Laser decoating of DLC films for tribological applications

Damaged DLC coatings usually require remanufacturing of the entire coated components starting from an industrial chemical de-coating step. Alternatively, a complete or local coating repair can be considered. To pursue this approach, however, a local coating removal is needed as first operation. In this context, controlled decoating based on laser sources can be a suitable and clean alternative to achieve a pre-fixed decoating depth with high accuracy. In the present study, we investigated a laser-based decoating process executed on multilayered DLC films for advanced tribological applications (deposited via a hybrid PVD/PE-CVD technique). The results were acquired via multifocal optical digital microscopy (MF-ODM), which allowed high-resolution 3D surface reconstruction as well as digital profilometry of the lasered and unlasered surface. The study identifies the most critical process parameters which influence the effective decoating depth and the post-decoating surface roughness. In particular, the role of pulse overlap (decomposed along orthogonal directions), laser fluence, number of lasing passes and assist gas is discussed in text. A first experimental campaign was designed to identify the best conditions to obtain full decoating of the DLC + DLC:Cr layers. It was observed that decreasing the marking speed to 200 mm/s was necessary to obtain a sufficient pulse overlap and a nearly planar ablation profile. By operating with microsecond pulses and 1 J/cm2 (fairly above the ablation threshold), less than 10 passes were needed to obtain full decoating of the lasered area with an etching rate of 1.1 μm/loop. Further experiments were then executed in order to minimise the roughness of the rest surface with the best value found at around 0.2 μm. Limited oxidation but higher Ra values were observed in Ar atmosphere

The Coronary Sinus Reducer; 5-year Dutch experience

Background: Refractory angina is a growing and major health-care problem affecting millions of patients with coronary artery disease worldwide. The Coronary Sinus Reducer (CSR) is a device that may be considered for the relief of symptoms of refractory angina. It causes increased venous pressure leading to a dilatation of arterioles and reduced arterial vascular resistance in the sub-endocardium. This study describes the 5‑year Dutch experience regarding safety and efficacy of the CSR. Methods: One hundred and thirty-two patients with refractory angina were treated with the CSR. The primary efficacy endpoint of the study was Canadian Cardiovascular Society (CCS) class improvement between baseline and 6‑month follow-up. The primary safety endpoint was successful CSR implantation in the absence of any device-related events. Results: Eighty-five patients (67%) showed improvement of at least 1 CCS class and 43 patients (34%) of at least 2 classes. Mean CCS class improved from 3.17 ± 0.61 to 2.12 ± 1.07 after implantation (P < 0.001). The CSR was successfully implanted in 99% of the patients and only minor complications during implantation were reported. Conclusion: The CSR is a simple, safe, and effective option for most patients with refractory angina. However, approximately thirty percent of the patients showed no benefit after implantation. Future studies should focus on the exact underlying mechanisms of action and reasons for non-response to better identify patients that could benefit most from this therapy

Appropriate use criteria for optical coherence tomography guidance in percutaneous coronary interventions Recommendations of the working group of interventional cardiology of the Netherlands Society of Cardiology

Introduction: Optical coherence tomography (OCT) enables detailed imaging of the coronary wall, lumen and intracoronary implanted devices. Responding to the lack of specific appropriate use criteria (AUC) for this technique, we conducted a literature review and a procedure for appropriate use criteria. Methods: Twenty-one of all 184 members of the Dutch Working Group on Interventional Cardiology agreed to evaluate 49 pre-specified cases. During a meeting, factual indications were established whereupon members individually rated indications on a 9-point scale, with the opportunity to substantiate their scoring. Results: Twenty-six indications were rated ‘Appropriate’, eighteen indications ‘May be appropriate’, and five ‘Rarely appropriate’. Use of OCT was unanimously considered ‘Appropriate’ in stent thrombosis, and ‘Appropriate’ for guidance in PCI, especially in distal left main coronary artery and proximal left anterior descending coronary artery, unexplained angiographic abnormalities, and use of bioresorbable vascular scaffold (BVS). OCT was considered ‘Rarely Appropriate’ on top of fractional flow reserve (FFR) for treatment indication, assessment of strut coverage, bypass anastomoses or assessment of proximal left main coronary artery. Conclusions: The use of OCT in stent thrombosis is unanimously considered ‘Appropriate’ by these experts. Varying degrees of consensus exists on the appropriate use of OCT in other settings

Less bleeding by omitting aspirin in non-ST-segment elevation acute coronary syndrome patients: Rationale and design of the LEGACY study

BACKGROUND: Early aspirin withdrawal, also known as P2Y12-inhibitor monotherapy, following percutaneous coronary intervention (PCI) for non-ST-segment elevation acute coronary syndrome (NSTE-ACS) can reduce bleeding without a trade-off in efficacy. Still the average daily bleeding risk is highest during the first months and it remains unclear if aspirin can be omitted immediately following PCI. METHODS: The LEGACY study is an open-label, multicenter randomized controlled trial evaluating the safety and efficacy of immediate P2Y12-inhibitor monotherapy versus dual antiplatelet therapy (DAPT) for 12 months in 3,090 patients. Patients are randomized immediately following successful PCI for NSTE-ACS to 75-100 mg aspirin once daily versus no aspirin. The primary hypothesis is that immediately omitting aspirin is superior to DAPT with respect to major or minor bleeding defined as Bleeding Academic Research Consortium type 2, 3, or 5 bleeding, while maintaining noninferiority for the composite of all-cause mortality, myocardial infarction and stroke compared to DAPT. CONCLUSIONS: The LEGACY study is the first randomized study that is specifically designed to evaluate the impact of immediately omitting aspirin, and thus treating patients with P2Y12-inhibitor monotherapy, as compared to DAPT for 12 months on bleeding and ischemic events within 12 months following PCI for NSTE-ACS

Prevention of congenital malformations and other adverse pregnancy outcomes with 4.0 mg of folic acid : community-based randomized clinical trial in Italy and the Netherlands

Background: In 2010 a Cochrane review confirmed that folic acid (FA) supplementation prevents the first- and second-time occurrence of neural tube defects (NTDs). At present some evidence from observational studies supports the hypothesis that FA supplementation can reduce the risk of all congenital malformations (CMs) or the risk of a specific and selected group of them, namely cardiac defects and oral clefts. Furthermore, the effects on the prevention of prematurity, foetal growth retardation and pre-eclampsia are unclear.Although the most common recommendation is to take 0.4 mg/day, the problem of the most appropriate dose of FA is still open.The aim of this project is to assess the effect a higher dose of peri-conceptional FA supplementation on reducing the occurrence of all CMs. Other aims include the promotion of pre-conceptional counselling, comparing rates of selected CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age, abruptio placentae.Methods/Design: This project is a joint effort by research groups in Italy and the Netherlands. Women of childbearing age, who intend to become pregnant within 12 months are eligible for the studies. Women are randomly assigned to receive 4 mg of FA (treatment in study) or 0.4 mg of FA (referent treatment) daily. Information on pregnancy outcomes are derived from women-and-physician information.We foresee to analyze the data considering all the adverse outcomes of pregnancy taken together in a global end point (e.g.: CMs, miscarriage, pre-eclampsia, preterm birth, small for gestational age). A total of about 1,000 pregnancies need to be evaluated to detect an absolute reduction of the frequency of 8%. Since the sample size needed for studying outcomes separately is large, this project also promotes an international prospective meta-analysis.Discussion: The rationale of these randomized clinical trials (RCTs) is the hypothesis that a higher intake of FA is related to a higher risk reduction of NTDs, other CMs and other adverse pregnancy outcomes. Our hope is that these trials will act as catalysers, and lead to other large RCTs studying the effects of this supplementation on CMs and other infant and maternal outcomes.Trial registration: Italian trial: ClinicalTrials.gov Identifier: NCT01244347.Dutch trial: Dutch Trial Register ID: NTR3161

Appropriate use criteria for optical coherence tomography guidance in percutaneous coronary interventions: Recommendations of the working group of interventional cardiology of the Netherlands Society of Cardiology

Introduction: Optical coherence tomography (OCT) enables detailed imaging of the coronary wall, lumen and intracoronary implanted devices. Responding to the lack of specific appropriate use criteria (AUC) for this technique, we conducted a literature review and a procedure for appropriate use criteria. Methods: Twenty-one of all 184 members of the Dutch Working Group on Interventional Cardiology agreed to evaluate 49 pre-specified cases. During a meeting, factual indications were established whereupon members individually rated indications on a 9-point scale, with the opportunity to substantiate their scoring. Results: Twenty-six indications were rated ‘Appropriate’, eighteen indications ‘May be appropriate’, and five ‘Rarely appropriate’. Use of OCT was unanimously considered ‘Appropriate’ in stent thrombosis, and ‘Appropriate’ for guidance in PCI, especially in distal left main coronary artery and proximal left anterior descending coronary artery, unexplained angiographic abnormalities, and use of bioresorbable vascular scaffold (BVS). OCT was considered ‘Rarely Appropriate’ on top of fractional flow reserve (FFR) for treatment indication, assessment of strut coverage, bypass anastomoses or assessment of proximal left main coronary artery. Conclusions: The use of OCT in stent thrombosis is unanimously considered ‘Appropriate’ by these experts. Varying degrees of consensus exists on the appropriate use of OCT in other settings

Impact of 4D PET-CT on SUV Quantification in Lung Tumors: How Many Phase-bins?

Scientific Formal (Paper) Sessio

Radiosurgical options in neuro-oncology: a review on current tenets and future opportunities. Part I: therapeutic strategies.

Stereotactic radiosurgery can nowadays be considered not only as a potential adjuvant to surgical treatment of several neuro-oncological pathologies, including primary tumors and metastatic lesions, but in some cases also as a valuable alternative tailored option. In Part I of the review, we propose a dissertation focused on the different irradiation stereotactic radiosurgery techniques to date available for clinical indications more relevant to oncologists and oncologic surgeons, such as high-grade and low-grade gliomas, metastases and meningiomas. It is noteworthy that the most recent body of literature correlated with this topic shows that the therapeutic results presently achievable are revolutionizing the way patients are diagnosed and managed worldwide. As we sought to shed light on the current potentialities of stereotactic radiosurgery, we must consider that to exploit all the benefits provided by this shift in clinical practice, a profound awareness by all practitioners involved in the care of neoplastic patients is certainly warranted

In phantom evaluation of a CT iterative reconstruction algorithm

Extended abstrac

Dose reduction and image quality in CT examinations using an iterative reconstruction algorithm: a phantom study

The purpose of this work is to evaluate the potential dose reduction in computed tomography (CT) examinations using an iterative algorithm compared to a filtered backprojection (FBP) reconstruction, analyzing image quality parameters. A 256 slice CT scanner, equipped with software for both FBP and iterative reconstruction, and a CT dedicated phantom were used. The image quality was evaluated by analyzing five different parameters: CT number constancy, signal to noise ratio (SNR), contrast to noise ratio (CNR), non-uniformity and axial spatial resolution (modulation transfer function, MTF). The CNR was evaluated on a low contrast insert and on a high contrast teflon insert, while the MTF was evaluated on a high density bead. The analysis was performed both on images obtained with FBP reconstruction and with the iterative algorithm (level 1 to 6). CT numbers were consistent between standard FBP and the iterative reconstruction. Non-uniformity and spatial resolution were not affected by the use of the iterative algorithm, and the SNR and the CNR were improved with the iterative algorithm, as a function of the level of iteration used. Comparing FBP to the sixth level of iteration, in a 120 kV scan performed at 200 mAs, a mean 43.6% noise reduction was observed and for the SNR and the CNR, a mean improvement of 70.9% and 70.6%, respectively, was obtained. A mean dose reduction of 36.5% was estimated using iterative reconstruction at level 3 without loss of image quality. The use of the iterative reconstruction method offers the possibility to improve image quality or to reduce patient dose in CT examinations, or a combination of these aspects. In our experience, reducing the tube current by 30% compared to the FBP scan and reconstructing the images by means of the iterative algorithm (level 3) resulted in equivalent image quality for both methods