We report resonant feedback random lasing from dye-doped biopolymer films, consisting of a deoxyribonucleic acid-cetyltrimethylammonium (DNA-CTMA) complex doped with DCM dye. In the proposed devices, the optical feedback for random lasing is given by scattering centers randomly positioned along the edges of the active area. Scattering elements are either titanium dioxide nanoparticles or random defects at the interface between active polymer and air. Different emission spectra are observed, depending on the geometry of the excited area. A single random resonator with dimensions of 2.6 mm x 0.65 mm is fabricated and random emission with resonant feedback is obtained by uniformly pumping the full device.
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http://dx.doi.org/10.1364/OE.23.029954 | DOI Listing |
Space payloads in orbit are vulnerable to small vibrations from satellite platforms, which can degrade their performance. Traditional methods typically involve installing a passive vibration isolation system between the platform and the payload. However, such systems are usually effective only for high-frequency, large-amplitude vibrations and perform poorly in isolating low-frequency vibrations and resonances below 10 Hz.
View Article and Find Full Text PDFEur J Radiol Open
June 2025
Institution of Molecular Medicine and Surgery (MMK), Karolinska Institutet, Stockholm, Sweden.
Background: High-quality assessment of prostate MRI is fundamental in both clinical practice and screening. There is a lack of national level data on variability in prostate volume measurement and PI-RADS assessment. Methods of quality assurance need to be developed.
View Article and Find Full Text PDFJ Med Syst
January 2025
Department of Neurosurgery, University Medical Centre Utrecht, Utrecht, The Netherlands.
This study aimed to develop and validate a cost-effective, customizable patient-specific phantom for simulating external ventricular drain placement, combining image segmentation, 3-D printing and molding techniques. Two variations of the phantom were created based on patient MRI data, integrating a realistic skin layer with anatomical landmarks, a 3-D printed skull, an agarose polysaccharide gel brain, and a ventricular cavity. To validate the phantom, 15 neurosurgeons, residents, and physician assistants performed 30 EVD placements.
View Article and Find Full Text PDFTheranostics
January 2025
Lab of Molecular Imaging and Translational Medicine (MITM), Engineering Research Center of Molecular and Neuro Imaging, Ministry of Education, School of Life Science and Technology, Xidian University & International Joint Research Center for Advanced Medical Imaging and Intelligent Diagnosis and Treatment, Xi'an, Shaanxi, 710126, P. R. China.
The quick and accurate detection of colorectal cancer (CRC) is essential for improving the treatment efficacy and patient survival, which nevertheless remains challenging due to low specificity and sensitivity of current CRC diagnostic approaches. Therefore, providing a robust solution for real-time and accurate tumor delineation is highly desirable. We report a novel polyacrylic acid-mediated strategy to develop the endogenous hydrogen sulfide (HS)-activated NIR-II probe DCNP@PB for specific visualization of CRC and image-guided tumor surgery.
View Article and Find Full Text PDFSurg Endosc
December 2024
Department of Mechanical Engineering and Applied Mechanics, University of Pennsylvania, Philadelphia, USA.
Background: New surgeons experience heavy workload during robot-assisted surgery partially because they must use vision to compensate for the lack of haptic feedback. We hypothesize that providing realistic haptic feedback during dry-lab simulation training may accelerate learning and reduce workload during subsequent surgery on patients.
Methods: We conducted a single-blinded study with 12 general surgery residents (third and seventh post-graduate year, PGY) randomized into haptic and control groups.
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