keyword
MENU ▼
Read by QxMD icon Read
search

PSF

keyword
https://www.readbyqxmd.com/read/28649154/skin-dose-mapping-for-non-uniform-x-ray-fields-using-a-backscatter-point-spread-function
#1
Sarath Vijayan, Zhenyu Xiong, Alok Shankar, Stephen Rudin, Daniel R Bednarek
Beam shaping devices like ROI attenuators and compensation filters modulate the intensity distribution of the x-ray beam incident on the patient. This results in a spatial variation of skin dose due to the variation of primary radiation and also a variation in backscattered radiation from the patient. To determine the backscatter component, backscatter point spread functions (PSF) are generated using EGS Monte-Carlo software. For this study, PSF's were determined by simulating a 1 mm beam incident on the lateral surface of an anthropomorphic head phantom and a 20 cm thick PMMA block phantom...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28648903/social-frailty-and-functional-disability-findings-from-the-singapore-longitudinal-ageing-studies
#2
Nigel Teo, Qi Gao, Ma Shwe Zin Nyunt, Shiou Liang Wee, Tze-Pin Ng
BACKGROUND/OBJECTIVE: To examine the association between the social frailty (SF) phenotype and functional disability, independently of the physical frailty (PF) phenotype, and compare the abilities of the PF, SF, and combined social and physical (PSF) indexes for predicting functional disability. METHOD: Cross-sectional and longitudinal analyses of a population-based cohort (Singapore Longitudinal Ageing Study, SLAS-1) of 2406 community-dwelling older adults with 3 years of follow-up (N = 1254 and N = 1557 for instrumental activity of daily living (IADL) disability and severe disability (≥3 basic ADL) respectively)...
July 1, 2017: Journal of the American Medical Directors Association
https://www.readbyqxmd.com/read/28633417/polypyrimidine-tract-binding-protein-ptb-and-ptb-associated-splicing-factor-in-cvb3-infection-an-itaf-for-an-itaf
#3
Pratik Dave, Biju George, Divya Khandige Sharma, Saumitra Das
The 5΄ UTR of Coxsackievirus B3 (CVB3) contains internal ribosome entry site (IRES), which allows cap-independent translation of the viral RNA and a 5΄-terminal cloverleaf structure that regulates viral replication, translation and stability. Here, we demonstrate that host protein PSF (PTB associated splicing factor) interacts with the cloverleaf RNA as well as the IRES element. PSF was found to be an important IRES trans acting factor (ITAF) for efficient translation of CVB3 RNA. Interestingly, cytoplasmic abundance of PSF protein increased during CVB3 infection and this is regulated by phosphorylation status at two different amino acid positions...
June 15, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28632535/perioperative-surgical-home-evaluation-of-a-new-protocol-focused-on-a-multidisciplinary-approach-to-manage-children-undergoing-posterior-spinal-fusion-operation
#4
Eugene Kim, Brian Lee, Giovanni Cucchiaro
BACKGROUND: The concept of Perioperative Surgical Home has been gaining significant attention in surgical centers. This model is delivering and improving coordinated care in a cost-effective manner to patients undergoing surgical procedures. It starts with the decision for surgical intervention, continues to the intraoperative and postoperative periods, and follows into long-term recovery. Constant re-evaluation of outcomes and modifications of delivery provides a feedback loop for improvement...
June 17, 2017: Anesthesia and Analgesia
https://www.readbyqxmd.com/read/28629055/a-novel-kind-of-polysulfone-material-with-excellent-biocompatibility-modified-by-the-sulfonated-hydroxypropyl-chitosan
#5
Tian-Ming Liu, Jing-Jie Xu, Yun-Ren Qiu
In order to ameliorate the biocompatibility of polysulfone (PSf), sulfonated hydroxypropyl chitosan (SHPCS) was grafted from PSf membrane material by Schiff-Base reaction. The original and modified membranes were characterized by attenuated total reflectance-Fourier transform infrared spectroscope (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), water contact angle (WCA) measurement, tensile strength test and antibacterial test in vitro, and the results indicated that the PSf modified by SHPCS (PSf-SHPCS) was synthesized successfully, the hydrophilicity of PSf-SHPCS membrane was improved to a great extent, all the membranes possessed good stability in physiological condition and the PSf-SHPCS membrane had good antibacterial property...
October 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28619655/comparison-of-the-spatial-resolution-of-source-imaging-techniques-in-high-density-eeg-and-meg
#6
T Hedrich, G Pellegrino, E Kobayashi, J M Lina, C Grova
BACKGROUND: The present study aims at evaluating and comparing electrical and magnetic distributed source imaging methods applied to high-density Electroencephalography (hdEEG) and Magnetoencephalography (MEG) data. We used resolution matrices to characterize spatial resolution properties of Minimum Norm Estimate (MNE), dynamic Statistical Parametric Mapping (dSPM), standardized Low-Resolution Electromagnetic Tomography (sLORETA) and coherent Maximum Entropy on the Mean (cMEM, an entropy-based technique)...
June 13, 2017: NeuroImage
https://www.readbyqxmd.com/read/28615791/monte-carlo-investigation-of-backscatter-point-spread-function-for-x-ray-imaging-examinations
#7
Zhenyu Xiong, Sarath Vijayan, Stephen Rudin, Daniel R Bednarek
X-ray imaging examinations, especially complex interventions, may result in relatively high doses to the patient's skin inducing skin injuries. A method was developed to determine the skin-dose distribution for non-uniform x-ray beams by convolving the backscatter point-spread-function (PSF) with the primary-dose distribution to generate the backscatter distribution that, when added to the primary dose, gives the total-dose distribution. This technique was incorporated in the dose-tracking system (DTS), which provides a real-time color-coded 3D-mapping of skin dose during fluoroscopic procedures...
February 11, 2017: Proceedings of SPIE
https://www.readbyqxmd.com/read/28614287/nasal-swab-screening-for-staphylococcus-aureus-in-spinal-deformity-patients-treated-with-growing-rods
#8
Scott J Luhmann, June C Smith
BACKGROUND: Surgical-site infections are one of the most concerning complications in patients treated with growing rods (GR). The purpose of this study was to evaluate the use of preoperative screening for Staphylococcus aureus (SA) for all growing spine procedures, and if this would permit alteration of prophylactic antibiotics to cover the identified resistances. METHODS: All patients were identified who had SA screening during the course of GR treatment. In otal, 34 patients [23 neuromuscular (NMS), 4 congenital, 4 idiopathic scoliosis (IS), and 3 syndromic] were identified who had 111 preoperative screenings [79 lengthenings, 23 insertions, 6 revisions, and 3 conversions to posterior spinal fusions (PSF)]...
June 13, 2017: Journal of Pediatric Orthopedics
https://www.readbyqxmd.com/read/28604495/when-do-patients-return-to-physical-activities-and-athletics-after-scoliosis-surgery-a-validated-patient-questionnaire-based-study
#9
Vishal Sarwahi, Stephen Wendolowski, Rachel Gecelter, Kathleen Maguire, Melanie Gambassi, Dana Orlando, Yungtai Lo, Terry Amaral
STUDY DESIGN: A retrospective chart review with a survey OBJECTIVES.: This study seeks to determine time of return to normal, physical and athletic activities and delaying factors after all pedicle screw fixation. SUMMARY OF BACKGROUND DATA: Return to athletic activity after PSF in AIS is largely dependent on surgeon's philosophy. Some allow contact and collision sports by 6 and 12 months, while others avoid contact sports for 1 year and never allow collision sports...
June 9, 2017: Spine
https://www.readbyqxmd.com/read/28601381/optimal-reconstruction-matrix-and-pet-image-filtration-for-point-spread-function-and-time-of-flight-reconstruction-a-phantom-study
#10
Jaroslav Ptáček, Pavel Karhan, Petr Fiala
INTRODUCTION: The aim of this study was to determine the optimal image matrix and half-width of the Gaussian filter after iterative reconstruction of the PET image with point-spread function (PSF) and time-of-flight (TOF) correction, based on measuring the recovery coefficient (RC) curves. The measured RC curves were compared to those from an older system which does not use PSF and TOF corrections. MATERIALS AND METHODS: The measurements were carried out on a NEMA IEC Body Phantom...
June 7, 2017: Physica Medica: PM
https://www.readbyqxmd.com/read/28598338/polysulfone-ultrafiltration-membrane-incorporated-with-ag-sio2-nanohybrid-for-effective-fouling-control
#11
Huiqing Wu, Jing Huang, Yuejun Liu
An anti-fouling hybrid membrane was prepared by incorporating Ag-SiO2 nanohybrid into a polysulfone (PSf) matrix. The addition of Ag-SiO2 can significantly improve the hydrophilicity, separation property, anti-fouling ability, and especially anti-bacterial activity of hybrid membranes. The optimum performance of the Ag-SiO2/PSf hybrid membrane is achieved when the concentration of Ag-SiO2 is as low as 0.45 wt%. Compared with PSf membrane and SiO2/PSf hybrid membrane, the Ag-SiO2/PSf hybrid membrane displays the best overall properties...
June 2017: Journal of Water and Health
https://www.readbyqxmd.com/read/28595069/kinetic-analysis-of-aerobic-biotransformation-pathways-of-a-perfluorooctane-sulfonate-pfos-precursor-in-distinctly-different-soils
#12
Lilan Zhang, Linda S Lee, Junfeng Niu, Jinxia Liu
With the phaseout of perfluorooctane sulfonate (PFOS) production in most countries and its well known recalcitrance, there is a need to quantify the potential release of PFOS from precursors previously or currently being emitted into the environment. Aerobic biodegradation of N-ethyl perfluorooctane sulfonamidoethanol (EtFOSE) was monitored in two soils from Indiana, USA: an acidic forest silt loam (FRST-48, pH = 5.5) and a high pH agricultural loam (PSF-49, pH = 7.8) with similar organic carbon contents (2...
June 5, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28594542/development-of-hybrid-ultrafiltration-membranes-with-improved-water-separation-properties-using-modified-superhydrophilic-metal-organic-framework-nanoparticles
#13
Huazhen Sun, Beibei Tang, Peiyi Wu
Metal-organic frameworks (MOFs) are being intensively explored as filler materials for polymeric membranes primarily due to their high polymer affinity, large pore volumes, and alterable pore functionalities, but the development of MOF-based ultrafiltration (UF) membranes for water treatment lags behind. Herein, poly(sulfobetaine methacrylate) (PSBMA)-functionalized MOF UiO-66-PSBMA was developed, and incorporated into polysulfone (PSf) casting solution to fabricate novel hybrid UF membranes via phase-inversion method...
June 14, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28594468/application-of-an-advanced-maximum-likelihood-estimation-restoration-method-for-enhanced-resolution-and-contrast-in-second-harmonic-generation-microscopy
#14
Mayandi Sivaguru, Mohammad M Kabir, Manas Rangan Gartia, David S C Biggs, Barghav S Sivaguru, Vignesh A Sivaguru, Glenn A Fried, Gang Logan Liu, Sakthivel Sadayappan, Kimani C Toussaint
Second-harmonic generation (SHG) microscopy has gained popularity because of its ability to perform submicron, label-free imaging of noncentrosymmetric biological structures, such as fibrillar collagen in the extracellular matrix environment of various organs with high contrast and specificity. Because SHG is a two-photon coherent scattering process, it is difficult to define a point spread function (PSF) for this modality. Hence, compared to incoherent two-photon processes like two-photon fluorescence, it is challenging to apply the various PSF-engineering methods to improve the spatial resolution to be close to the diffraction limit...
June 8, 2017: Journal of Microscopy
https://www.readbyqxmd.com/read/28591074/different-fusion-approaches-for-single-level-lumbar-spondylolysis-have-similar-perioperative-outcomes
#15
Raj J Gala, Patawut Bovonratwet, Matthew L Webb, Arya G Varthi, Michael D Daubs, Jonathan N Grauer
STUDY DESIGN: Retrospective cohort study OBJECTIVE.: To compare perioperative adverse events for patients with lumbar spondylolysis treated with transforaminal lumbar interbody fusion (TLIF), posterior spinal fusion (PSF), combined anterior and posterior fusion (AP fusion), or anterior lumbar interbody fusion (ALIF). SUMMARY OF BACKGROUND DATA: Prior cohort studies have shown similar long-term outcomes for different surgical approaches for this indication, but potential differences in thirty day perioperative adverse events have not been well characterized...
June 6, 2017: Spine
https://www.readbyqxmd.com/read/28583635/influence-of-pet-reconstruction-technique-and-matrix-size-on-qualitative-and-quantitative-assessment-of-lung-lesions-on-18f-fdg-pet-a-prospective-study-in-37-cancer-patients
#16
Georg Riegler, Georgios Karanikas, Ivo Rausch, Albert Hirtl, Karem El-Rabadi, Wolfgang Marik, Christopher Pivec, Michael Weber, Helmut Prosch, Marius Mayerhoefer
PURPOSE: To evaluate the influence of point spread function (PSF)-based reconstruction and matrix size for PET on (1) lung lesion detection and (2) standardized uptake values (SUV). METHODS: This prospective study included oncological patients who underwent [18F]-FDG-PET/CT for staging. PET data were reconstructed with a 2D ordered subset expectation maximization (OSEM) algorithm, and a 2D PSF-based algorithm (TrueX), separately with two matrix sizes (168×168 and 336×336)...
May 2017: European Journal of Radiology
https://www.readbyqxmd.com/read/28574882/surgical-outcomes-of-posterior-spinal-fusion-alone-using-cervical-pedicle-screw-constructs-for-cervical-disorders-associated-with-athetoid-cerebral-palsy
#17
Kei Watanabe, Toru Hirano, Keiichi Katsumi, Masayuki Ohashi, Hirokazu Shoji, Akiyoshi Yamazaki, Tomohiro Izumi, Kazuhiro Hasegawa, Takui Ito, Naoto Endo
STUDY DESIGN: Retrospective case series. OBJECTIVE: To investigate clinical outcomes after posterior spinal fusion (PSF) using cervical pedicle screw (CPS) constructs for cervical disorders associated with athetoid cerebral palsy (CP). SUMMARY OF BACKGROUND DATA: Traditionally, most patients with cervical myelopathy associated with CP have required combined anterior and posterior fusion to achieve solid stability against severe involuntary movement...
June 1, 2017: Spine
https://www.readbyqxmd.com/read/28571380/local-glass-transition-temperature-tg-z-of-polystyrene-next-to-different-polymers-hard-vs-soft-confinement
#18
Roman R Baglay, Connie B Roth
The depth to which the local glass transition temperature Tg and alpha-relaxations are perturbed near a boundary is believed to be related to the characteristic length scales associated with cooperative dynamics in dynamically heterogeneous glasses. Following our recent work [R. R. Baglay and C. R. Roth, J. Chem. Phys. 143, 111101 (2015)] that measured a very broad 350-400 nm local Tg(z) profile across a glassy-rubbery interface of polystyrene (PS)/poly(n-butyl methacrylate) (PnBMA), we compare here how the Tg(z) profile in PS varies when changing the neighboring polymer from a lower Tg material to a higher Tg material...
May 28, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28560574/eortc-pet-response-criteria-are-more-influenced-by-reconstruction-inconsistencies-than-percist-but-both-benefit-from-the-earl-harmonization-program
#19
Charline Lasnon, Elske Quak, Pierre-Yves Le Roux, Philippe Robin, Michael S Hofman, David Bourhis, Jason Callahan, David S Binns, Cédric Desmonts, Pierre-Yves Salaun, Rodney J Hicks, Nicolas Aide
BACKGROUND: This study evaluates the consistency of PET evaluation response criteria in solid tumours (PERCIST) and European Organisation for Research and Treatment of Cancer (EORTC) classification across different reconstruction algorithms and whether aligning standardized uptake values (SUVs) to the European Association of Nuclear Medicine acquisition (EANM)/EARL standards provides more consistent response classification. MATERIALS AND METHODS: Baseline (PET1) and response assessment (PET2) scans in 61 patients with non-small cell lung cancer were acquired in protocols compliant with the EANM guidelines and were reconstructed with point-spread function (PSF) or PSF + time-of-flight (TOF) reconstruction for optimal tumour detection and with a standardized ordered subset expectation maximization (OSEM) reconstruction known to fulfil EANM harmonizing standards...
December 2017: EJNMMI Physics
https://www.readbyqxmd.com/read/28557801/a-comprehensive-model-for-x-ray-projection-imaging-system-efficiency-and-image-quality-characterization-in-the-presence-of-scattered-radiation
#20
P Monnin, F R Verdun, H Bosmans, S Rodríguez Pérez, N W Marshall
This work proposes a method for assessing the detective quantum efficiency (DQE) of radiographic imaging systems that include both the x-ray detector and the antiscatter device. Cascaded linear analysis of the antiscatter device efficiency (DQEASD) with the x-ray detector DQE is used to develop a metric of system efficiency (DQEsys); the new metric is then related to the existing system efficiency parameters of effective DQE (eDQE) and generalized DQE (gDQE). The effect of scatter on signal transfer was modelled through its point spread function (PSF), leading to an x-ray beam transfer function (BTF) that multiplies with the classical presampling modulation transfer function (MTF) to give the system MTF...
June 23, 2017: Physics in Medicine and Biology
keyword
keyword
67214
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"