1,777 research outputs found
Virtual Machining: Capabilities and Challenges of Process Simulations in the Aerospace Industry
AbstractMilling processes for the manufacturing of parts for aerospace applications can be influenced by various effects. When machining structural parts with high material removal rates, the stiffness of the machine tool can be a limiting factor because chatter vibrations. Additionally, vibrations of thin-walled structures, e. g., the blades of impellers or turbines, can lead to chatter vibrations and surface location errors. Thermo-mechanical deformations are another cause for violations of given shape tolerances. Geometric physically-based process simulations can be used to analyze milling processes with regard to these effects in order to optimize the process parameters. In this paper, an overview of several applications of a geometric physically-based simulation system for analyzing different effects during milling processes is presented. Depending on the relevant effects, process forces, the dynamic behaviour of the tool-spindle-machine system, vibrations of workpieces and fixture systems, as well as thermo-mechanical deformations are calculated
Liver Trauma Management
Liver trauma is responsible for the majority of penetrating abdominal trauma and is the third most common injury caused by firearms. Presenting a 20% mortality rate, it is an organ with wide and complex vascularization, receiving blood from the hepatic veins and portal vein, as well as from the hepatic arteries. The diagnosis is not always simple in polytrauma patients and contains a wide range of exams such as computerized tomography and diagnostic peritoneal lavage. Treatment depends mostly on a few factors such as the patient’s hemodynamic stability, the degree of injury according to the AAST classification, the resources available, and the surgeon’s expertise. Considering these factors, minor lesions can be treated mostly with a conservative approach in hemodynamically stable patients. Embolization by arteriography has shown good results in major lesions in clinically stable patients as well. On the other hand, more complex lesions associated with hemodynamically unstable patients may indicate damage control surgery applying techniques such as temporary liver packing and clamping the pedicle to restore the hemodynamic status. This chapter aims to describe those techniques and their indications in liver trauma
The BioGRID Interaction Database: 2011 update
The Biological General Repository for Interaction Datasets (BioGRID) is a public database that archives and disseminates genetic and protein
interaction data from model organisms and humans
(http://www.thebiogrid.org). BioGRID currently holds 347 966
interactions (170 162 genetic, 177 804 protein) curated from both
high-throughput data sets and individual focused studies, as derived
from over 23 000 publications in the primary literature. Complete
coverage of the entire literature is maintained for budding yeast
(Saccharomyces cerevisiae), fission yeast (Schizosaccharomyces pombe)
and thale cress (Arabidopsis thaliana), and efforts to expand curation
across multiple metazoan species are underway. The BioGRID houses 48
831 human protein interactions that have been curated from 10 247
publications. Current curation drives are focused on particular areas
of biology to enable insights into conserved networks and pathways that
are relevant to human health. The BioGRID 3.0 web interface contains
new search and display features that enable rapid queries across
multiple data types and sources. An automated Interaction Management
System (IMS) is used to prioritize, coordinate and track curation
across international sites and projects. BioGRID provides interaction
data to several model organism databases, resources such as Entrez-Gene
and other interaction meta-databases. The entire BioGRID 3.0 data
collection may be downloaded in multiple file formats, including PSI MI
XML. Source code for BioGRID 3.0 is freely available without any
restrictions
Does oral sodium bicarbonate therapy improve function and quality of life in older patients with chronic kidney disease and low-grade acidosis (the BiCARB trial)? Study protocol for a randomized controlled trial
Date of acceptance: 01/07/2015 © 2015 Witham et al. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. Acknowledgements UK NIHR HTA grant 10/71/01. We acknowledge the financial support of NHS Research Scotland in conducting this trial.Peer reviewedPublisher PD
Clopidogrel discontinuation after acute coronary syndromes: frequency, predictors and associations with death and myocardial infarction—a hospital registry-primary care linked cohort (MINAP–GPRD)
AIMS: Adherence to evidence-based treatments and its consequences after acute myocardial infarction (MI) are poorly defined. We examined the extent to which clopidogrel treatment initiated in hospital is continued in primary care; the factors predictive of clopidogrel discontinuation and the hazard of death or recurrent MI. METHODS AND RESULTS: We linked the Myocardial Ischaemia National Audit Project registry and the General Practice Research Database to examine adherence to clopidogrel in primary care among patients discharged from hospital after MI (2003-2009). Hospital Episode Statistics and national mortality data were linked, documenting all-cause mortality and non-fatal MI. Of the 7543 linked patients, 4650 were prescribed clopidogrel in primary care within 3 months of discharge. The adjusted odds of still being prescribed clopidogrel at 12 months were similar following non-ST-elevation myocardial infarction (NSTEMI) 53% (95% CI, 51-55) and ST-elevation myocardial infarction (STEMI) 54% (95% CI, 52-56), but contrast with statins: NSTEMI 84% (95% CI, 82-85) and STEMI 89% (95% CI, 87-90). Discontinuation within 12 months was more frequent in older patients [>80 vs. 40-49 years, adjusted hazard ratio (HR) 1.50 (95% CI, 1.15-1.94)] and with bleeding events [HR 1.34 (95% CI, 1.03-1.73)]. 18.15 patients per 100 person-years (95% CI, 16.83-19.58) died or experienced non-fatal MI in the first year following discharge. In patients who discontinued clopidogrel within 12 months, the adjusted HR for death or non-fatal MI was 1.45 (95% CI, 1.22-1.73) compared with untreated patients, and 2.62 (95% CI, 2.17-3.17) compared with patients persisting with clopidogrel treatment. CONCLUSION: This is the first study to use linked registries to determine persistence of clopidogrel treatment after MI in primary care. It demonstrates that discontinuation is common and associated with adverse outcomes
Coordinated effects of sequence variation on DNA binding, chromatin structure, and transcription.
DNA sequence variation has been associated with quantitative changes in molecular phenotypes such as gene expression, but its impact on chromatin states is poorly characterized. To understand the interplay between chromatin and genetic control of gene regulation, we quantified allelic variability in transcription factor binding, histone modifications, and gene expression within humans. We found abundant allelic specificity in chromatin and extensive local, short-range, and long-range allelic coordination among the studied molecular phenotypes. We observed genetic influence on most of these phenotypes, with histone modifications exhibiting strong context-dependent behavior. Our results implicate transcription factors as primary mediators of sequence-specific regulation of gene expression programs, with histone modifications frequently reflecting the primary regulatory event
- …