Pilot scale studies on the beneficiation of complex sulphides by flotation column

Experiments using pilot size flotation Column as cleaner cell were conducted to evolve a suitable flow sheet for the production of bulk sulphide concentrates of Cu-Pb-Zn. The flotalion circuit consisting of roughing, scavenging, and two stage cleaning by conventional flotation machines was compared with the circuit where two stage cleaning operation was replaced with single stage cleaning by flotation column. It is clearly demonstrated that a single stage cleaning by flotation column is more efficient and sufficient to obtain bulk concentrate suitable for further processing. Of the two types of sparger systems used viz, TURBO and MICROCEL, the former was found to be better to achieve high quality concentrate

Circuit simplification by adopting flotation columns.

Pilot scale studics on the beneficiation of low-grade fluorspar and copper-lead-zinc ore were investigated using flotation columns. Acidspar concentrates suitable for HF production can be produced by adopting two-stage column cleaning in place of multi-stage cleaning by conventional flotation cells. A three-column canfiguration in the place of four-stage cleaning in acidspar circuit and four in metspar circuit was suggested. Similarly, it was demonstrated that a single stage cleaning by flotation column was found to be sufficient in the plnce of two-stage cleaning by conventional flotation cells to obtain bulk concentrates of Cu-Pb-Zn

Osteonecrosis in patients with acute lymphoblastic leukaemia: a national questionnaire study

Objectives: To establish prevalence, management and long-term outcomes of osteonecrosis (ON) in young people diagnosed with acute lymphoblastic leukaemia (ALL) between 2003 and 2011. Design, setting, participants: This study assessed ON in 3113 patients aged 1–24 years who participated in the UK national leukaemia study UKALL 2003. UKALL 2003 recruited patients in 40 UK hospitals between 2003 and 2011 and included patients between ages 1 and 25 diagnosed with ALL. Results: 170 patients were diagnosed with ON, giving a prevalence of 5.5%. The multivariable analysis showed that the risk of ON was highest for children aged between 10 and 20 years (ages 10–15 years, OR 23.7, 95% CI 14.8 to 38.0; ages 16–20 years, OR 22.5, 95% CI 12.7 to 39.8, compared with age <10 years). Among ethnic groups, Asian patients had the highest risk of ON (OR 1.92, 95% CI 1.1 to 3.6, compared with White patients). Eighty-five per cent of patients with ON had multifocal ON. Thirty-eight per cent of patients with ON required surgery and 19% of patients with ON required a hip replacement. Fifteen per cent of patients who had surgery still describe significant disability or use of a wheelchair. Conclusions: ON has considerable morbidity for patients being treated for ALL, with a high burden of surgery. Age and ethnicity were found to be the most significant risk factors for development of ON, with Asian patients and patients aged 10–20 years at diagnosis of ALL at greatest risk. These results will help risk stratify patients at diagnosis of ALL, and help tailor future prospective studies in this area

Barriers to adherence in juvenile idiopathic arthritis: A multicenter collaborative experience and preliminary results

© 2018. All rights reserved. Objective. Nonadherence is currently an underrecognized and potentially modifiable obstacle to care in juvenile idiopathic arthritis (JIA). The purpose of our study was to design and implement a standardized approach to identifying adherence barriers for youth with JIA across 7 pediatric rheumatology clinics through the Pediatric Rheumatology Care and Outcomes Improvement Network (PR-COIN) and to assess the frequency of adherence barriers in patients and their caregivers across treatment modalities. Methods. An iterative process using coproduction among parents and providers of patients with JIA was used to design the Barriers Assessment Tool to screen for adherence barriers across 4 treatment modalities (i.e., oral medications, injectable medications, infusions, and physical/occupational therapy). This tool was implemented in 7 rheumatology clinics across the United States and patient responses were collected for analysis. Results. Data were collected from 578 parents and 99 patients (n = 44 parent-child dyads). Seventy-seven percent (n = 444) of caregivers and 70% (n = 69) of patients reported at least 1 adherence barrier across all treatment components. The most commonly reported adherence barriers included worry about future consequences of therapy, pain, forgetting, side effects, and embarrassment related to the therapy. There was no significant difference between endorsement of barriers between parents and adolescents. Conclusion. Implementing a standardized tool assessing adherence barriers in the JIA population across multiple clinical settings is feasible. Systematic screening sheds light on the factors that make adherence difficult in JIA and identifies targets for future adherence interventions in clinical practice

A Pediatric Infectious Disease Perspective of SARS-CoV-2 and COVID-19 in Children.

Understanding the role that children play in the clinical burden and propagation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) responsible for novel coronavirus (COVID-19) infections is emerging. While the severe manifestations and acute clinical burden of COVID-19 has largely spared children compared to adults, understanding the epidemiology, clinical presentation, diagnostics, management, and prevention opportunities as well as the social and behavioral impacts on child health is vital. Foremost is clarifying the contribution of asymptomatic and mild infections to transmission within the household and community and the clinical and epidemiologic significance of uncommon severe post-infectious complications. Herein we summarize the current knowledge, identify useful resources, and outline research opportunities. Pediatric infectious disease clinicians have a unique opportunity to advocate for the inclusion of children in epidemiological, clinical, treatment and prevention studies to optimize their care, as well as to represent children in the development of guidance and policy during pandemic response

Modelling small block aperture in an in-house developed GPU-accelerated Monte Carlo-based dose engine for pencil beam scanning proton therapy

Purpose: To enhance an in-house graphic-processing-unit (GPU) accelerated virtual particle (VP)-based Monte Carlo (MC) proton dose engine (VPMC) to model aperture blocks in both dose calculation and optimization for pencil beam scanning proton therapy (PBSPT)-based stereotactic radiosurgery (SRS). Methods and Materials: A block aperture module was integrated into VPMC. VPMC was validated by an opensource code, MCsquare, in eight water phantom simulations with 3cm thick brass apertures: four were with aperture openings of 1, 2, 3, and 4cm without a range shifter, while the other four were with same aperture opening configurations with a range shifter of 45mm water equivalent thickness. VPMC was benchmarked with MCsquare and RayStation MC for 10 patients with small targets (average volume 8.4 cc). Finally, 3 patients were selected for robust optimization with aperture blocks using VPMC. Results: In the water phantoms, 3D gamma passing rate (2%/2mm/10%) between VPMC and MCsquare were 99.71$\pm$0.23%. In the patient geometries, 3D gamma passing rates (3%/2mm/10%) between VPMC/MCsquare and RayStation MC were 97.79$\pm$2.21%/97.78$\pm$1.97%, respectively. The calculation time was greatly decreased from 112.45$\pm$114.08 seconds (MCsquare) to 8.20$\pm$6.42 seconds (VPMC), both having statistical uncertainties of about 0.5%. The robustly optimized plans met all the dose-volume-constraints (DVCs) for the targets and OARs per our institutional protocols. The mean calculation time for 13 influence matrices in robust optimization by VPMC was 41.6 seconds. Conclusion: VPMC has been successfully enhanced to model aperture blocks in dose calculation and optimization for the PBSPT-based SRS.Comment: 3 tables, 3 figure