100 research outputs found

    Iron-induced relaxation mechanisms in the human substantia nigra: Towards quantifying iron load in dopaminergic neurons

    No full text
    Pathological iron accumulation in the human brain is a biomarker for neurodegeneration. Several diagnostically promising MR- based methods for in vivo iron quantification were proposed, based on the empirical relationship between R 2 * and iron concentration. However, these do not account for different chemical forms and cellular distribution of iron. We combined post mortem MRI, advanced quantitative histology and biophysical modeling to develop a generative theory linking obtained iron concentrations to quantitative MR parameters. The impact of nanoscale molecular interaction of water with iron and of iron-rich dopaminergic neurons was quantified in substantia nigra

    Empowerment evaluation of a Swedish gender equity plan

    Get PDF
    Background: Empowerment is essential for gender equity and health. The city of Malmö, Sweden, has formulated a development plan for gender equity integration (GEIDP). A ‘Policy Empowerment Index’ (PEI) was previously developed to assess the empowerment potential of policies. Objectives: To pilot-evaluate the GEIDP's potential for empowerment and to test the PEI for future policy evaluations. Design: The GEIDP was analyzed and scored according to electronically retrieved evidence on constituent opinion, participation, capacity development, evaluation–adaptation, and impact. Results: The plan's PEI score was 64% (CI: 48–78) and was classified as ‘enabling’, ranging between ‘enabling’ and ‘supportive’. The plan's strengths were: 1) constituent knowledge and concern; 2) peripheral implementation; 3) protection of vulnerable groups; and 4) evaluation/adaptation procedures. It scored average on: 1) policy agenda setting; 2) planning; 3) provisions for education; 4) network formation; 5) resource mobilization. The weakest point was regarding promotion of employment and entrepreneurship. Conclusions: The PEI evaluation highlighted the plan's potential of constituency empowerment and proposed how it could be augmented

    3D printed catalytic reactors for aerobic selective oxidation of benzyl alcohol into benzaldehyde in continuous multiphase flow

    Get PDF
    In this work, novel, patterned monolithic reactors were devised to explore more efficient routes for reactant conversion in order to investigate their potential to replace the packed bed and batch reactors conventionally employed in chemical industries. Well-defined bimetallic formulations were developed to substitute platinum group metals and critical raw materials such as palladium and cobalt, at least in part, by less active, but more sustainable and cost-effective metals such as earth-abundant iron. FePd and FeCo based monoliths were 3D printed and stacked in a continuous flow tubular reactor for testing the selective oxidation of benzyl alcohol (BA) into benzaldehyde (BZ) under mild conditions (80–100 °C and atmospheric pressure). The novel monolithic reactors were evaluated against current state-of-the-art reactor technologies, conventional packed bed and batch reactors. The FeCo- and FePd-Al2O3-supported monolithic catalyst beds showed higher conversion and TOF than their packed bed counterparts under the same operating conditions, revealing the impact of the novel design on both regular geometry and composition. What is of particular interest in the catalytic measurements shown is that the combined stacking of two monoliths in a flow reactor, Al2O3-supported Fe and GO-supported FePd catalysts, can significantly improve the performance with an increase in TOF of up to 90% in comparison to their FePd analogues. Mathematical modelling was used to obtain additional insights into the physical and chemical processes governing the rate of BA conversion. It was found that due to the flow regime inside the microchannels, an axial dispersion model was appropriate, which allowed for mapping the concentration profiles of the reactants and products within the respective monolith geometries

    Effects of bovine serum albumin on light activated antimicrobial surfaces

    Get PDF
    Bovine serum albumin (BSA) is currently recommended as an interfering substance to emulate organic soiling, in evaluating the efficacy of disinfectants. The European Standard recommends 0.03% BSA to test clean conditions and 0.3% for dirty conditions. Reactive oxygen species are known to exert excellent antimicrobial activity with low specificity against a broad range of pathogens. Herein, we present our data from the first study of the effects of the addition of BSA on the antibacterial activity of light activated antimicrobial surfaces. Light activated antimicrobial surfaces were made from polyurethane swell-encapsulated with gold nanoparticles (AuNPs) coated with the light active triarylmethane dye, crystal violet (PU-AuNP-CV). The antibacterial efficacy of the antimicrobial substrates was tested against two strains of Staphylococcus aureus 8325-4, a well-characterised laboratory strain and MRSA 4742, a recent clinical isolate, in the presence of 0.1% to 1% BSA by irradiating the substrates with a fluorescent lamp (300 lux). After 6 hours of irradiation, the number of surviving bacteria was determined. The results showed that BSA reduced the antibacterial efficacy of all the PU-AuNP-CV surfaces with increasing BSA concentrations resulting in a progressive reduction in antibacterial activity towards the bacteria tested. However, the light activated surfaces did perform well at 0.1 and 0.25% BSA levels, showing they may have potential for real world environments with low levels of organic soiling

    Robotic multiquadrant colorectal procedures: A single-center experience and a systematic review of the literature

    Get PDF
    Purpose: Robotic surgery has been progressively implemented for colorectal procedures but is still limited for multiquadrant abdominal resections. The present study aims to describe our experience in robotic multiquadrant colorectal surgeries and provide a systematic review and meta-analysis of the literature investigating the outcomes of robotic total proctocolectomy (TPC), total colectomy (TC), subtotal colectomy (STC), or completion proctectomy (CP) compared to laparoscopy. Methods: At our institution 16 consecutive patients underwent a 2- or 3-stage totally robotic total proctocolectomy (TPC) with ileal pouch-anal anastomosis. A systematic review of the literature was performed to select studies on robotic and laparoscopic multiquadrant colorectal procedures. Meta-analyses were used to compare the two approaches. Results: In our case series, 14/16 patients underwent a 2-stage robotic TPC for ulcerative colitis with a mean operative time of 271.42 (SD:37.95) minutes. No conversion occurred. Two patients developed postoperative complications. The mean hospital stay was 8.28 (SD:1.47) days with no readmissions. Mortality was nil. All patients underwent loop-ileostomy closure, and functional outcomes were satisfactory. The literature appraisal was based on 23 retrospective studies, including 736 robotic and 9,904 laparoscopic multiquadrant surgeries. In the robotic group, 36 patients underwent STC, 371 TC, 166 TPC, and 163 CP. Pooled data analysis showed that robotic TC and STC had a lower conversion rate (OR = 0.17;95% CI, 0.04–0.82; p = 0.03) than laparoscopic TC and STC. The robotic approach was associated with longer operative time for TC and STC (MD = 104.64;95% CI, 18.42–190.87; p = 0.02) and TPC and CP (MD = 38.8;95% CI, 18.7–59.06; p = 0.0002), with no differences for postoperative complications and hospital stay. Reports on urological outcomes, sexual dysfunction, and quality of life were missing. Conclusions: Our experience and the literature suggest that robotic multiquadrant colorectal surgery is safe and effective, with low morbidity and mortality rates. Nevertheless, the overall level of evidence is low, and functional outcomes of robotic approach remain largely unknown. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier: CRD42022303016

    Continuous flow synthesis of ultrasmall gold nanoparticles in a microreactor using trisodium citrate and their SERS performance

    Get PDF
    Ultrasmall gold nanoparticles were synthesized without strong capping agents by using a capillary-based continuous flow system. A mixture of gold(III) chloride trihydrate and trisodium citrate flowed through capillaries at elevated temperature. The effect of capillary material (polytetrafluoroethylene, fluorinated ethylene propylene, polyetheretherketone, fused silica), surface-to-volume ratio (capillary internal diameter 0.3–1 mm), average residence time (1.5–30 min) and temperature (70–100 °C) were investigated. At a flow rate of 0.006 ml/min (residence time 30 min), 100 °C, 275 kPa back pressure, citrate/gold molar ratio 3.15 and using PTFE capillary tubing with an inner diameter of 0.3 mm, very small (1.9 ± 0.2 nm) nanoparticles were obtained. For comparison, experiments were also performed under the same experimental conditions, but in slug flow using octane as segmenting fluid, thus isolating the reactants from the tubing wall. The synthesized particles were 17.4 ± 1.4 nm for segmented flow, demonstrating the important effect of the capillary wall surface. The performance of these citrate-capped gold nanoparticles was tested for Surface-Enhanced Raman Scattering (SERS). The average enhancement factor (AEF) of 2 nm gold nanoparticles capped by citrate from our work (AEF = 1.54 × 108) was nearly double when compared to 2 nm phosphate-capped commercial gold nanoparticles (AEF = 7.34 × 107). The adsorption of analyte molecules onto citrate-capped gold surface was easier due to the weaker binding strength of the carboxylate ligand and more hotspots formed with narrower gaps between neighbouring particles, giving rise to improved enhancement. This work has been selected by the Editors as a Featured Cover Article for this issue

    Towards microfluidic reactors for in situ synchrotron infrared studies

    Get PDF
    Anodically bonded etched silicon microfluidic devices that allow infrared spectroscopic measurement of solutions are reported. These extend spatially well-resolved in situ infrared measurement to higher temperatures and pressures than previously reported, making them useful for effectively time-resolved measurement of realistic catalytic processes. A data processing technique necessary for the mitigation of interference fringes caused by multiple reflections of the probe beam is also describe

    Treatment of chronic anterior shoulder dislocation by open reduction and simultaneous Bankart lesion repair

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Untreated chronic shoulder dislocation eventually leads to functional disability and pain. Open reduction with different fixation methods have been introduced for most chronic shoulder dislocation. We hypothesized that open reduction and simultaneous Bankart lesion repair in chronic anterior shoulder dislocation obviates the need for joint fixation and leads to better results than previously reported methods.</p> <p>Methods</p> <p>Eight patients with chronic anterior dislocation of shoulder underwent open reduction and capsulolabral complex repair after an average delay of 10 weeks from injury. Early motion was allowed the day after surgery in the safe position and the clinical and radiographic results were analyzed at an average follow-up of one year.</p> <p>Results</p> <p>The average Rowe and Zarin's score was 86 points. Four out of eight shoulders were graded as excellent, three as good and one as fair (Rowe and Zarins system). All patients were able to perform their daily activities and they had either mild or no pain. Anterior active forward flexion loss averaged 18 degrees, external active rotation loss averaged 17.5 degrees and internal active rotation loss averaged 3 vertebral body levels. Mild degenerative joint changes were noted in one patient.</p> <p>Conclusion</p> <p>The results show that the overall prognosis for this method of operation is more favorable than the previously reported methods and we recommend concomitant open reduction and capsulolabral complex repair for the treatment of old anterior shoulder dislocation.</p> <p>Level of Evidence</p> <p>Therapeutic study, Level IV (case series [no, or historical, control group])</p
    corecore