Life cycle assessment of using powder and liquid precursors in plasma spraying : the case of yttria-stabilized zirconia

International audiencePlasma spraying using liquid precursors makes possible the production of finely-structured coatings and thin coatings. This technology has been investigated for nearly ten years in many laboratories and applications are now emerging, using conventional plasma equipment except for the feedstock injection system. While superior quality is expected from the nano-structured coatings, the question remains as to the impacts of using liquid precursors on the environment. In this study, we used the life cycle assessment (LCA) methodology to compare the conventional plasma spray process using powder feedstock, with injection of the precursor in the form of a liquid solution or suspension. The LCA methodology consists of identifying and comparing the environmental impacts of feedstock, energy inputs, products and emissions (solid, liquid and gaseous) of these two alternatives. The LCA study was carried out using the SimaPro program developed in the Netherlands and a peer-reviewed database of upstream materials and energy (EcoInvent v.2). The specific application studied was the plasma spraying of yttria-stabilized zirconia

Multispectral real-time fluorescence imaging for intraoperative detection of the sentinel lymph node in gynecologic oncology.

The prognosis in virtually all solid tumors depends on the presence or absence of lymph node metastases. Surgical treatment most often combines radical excision of the tumor with a full lymphadenectomy in the drainage area of the tumor. However, removal of lymph nodes is associated with increased morbidity due to infection, wound breakdown and lymphedema. As an alternative, the sentinel lymph node procedure (SLN) was developed several decades ago to detect the first draining lymph node from the tumor. In case of lymphogenic dissemination, the SLN is the first lymph node that is affected (Figure 1). Hence, if the SLN does not contain metastases, downstream lymph nodes will also be free from tumor metastases and need not to be removed. The SLN procedure is part of the treatment for many tumor types, like breast cancer and melanoma, but also for cancer of the vulva and cervix. The current standard methodology for SLN-detection is by peritumoral injection of radiocolloid one day prior to surgery, and a colored dye intraoperatively. Disadvantages of the procedure in cervical and vulvar cancer are multiple injections in the genital area, leading to increased psychological distress for the patient, and the use of radioactive colloid. Multispectral fluorescence imaging is an emerging imaging modality that can be applied intraoperatively without the need for injection of radiocolloid. For intraoperative fluorescence imaging, two components are needed: a fluorescent agent and a quantitative optical system for intraoperative imaging. As a fluorophore we have used indocyanine green (ICG). ICG has been used for many decades to assess cardiac function, cerebral perfusion and liver perfusion. It is an inert drug with a safe pharmaco-biological profile. When excited at around 750 nm, it emits light in the near-infrared spectrum around 800 nm. A custom-made multispectral fluorescence imaging camera system was used. The aim of this video article is to demonstrate the detection of the SLN using intraoperative fluorescence imaging in patients with cervical and vulvar cancer. Fluorescence imaging is used in conjunction with the standard procedure, consisting of radiocolloid and a blue dye. In the future, intraoperative fluorescence imaging might replace the current method and is also easily transferable to other indications like breast cancer and melanoma

Seasonal yield and fuel consumed for domestic, organic waste collections in currently operational door-to-door and bring-type collection systems

The European Commission is tightening waste laws, and many local authorities, particularly in countries with low recycling rates, face the question of what system to introduce for the source-separate collection of food waste from householders. This study provides empirical data in form of fuel consumed and waste yield from four councils that already have source separate organic waste collections in operation. Two systems were compared: (i) door-to-door collection and (ii) bring systems where the householder walks to the bin in her/his street to drop off organic waste. Fuel consumption for the collection operation with the bring system was dramatically lower compared to the door-to-door system. Organic waste yield was constant over the observation year in the door-to-door system employing small 20- to 30-litre bins, but increased notably in the summer with the bring system that used 240-litre bins. The metric used to quantify seasonality was the summer/winter yield ratio. As commercial waste companies do not normally allow the making of data public, this is a rare opportunity to learn from collection systems currently in operation

Near-infrared fluorescence (NIRF) imaging in breast-conserving surgery: Assessing intraoperative techniques in tissue-simulating breast phantoms.

Breast-conserving surgery (BCS) results in tumour-positive surgical margins in up to 40% of the patients. Therefore, new imaging techniques are needed that support the surgeon with real-time feedback on tumour location and margin status. In this study, the potential of near-infrared fluorescence (NIRF) imaging in BCS for pre- and intraoperative tumour localization, margin status assessment and detection of residual disease was assessed in tissue-simulating breast phantoms.Breast-shaped phantoms were produced with optical properties that closely match those of normal breast tissue. Fluorescent tumour-like inclusions containing indocyanine green (ICG) were positioned at predefined locations in the phantoms to allow for simulation of (i) preoperative tumour localization, (ii) real-time NIRF-guided tumour resection, and (iii) intraoperative margin assessment. Optical imaging was performed using a custom-made clinical prototype NIRF intraoperative camera.Tumour-like inclusions in breast phantoms could be detected up to a depth of 21 mm using a NIRF intraoperative camera system. Real-time NIRF-guided resection of tumour-like inclusions proved feasible. Moreover, intraoperative NIRF imaging reliably detected residual disease in case of inadequate resection.We evaluated the potential of NIRF imaging applications for BCS. The clinical setting was simulated by exploiting tissue-like breast phantoms with fluorescent tumour-like agarose inclusions. From this evaluation, we conclude that intraoperative NIRF imaging is feasible and may improve BCS by providing the surgeon with imaging information on tumour location, margin status, and presence of residual disease in real-time. Clinical studies are needed to further validate these results