1,838 research outputs found

    Survival Rate, Fracture Strength and Failure Mode of Ceramic Implant Abutments After Chewing Simulation

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    The aim of this study was to compare titanium-reinforced ZrO2 and pure Al2O3 abutments regarding their outcome after chewing simulation and static loading. Forty-eight standard diameter implants with an external hexagon were divided into three groups of 16 implants each and restored with three different types of abutments (group A: ZrO2 abutments with titanium inserts; group B: densely sintered high-purity Al2O3 abutments; group C: titanium abutments). All abutments were fixated on the implants with gold-alloy screws at 32 Ncm torque, and metal crowns were adhesively cemented onto the abutments. The specimens were exposed to 1.2 million cycles in a chewing simulator. Surviving specimens were subsequently loaded until fracture in a static testing device. Fracture loads (N) and fracture modes were recorded. A Wilcoxon Rank test to compare fracture loads among the 3 groups and a Fisher exact test to detect group differences in fracture modes were used for statistical evaluation (

    Taphonomic Criteria for Identifying Iberian Lynx Dens in Quaternary Deposits

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    For decades, taphonomists have dedicated their efforts to assessing the nature of the massive leporid accumulations recovered at archaeological sites in the northwestern Mediterranean region. Their interest lying in the fact that the European rabbit constituted a critical part of human subsistence during the late Pleistocene and early Holocene. However, rabbits are also a key prey in the food webs of Mediterranean ecosystems and the base of the diet for several specialist predators, including the Iberian lynx (Lynx pardinus). For this reason, the origin of rabbit accumulations in northwestern Mediterranean sites has proved a veritable conundrum. Here, we present the zooarchaeological and taphonomic study of more than 3000 faunal and 140 coprolite remains recovered in layer IIIa of Cova del Gegant (Catalonia, Spain). Our analysis indicates that this layer served primarily as a den for the Iberian lynx. The lynxes modified and accumulated rabbit remains and also died at the site creating an accumulation dominated by the two taxa. However, other agents and processes, including human, intervened in the final configuration of the assemblage. Our study contributes to characterizing the Iberian lynx fossil accumulation differentiating between the faunal assemblages accumulated by lynxes and hominins

    The influence of diabetes mellitus on the spectrum of uropathogens and the antimicrobial resistance in elderly adult patients with urinary tract infection

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    BACKGROUND: The role of Diabetes mellitus (DM) in the etiology and in the antimicrobial resistance of uropathogens in patients with urinary tract infection has not been well clarified. For this reason we have evaluated the spectrum of uropathogens and the profile of antibiotic resistance in both diabetic and non diabetic patients with asymptomatic urinary tract infection (UTI). METHODS: Urinary isolates and their patterns of susceptibility to the antimicrobials were evaluated in 346 diabetics (229 females and 117 males) and 975 non diabetics (679 females and 296 males) who were screened for significant bacteriuria (≄10(5 )CFU/mL urine). The mean age of diabetic and non diabetic patients was respectively 73.7 yrs ± 15 S.D. and 72.7 ± 24 (p = NS). RESULTS: Most of our patients had asymptomatic UTI. The most frequent causative organisms of bacteriuria in females with and without DM were respectively : E. coli 54.1% vs 58.2% (p = NS), Enterococcus spp 8.3% vs 6.5% (p = NS), Pseudomonas spp 3.9 vs 4.7% (p = NS). The most frequent organisms in diabetic and non diabetic males were respectively E. coli 32.5% vs 31.4% (p = NS), Enterococcus spp 9.4% vs 14.5% (p = NS), Pseudomonas spp 8.5% vs 17.2% (p = <0.02). A similar isolation rate of E. coli, Enterococcus spp and Pseudomonas spp was also observed in patients with indwelling bladder catheter with and without DM. No significant differences in resistance rates to ampicillin, nitrofurantoin, cotrimoxazole and ciprofloxacin of E. coli and Enteroccus spp were observed between diabetic and non diabetic patients. CONCLUSION: In our series of patients with asymptomatic UTI (mostly hospital acquired), diabetes mellitus per se does not seem to influence the isolation rate of different uropathogens and their susceptibility patterns to antimicrobials

    Early Developmental Responses to Seedling Environment Modulate Later Plasticity to Light Spectral Quality

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    Correlations between developmentally plastic traits may constrain the joint evolution of traits. In plants, both seedling de-etiolation and shade avoidance elongation responses to crowding and foliage shade are mediated by partially overlapping developmental pathways, suggesting the possibility of pleiotropic constraints. To test for such constraints, we exposed inbred lines of Impatiens capensis to factorial combinations of leaf litter (which affects de-etiolation) and simulated foliage shade (which affects phytochrome-mediated shade avoidance). Increased elongation of hypocotyls caused by leaf litter phenotypically enhanced subsequent elongation of the first internode in response to low red∶far red (R∶FR). Trait expression was correlated across litter and shade conditions, suggesting that phenotypic effects of early plasticity on later plasticity may affect variation in elongation traits available to selection in different light environments

    Food consumption frequency and perceived stress and depressive symptoms among students in three European countries

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    Mikolajczyk RT, El Ansari W, Maxwell AE. Food consumption frequency and perceived stress and depressive symptoms among students in three European countries. Nutrition Journal. 2009;8(1):31.Background: Certain foods might be more frequently eaten under stress or when higher levels of depressive symptoms are experienced. We examined whether poor nutritional habits are associated with stress and depressive symptoms and whether the relationships differ by country and gender in a sample from three European countries collected as part of a Cross National Student Health Survey. Methods: A cross-sectional survey was conducted among first-year students in Germany (N = 696), Poland (N = 489) and Bulgaria (N = 654). Self-administered questionnaires included a 12-item food frequency questionnaire, Cohen's Perceived Stress Scale, and a modified Beck Depression Index. Linear regression analyses were conducted for two outcomes, perceived stress and depressive symptoms. Results: Food consumption frequencies differed by country and gender, as did depressive symptoms and perceived stress. For male students, none of the food consumption groups were associated with perceived stress or depressive symptoms. In females, perceived stress was associated with more frequent consumption of sweets/fast foods and less frequent consumption of fruits/vegetables. Additionally, depressive symptoms were associated with less frequent consumption of fruits/vegetables and meat. Conclusion: Our data show consistent associations between unhealthy food consumption and depressive symptoms and perceived stress among female students from three European countries, but not among male students. This suggests that efforts to reduce depressive symptoms and stress among female students may also lead to the consumption of healthier foods and/or vice-versa

    The effect of exposure to synthetic pheromone lures on male Zygaena filipendulae mating behaviour: implications for monitoring species of conservation interest

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    Pheromone based monitoring of insects of conservation value has the potential to revolutionise the way in which surveys are carried out. However, due to their effective use in pest management, concerns have been raised about potential negative effects of pheromone exposure on populations of rare insects. The effect of exposure to synthetic pheromone lures on male mating behaviour was examined in laboratory and field conditions using the six spot burnet moth Zygaena filipendulae (Linnaeus, 1758). For the laboratory experiment larvae were collected and cultured separately under controlled conditions. Virgin males were exposed to a synthetic pheromone lure for 24 h; then tested for responsiveness immediately after this exposure, 1 and 24 h later. Control males were tested three times: initially, 1 h later and 24 h later. The time taken for males to detect females, shown by exposure of their anal claspers, and the time taken for males to locate females were recorded. No significant difference was found between the time taken for control and exposed males to detect or locate females, and no significant difference between the proportions of males that successfully located females in exposed and control groups was found. In the field experiment the time males spent in the presence of contained females, both with and without a pheromone lure present, was recorded. Males spent more time in the presence of the females when the pheromone lure was present. Both experiments indicate male Z. filipendulae mating behaviour is not adversely affected by exposure to synthetic pheromone lures

    Platelets generated from human embryonic stem cells are functional in vitro and in the microcirculation of living mice

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    Platelets play an essential role in hemostasis and atherothrombosis. Owing to their short storage time, there is constant demand for this life-saving blood component. In this study, we report that it is feasible to generate functional megakaryocytes and platelets from human embryonic stem cells (hESCs) on a large scale. Differential-interference contrast and electron microscopy analyses showed that ultrastructural and morphological features of hESC-derived platelets were indistinguishable from those of normal blood platelets. In functional assays, hESC-derived platelets responded to thrombin stimulation, formed microaggregates, and facilitated clot formation/retraction in vitro. Live cell microscopy demonstrated that hESC-platelets formed lamellipodia and filopodia in response to thrombin activation, and tethered to each other as observed in normal blood. Using real-time intravital imaging with high-speed video microscopy, we have also shown that hESC-derived platelets contribute to developing thrombi at sites of laser-induced vascular injury in mice, providing the first evidence for in vivo functionality of hESC-derived platelets. These results represent an important step toward generating an unlimited supply of platelets for transfusion. Since platelets contain no genetic material, they are ideal candidates for early clinical translation involving human pluripotent stem cells

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  Όb-1 of data as a function of transverse momentum (pT) and the transverse energy (ÎŁETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∌0) correlation that grows rapidly with increasing ÎŁETPb. A long-range “away-side” (Δϕ∌π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ÎŁETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ÎŁETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁥2Δϕ modulation for all ÎŁETPb ranges and particle pT
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