Publications by authors named "John Markert"

Article Synopsis
  • Accurate intraoperative diagnosis of primary CNS lymphoma (PCNSL) is vital for surgical decisions but is challenging due to similar features with other CNS diseases; a new method combines stimulated Raman histology (SRH) with deep learning to improve this process.
  • The RapidLymphoma system uses a portable Raman microscope to create virtual images of tissue samples in under three minutes and employs a deep learning model trained on 54,000 images, allowing it to detect PCNSL and differentiate it from other conditions effectively.
  • In testing, RapidLymphoma achieved a high accuracy rate of 97.81%, performing better than traditional methods, and demonstrated its capability to identify specific histological features crucial for diagnosis, providing quick feedback
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Article Synopsis
  • Accurate intraoperative diagnosis of primary CNS lymphoma (PCNSL) is challenging due to overlapping features with other CNS conditions, but a new method combining stimulated Raman histology (SRH) and deep learning seeks to improve this.
  • The deep learning system, RapidLymphoma, analyzes unprocessed tissue samples quickly, achieving high accuracy in distinguishing PCNSL from other entities, with an overall accuracy of 97.81% in a test cohort.
  • RapidLymphoma not only provides rapid diagnostic results but also visual feedback, aiding surgical decision-making and potential treatment strategies within a critical timeframe.
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Background: Percutaneous microwave ablation (pMWA) is a minimally invasive procedure that uses a microwave antenna placed at the tip of a needle to induce lethal tissue heating. It can treat cancer and other diseases with lower morbidity than conventional surgery, but one major limitation is the lack of control over the heating region around the ablation needle. Superparamagnetic iron oxide nanoparticles have the potential to enhance and control pMWA heating due to their ability to absorb microwave energy and their ease of local delivery.

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Purpose: The purpose of this study was to assess ocular coat mechanical behavior using controlled ocular microvolumetric injections (MVI) of 15 µL of balanced salt solution (BSS) infused over 1 second into the anterior chamber (AC) via a syringe pump.

Methods: Intraocular pressure (IOP) was continuously recorded at 200 Hz with a validated implantable IOP telemetry system in 7 eyes of 7 male rhesus macaques (nonhuman primates [NHPs]) during 5 MVIs in a series at native (3 trials), 15 and 20 mm Hg baseline IOPs, repeated in 2 to 5 sessions at least 2 weeks apart. Ocular rigidity coefficients (K) and ocular pulse volume (PV) were calculated for each trial.

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Purpose: To characterize relationships between intraocular pressure (IOP), mean arterial pressure (MAP), ocular perfusion pressure (OPP), IOP transient impulse, and IOP baseline impulse using continuous telemetry in nonhuman primates.

Methods: We used our validated implantable telemetry system to wirelessly record bilateral IOP and arterial BP at 500 Hz in 7 eyes of 4 male rhesus macaques, aged 4 to 5 years. IOP, MAP, OPP, IOP transient impulse, and IOP baseline impulse were averaged into 1-hour periods over 20 days for each NHP.

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We report the effects of oxygen pressure during growth ([Formula: see text]) on the electronic and magnetic properties of PrAlO films grown on [Formula: see text]-terminated SrTiO substrates. Resistivity measurements show an increase in the sheet resistance as [Formula: see text] is increased. The saturation of the sheet resistance down to 0.

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We describe the synthesis, characterization, and use of hybrid nanoparticles with a superparamagnetic iron oxide (SPIO) core and a gold nanoshell. These multifunctional nanoparticles, designated SPIO-Au nanoshells, displayed superparamagnetic characteristics and a significant absorbance in the near-infrared (NIR) region of the electromagnetic spectrum. In addition, they exhibited high transverse relaxivity, , and a large ratio and therefore could be imaged by MRI to obtain T-weighted images.

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New bimetallic copper(I) and copper(II) complexes of dipyrromethane-derived Schiff base macrocycles are reported. Two different structural motifs were identified, providing support for the notion that ligands of this type can support a variety of coordination modes. In the case of the Cu(I) complexes, the metal centers were found to have a distorted tetrahedral geometry and be coordinated to two imine nitrogens on each side of the ligand, with the exact structure depending on the choice of Schiff base macrocycle.

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The coordination chemistry of the Schiff base polypyrrolic octaaza macrocycle 1 toward late first-row transition metals was investigated. Binuclear complexes with the divalent cations Ni(II), Cu(II), and Zn(II) and with the monovalent cation Cu(I) were prepared and characterized. Air oxidation of the Cu(I) ions in the latter complex to their divalent oxidation state resulted in a change in the coordination mode relative to the macrocycle.

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Self-organized Co nanoplatelets with a singular height, quantized lateral sizes, and unique shape and orientation have been fabricated on a template consisting of ordered Al nanocluster arrays on Si(111)-7 x 7 surfaces. Despite their small volume (a few nm(3)), these nanomagnets exhibit an unusually high blocking temperature (>100 K). The perpendicular direction for easy magnetization, the high blocking temperature, the size tunability, and the epitaxial growth on Si substrates make these nanomagnets important for applications in information technology.

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