A general-purpose machine learning Pt interatomic potential for an accurate description of bulk, surfaces and nanoparticles

A Gaussian approximation machine learning interatomic potential for platinum is presented. It has been trained on DFT data computed for bulk, surfaces and nanostructured platinum, in particular nanoparticles. Across the range of tested properties, which include bulk elasticity, surface energetics and nanoparticle stability, this potential shows excellent transferability and agreement with DFT, providing state-of-the-art accuracy at low computational cost. We showcase the possibilities for modeling of Pt systems enabled by this potential with two examples: the pressure-temperature phase diagram of Pt calculated using nested sampling and a study of the spontaneous crystallization of a large Pt nanoparticle based on classical dynamics simulations over several nanoseconds

Chlamydia pneumoniae aggravates vein graft intimal hyperplasia in a rat model

<p>Abstract</p> <p>Background</p> <p>Along with angioplasty, autologus vein grafts are commonly used for artery bypass grafting in patients with advanced arterial stenosis and drug-resistant angina pectoris. Although initially a successful procedure, long-term functionality is limited due to proliferation and migration of smooth muscle cells. Like in atherosclerosis, common chronic infections caused by viruses and bacteria may contribute to this process of vein graft failure. Here we investigated the possible role of <it>Chlamydia pneumoniae </it>(<it>Cpn</it>) in the pathogenesis of venous graft failure in an experimental animal model. In 2 groups (n = 10 rats/group), an epigastric vein-to-common femoral artery interposition graft was placed. Immediately thereafter, rats were infected with <it>Cpn </it>(5*10⁸IFU) or injected with control solutions. Rats were sacrificed three weeks after surgery and the grafts were harvested for morphometrical and immunohistochemical analysis.</p> <p>Results</p> <p><it>Cpn </it>administration immediately after vein grafting resulted in a significant increase in medial cross-sectional area, wall thickness and total wall area. There were no significant differences in T-cell or macrophage influx. Likewise, although positive immunostaining for both HSP60 and CRP could be detected, no differences were found between groups. Based on the observation that the number of cells/μm²was also not altered, we conclude that Cpn infection stimulates smooth muscle cell proliferation by hereunto unknown molecular mechanisms, resulting in a significant increase in intimal hyperplasia.</p> <p>Conclusion</p> <p>In conclusion, in a well defined animal model we present here for the first time evidence for a role of <it>Chlamydia pneumoniae </it>in the process of venous graft failure.</p

Fault interpretation in seismic reflection data: an experiment analyzing the impact of conceptual model anchoring and vertical exaggeration

[EN]This paper presents an analysis on the limitations and advantages that some types of seismic data display present on the interpretation of the dataset

Do MRI features at baseline predict radiographic joint space narrowing in the medial compartment of the osteoarthritic knee 2 years later?

This is the final version of the article. Available from Springer Verlag via the DOI in this record.PURPOSE: The purpose of the study was to relate magnetic resonance imaging (MRI) features at baseline with radiographically determined joint space narrowing (JSN) in the medial compartment of the knee after 2 years in a group of patients with symptomatic osteoarthritis at multiple joint sites. MATERIALS AND METHODS: MRI of the knee and standardized radiographs were obtained at baseline and after 2 years in 186 patients (81% female; aged 43-76 years; mean 60 years). MRI was analyzed for bone marrow lesions, cysts, osteophytes, hyaline cartilage defects, joint effusion, and meniscal pathology in the medial compartment. Radiographs were scored semiquantitatively for JSN in the medial tibiofemoral joint using the Osteoarthritis Research Society International (OARSI) atlas. Radiological progression was defined as > or =1 grade increase. Associations between baseline magnetic resonance (MR) parameters and subsequent radiographic JSN changes were assessed using logistic regression. Relative risk (RR) was then calculated. RESULTS: Radiographic progression of JSN was observed in 17 (9.1%) of 186 patients. Eleven patients had a Kellgren and Lawrence (KL) score of > or =2. A significant association was observed between all patients and meniscal tears (RR 3.57; confidence interval (CI) 1.08-10.0) and meniscal subluxation (RR 2.73; CI 1.20-5.41), between KL or = 2 and meniscus tears (RR 8.91; CI 1.13-22.84) and radiographic JSN 2 years later. Follow-up MR in 15 of 17 patients with progressive JSN showed only new meniscal abnormalities and no progression of cartilage loss. CONCLUSION: Meniscal pathology (tears and/or meniscal subluxation) was the only MRI parameter to be associated with subsequent radiographic progression of JSN in the medial tibiofemoral compartment on a radiograph 2 years later, as assessed by the OARSI score

Do high molecular weight adiponectin levels associate with radiographic progression in early rheumatiod arthritis and hand osteoarthritis?

Pathophysiology and treatment of rheumatic disease