817 research outputs found
Seniorenläufer werden schneller und gewinnen Ultramarathons
Quintessenz
• Seniorensportler (Läufer über 35 Jahre) dominieren Ultramarathons, also Läufe, die länger sind als die klassische Marathondistanz von 42,195 km.
• Aus physiologischer Sicht wird mit ca. 35 Jahren der Leistungszenit im Langstrecken-Laufsport überschritten.
• Das Alter der Spitzenleistung im Ultralaufen steigt mit zunehmender Distanz und/oder der Dauer eines Ultramarathons.
• Lebenslanger Ausdauersport vermindert die altersbedingte Abnahme der maximalen Sauerstoffaufnahme um ca. 50%.
• Eine Abnahme der Muskelmasse ist kein unabwendbares Schicksal, denn regelmässiges Training lässt den altersbedingten jährlichen Abbau auf bis zu 0,5% schrumpfen
Risk Prediction Scores for Postoperative Mortality After Esophagectomy: Validation of Different Models
Background: Different prediction models for operative mortality after esophagectomy have been developed. The aim of this study is to independently validate prediction models from Philadelphia, Rotterdam, Munich, and the ASA. Methods: The scores were validated using logistic regression models in two cohorts of patients undergoing esophagectomy for cancer from Switzerland (n = 170) and Australia (n = 176). Results: All scores except ASA were significantly higher in the Australian cohort. There was no significant difference in 30-day mortality or in-hospital death between groups. The Philadelphia and Rotterdam scores had a significant predictive value for 30-day mortality (p = 0.001) and in-hospital death (p = 0.003) in the pooled cohort, but only the Philadelphia score had a significant prediction value for 30-day mortality in both cohorts. Neither score showed any predictive value for in-hospital death in Australians but were highly significant in the Swiss cohort. ASA showed only a significant predictive value for 30-day mortality in the Swiss. For in-hospital death, ASA was a significant predictor in the pooled and Swiss cohorts. The Munich score did not have any significant predictive value whatsoever. Conclusion: None of the scores can be applied generally. A better overall predictive score or specific prediction scores for each country should be develope
Rapidly Destructive Staphylococcus epidermidis Endocarditis
Abstract : A 29-year-old man with rapidly destructive Staphylococcus epidermidis endocarditis after mitral valve reconstruction is presented. Resistance to rifampin and teicoplanin occurred during antibiotic treatment resulting in clinical failure and valve destruction. Subsequently, the patient was successfully treated, by combining valve replacement with antibiotic therapy including quinupristin/dalfopristin, levofloxacin, and vancomycin. In conclusion, S. epidermidis can cause rapid valve destruction with large vegetations, and combination of surgery and antibiotic therapy may be necessar
The anterior center edge angle in Lequesne's false profile view: interrater correlation, dependence on pelvic tilt and correlation to anterior acetabular coverage in the sagital plane. A cadaver study
Introduction: Lequesne's vertical-center-anterior margin (VCA) angle measured on the false profile view of the pelvis aims at quantifying the anterior acetabular coverage of the femoral head. The anterior delimitation of the acetabular roof is often defined on the false profile view but there are no data on its interrater reliability. Additionally, it is not known how pelvic tilt may influence this angle. Finally, the plane in which this angle is measured lies at an angle of 65° to the sagittal plane and we wondered if this angle would be transposable to the anterior acetabular coverage measured in the sagittal plane. Methods: Eight hips from four cadaver pelvises were investigated by means of a total of 72 false profile views, each taken in defined pelvic inclinations at 5° increments ranging from −20° to +20°, and the VCA angle measured by three independent raters. A computed tomography (CT) of each hip was performed in a neutral pelvic tilt position and a sagittal 2D reconstruction calculated in order to measure anterior coverage in the sagittal plane. The interrater reliability of the VCA angles was assessed using the intra-class correlation coefficient (ICC). The dependence of the VCA angle on pelvic tilt was assessed by regression analysis. The Correlation between the VCA angle and anterior coverage in the sagittal plane of the CT was analyzed using a simple linear regression model. Results: The interrater reliability for measurements of the VCA angle was almost perfect (ICC:0.97). Regression analysis showed that each degree of pelvic tilt was accompanied by a change of the VCA angle by a value of 0.63° (P<0.001). A low correlation between the VCA angle measured in the false profile view and the anterior coverage in the sagittal plane was statistically not significant (r=0.667, P=0.06). Conclusions: Lequesne's VCA angle has an excellent interrater reliability and represents a reliable measure of acetabular dysplasia for comparisons with published data. Lequesne's VCA angle is influenced by pelvic tilt in a linear manner. Performing the false profile view in a standing position may reduce the clinical relevance of this dependency on pelvic tilt. The correlation of Lequesne's VCA angle to anterior acetabular coverage in the sagittal plane is low and therefore unsuitable to be transposed into the sagittal plan
The evolution of pebble size and shape in space and time
We propose a mathematical model which suggests that the two main geological
observations about shingle beaches, i.e. the emergence of predominant pebble
size ratios and strong segregation by size are interrelated. Our model is a
based on a system of ODEs called the box equations, describing the evolution of
pebble ratios. We derive these ODEs as a heuristic approximation of Bloore's
PDE describing collisional abrasion. While representing a radical
simplification of the latter, our system admits the inclusion of additional
terms related to frictional abrasion. We show that nontrivial attractors
(corresponding to predominant pebble size ratios) only exist in the presence of
friction. By interpreting our equations as a Markov process, we illustrate by
direct simulation that these attractors may only stabilized by the ongoing
segregation process.Comment: 22 pages, 8 figure
Holographic Superconductors with Lifshitz Scaling
Black holes in asymptotically Lifshitz spacetime provide a window onto finite
temperature effects in strongly coupled Lifshitz models. We add a Maxwell gauge
field and charged matter to a recently proposed gravity dual of 2+1 dimensional
Lifshitz theory. This gives rise to charged black holes with scalar hair, which
correspond to the superconducting phase of holographic superconductors with z >
1 Lifshitz scaling. Along the way we analyze the global geometry of static,
asymptotically Lifshitz black holes at arbitrary critical exponent z > 1. In
all known exact solutions there is a null curvature singularity in the black
hole region, and, by a general argument, the same applies to generic Lifshitz
black holes.Comment: 23 pages, 4 figures; v2: added references; v3: matches published
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Cytosine-to-Uracil Deamination by SssI DNA Methyltransferase
The prokaryotic DNA(cytosine-5)methyltransferase M.SssI shares the specificity of eukaryotic DNA methyltransferases (CG) and is an important model and experimental tool in the study of eukaryotic DNA methylation. Previously, M.SssI was shown to be able to catalyze deamination of the target cytosine to uracil if the methyl donor S-adenosyl-methionine (SAM) was missing from the reaction. To test whether this side-activity of the enzyme can be used to distinguish between unmethylated and C5-methylated cytosines in CG dinucleotides, we re-investigated, using a sensitive genetic reversion assay, the cytosine deaminase activity of M.SssI. Confirming previous results we showed that M.SssI can deaminate cytosine to uracil in a slow reaction in the absence of SAM and that the rate of this reaction can be increased by the SAM analogue 5’-amino-5’-deoxyadenosine. We could not detect M.SssI-catalyzed deamination of C5-methylcytosine (m5C). We found conditions where the rate of M.SssI mediated C-to-U deamination was at least 100-fold higher than the rate of m5C-to-T conversion. Although this difference in reactivities suggests that the enzyme could be used to identify C5-methylated cytosines in the epigenetically important CG dinucleotides, the rate of M.SssI mediated cytosine deamination is too low to become an enzymatic alternative to the bisulfite reaction. Amino acid replacements in the presumed SAM binding pocket of M.SssI (F17S and G19D) resulted in greatly reduced methyltransferase activity. The G19D variant showed cytosine deaminase activity in E. coli, at physiological SAM concentrations. Interestingly, the C-to-U deaminase activity was also detectable in an E. coli ung+ host proficient in uracil excision repair
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Implementation research for the prevention of antimicrobial resistance and healthcare-associated infections; 2017 Geneva infection prevention and control (IPC)-think tank (part 1)
Background
Around 5–15% of all hospital patients worldwide suffer from healthcare-associated infections (HAIs), and years of excessive antimicrobial use in human and animal medicine have created emerging antimicrobial resistance (AMR). A considerable amount of evidence-based measures have been published to address these challenges, but the largest challenge seems to be their implementation.
Methods
In June 2017, a total of 42 experts convened at the Geneva IPC-Think Tank to discuss four domains in implementation science: 1) teaching implementation skills; 2) fostering implementation of IPC and antimicrobial stewardship (AMS) by policy making; 3) national/international actions to foster implementation skills; and 4) translational research bridging social sciences and clinical research in infection prevention and control (IPC) and AMR.
Results
Although neglected in the past, implementation skills have become a priority in IPC and AMS. They should now be part of any curriculum in health care, and IPC career paths should be created. Guidelines and policies should be aligned with each other and evidence-based, each document providing a section on implementing elements of IPC and AMS in patient care. International organisations should be advocates for IPC and AMS, framing them as patient safety issues and emphasizing the importance of implementation skills. Healthcare authorities at the national level should adopt a similar approach and provide legal frameworks, guidelines, and resources to allow better implementation of patient safety measures in IPC and AMS. Rather than repeating effectiveness studies in every setting, we should invest in methods to improve the implementation of evidence-based measures in different healthcare contexts. For this, we need to encourage and financially support collaborations between social sciences and clinical IPC research.
Conclusions
Experts of the 2017 Geneva Think Tank on IPC and AMS, CDC, and WHO agreed that sustained efforts on implementation of IPC and AMS strategies are required at international, country, and hospital management levels, to provide an adequate multimodal framework that addresses (not exclusively) leadership, resources, education and training for implementing IPC and AMS. Future strategies can build on this agreement to make strategies on IPC and AMS more effective
Alveolar Echinococcosis of the Liver in an Adult with Human Immunodeficiency Virus Type-1 Infection
Abstract. : We describe a patient with human immunodeficiency virus type-1 (HIV) infection and alveolar echinococcosis (AE) with a focus on two messages. Despite being severely immunocompromised over years the patient exhibited a long-term asymptomatic course of AE. This is in clear contrast to reports describing accelerated courses of AE in immunocompromised patients. The patient had therapeutic mebendazole drug levels with only 1/10 of the normal drug dose. He was co-treated with protease inhibitors for his HIV infection. These drugs are known as strong inhibitors of cytochrome P450 3A4 (CYP3A4)-dependent metabolism. We speculate that benzimidazoles and protease inhibitors interfere at the CYP3A4-level. The first report of co-infection of HIV and accelerated AE was in a young girl with an extremely low CD4 cell count and an abrogated lymphoproliferative responsiveness to parasite antigen stimulation. Since the CD4 cell count in our patient remained in the range of 27-150 cells/µl, we speculate that there was a critical threshold of immunosupression for constraining AE. Initial treatment with albendazole for AE added to the current highly active antiretroviral treatment (HAART), and suppressive toxoplasmosis therapy became complicated by pancytopenia. After full recovery of the bone marrow, mebendazole was introduced with a new HAART and the previously prescribed toxoplasmosis maintenance therapy. Surprisingly, efficient mebendazole levels were achieved with an uncommonly low dose. These observations suggest that the benzimidazoles, albendazole and mebendazole, may interact with protease inhibitors, which are known for their strong inhibition of the CYP3A
Thermal Correlators in Holographic Models with Lifshitz scaling
We study finite temperature effects in two distinct holographic models that
exhibit Lifshitz scaling, looking to identify model independent features in the
dual strong coupling physics. We consider the thermodynamics of black branes
and find different low-temperature behavior of the specific heat. Deformation
away from criticality leads to non-trivial temperature dependence of
correlation functions and we study how the characteristic length scale in the
two point function of scalar operators varies as a function of temperature and
deformation parameters.Comment: 28 pages, 8 figures; typos corrected, references added, published
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