2,615 research outputs found
Risk entanglement and the social relationality of risk
Relational accounts of risk explain variation in risk perception through situated cognitions defining risk as a relationship between ârisk objectsâ and âobjects at riskâ. We extend this approach to include not only the relational constitution of cognitive risk objects, but also of the different actors assessing risk. Risk in this perspective is relational because it establishes a link between two different cognitive objects and between two (or more) actors. We argue that this is the case when at least two actors refer to a common risk object while retaining distinct objects at risk. We call this a constellation of risk entanglement across actors. We illustrate our theoretical arguments using data from 68 qualitative interviews and ethnographic fieldwork in the German finance-state nexus. Our analyses indicate how risk entanglement affects and transforms the fundamental logics according to which both of these fields operate
N,N'-dimethylperylene-3,4,9,10-bis(dicarboximide) on alkali halide(001) surfaces
The growth of N,N'-dimethylperylene-3,4,9,10-bis(dicarboximide) (DiMe-PTCDI)
on KBr(001) and NaCl(001) surfaces has been studied. Experimental results have
been achieved using frequency modulation atomic force microscopy at room
temperature under ultra-high vacuum conditions. On both substrates, DiMe-PTCDI
forms molecular wires with a width of 10 nm, typically, and a length of up to
600 nm at low coverages. All wires grow along the [110] direction (or
[10] direction, respectively) of the alkali halide (001) substrates.
There is no wetting layer of molecules: Atomic resolution of the substrates can
be achieved between the wires. The wires are mobile on KBr surface but
substantially more stable on NaCl. A p(2 x 2) superstructure in brickwall
arrangement on the ionic crystal surfaces is proposed based on electrostatic
considerations. Calculations and Monte-Carlo simulations using empirical
potentials reveal possible growth mechanisms for molecules within the first
layer for both substrates, also showing a significantly higher binding energy
for NaCl(001). For KBr, the p(2 x 2) superstructure is confirmed by the
simulations, for NaCl, a less dense, incommensurate superstructure is
predicted.Comment: 5 pages, 5 figure
Syndesmotic Internal Braceâą for anatomic distal tibiofibular ligament augmentation
Reconstruction of unstable syndesmotic injuries is not trivial, and there is no generally accepted treatment guidelines. Thus, there still remain considerable controversies regarding diagnosis, classification and treatment of syndesmotic injuries. Syndesmotic malreduction is the most common indication for early re-operation after ankle fracture surgery, and widening of the ankle mortise by only 1 mm decreases the contact area of the tibiotalar joint by 42%. Outcome of ankle fractures with syndesmosis injury is worse than without, even after surgical syndesmotic stabilization. This may be due to a high incidence of syndesmotic malreduction revealed by increasing postoperative computed tomography controls. Therefore, even open visualization of the syndesmosis during the reduction maneuver has been recommended. Thus, the most important clinical predictor of outcome is consistently reported as accuracy of anatomic reduction of the injured syndesmosis. In this context the TightRopeÂź system is reported to have advantages compared to classical syndesmotic screws. However, rotational instability of the distal fibula cannot be safely limited by use of 1 or even 2 TightRopesÂź. Therefore, we developed a new syndesmotic InternalBraceTM technique for improved anatomic distal tibiofibular ligament augmentation to protect healing of the injured native ligaments. The InternalBraceTM technique was developed by Gordon Mackay from Scotland in 2012 using SwiveLocksÂź for knotless aperture fixation of a FiberTapeÂź at the anatomic footprints of the augmented ligaments, and augmentation of the anterior talofibular ligament, the deltoid ligament, the spring ligament and the medial collateral ligaments of the knee have been published so far. According to the individual injury pattern, patients can either be treated by the new syndesmotic InternalBraceTM technique alone as a single anterior stabilization, or in combination with one posteriorly directed TightRopeÂź as a double stabilization, or in combination with one TightRopeÂź and a posterolateral malleolar screw fixation as a triple stabilization. Moreover, the syndesmotic InternalBraceTM technique is suitable for anatomic refixation of displaced bony avulsion fragments too small for screw fixation and for indirect reduction of small posterolateral tibial avulsion fragments by anatomic reduction of the anterior syndesmosis with an InternalBraceTM after osteosynthesis of the distal fibula. In this paper, comprehensively illustrated clinical examples show that anatomic reconstruction with rotational stabilization of the syndesmosis can be realized by use of our new syndesmotic InternalBraceTM technique. A clinical trial for evaluation of the functional outcomes has been started at our hospital
On the Laplace Approximation as Model Selection Criterion for Gaussian Processes
Model selection aims to find the best model in terms of accuracy,
interpretability or simplicity, preferably all at once. In this work, we focus
on evaluating model performance of Gaussian process models, i.e. finding a
metric that provides the best trade-off between all those criteria. While
previous work considers metrics like the likelihood, AIC or dynamic nested
sampling, they either lack performance or have significant runtime issues,
which severely limits applicability. We address these challenges by introducing
multiple metrics based on the Laplace approximation, where we overcome a severe
inconsistency occuring during naive application of the Laplace approximation.
Experiments show that our metrics are comparable in quality to the gold
standard dynamic nested sampling without compromising for computational speed.
Our model selection criteria allow significantly faster and high quality model
selection of Gaussian process models
Impairments of Biological Motion Perception in Congenital Prosopagnosia
Prosopagnosia is a deficit in recognizing people from their faces. Acquired prosopagnosia results after brain damage, developmental or congenital prosopagnosia (CP) is not caused by brain lesion, but has presumably been present from early childhood onwards. Since other sensory, perceptual, and cognitive abilities are largely spared, CP is considered to be a stimulus-specific deficit, limited to face processing. Given that recent behavioral and imaging studies indicate a close relationship of face and biological-motion perception in healthy adults, we hypothesized that biological motion processing should be impaired in CP. Five individuals with CP and ten matched healthy controls were tested with diverse biological-motion stimuli and tasks. Four of the CP individuals showed severe deficits in biological-motion processing, while one performed within the lower range of the controls. A discriminant analysis classified all participants correctly with a very high probability for each participant. These findings demonstrate that in CP, impaired perception of faces can be accompanied by impaired biological-motion perception. We discuss implications for dedicated and shared mechanisms involved in the perception of faces and biological motion
Pulsatile ex vivo perfusion of human saphenous vein grafts under controlled pressure conditions increases MMP-2 expression
<p>Abstract</p> <p>Background</p> <p>The use of human saphenous vein grafts (HSVGs) as a bypass conduit is a standard procedure in the treatment of coronary artery disease while their early occlusion remains a major problem.</p> <p>Methods</p> <p>We have developed an <it>ex vivo </it>perfusion system, which uses standardized and strictly controlled hemodynamic parameters for the pulsatile and non-static perfusion of HSVGs to guarantee a reliable analysis of molecular parameters under different pressure conditions. Cell viability of HSVGs (n = 12) was determined by the metabolic conversion of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) into a purple formazan dye.</p> <p>Results</p> <p>Under physiological flow rates (10 mmHg) HSVGs remained viable for two weeks. Their exposure to arterial conditions (100 mmHg) was possible for one week without important reduction in viability. Baseline expression of matrix metalloproteinase-2 (MMP-2) after venous perfusion (2.2 ± 0.5, n = 5) was strongly up-regulated after exposure to arterial conditions for three days (19.8 ± 4.3) or five days (23.9 ± 6.1, p < 0.05). Zymographic analyses confirmed this increase on the protein level. Our results suggest that expression and activity of MMP-2 are strongly increased after exposure of HSVGs to arterial hemodynamic conditions compared to physiological conditions.</p> <p>Conclusion</p> <p>Therefore, our system might be helpful to more precisely understand the molecular mechanisms leading to an early failure of HSVGs.</p
Regional transplant rates depend more on physician-dependent variables than on proximity to transplant center
Purpose The objective of this work was to uncover inequalities in access to liver transplantation in Bavaria, Germany. Methods For this purpose, the annual transplantation rate per 1 million inhabitants for the respective districts was determined from the aggregated postal codes of the place of residence of transplanted patients. The variables examined were proximity and travel time to the nearest transplant center, as well as the care category of the regional hospital. In addition, we assessed whether the head of gastroenterology at the regional hospital through which liver transplant candidates are referred was trained at a liver transplant center. Results We could not demonstrate a direct relationship between proximity or travel time to the nearest transplant center and access to liver transplantation. Multivariate regression analysis shows that liver transplant training ( p â<â0.0001) of the chief physician (gastroenterologist) of the regional hospital was the most decisive independent factor for access to liver transplantation within a district. Conclusion We show that the transplant training experience of the head of gastroenterology at a regional hospital is an independent factor for the regional transplantation rate. Therefore, it appears important to maintain some liver transplant expertise outside the transplant centers in order to properly identify and assign potential transplant candidates for transplantation.Open Access funding enabled and organized by Projekt DEAL.UniversitĂ€tsklinik MĂŒnchen (6933
A genetic validation study reveals a role of vitamin D metabolism in the response to interferon-alfa-based therapy of chronic hepatitis C
Background: To perform a comprehensive study on the relationship between vitamin D metabolism and the response to interferon-α-based therapy of chronic hepatitis C.
Methodology/Principal Findings: Associations between a functionally relevant polymorphism in the gene encoding the vitamin D 1α-hydroxylase (CYP27B1-1260 rs10877012) and the response to treatment with pegylated interferon-α (PEG-IFN-α) and ribavirin were determined in 701 patients with chronic hepatitis C. In addition, associations between serum concentrations of 25-hydroxyvitamin D3 (25[OH]D3) and treatment outcome were analysed. CYP27B1-1260 rs10877012 was found to be an independent predictor of sustained virologic response (SVR) in patients with poor-response IL28B genotypes (15% difference in SVR for rs10877012 genotype AA vs. CC, p = 0.02, OR = 1.52, 95% CI = 1.061â2.188), but not in patients with favourable IL28B genotype. Patients with chronic hepatitis C showed a high prevalence of vitamin D insufficiency (25[OH]D3<20 ng/mL) during all seasons, but 25(OH)D3 serum levels were not associated with treatment outcome.
Conclusions/Significance: Our study suggests a role of bioactive vitamin D (1,25[OH]2D3, calcitriol) in the response to treatment of chronic hepatitis C. However, serum concentration of the calcitriol precursor 25(OH)D3 is not a suitable predictor of treatment outcome
Limited access to liver transplantation and TIPS despite high mortality, healthcare resource use and costs of cirrhosis in Germany
Background and Aims
Data on number of patients with cirrhosis in Germany are limited. We therefore aimed to estimate prevalence, comorbidities, mortality, utilization of healthcare resources and costs of patients with cirrhosis and incidence of decompensation of cirrhosis in Germany.
Methods
This longitudinal observational study was based on an anonymized representative claims database including 4.9âmillion persons insured by a statutory health insurance (SHI) between 2015â2020. Patients with decompensated and compensated cirrhosis were selected via diagnostic ICD codes and followed for 2âyears.
Results
Prevalence of cirrhosis in 2015 was 250/100â000, resulting in 201â747 (95% CI: 197â540â206â040) patients extrapolated to the German population. Out of all patients with compensated cirrhosis in 2015 who did not deceased, 16.0% developed a decompensation within 3âyears. Overall, 978 patients (Ă-age: 68âyears; 60% male) were included in the decompensated, and 5135 patients (Ă-age: 66âyears; 59% male) in the compensated cirrhosis cohort. Patients with decompensated cirrhosis had a higher burden of comorbidities (Charlson Comorbidity Index 7.3 vs. 4.4) and 3 times higher costs per quarter (7172â⏠vs. 2213ââŹ) than patients with compensated cirrhosis. 1-year mortality after decompensation was 51% compared to 8% in compensated cirrhosis. Of note, only few patients with decompensated cirrhosis received a liver transplantation or transjugular intrahepatic portosystemic shunts (TIPS) (1% and 5%).
Conclusion
Patients with cirrhosis have a high healthcare burden in especially decompensated stage. Accordingly, 1-year mortality of decompensated cirrhosis in Germany is high. Despite high health resource utilization, only few patients have access to liver transplantation or TIPS
Pathophysiological role of prostanoids in coagulation of the portal venous system in liver cirrhosis
BACKGROUND: Prostanoids are important regulators of platelet aggregation and thrombotic arterial diseases. Their involvement in the development of portal vein thrombosis, frequent in decompensated liver cirrhosis, is still not investigated. METHODS: Therefore, we used pro-thrombotic venous milieu generation by bare metal stent transjugular intrahepatic portosystemic shunt insertion, to study the role of prostanoids in decompensated liver cirrhosis. Here, 89 patients receiving transjugular intrahepatic portosystemic shunt insertion were included in the study, and baseline levels of thromboxane B2, prostaglandin D2 and prostaglandin E2 were measured in the portal and the hepatic vein. RESULTS: While the hepatic vein contained higher levels of thromboxane B2 than the portal vein, levels of prostaglandin E2 and D2 were higher in the portal vein (all P<0.0001). Baseline concentrations of thromboxane B2 in the portal vein were independently associated with an increase of portal hepatic venous pressure gradient during short term follow-up, as an indirect sign of thrombogenic potential (multivariable P = 0.004). Moreover, severity of liver disease was inversely correlated with portal as well as hepatic vein levels of prostaglandin D2 and E2 (all P<0.0001). CONCLUSIONS: Elevated portal venous thromboxane B2 concentrations are possibly associated with the extent of thrombogenic potential in patients with decompensated liver cirrhosis. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03584204
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