Considering the birefringence of the gain medium, we propose a selection rule for designing cavity configurations that enable the generation of radially and azimuthally polarized laser beams with a low beam quality factor, i.e., high beam quality. Using this rule, all stable regions can support cylindrical vector (CV) beams by using the position of the end mirror as the tuning parameter to vary the cavity configuration. Such cavity configurations tend to sustain the fundamental or lowest-order CV beam, and radially or azimuthally polarized beams can be obtained simply by varying the tuning parameter. Based on experimental measurements of the beam quality factor and polarization characteristics, we verified our analyses and simulations for a four-element laser system.
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http://dx.doi.org/10.1364/OE.416353 | DOI Listing |
BMC Cancer
January 2025
Exercise Medicine Research Institute, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA, 6027, Australia.
Background: Tumour hypoxia resulting from inadequate perfusion is common in many solid tumours, including prostate cancer, and constitutes a major limiting factor in radiation therapy that contributes to treatment resistance. Emerging research in preclinical animal models indicates that exercise has the potential to enhance the efficacy of cancer treatment by modulating tumour perfusion and reducing hypoxia; however, evidence from randomised controlled trials is currently lacking. The 'Exercise medicine as adjunct therapy during RADIation for CAncer of the prostaTE' (ERADICATE) study is designed to investigate the impact of exercise on treatment response, tumour physiology, and adverse effects of treatment in prostate cancer patients undergoing external beam radiation therapy (EBRT).
View Article and Find Full Text PDFSci Rep
January 2025
Radiation Safety and Quality Assurance division, National Cancer Center Hospital East, Chiba, 277-8577, Japan.
The impact of three-dimensional (3D) dose delivery accuracy of C-arm linacs on the planning target volume (PTV) margin was evaluated for non-coplanar intracranial stereotactic radiosurgery (SRS). A multi-institutional 3D starshot test using beams from seven directions was conducted at 22 clinics using Varian and Elekta linacs with X-ray CT-based polymer gel dosimeters. Variability in dose delivery accuracy was observed, with the distance between the imaging isocenter and each beam exceeding 1 mm at one institution for Varian and nine institutions for Elekta.
View Article and Find Full Text PDFFood Chem
January 2025
Zhujiang Hospital, Southern Medical University, Guangzhou 510280, China; Faculty of Medicinal Plants and Pharmacognosy, School of Traditional Chinese Medicine, Southern Medical University, Guangzhou 510515, China. Electronic address:
Currently, there remains a debate regarding the functional microorganisms responsible for the quality formation of Guang Chenpi (GCP). Thus, the metabolite profiles and microbial diversity of GCP samples subjected to natural treatment versus those sterilized via electron beam irradiation were investigated over a three-year period. It was found the main constituents of GCP were influenced both by spontaneous changes and microbial activity.
View Article and Find Full Text PDFPhys Med Biol
January 2025
Electrical and Computer Engineering, University of Massachusetts Lowell, Ball Hall, 1 University Ave, Lowell, Massachusetts, 01854, UNITED STATES.
Objective: X-ray photon-counting detectors (PCDs) have recently gained popularity due to their capabilities in energy discrimination power, noise suppression, and resolution refinement. The latest extremity photon-counting computed tomography (PCCT) scanner leverages these advantages for tissue characterization, material decomposition, beam hardening correction, and metal artifact reduction. However, technical challenges such as charge splitting and pulse pileup can distort the energy spectrum and compromise image quality.
View Article and Find Full Text PDFJ Dent Sci
January 2025
Department of Periodontology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University & Shandong Key Laboratory of Oral Tissue Regeneration & Shandong Engineering Research Center of Dental Materials and Oral Tissue Regeneration & Shandong Provincial Clinical Research Center for Oral Diseases, Jinan, China.
Background/purpose: Progesterone (PG) is sex steroid hormone that commonly used to control menopausal symptoms, but its exact role in periodontitis remains unclear. This study aimed to investigate the effects of PG on periodontitis in perimenopausal women and in an experimental rat model.
Materials And Methods: Total 412 perimenopausal women with periodontitis and a history of PG deficiency-induced uterine dysfunctional bleeding were enrolled, among which 209 women had been treated with PG.
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