Synthesis of multifunctional nanoparticles for imaging and enhancement in therapy

The purpose of this work was to synthesize nanoparticles composed of high atomic number elements and semiconductor material in a core/shell structure for the potential to be used as enhancers for radiotherapy as well as luminescence imaging platforms. Additionally, to quantify their role in free radical production after exposure to ionizing radiation through chemical routes. Spherical gold nanoparticles were synthesized via a citrate stabilizer method. Two sizes of 12nm and 25 nm gold spheres were used as the cores for the europium-doped gadolinium vanadate flower-shaped shell. The production of 7-hydroxycoumarin-3-carboxylic acid in an aqueous environment upon kV irradiation of its precursor, coumarin-3-carboxylic acid, was assessed and used as a fluorescence detector for hydroxyl radicals. The quantification of excess or moderation of hydroxyl radicals in the presence of the nanomaterial as compared to a control sample can indicate the potential for increased DNA damage for purposes such as tumor control. This work indicates the potential for physical and chemical enhancement in the presence of nanomaterials

The Effect of Confinement on Fe2O3 Nanoparticles in Free Diffusion and with a Horizontal Magnetic Field

We investigated the magnitude of the confinement effect\u27s influence on the free diffusion of Iron Oxide Fe2O3 in pure water contained in cells of different volumes and also that of an applied magnetic field. A shadowgraph apparatus consisting of a super luminous diode (SLD) source, a CCD camera, and achromatic lenses was used to record and analyze the changing indices of refraction due to the presence of concentration-driven fluctuations as the solution diffuses. Extracted frames from this recording were processed through a Differential Dynamic Algorithm (DDA) that determined the dynamics of the process, such as the structure function. The results generated by the DDA was further analyzed to determine how the amplitude of concentration fluctuations change over time and how long those fluctuations are present, revealing a dependency of the dynamics on the size of the cell containing the solution

Dosimetric Advantage of Combined IMRT for Whole Lung and Abdomen Irradiation for Wilms Tumor

Purpose: In patients with Wilms tumor with lung metastases, a cardiac-sparing intensity modulated radiation therapy (CS-IMRT) technique is increasingly being adopted for whole lung irradiation. However, the standard technique for flank and whole abdomen radiation remains 2-dimensional anterioposterior (AP), and overlap at the junction between the whole lung CS-IMRT and abdominal AP fields can result in overdose to normal organs. Here, we compared the dosimetry of patients who received whole lung irradiation and flank or abdominal radiation therapy with CS-IMRT with AP abdominal field (IMRT-AP) versus CS-IMRT with IMRT abdominal field (combined IMRT). Methods and Materials: We retrospectively reviewed the radiation plans of 2 patients with Wilms tumor who received CS-IMRT and flank or whole abdomen irradiation with a combined IMRT approach. Comparison IMRT-AP plans were generated with equivalent target coverage of 95% receiving the prescribed dose. Maximum doses to normal organs were compared at the junctional overlap. Results: Overlap at the junction between CS-IMRT and abdominal fields resulted in a significantly lower dose with combined IMRT plans compared with IMRT-AP plan. Differences in maximum doses (in cGy) to normal organs between combined IMRT versus IMRT-AP plans were most significant in the vertebral body (patient 1 = 1277 vs 2065; patient 2 = 1334 vs 2287), lungs (patient 1 = 1298 vs 2081; patient 2 = 1234 vs 1820), spinal cord (patient 1 = 1235 vs 1975; patient 2 = 1345 vs 2253), stomach (patient 1 = 1264 vs 1977; patient 2 = 1118 vs 2062), and liver (patient 1 = 1297 vs 1889; patient 2 = 1334 vs 2237). Conclusions: The combined IMRT approach for Wilms patients who require whole lung and abdomen irradiation can provide more uniform dose distribution in the junction area and significantly lower doses to normal organs at the junctional overlap

An appraisal of respiratory system compliance in mechanically ventilated covid-19 patients

BackgroundHeterogeneous respiratory system static compliance (CRS) values and levels of hypoxemia in patients with novel coronavirus disease (COVID-19) requiring mechanical ventilation have been reported in previous small-case series or studies conducted at a national level.MethodsWe designed a retrospective observational cohort study with rapid data gathering from the international COVID-19 Critical Care Consortium study to comprehensively describe CRS—calculated as: tidal volume/[airway plateau pressure-positive end-expiratory pressure (PEEP)]—and its association with ventilatory management and outcomes of COVID-19 patients on mechanical ventilation (MV), admitted to intensive care units (ICU) worldwide.ResultsWe studied 745 patients from 22 countries, who required admission to the ICU and MV from January 14 to December 31, 2020, and presented at least one value of CRS within the first seven days of MV. Median (IQR) age was 62 (52–71), patients were predominantly males (68%) and from Europe/North and South America (88%). CRS, within 48 h from endotracheal intubation, was available in 649 patients and was neither associated with the duration from onset of symptoms to commencement of MV (p = 0.417) nor with PaO2/FiO2 (p = 0.100). Females presented lower CRS than males (95% CI of CRS difference between females-males: − 11.8 to − 7.4 mL/cmH2O p RS was marginal (p = 0.139). Ventilatory management varied across CRS range, resulting in a significant association between CRS and driving pressure (estimated decrease − 0.31 cmH2O/L per mL/cmH20 of CRS, 95% CI − 0.48 to − 0.14, p RS (+ 10 mL/cm H2O) was only associated with being discharge from the ICU within 28 days (HR 1.14, 95% CI 1.02–1.28, p = 0.018).ConclusionsThis multicentre report provides a comprehensive account of CRS in COVID-19 patients on MV. CRS measured within 48 h from commencement of MV has marginal predictive value for 28-day mortality, but was associated with being discharged from ICU within the same period. Trial documentation: Available at https://www.covid-critical.com/study.Trial registration: ACTRN12620000421932