394 research outputs found
Nonlinear approach to difference imaging in diffuse optical tomography
Difference imaging aims at recovery of the change in the optical properties of a body based on measurements before and after the change. Conventionally, the image reconstruction is based on using difference of the measurements and a linear approximation of the observation model. One of the main benefits of the linearized difference reconstruction is that the approach has a good tolerance to modeling errors, which cancel out partially in the subtraction of the measurements. However, a drawback of the approach is that the difference images are usually only qualitative in nature and their spatial resolution can be weak because they rely on the global linearization of the nonlinear observation model. To overcome the limitations of the linear approach, we investigate a nonlinear approach for difference imaging where the images of the optical parameters before and after the change are reconstructed simultaneously based on the two datasets. We tested the feasibility of the method with simulations and experimental data from a phantom and studied how the approach tolerates modeling errors like domain truncation, optode coupling errors, and domain shape errors
Increasing the Inflammatory Competence of Macrophages with IL-6 or with Combination of IL-4 and LPS Restrains the Invasiveness of Pancreatic Cancer Cells
Recent studies suggest that pro-inflammatory type M1 macrophages inhibit tumor progression and that anti-inflammatory M2 macrophages enhance it. The aim of this study was to examine the interaction of type M1 and M2 macrophages with pancreatic cancer cells. We studied the migration rate of fluorescein stained pancreatic cancer cells on Matrigel cultured alone or with Granulocyte- Macrophage Colony Stimulating Factor (GM-CSF) differentiated macrophages or with Macrophage Colony Stimulating Factor (M-CSF) differentiated macrophages, skewing the phenotype towards pro- and anti-inflammatory direction, respectively. Macrophage differentiation was assessed with flow cytometry and the cytokine secretion in cell cultures with cytokine array. Both GM-CSF and M-CSF differentiated macrophages increased the migration rate of primary pancreatic adenocarcinoma cell line (MiaPaCa-2) and metastatic cell line (HPAF-II). Stimulation with IL6 or IL4+ LPS reversed the macrophages' increasing effect on the migration rate of Mi-aPaCa-2 completely and partly of HPAF-II. Co-culture with MiaPaCa-2 reduced the inflammatory cytokine secretion of GM-CSF differentiated macrophages. Co-culture of macrophages with pancreatic cancer cells seem to change the inflammatory cytokine profile of GM-CSF differentiated macrophages and this might explain why also GM-CSF differentiated macrophages promoted the invasion. Adding IL6 or IL4+ LPS to the cell culture with MiaPaCa-2 and GM-CSF or M-CSF differentiated macrophages increased the secretion of inflammatory cytokines and this could contribute to the reversion of the macrophage induced increase of cancer cell migration rate.Peer reviewe
European Psychiatric Association (EPA) guidance on forensic psychiatry : Evidence based assessment and treatment of mentally disordered offenders
Forensic psychiatry in Europe is a specialty primarily concerned with individuals who have either offended or present a risk of doing so, and who also suffer from a psychiatric condition. These mentally disordered offenders (MDOs) are often cared for in secure psychiatric environments orprisons. In this guidance paper we first present an overview of the field of forensic psychiatry from a European perspective. We then present a review of the literature summarising the evidence on the assessment and treatment of MDOs under the following headings: The forensic psychiatrist as expert witness, risk, treatment settings for mentally disordered offenders, and what works for MDOs. We undertook a rapid review of the literature with search terms related to: forensic psychiatry, review articles, randomised controlled trials and best practice. We searched the Medline, Embase, PsycINFO, and Cochrane library databases from 2000 onwards for adult groups only. We scrutinised publications for additional relevant literature, and searched the websites of relevant professional organisations for policies, statements or guidance of interest. We present the findings of the scientific literature as well as recommendations for best practice drawing additionally from the guidance documents identified. We found that the evidence base for forensic-psychiatric practice is weak though there is some evidence to suggest that psychiatric care produces better outcomes than criminal justice detention only. Practitioners need to follow general psychiatric guidance as well as that for offenders, adapted for the complex needs of this patient group, paying particular attention to long-term detention and ethical issues. (C) 2017 Elsevier Masson SAS. All rights reserved.Peer reviewe
Three-dimensional electrical impedance tomography to monitor unsaturated moisture ingress in cement-based materials
The development of tools to monitor unsaturated moisture flow in cement-based material is of great importance, as most degradation processes in cement-based materials take place in the presence of moisture. In this paper, the feasibility of electrical impedance tomography (EIT) to monitor three-dimensional (3D) moisture flow in mortar containing fine aggregates is investigated. In the experiments, EIT measurements are taken during moisture ingress in mortar, using electrodes attached on the outer surface of specimens. For EIT, the so-called difference imaging scheme is adopted to reconstruct the change of the 3D electrical conductivity distribution within a specimen caused by the ingress of water into mortar. To study the ability of EIT to detect differences in the rate of ingress, the experiment is performed using plain water and with water containing a viscosity-modifying agent yielding a slower flow rate. To corroborate EIT, X-ray computed tomography (CT) and simulations of unsaturated moisture flow are carried out. While X-ray CT shows contrast with respect to background only in highly saturated regions, EIT shows the conductivity change also in the regions of low degree of saturation. The results of EIT compare well with simulations of unsaturated moisture flow. Moreover, the EIT reconstructions show a clear difference between the cases of water without and with the viscosity-modifying agent and demonstrate the ability of EIT to distinguish between different flow rates
Can Electrical Resistance Tomography be used for imaging unsaturated moisture flow in cement-based materials with discrete cracks?
Previously, it has been shown that Electrical Resistance Tomography (ERT) can be used for monitoring moisture flow in undamaged cement-based materials. In this work, we investigate whether ERT could be used for imaging three-dimensional (3D) unsaturated moisture flow in cement-based materials that contain discrete cracks. Novel computational methods based on the so-called absolute imaging framework are developed and used in ERT image reconstructions, aiming at a better tolerance of the reconstructed images with respect to the complexity of the conductivity distribution in cracked material. ERT is first tested using specimens with physically simulated cracks of known geometries, and corroborated with numerical simulations of unsaturated moisture flow. Next, specimens with loading-induced cracks are imaged; here, ERT reconstructions are evaluated qualitatively based on visual observations and known properties of unsaturated moisture flow. Results indicate that ERT is a viable method of visualizing 3D unsaturated moisture flow in cement-based materials with discrete cracks
Transendothelial migration of human umbilical mesenchymal stem cells across uterine endothelial monolayers: junctional dynamics and putative mechanisms
Introduction: During pregnancy, fetal stem cells can transfer to the maternal circulation and participate in tissue repair. How they transmigrate across maternal endothelial barriers and whether they can subsequently influence maternal endothelial integrity is not known.
Methods: Mesenchymal stem cells (WJ-MSC) were isolated from Wharton's jelly and their interactions with human uterine microvascular endothelial cell (HUtMEC) monolayers, junctional occupancy and expression/phosphorylation of vascular endothelial (VE)- cadherin and vascular endothelial growth factor (VEGF-A) secretion was studied over 48h by real time, confocal microscopy, immunoblotting and ELISA.
Results: WJ-MSC displayed exploratory behaviour with interrogation of paracellular openings and spreading into the resultant increased gaps followed by closing of the endothelium over the WJ-MSC. 62% of added cells crossed within 22h to sub-endothelial niches. There was a concomitant loss of junctional VE-cadherin in HUtMEC followed by a full return and increased VE-cadherin expression after 22h. During early hours, VE-cadherin showed a transient phosphorylation at Tyrosine (Tyr)-685 when VEGF-A secretion were high. From 16 to 22h, there was increased de-phosphorylation of Tyr-731. Anti-VEGF-A blocked Tyr-685 phosphorylation but not the decrease in P-Tyr731; this partially inhibited WJ-MSC transmigration.
Discussion: Fetal WJ-MSC can traverse uterine endothelial monolayers by mediating a non-destructive paracellular pathway. They can promote junctional stability of uterine endothelium from the sub-endothelial niche. Mechanistically, WJ-MSC induces VEGF-dependent phosphorylation events linked with paracellular permeability and VEGF-independent de-phosphorylation events associated with leukocyte extravasation. Our data also allows consideration of a possible role of fetal MSC in mature functioning of the uterine vasculature needed for optimal utero-placental perfusion
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Risk Factors in Heating, Ventilating, and Air-Conditioning Systemsfor Occupant Symptoms in U.S. Office Buildings: the EPA BASE Study
Nonspecific building-related symptoms among occupants of modern office buildings worldwide are common and may be associated with important reductions in work performance, but their etiology remains uncertain. Characteristics of heating, ventilating, and air-conditioning (HVAC) systems in office buildings that increase risk of indoor contaminants or reduce effectiveness of ventilation may cause adverse exposures and subsequent increase in these symptoms among occupants. We analyzed data collected by the U.S. EPA from a representative sample of 100 large U.S. office buildings--the Building Assessment and Survey Evaluation (BASE) study--using multivariate logistic regression models with generalized estimating equations adjusted for potential personal and building confounders. We estimated odds ratios (ORs) and 95% confidence intervals (CIs) for associations between seven building-related symptom outcomes and selected HVAC system characteristics. Among factors of HVAC design or configuration: Outdoor air intakes less than 60 m above the ground were associated with approximately doubled odds of most symptoms assessed. Sealed (non-operable) windows were associated with increases in skin and eye symptoms (ORs= 1.9, 1.3, respectively). Outdoor air intake without an intake fan was associated with an increase in eye symptoms (OR=1.7). Local cooling coils were associated with increased headache (OR=1.5). Among factors of HVAC condition, maintenance, or operation: the presence of humidification systems in good condition was associated with an increase in headache (OR=1.4), whereas the presence of humidification systems in poor condition was associated with increases in fatigue/difficulty concentrating, as well as upper respiratory symptoms (ORs=1.8, 1.5). No regularly scheduled inspections for HVAC components was associated with increased eye symptoms, cough and upper respiratory symptoms (ORs=2.2, 1.6, 1.5). Less frequent cleaning of cooling coils or drip pans was associated with increased headache (OR=1.6). Fair or poor condition of duct liner was associated with increased upper respiratory symptoms (OR=1.4). Most of the many potential risk factors assessed here had not been investigated previously, and associations found with single symptoms may have been by chance, including several associations that were the reverse of expected. Risk factors newly identified in these analyses that deserve attention include outdoor air intakes less than 60 m above the ground, lack of operable windows, poorly maintained humidification systems, and lack of scheduled inspection for HVAC systems. Infrequent cleaning of cooling coils and drain pans were associated with increases in several symptoms in these as well as prior analyses of BASE data. Replication of these findings is needed, using more objective measurements of both exposure and health response. Confirmation of the specific HVAC factors responsible for increased symptoms in buildings, and development of prevention strategies could have major public health and economic benefits worldwide
The Core Interaction of Platforms: How Startups Connect Users and Producers
The platform economy is disrupting innovation while presenting both opportunities and challenges for startups. Platforms support value creation between multiple participant groups, and this operationalization of an ecosystem's value co-creation represents the "core interaction" of a platform. This article focuses on that core interaction and studies how startups connect producers and users in value-creating core interaction through digital platforms. The study is based on an analysis of 29 cases of platform startups interviewed at a leading European startup event. The studied startups were envisioning even millions of users and hundreds or thousands of producers co-creating value on their platforms. In such platform businesses, our results highlight the importance of attracting a large user pool, providing novel services to those users, offering a new market for producers, supporting the core interaction in various ways, and utilizing elements of the platform canvas - an adaptation of the business model canvas, which we have accommodated for platform-based business models - to accomplish these goals
Poor 10-year survivorship of hip resurfacing arthroplasty: 5,098 replacements from the Finnish Arthroplasty Register
Background and purpose In a previous registry report, short-term implant survival of hip resurfacing arthroplasty (HRA) in Finland was found to be comparable to that of total hip arthroplasty (THA). Since then, it has become evident that adverse reactions to metal debris (ARMDs) may also be associated with HRA, not only with large-diameter head metal-on-metal THA. The aim of the study was to assess medium- to long-term survivorship of HRA based on the Finnish Arthroplasty Register (FAR).Patients and methods 5,068 HRAs performed during the period 2001-2013 in Finland were included. Kaplan-Meier survival analysis was used to calculate survival probabilities and their 95% confidence intervals (CIs). Cox multiple regression, with adjustment for age, sex, diagnosis, femoral head size, and hospital volume was used to analyze implant survival of HRA devices with revision for any reason as endpoint. The reference group consisted of 6,485 uncemented Vision/Bimetric and ABG II THAs performed in Finland over the same time period.Results The 8-year survival, with any revision as an endpoint, was 93% (CI: 92-94) for Birmingham Hip Resurfacing (BHR), 86% (CI: 78-94) for Corin, 91% (CI: 89-94) for ReCap, 92% (CI: 89-96) for Durom, and was 72% (CI: 69-76) for the Articular Surface Replacement (ASR). The 10-year survival, with any revision as an endpoint, for reference THAs was 92% (CI: 91-92) and for all HRAs it was 86% (CI: 84-87%). Female HRA patients had about twice the revision risk of male patients. ASR had an inferior outcome: the revision risk was 4-fold higher than for BHR, the reference implant.Interpretation The 10-year implant survival of HRAs is 86% in Finland. According to new recommendations from NICE (The National Institute for Health and Care Excellence), an HRA/THA should have a revision rate of 5% or less at 10 years. None of the HRAs studied achieved this goal
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