually-inserted needles in regard to length of procedure, patient pain, complications, user satisfaction, and pathological analysis of the specimens.</p> <p>Methods</p> <p>Adult patients requiring marrow sampling procedures were randomized for a Manual or Powered device. Visual Analog Scale (VAS) pain scores were captured immediately following the procedure and 1 and 7 days later. Procedure time was measured and core specimens were submitted to pathology for grading.</p> <p>Results</p> <p>Ten sites enrolled 102 patients into the study (Powered, n = 52; Manual, n = 50). Mean VAS scores for overall procedural pain were not significantly different between the arms (3.8 ± 2.8 for Powered, 3.5 ± 2.3 for Manual [p = 0.623]). A day later, more patients who underwent the Powered procedure were pain-free (67%) than those patients in the Manual group (33%; p = 0.003). One week later, there was no difference (83% for Powered patients; 76% for Manual patients.) Mean procedure time was 102.1 ± 86.4 seconds for the Powered group and 203.1 ± 149.5 seconds for the Manual group (p < 0.001). Pathology assessment was similar in specimen quality, but there was a significant difference in the specimen volume between the devices (Powered: 36.8 ± 21.2 mm<sup>3</sup>; Manual: 20.4 ± 9.0 mm<sup>3</sup>; p = 0.039). Two non-serious complications were experienced during Powered procedures (4%); but none during Manual procedures (p = 0.495).</p> <p>Conclusions</p> <p>The results of this first trial provide evidence that the Powered device delivers larger-volume bone marrow specimens for pathology evaluation. In addition, bone marrow specimens were secured more rapidly and subjects experienced less intermediate term pain when the Powered device was employed. Further study is needed to determine if clinicians more experienced with the Powered device will be able to use it in a manner that significantly reduces needle insertion pain; and to compare a larger sample of pathology specimens obtained using the Powered device to those obtained using traditional manual biopsy needles.</p

    Improving simultaneous saccharification and co-fermentation of pretreated wheat straw using both enzyme and substrate feeding

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    <p>Abstract</p> <p>Background</p> <p>Simultaneous saccharification and co-fermentation (SSCF) has been recognized as a feasible option for ethanol production from xylose-rich lignocellulosic materials. To reach high ethanol concentration in the broth, a high content of water-insoluble solids (WIS) is needed, which creates mixing problems and, furthermore, may decrease xylose uptake. Feeding of substrate has already been proven to give a higher xylose conversion than a batch SSCF. In the current work, enzyme feeding, in addition to substrate feeding, was investigated as a means of enabling a higher WIS content with a high xylose conversion in SSCF of a xylose-rich material. A recombinant xylose-fermenting strain of <it>Saccharomyces cerevisiae </it>(TMB3400) was used for this purpose in fed-batch SSCF experiments of steam-pretreated wheat straw.</p> <p>Results</p> <p>By using both enzyme and substrate feeding, the xylose conversion in SSCF could be increased from 40% to 50% in comparison to substrate feeding only. In addition, by this design of the feeding strategy, it was possible to process a WIS content corresponding to 11% in SSCF and obtain an ethanol yield on fermentable sugars of 0.35 g g<sup>-1</sup>.</p> <p>Conclusion</p> <p>A combination of enzyme and substrate feeding was shown to enhance xylose uptake by yeast and increase overall ethanol yield in SSCF. This is conceptually important for the design of novel SSCF processes aiming at high-ethanol titers. Substrate feeding prevents viscosity from becoming too high and thereby allows a higher total amount of WIS to be added in the process. The enzyme feeding, furthermore, enables keeping the glucose concentration low, which kinetically favors xylose uptake and results in a higher xylose conversion.</p

    Isotope evidence for the use of marine resources in the Eastern Iberian Mesolithic

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    There are relatively few coastal Mesolithic sites in the Iberian Mediterranean region, probably due to a number of factors including sea level changes and the disappearance of sites due to agriculture and urbanisation. However, recent excavations have uncovered inland sites that have marine faunal remains (i.e. molluscs and fish) and lithics from the coastal area, which both indicate interactions between the coast and the upland valleys. These inland sites are located at a distance of 30e50 km from todayÂżs coastline and are at altitudes higher than 1000 m. We report on additional information on the links between the coast and these inland sites through the use of dietary isotope analysis (carbon and nitrogen stable isotope analysis) of collagen extracted from human and faunal remains at the sites of Coves de Santa Maira, Penya del Comptador and Cingle del Mas Nou. The results indicate that Mesolithic diet in this region was largely based on C3 terrestrial resources, but there was measurable evidence of low-level consumption of marine resources at both coastal and inland sites

    Adsorption at cell surface and cellular uptake of silica nanoparticles with different surface chemical functionalizations: impact on cytotoxicity

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    International audienceSilica nanoparticles are particularly interesting for medical applications because of the high inertness and chemical stability of silica material. However, at the nanoscale their innocuousness must be carefully verified before clinical use. The aim of this study was to investigate the in vitro biological toxicity of silica nanoparticles depending on their surface chemical functionalization. To that purpose, three kinds of 50 nm fluorescent silica-based nanoparticles were synthesized: 1) sterically stabilized silica nanoparticles coated with neutral polyethylene glycol (PEG) molecules, 2) positively charged silica nanoparticles coated with amine groups and 3) negatively charged silica nanoparticles coated with carboxylic acid groups. RAW 264.7 murine macrophages were incubated for 20 hours with each kind of nanoparticles. Their cellular uptake and adsorption at the cell membrane were assessed by a fluorimetric assay and cellular responses were evaluated in terms of cytotoxicity, pro-inflammatory factor production and oxidative stress. Results showed that the highly positive charged nanoparticle, were the most adsorbed at cell surface and triggered more cytotoxicity than other nanoparticles types. To conclude, this study clearly demonstrated that silica nanoparticles surface functionalization represents a key parameter in their cellular uptake and biological toxicity

    Experiences of being exposed to intimate partner violence during pregnancy

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    In this study a phenomenological approach was used in order to enter deeply into the experience of living with violence during pregnancy. The aim of the study was to gain a deeper understanding of women's experiences of being exposed to intimate partner violence (IPV) during pregnancy. The data were collected through in-depth interviews with five Norwegian women; two during pregnancy and three after the birth. The women were between the age of 20 and 38 years. All women had received support from a professional research and treatment centre. The essential structure shows that IPV during pregnancy is characterized by difficult existential choices related to ambivalence. Existential choices mean questioning one's existence, the meaning of life as well as one's responsibility for oneself and others. Five constituents further explain the essential structure: Living in unpredictability, the violence is living in the body, losing oneself, feeling lonely and being pregnant leads to change. Future life with the child is experienced as a possibility for existential change. It is important for health professionals to recognize and support pregnant women who are exposed to violence as well as treating their bodies with care and respect

    Heavy reliance on plants for Romanian cave bears evidenced by amino acid nitrogen isotope analysis

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    Heavy reliance on plants is rare in Carnivora and mostly limited to relatively small species in subtropical settings. The feeding behaviors of extinct cave bears living during Pleistocene cold periods at middle latitudes have been intensely studied using various approaches including isotopic analyses of fossil collagen. In contrast to cave bears from all other regions in Europe, some individuals from Romania show exceptionally high ÎŽ15N values that might be indicative of meat consumption. Herbivory on plants with high ÎŽ15N values cannot be ruled out based on this method, however. Here we apply an approach using the ÎŽ15N values of individual amino acids from collagen that offsets the baseline ÎŽ15N variation among environments. The analysis yielded strong signals of reliance on plants for Romanian cave bears based on the ÎŽ15N values of glutamate and phenylalanine. These results could suggest that the high variability in bulk collagen ÎŽ15N values observed among cave bears in Romania reflects niche partitioning but in a general trophic context of herbivory

    Prevalence and risk of protein-energy wasting assessed by subjective global assessment in older adults with advanced chronic kidney disease:results from the EQUAL study

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    Prevalence and risk factors for protein-energy wasting (PEW) are poorly studied in the nondialysis, older population with advanced chronic kidney disease (CKD). Our aim was to evaluate the prevalence of PEW in advanced stage CKD patients aged greater than 65 years. Furthermore, we aimed to describe risk factors for PEW in the overall study population and among obese individuals. Prospective observational cohort study. 2not on dialysis attending nephrology care. PEW was assessed by 7-point Subjective Global Assessment (7-p SGA). 2), 25% were diagnosed with protein wasting. Risk factors for SGA ≀5 in obese people were similar to those for the overall study population. This European multicenter study shows that the prevalence of PEW is high in patients with advanced CKD aged >65 years. The risk of PEW increases substantially with age and is commonly characterized by muscle wasting. Our study suggests that focus on nutrition should start early in the follow-up of older adults with CK
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