Vânia Oliveira

Review on micro-direct methanol fuel cells

Fuel cells have unique technological attributes: efficiency, minimization of moving parts and low emissions. The Direct Methanol Fuel Cell (DMFC) has attracted much attention due to its potential applications as a power source for transportation and portable electronic devices. With the advance of micromachining technologies, miniaturization of power sources became one of the trends of evolution of research in this area. Based on the advantages of the scaling laws, miniaturization promises higher efficiency and performance of power generating devices, so, MicroDMFC is an emergent technology. There has been a growing interest in the development of this type of micro cells in the last years, resulting both in experimental studies (operating conditions, cell design and new materials) and in modeling studies. Despite the increase in the knowledge acquired, many challenges are still to be reached. This paper provides a detailed comprehensive review both on fundamental and technological aspects of micro-direct methanol fuel cells. Special attention is devoted to systematization of published results on experimental area since to date and also to a special section dedicated to modeling studies.

Carpal tunnel syndrome due to a plexiform neurofibroma of the median nerve in a neurofibromatosis type 1 patient: clinical approach.

The authors report the case of a 56-year-old male patient with neurofibromatosis type 1 (NF1) diagnosed during adolescence and with an insidious clinical evolution, characterised by an exuberant cutaneous involvement, referred to the orthopaedics outpatient clinic presenting with carpal tunnel syndrome secondary to a plexiform neurofibroma of the median nerve. A comprehensive clinical approach is discussed, considering the natural history of the disease and its potential complications, as well as the lack of consensus regarding standard therapeutic options for the compressive peripheral neuropathies in the NF1 disease.

Optimization of a single chamber microbial fuel cell using Lactobacillus pentosus: Influence of design and operating parameters

Microbial fuel cells (MFCs) have been receiving an increased attention over the last years due to their potential to combat two global problems: waste pollution and energy demand. Additionally, when a wastewater is used, MFCs can perform its treatment while recovering energy, leading to the possibility of energy-producing wastewater treatment plants, offsetting their operational costs. However, to overcome their current limitations (lower power outputs and higher costs), a clear understanding of the effect of operation and design parameters on its overall performance is mandatory. Therefore, the goal of this work was to evaluate the effect of operating conditions - batch cycle and yeast extract concentration, and design parameters - anode electrode area, membrane thickness and active area, on the overall performance of a single chamber MFC. The MFC operated with a pure culture of Lactobacillus pentosus and a synthetic wastewater based on a real dairy industry effluent. The overall performance was evaluated through the power output and the COD removal rate. Additionally, the biofilm formed at the anode electrode was characterized in terms of biomass, proteins and polysaccharides content. For the conditions used in this work, a maximum power density of 5.04 ± 0.39 mW/m2 was achieved with an anode electrode area of 61 cm2, a batch cycle of 48 h, 50 mg/L of yeast extract and a Nafion 212 membrane with an active area of 25 cm2. The different conditions tested had a clear effect on the MFC energy production and biofilm characteristics, but not on the ability of L. pentosus to treat the dairy wastewater. The COD removal rates were in the range between 42% and 58%, for all the conditions tested.

CT-Guided Percutaneous Radiofrequency Thermal Ablation of Osteoid Osteoma

Pedro Manuel Serrano*, João Maia Rosa, Luís Coutinho, Marta Santos Silva, Vânia Oliveira and Pedro Cardoso Serviço de Ortopedia e Traumatologia, Portugal *Corresponding author: Pedro Manuel Serrano, Serviço de Ortopedia e Traumatologia, Hospital de Santo António, Portugal Submission: April 23, 2018; Published: May 23, 2018 CT-Guided Percutaneous Radiofrequency Thermal Ablation of Osteoid Osteoma Research Article

Thermoablation in spinal osteoid osteomas

The Osteoid osteoma (OO) is a painful, self-limited bone tumor that can persist for several weeks, months or even years. Typically, the pain is worse at night and often is controlled with nonsteroidal antiinflammatory drugs (NSAID).1 It commonly occurs in male teenagers and young adults, with predilection for long bones of the lower limbs (femur and tibia).2 Ten to twenty percent of the lesions occur in the spine, with painful scoliosis and muscle spasm. The posterior elements of the vertebrae are the more affected structures.3–5

Pseudotumor complicating a well-fixed ceramic-on-polyethylene total hip arthroplasty

A suspicious area surrounding hardware components, usually following arthroplasty, should raise awareness to a possible particle related disease. Even in the presence of confusing or less typical symptoms, clinicians and surgeons must join efforts to diagnose and treat the patient effectively and in the appropriate time.

Fine needle aspiration for the diagnosis and treatment of musculoskleletal tumours

Objective The aim of this study was to evaluate the diagnostic accuracy of FNA and analyse its efficacy in enabling the initiation of treatment in musculoskeletal tumours. Methods A total of 130 FNA were performed (94 bone and 36 soft tissue lesions) guided by CT scan (n = 64), ultrasonography (n = 36) and radioscopy (n = 30). Diagnostic yield and accuracy were evaluated. A diagnosis was considered accurate when confirmed by histology or ulterior clinical/imaging evaluation. Exclusion of malignancy or infection was considered as diagnoses. Results Ninety diagnoses (69.2%) were obtained: 87 (96.7%) were accurate and 3 were wrong. FNA was non-diagnostic in 40 cases (30.8%) but in 15 (11.5%) it has been possible to conclude if the lesion was malignant (n = 6) or benign (n = 9). This method was completely inconclusive in 25 cases (19.2%). Conclusion Despite the low diagnostic yield, accuracy was high. FNA allowed the initiation of treatment in all 87 patients with a correct diagnosis and in 9 in which malignancy was excluded. Two of the 6 biopsies with the information of malignancy were soft tissue lesions. Even here, treatment could be done, as the majority of soft tissue sarcoma protocols begin with surgery. This study validates FNA as a method with a high diagnostic accuracy.