Results 1 to 10 of about 717,720 (220)

On a class of PDEs with nonlinear distributed in space and time state-dependent delay term [PDF]

arXiv, 2006
A new class of nonlinear partial differential equations with distributed in space and time state-dependent delay is investigated. We find appropriate assumptions on the kernel function which represents the state-dependent delay and discuss advantages of this class.
Alexander V. Rezounenko
openalex   +3 more sources

COMP Report: CPQR technical quality control guidelines for use of positron emission tomography/computed tomography in radiation treatment planning

Journal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Positron emission tomography with x‐ray computed tomography (PET/CT) is increasingly being utilized for radiation treatment planning (RTP). Accurate delivery of RT therefore depends on quality PET/CT data. This study covers quality control (QC) procedures required for PET/CT for diagnostic imaging and incremental QC required for RTP.
Ran Klein, Mike Oliver, Dan La Russa, John Agapito, Stewart Gaede, JeanPierre Bissonnette, Arman Rahmim, Carlos Uribe   +7 more
wiley   +1 more source

Application value of contrast‐enhanced ultrasound in preoperative localization of microwave ablation for primary hyperparathyroidism

Journal of Applied Clinical Medical Physics, Volume 23, Issue 12, December 2022., 2022
Abstract Background Ultrasonography (US) and 99mTechnetium‐sestamibi scintigraphy (99mTc‐MIBI) are currently first‐line imaging modalities to localize parathyroid adenomas with sensitivities of 80% and 84%, respectively. Therefore, finding other modalities to further improve the diagnostic accuracy for preoperative localization is critically needed ...
Fangyi Liu, Li Zang, Yunlin Li, Zhiwei Guan, Yang Liu, Xiaoling Yu, Zhiyu Han, Ping Liang   +7 more
wiley   +1 more source

Stability for nonautonomous linear differential systems with infinite delay [PDF]

Journal of Dynamics and Differential Equations, 2020, 2020
We study the stability of general $n$-dimensional nonautonomous linear differential equations with infinite delays. Delay independent criteria, as well as criteria depending on the size of some finite delays are established. In the first situation, the effect of the delays is dominated by non-delayed diagonal negative feedback terms, and sufficient ...
arxiv   +1 more source

A potential biomarker of cognitive impairment: The olfactory dysfunction and its genes expression

Annals of Clinical and Translational Neurology, Volume 9, Issue 12, Page 1884-1897, December 2022., 2022
Abstract Objective Accumulation evidence has reported that olfactory impairment may be an essential clinical marker and predictor of mild cognitive impairment or Alzheimer's disease. Method Participants were enrolled in the population‐based, prospective study in Fuxin county, Liaoning province, China between 2019 and 2021.
Jiayi Song, Jiahui Xu, Wei Yuan, Ruixue Li, Hui Guo, Hanshu Gao, Cuiying Gu, Wenjing Feng, Yanan Ma, Haiqiang Guo, Zhaoqing Sun, Liqiang Zheng   +11 more
wiley   +1 more source

Vascular endothelial‐cadherin as a marker of endothelial injury in preclinical Alzheimer disease

Annals of Clinical and Translational Neurology, Volume 9, Issue 12, Page 1926-1940, December 2022., 2022
Abstract Objective Endothelial dysfunction is an early and prevalent pathology in Alzheimer disease (AD). We here investigate the value of vascular endothelial‐cadherin (VEC) as a cerebrospinal fluid (CSF) marker of endothelial injury in preclinical AD.
Rawan Tarawneh, Rachel S. Kasper, Jessie Sanford, Chia‐Ling Phuah, Jason Hassenstab, Carlos Cruchaga   +5 more
wiley   +1 more source

Early‐onset Alzheimer's disease shows a distinct neuropsychological profile and more aggressive trajectories of cognitive decline than late‐onset

Annals of Clinical and Translational Neurology, Volume 9, Issue 12, Page 1962-1973, December 2022., 2022
Abstract Objectives Early‐ and late‐onset Alzheimer's disease (EOAD and LOAD) share the same neuropathological traits but show distinct cognitive features. We aimed to explore baseline and longitudinal outcomes of global and domain‐specific cognitive function in a well characterized cohort of patients with a biomarker‐based diagnosis.
Adrià Tort‐Merino, Neus Falgàs, Isabel E. Allen, Mircea Balasa, Jaume Olives, José Contador, Magdalena Castellví, Jordi Juncà‐Parella, Núria Guillén, Sergi Borrego‐Écija, Bea Bosch, Guadalupe Fernández‐Villullas, Oscar Ramos‐Campoy, Anna Antonell, Lorena Rami, Raquel Sánchez‐Valle, Albert Lladó   +16 more
wiley   +1 more source

Two models of partial differential equations with discrete and distributed state-dependent delays [PDF]

Journal of Mathematical Analysis and Applications. Volume 326, Issue 2, (15 February 2007), Pages 1031-1045., 2005
This work is the first attempt to treat partial differential equations with discrete (concentrated) state-dependent delay. The main idea is to approximate the discrete delay term by a sequence of distributed delay terms (all with state-dependent delays).
arxiv   +1 more source

Amplitude death in systems of coupled oscillators with distributed-delay coupling [PDF]

Eur. Phys. J. B 84, 307-315 (2011), 2012
This paper studies the effects of coupling with distributed delay on the suppression of oscillations in a system of coupled Stuart-Landau oscillators. Conditions for amplitude death are obtained in terms of strength and phase of the coupling, as well as the mean time delay and the width of the delay distribution for uniform and gamma distributions ...
arxiv   +1 more source

Mapping dynamical systems with distributed time delays to sets of ordinary differential equations [PDF]

, 2023
Real-world dynamical systems with retardation effects are described in general not by a single, precisely defined time delay, but by a range of delay times. An exact mapping onto a set of $N+1$ ordinary differential equations exists when the respective delay distribution is given in terms of a gamma distribution with discrete exponents.
arxiv   +1 more source