Tension pneumocephalus following suboccipital sitting craniotomy in the pediatric population

Background Sitting craniotomy often results in entrapment of air in fluid-filled intracranial cavities. Gas under pressure exerts a deleterious effect on adjacent nervous tissue, resulting in clinical deterioration. Aim of study To assess the incidence of tension pneumocephalus (TP) and to define risk factors associated therewith. Material and method Analysis included 100 consecutive patients (57 boys, 43 girls, mean age 9.7 y) undergoing suboccipital sitting craniotomy since 2012 to 2014. Results In our material (n=100) TP was seen in 7 cases, asymptomatic pneumocephalus (AP) in 77 and no pneumocephalus (NP) in 16. Tumor types encountered were typical for pediatric population. In the TP group (n=7) the ratio of low-grade to high-grade tumors was 5:2, in the AP group (n=77) 2:1 and in the NP group (n=16) 1:1. Preoperative hydrocephalus was present in 21 cases (21%, mean incidence), thereof 3 in the TP group (3/7; 42.8%), 12 in AP group (12/77; 15.5%) and 6 in the NP group (6/16; 37.5%). All TP patients received an emergency external drainage, thereof 4 required a permanent ventriculo-peritoneal shunt (57.1%), while AP and NP patients combined (n=93) required a permanent shunt in 4 cases only (4.3%). TP-associated morbidity (n=2) consisted in a significant deterioration of neurological condition. Conclusions TP is a relatively rare but potentially serious complication of suboccipital sitting craniotomy. Risk factors for TP are low-grade tumor and pre-existing long-standing hydrocephalus. TP requires emergency decompression by temporary external drainage. TP patients significantly more often require a permanent CSF shunt

Modern Microelectronic Technologies in Fabrication of RFID Tags

This paper presents fabrication of RFID tags, especially antennas for HF band (13.56 MHz), on cheap flexible substrates. The physicochemical, geometrical, DC and AC electrical properties as well as long-term stability (under thermal, moisture-thermal and mechanical exposures) have been characterized for several low-temperature polymer thick-film conductive films made on various paper or foil substrates. Resistance measurement during curing has been used for investigation of polymerization velocity, which is very important for increase of process capacity

Tunneling-percolation origin of nonuniversality: theory and experiments

A vast class of disordered conducting-insulating compounds close to the percolation threshold is characterized by nonuniversal values of transport critical exponent t, in disagreement with the standard theory of percolation which predicts t = 2.0 for all three dimensional systems. Various models have been proposed in order to explain the origin of such universality breakdown. Among them, the tunneling-percolation model calls into play tunneling processes between conducting particles which, under some general circumstances, could lead to transport exponents dependent of the mean tunneling distance a. The validity of such theory could be tested by changing the parameter a by means of an applied mechanical strain. We have applied this idea to universal and nonuniversal RuO2-glass composites. We show that when t > 2 the measured piezoresistive response \Gamma, i. e., the relative change of resistivity under applied strain, diverges logarithmically at the percolation threshold, while for t = 2, \Gamma does not show an appreciable dependence upon the RuO2 volume fraction. These results are consistent with a mean tunneling dependence of the nonuniversal transport exponent as predicted by the tunneling-percolation model. The experimental results are compared with analytical and numerical calculations on a random-resistor network model of tunneling-percolation.Comment: 13 pages, 12 figure

Development of a behaviour change intervention: a case study on the practical application of theory

BACKGROUND: Use of theory in implementation of complex interventions is widely recommended. A complex trial intervention, to enhance self-management support for people with osteoarthritis (OA) in primary care, needed to be implemented in the Managing Osteoarthritis in Consultations (MOSAICS) trial. One component of the trial intervention was delivery by general practitioners (GPs) of an enhanced consultation for patients with OA. The aim of our case study is to describe the systematic selection and use of theory to develop a behaviour change intervention to implement GP delivery of the enhanced consultation. METHODS: The development of the behaviour change intervention was guided by four theoretical models/frameworks: i) an implementation of change model to guide overall approach, ii) the Theoretical Domains Framework (TDF) to identify relevant determinants of change, iii) a model for the selection of behaviour change techniques to address identified determinants of behaviour change, and iv) the principles of adult learning. Methods and measures to evaluate impact of the behaviour change intervention were identified. RESULTS: The behaviour change intervention presented the GPs with a well-defined proposal for change; addressed seven of the TDF domains (e.g., knowledge, skills, motivation and goals); incorporated ten behaviour change techniques (e.g., information provision, skills rehearsal, persuasive communication); and was delivered in workshops that valued the expertise and professional values of GPs. The workshops used a mixture of interactive and didactic sessions, were facilitated by opinion leaders, and utilised 'context-bound communication skills training.' Methods and measures selected to evaluate the behaviour change intervention included: appraisal of satisfaction with workshops, GP report of intention to practise and an assessment of video-recorded consultations of GPs with patients with OA. CONCLUSIONS: A stepped approach to the development of a behaviour change intervention, with the utilisation of theoretical frameworks to identify determinants of change matched with behaviour change techniques, has enabled a systematic and theory-driven development of an intervention designed to enhance consultations by GPs for patients with OA. The success of the behaviour change intervention in practice will be evaluated in the context of the MOSAICS trial as a whole, and will inform understanding of practice level and patient outcomes in the trial

Preparation and characterization of novel polymer-based gel electrolyte for dye-sensitized solar cells based on poly(vinylidene fluoride-cohexafluoropropylene) and poly(acrylonitrile-cobutadiene) or poly(dimethylsiloxane) bis(3-aminopropyl) copolymers

Polymer gel electrolytes based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and poly(acrylonitrile-co-butadiene) (PAB) or poly(dimethylsiloxane) bis(3-aminopropyl)-terminated (PDES-bAP) copolymers were prepared and investigated in dye-sensitized solar cells (DSSCs). Selected optical and electrochemical properties of all compositions with various ratio from 9:1 to 6:4 were investigated towards DSSC applications. The highest value of power conversion efficiency equal to 5.07% was found for DSSCs containing a PVDF-HPF:PAB (9:1) gel electrolyte. Compositions of electrolytes were additionally tested by electrochemical impedance spectroscopy. The influence of the ratio and type of polymers used as an additive to PVDF-HPF on absorption wavelengths, energy gap, and Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) levels were investigated. Individual components of DSSCs, such as the TiO2 layer and platinum nanoparticles, were imaged by scanning electron microscope. Finally, a DSSC module with six electrically separated solar cells with a 7 × 80 mm2 active area was constructed based on gel electrolytes and tested. © 2020 by the authors

Electrostatic considerations affecting the calculated HOMO-LUMO gap in protein molecules.

A detailed study of energy differences between the highest occupied and lowest unoccupied molecular orbitals (HOMO-LUMO gaps) in protein systems and water clusters is presented. Recent work questioning the applicability of Kohn-Sham density-functional theory to proteins and large water clusters (E. Rudberg, J. Phys.: Condens. Mat. 2012, 24, 072202) has demonstrated vanishing HOMO-LUMO gaps for these systems, which is generally attributed to the treatment of exchange in the functional used. The present work shows that the vanishing gap is, in fact, an electrostatic artefact of the method used to prepare the system. Practical solutions for ensuring the gap is maintained when the system size is increased are demonstrated. This work has important implications for the use of large-scale density-functional theory in biomolecular systems, particularly in the simulation of photoemission, optical absorption and electronic transport, all of which depend critically on differences between energies of molecular orbitals.Comment: 13 pages, 4 figure

Patient and public involvement in primary care research - an example of ensuring its sustainability

Background The international literature on patient and public involvement (PPI) in research covers a wide range of issues, including active lay involvement throughout the research cycle; roles that patients/public can play; assessing impact of PPI and recommendations for good PPI practice. One area of investigation that is less developed is the sustainability and impact of PPI beyond involvement in time-limited research projects. Methods This paper focuses on the issues of sustainability, the importance of institutional leadership and the creation of a robust infrastructure in order to achieve long-term and wide-ranging PPI in research strategy and programmes. Results We use the case of a Primary Care Research Centre to provide a historical account of the evolution of PPI in the Centre and identified a number of key conceptual issues regarding infrastructure, resource allocation, working methods, roles and relationships. Conclusions The paper concludes about the more general applicability of the Centre’s model for the long-term sustainability of PPI in research

Surface topography of hydroxyapatite affects ROS17/2.8 cells response

Hydroxyapatite (HA) has been used in orthopedic, dental, and maxillofacial surgery as a bone substitute. The aim of this investigation was to study the effect of surface topography produced by the presence of microporosity on cell response, evaluating: cell attachment, cell morphology, cell proliferation, total protein content, and alkaline phosphatase (ALP) activity. HA discs with different percentages of microporosity (< 5%, 15%, and 30%) were confected by means of the combination of uniaxial powder pressing and different sintering conditions. ROS17/2.8 cells were cultured on HA discs. For the evaluation of attachment, cells were cultured for two hours. Cell morphology was evaluated after seven days. After seven and fourteen days, cell proliferation, total protein content, and ALP activity were measured. Data were compared by means of ANOVA and Duncan’s multiple range test, when appropriate. Cell attachment (p = 0.11) and total protein content (p = 0.31) were not affected by surface topography. Proliferation after 7 and 14 days (p = 0.0007 and p = 0.003, respectively), and ALP activity (p = 0.0007) were both significantly decreased by the most irregular surface (HA30). These results suggest that initial cell events were not affected by surface topography, while surfaces with more regular topography, as those present in HA with 15% or less of microporosity, favored intermediary and final events such as cell proliferation and ALP activity

Self-reported quality care for knee osteoarthritis: comparisons across Denmark, Norway, Portugal and the UK

Objectives: To assess and compare patient perceived quality of osteoarthritis (OA) management in primary healthcare in Denmark, Norway, Portugal and the UK. Methods: Participants consulting with clinical signs and symptoms of knee OA were identified in 30 general practices and invited to complete a cross-sectional survey including quality indicators (QI) for OA care. A QI was considered as eligible if the participant had checked 'Yes' or 'No', and as achieved if the participant had checked 'Yes' to the indicator. The median percentage (with IQR and range) of eligible QIs achieved by country was determined and compared in negative binominal regression analysis. Achievement of individual QIs by country was determined and compared using logistic regression analyses. Results: A total of 354 participants self-reported QI achievement. The median percentage of eligible QIs achieved (checked 'Yes') was 48% (IQR 28%, 64%; range 0-100%) for the total sample with relatively similar medians across three of four countries. Achievement rates on individual QIs showed a large variation ranging from 11% (referral to services for losing weight) to 67% (information about the importance of exercise) with significant differences in achievement rates between the countries. Conclusions: The results indicated a potential for improvement in OA care in all four countries, but for somewhat different aspects of OA care. By exploring these differences and comparing healthcare services, ideas may be generated on how the quality might be improved across nations. Larger studies are needed to confirm and further explore the findings.EULAR Health Professional Grant; Norwegian Fund through the FYSIOPRIM project; National Institute for Health Research (NIHR) [RP-PG-0407-10 386]; Arthritis Research UK Centre in Primary Care grant [18139]; National Institute for Health Research (NIHR) Collaborations for Leadership in Applied Health Research and Care West Midlands by a Knowledge Mobilisation Research Fellowship from the National Institute for Health Research; National Institute for Health Research (NIHR); Fundacao para a Ciencia e Tecnologia [PEst-OE/MAT/UI0006/2014]info:eu-repo/semantics/publishedVersio