Results 71 to 80 of about 20,438 (217)

Clinical comparison of four commercial MRI phantoms on a 0.35T MR‐linac using a standard clinical TRUFI sequence at a single institution

Journal of Applied Clinical Medical Physics, Volume 26, Issue 9, September 2025.
Abstract Purpose Real‑time magnetic resonance–guided radiation therapy (MRgRT) integrates MRI with a linear accelerator (Linac) for gating and adaptive radiotherapy, which requires robust image‑quality assurance over a large field of view (FOV). Specialized phantoms capable of accommodating this extensive FOV are therefore essential.
Mateb Al Khalifa, Tianjun Ma, Haya Aljuaid, Siyong Kim, William Y. Song   +4 more
wiley   +1 more source

VODKA-JWST: Synchronized Growth of Two Supermassive Black Holes in a Massive Gas Disk? A 3.8 kpc Separation Dual Quasar at Cosmic Noon with the NIRSpec Integral Field Unit

The Astrophysical Journal
The search for dual supermassive black holes (SMBHs) is of immense interest in modern astrophysics. Galaxy mergers may fuel and produce SMBH pairs. Actively accreting SMBH pairs are observed as dual quasars, which are vital probes of SMBH growth.
Yuzo Ishikawa, Nadia L. Zakamska, Yue Shen, Xin Liu, Yu-Ching Chen, Hsiang-Chih Hwang, Andrey Vayner, David S. N. Rupke, Sylvain Veilleux, Dominika Wylezalek, Arran C. Gross, Swetha Sankar, Nadiia Diachenko   +12 more
doaj   +1 more source

Development and demonstration of end‐to‐end testing for intra‐fraction motion‐managed workflows

Medical Physics, Volume 52, Issue 9, September 2025.
Abstract Background Intra‐fraction motion management techniques, including beam gating and intra‐fraction drift correction (IDC), have recently been introduced on the Unity MR‐linac (Elekta AB, Stockholm, Sweden) to mitigate the dosimetric impact of motion during treatment.
Stijn Oolbekkink, Jochem W. H. Wolthaus, Bram van Asselen, Peter R. S. Stijnman, Bas W. Raaymakers   +4 more
wiley   +1 more source

The Physical Properties of Low-redshift FeLoBAL Quasars. IV. Optical–Near-IR Spectral Energy Distributions and Near-IR Variability Properties

The Astrophysical Journal
We present the optical–near-infrared spectral energy distributions (SED) and near-infrared variability properties of 30 low-redshift iron low-ionization Broad Absorption Line quasars (FeLoBALQs) and matched samples of LoBALQs and unabsorbed quasars ...
Karen M. Leighly, Hyunseop Choi, Michael Eracleous, Donald M. Terndrup, Sarah C. Gallagher, Gordon T. Richards   +5 more
doaj   +1 more source

Lensed quasar hosts

New Astronomy Reviews, 2006
8 pages, 6 figures, review article with C. Impey at the conference on "QSO Host Galaxies: Evolution and Environment", Aug. 29-Sep.
Hans-Walter Rix, Joseph Lehar, Charles R. Keeton, Chien Y. Peng, Brian McLeod, Christopher S. Kochanek, Chris Impey, Emilio E. Falco   +7 more
openaire   +3 more sources

Quantitative susceptibility mapping in magnetically inhomogeneous tissues

Magnetic Resonance in Medicine, Volume 94, Issue 3, Page 1044-1059, September 2025.
Abstract Purpose Conventional quantitative susceptibility mapping (QSM) methods rely on simplified physical models that assume isotropic and homogeneous tissue properties, leading to artifacts and inaccuracies in biological tissues. This study aims to develop and evaluate DEEPOLE, a deep learning–based method that incorporates macroscopically ...
Thomas Jochmann, Fahad Salman, Michael G. Dwyer, Niels Bergsland, Robert Zivadinov, Jens Haueisen, Ferdinand Schweser   +6 more
wiley   +1 more source

Cosmological Origin of Quasars [PDF]

Annals of the New York Academy of Sciences, 1995
Quasars are the earliest objects known to exist. We examine their origin in the context of popular models for structure formation in the universe. We show that seeds for quasar black holes could have originated from the initial cosmological collapse of overdense regions with unusually small rotation.
openaire   +3 more sources

Guselkumab in East Asians With Moderate‐to‐Severe Ulcerative Colitis: Subgroup Analysis of the QUASAR Induction and Maintenance Studies

Journal of Gastroenterology and Hepatology, Volume 40, Issue 9, Page 2197-2208, September 2025.
ABSTRACT Background and Aim The global QUASAR (NCT04033445) clinical program demonstrated the efficacy and safety of guselkumab, a dual‐acting interleukin‐23 p19 subunit inhibitor, as induction and maintenance therapy in participants with moderate to severely active ulcerative colitis (UC).
Baili Chen, Byong Duk Ye, Qian Cao, Fumihito Hirai, Masayuki Saruta, Minhu Chen, Susan Pelak, Nicole Shipitofsky, Ye Miao, Keira Herr, Bryan Wahking, Jianmin Zhuo, Tadakazu Hisamatsu   +12 more
wiley   +1 more source

A streamlined workflow for comprehensive 4DCT imaging QA with automated analysis of spatial integrity and image quality

Journal of Applied Clinical Medical Physics, Volume 26, Issue 8, August 2025.
Abstract Purpose A comprehensive 4DCT QA program that includes the assessment of spatial integrity and image quality of 4D phantom scans can be resource‐intensive, especially because the analysis burden scales with the number of motion traces used for QA.
Yunjie Yang, Donghoon Lee, Matthew Whitaker, Wendy Harris, Jeho Jeong, Shih‐Chi Lin, Ellen Yorke, Lakshmi Santanam, Grace Tang   +8 more
wiley   +1 more source

Machine Learning–based Search of High-redshift Quasars

The Astrophysical Journal Supplement Series
We present a machine learning search for high-redshift (5.0 < z < 6.5) quasars using the combined photometric data from the Dark Energy Spectroscopic Instrument (DESI) Imaging Legacy Surveys and the Wide-field Infrared Survey Explorer survey.
Guangping Ye, Huanian Zhang, Qingwen Wu
doaj   +1 more source