Search

Background: Despite the growing interest in CO2 angiography, some mechanical aspects related to CO2 injection still need to be deepened, and some improvements are still possible. This work explores the possibility of optimizing gas injection into small-sized arteries. Since the image quality depends on how the gas fills the vessel and is strongly dependent on injection flow, the possibility of controlling the flow is mandatory to obtain good results. To better control the flow, we propose to adjunct small tubes with known hydraulic resistances in parallel to the injection catheter, allowing the generation of the desired injection flow by modulating the injection pressure. Methods: Using a mechanical mock of the cardiovascular system, we measured pressures and flows of interest and acquired the optical images of the vessel during gas injections. We performed a simulation with four different calibrated adjunct resistances in various injection pressure conditions, with and without saline flushing. Results: Our tests demonstrated that the optimized injection of the gas maintains the same procedure durations and reduces the gas volume and the local pressure increase, avoiding the local gas "explosion" in the injection site. Conclusions: Our proposal appears effective and paves the way for research into optimizing clinical CO2 angiography procedures. [ABSTRACT FROM AUTHOR]

Background: Despite the growing interest in CO2 angiography, some mechanical aspects related to CO2 injection still need to be deepened, and some improvements are still possible. This work explores the possibility of optimizing gas injection into small-sized arteries. Since the image quality depends on how the gas fills the vessel and is strongly dependent on injection flow, the possibility of controlling the flow is mandatory to obtain good results. To better control the flow, we propose to adjunct small tubes with known hydraulic resistances in parallel to the injection catheter, allowing the generation of the desired injection flow by modulating the injection pressure. Methods: Using a mechanical mock of the cardiovascular system, we measured pressures and flows of interest and acquired the optical images of the vessel during gas injections. We performed a simulation with four different calibrated adjunct resistances in various injection pressure conditions, with and without saline flushing. Results: Our tests demonstrated that the optimized injection of the gas maintains the same procedure durations and reduces the gas volume and the local pressure increase, avoiding the local gas “explosion” in the injection site. Conclusions: Our proposal appears effective and paves the way for research into optimizing clinical CO2 angiography procedures.

Polymers have gained the attention of manufacturers due to their significant advantages such as low density, high corrosion resistance, and high humidity resistance. Producing high-precision polymeric components is one the most challenging issues especially in fabricating complex or micro-scale systems. Some of the machining techniques such as electro discharge machining (EDM) and electrochemical machining (ECM) cannot be employed for machining the non-conductive parts. Using abrasive particles is one of the best options for machining these types of materials. In this work, the capability of the acoustic energy for machining polyamide (PA) workpieces is studied. To this end, an experimental setup is installed and design of experiment (DoE) algorithm is employed to survey the effect of process parameters on surface roughness. Three parameters at three levels are considered as the effective factors of the process and the sensitivity of the surface roughness on the process factors is investigated. In the next step, a hybrid finite element/boundary element approach was used to discuss the relation of process parameters to the vibrational characteristics of the container, then the mechanism of the process was investigated employing the discrete element method. Finally, the surface topology of the optimal workpiece before and after the process was presented and compared. It was observed that acoustic energy can be considered as a vibration source of the container's floor to provide kinetic energy for machining PA parts on the nano-metric scale. Moreover, it was found that the initial roughness of the workpiece and the chosen parameters play a crucial role in the machining process. Experimental results show that in this technique by selecting appropriate process factors the surface roughness can be reduced up to 50%. [ABSTRACT FROM AUTHOR]

Aim: In this preliminary study, we aimed to confirm the clinical utility and safety of the new noncompliant balloon catheter River NC® (Balton, Poland). Materials & methods: The primary study end point was to verify balloon diameters calculated in quantitative coronary angiography (QCA) to diameters prespecified by the manufacturer and obtained at given pressures in subjects undergoing percutaneous coronary interventions. Results: Forty-two subjects were enrolled (73.8% multivessel disease; 40.5% type B1 lesions; 100% device success). No clinically significant differences between expected balloon diameters and QCA were registered in predilatation (2.36 ± 0.11 mm vs 2.43 ± 0.07 mm) and postdilatation (3.18 ± 0.19 mm vs 3.21 ± 0.31 mm). Conclusion: Our study results suggest that the River NC balloon is effective and safe. In the QCA evaluation, River NC balloon obtained prespecified diameters and lengths at applied pressures. Study registration: Office for Registration of Medicinal Products, Medical Devices and Biocidal Products (UR.D.WM.DNB.109.2019). In this study, we aimed to assess the utility and safety aspects of River NC® (Balton, Poland), a new type of catheter with thicker walls, which is used to stretch open a narrowed or blocked artery, the main blood vessels supplying the heart. Forty-two patients were included. Our study results suggested that the River NC balloon was effective and safe because it achieved the expected diameters and length when inserted into the patients. [ABSTRACT FROM AUTHOR]

Aim: In this preliminary study, we aimed to confirm the clinical utility and safety of the new noncompliant balloon catheter River NC® (Balton, Poland). Materials & methods: The primary study end point was to verify balloon diameters calculated in quantitative coronary angiography (QCA) to diameters prespecified by the manufacturer and obtained at given pressures in subjects undergoing percutaneous coronary interventions. Results: Forty-two subjects were enrolled (73.8% multivessel disease; 40.5% type B1 lesions; 100% device success). No clinically significant differences between expected balloon diameters and QCA were registered in predilatation (2.36 ± 0.11 mm vs 2.43 ± 0.07 mm) and postdilatation (3.18 ± 0.19 mm vs 3.21 ± 0.31 mm). Conclusion: Our study results suggest that the River NC balloon is effective and safe. In the QCA evaluation, River NC balloon obtained prespecified diameters and lengths at applied pressures. Study registration: Office for Registration of Medicinal Products, Medical Devices and Biocidal Products (UR.D.WM.DNB.109.2019). [ABSTRACT FROM AUTHOR]

The proton exchange membrane fuel cell (PEMFC) is an emission-free alternative to the internal combustion engine. Post-assembly, a PEMFC must be "activated', to elevate and stabilize its performance to a reproducible threshold value. This procedure is costly, time-consuming, and not suited for mass-production. This paper provides a detailed review of the break-in physical principles, activation procedures and characterization methods. First, all sparse knowledge from the literature is translated into a set of activation mechanisms. Activating a cell mainly alters the membrane electrode assembly morphology (e.g. catalyst layer porosity, catalyst size, shape and activity, polymer chain orientation). Second, an in-depth analysis off all break-in methods is provided. Cell components can be pre-activated using steam, acid, plasma or through compression. Dynamic, high temperature/pressure and supersaturated operation promote break-in kinetics. Generating oxidizing and reducing conditions is essential, and is achievable by short circuit, Cyclic Voltammetry, cathode starvation or reactant switch. Uniform activation over the cell surface is obtained with gas flow direction reversal or hydrogen pumping. Compression cycles minimize PEMFC contact resistances. Finally, deficiencies of conventional break-in characterization methods (to measure cell performance and impact on durability) are highlighted. Better reproducibility is achievable using advanced electrochemical characterization, post-mortem and cell output species analysis. • Each morphological change associated to PEM fuel cell break-in is detailed. • All ex-situ and in-situ activation methodologies are reviewed. • Break-in characterization methods are studied, and advanced solutions are proposed. • A critical analysis of the current "end-of-break-in" criteria is provided. [ABSTRACT FROM AUTHOR]

Signaling storm has degraded the service experience of the mobile subscriber. The main reasons that leading to mobile network signaling storm were presented, and some suggestions were also given for the solution from the perspective of both terminal and network. On one hand, the signaling in the air interface can be reduced by the way of heartbeat alignment in the terminal, on the other hand, paging mechanism optimization and paging area optimization can also reduce the effect of the signaling storm. The study item of 3GPP about small data packet transmission optimization was also introduced.

Scientific publications are the main vehicle to disseminate information in the field of biotechnology for wastewater treatment. Indeed, the new research paradigms and the application of high-throughput technologies have increased the rate of publication considerably. The problem is that manual curation becomes harder, prone-to-errors and time-consuming, leading to a probable loss of information and inefficient knowledge acquisition. As a result, research outputs are hardly reaching engineers, hampering the calibration of mathematical models used to optimize the stability and performance of biotechnological systems. In this context, we have developed a data curation workflow, based on text mining techniques, to extract numerical parameters from scientific literature, and applied it to the biotechnology domain. A workflow was built to process wastewater-related articles with the main goal of identifying physico-chemical parameters mentioned in the text. This work describes the implementation of the workflow, identifies achievements and current limitations in the overall process, and presents the results obtained for a corpus of 50 full-text documents.

Scientific publications are the main vehicle to disseminate information in the field of biotechnology for wastewater treatment. Indeed, the new research paradigms and the application of high-throughput technologies have increased the rate of publication considerably. The problem is that manual curation becomes harder, prone-to-errors and time-consuming, leading to a probable loss of information and inefficient knowledge acquisition. As a result, research outputs are hardly reaching engineers, hampering the calibration of mathematical models used to optimize the stability and performance of biotechnological systems. In this context, we have developed a data curation workflow, based on text mining techniques, to extract numerical parameters from scientific literature, and applied it to the biotechnology domain. A workflow was built to process wastewater-related articles with the main goal of identifying physico-chemical parameters mentioned in the text. This work describes the implementation of the workflow, identifies achievements and current limitations in the overall process, and presents the results obtained for a corpus of 50 full-text documents.

Indications for most forms of abdominoplasty are slight weight fluctuations or pregnancy. The steadily increasing number of patients with greater weight loss as well as the growing number of bariatric operations subsequently leads to a significant increase in body contouring procedures and places new challenges on plastic surgeons. After major weight loss patients present with extremely variable deformities in the lower and upper trunk as well as the extremities, which have to be treated individually with an appropriate procedure. The restoration of the lower trunk presents the first stage of the entire reconstruction process. The various modifications of abdominoplasty procedures with their various incision patterns and scar courses and the circumferential lower trunk dermatolipectomy represent advanced operations for every individual case. Plastic surgeons should be fully aware of differences and indications of every available procedure in the area of the lower trunk and should have the ability to offer the entire repertory for each individual deformity. A high postoperative patient satisfaction results from a customized procedure selection, the optimal implementation with a correspondingly low rate of complications and above-average patient care. [ABSTRACT FROM AUTHOR]

Aim: In this preliminary study, we aimed to confirm the clinical utility and safety of the new noncompliant balloon catheter River NC ® (Balton, Poland). Materials & methods: The primary study end point was to verify balloon diameters calculated in quantitative coronary angiography (QCA) to diameters prespecified by the manufacturer and obtained at given pressures in subjects undergoing percutaneous coronary interventions. Results: Forty-two subjects were enrolled (73.8% multivessel disease; 40.5% type B1 lesions; 100% device success). No clinically significant differences between expected balloon diameters and QCA were registered in predilatation (2.36 ± 0.11 mm vs 2.43 ± 0.07 mm) and postdilatation (3.18 ± 0.19 mm vs 3.21 ± 0.31 mm). Conclusion: Our study results suggest that the River NC balloon is effective and safe. In the QCA evaluation, River NC balloon obtained prespecified diameters and lengths at applied pressures. Study registration: Office for Registration of Medicinal Products, Medical Devices and Biocidal Products (UR.D.WM.DNB.109.2019).