Results 41 to 50 of about 782,566 (296)

Interpretation of in-air output ratio of wedged fields in different measurement conditions

Journal of Medical Signals and Sensors, 2019
Background: The collimator scatter factor (Sc) is one of the most important parameters in monitor unit (MU) calculation. There are several factors that impact Scvalues, including head structures, backscatter in dose monitoring chambers, and wedges.
Parinaz Mehnati, Farideh Biglari, Ali Jomehzadeh   +2 more
doaj   +1 more source

Evaluation of Iodine-123 and Iodine-131 SPECT activity quantification: a Monte Carlo study

EJNMMI Physics, 2021
Purpose The quantitative accuracy of Nuclear Medicine images, acquired for both planar and SPECT studies, is influenced by the isotope-collimator combination as well as image corrections incorporated in the iterative reconstruction process. These factors
Michaella Morphis, Johan A. van Staden, Hanlie du Raan, Michael Ljungberg   +3 more
doaj   +1 more source

VLBI observations of seven BL Lac objects from RGB sample

, 2007
We present EVN observations of seven BL Lac objects selected from the RGB sample. To investigate the intrinsic radiation property of BL Lac objects, we estimated the Doppler factor with the VLA or MERLIN core and the total 408 MHz luminosity for a sample
Albert, Antón, Augusto, Bondi, Caccianiga, Caccianiga, Cao, Cassaro, Cassaro, Cavallotti, Celotti, D. R. Jiang, Donato, Fan, Fanaroff, Fey, Fossati, Georganopoulos, Ghisellini, Ghisellini, Giommi, Giommi, Giovannini, Giovannini, Giroletti, Giroletti, Giroletti, Jorstad, Kollgaard, Kollgaard, Landt, Laurent-Muehleisen, Laurent-Muehleisen, Liu, Liu, Lähteenmäki, Machalski, Marchã, Marecki, Minfeng Gu, Murphy, Nieppola, Padovani, Padovani, Perlman, Perlman, Piner, Piner, Rector, Rector, Rector, Rector, Sambruna, Scott, Taylor, Taylor, Urry, Veron-Cetty, Wang, Xie, Yi Liu, Zhongzu Wu   +61 more
core   +1 more source

Structural instability impairs function of the UDP‐xylose synthase 1 Ile181Asn variant associated with short‐stature genetic syndrome in humans

FEBS Letters, EarlyView.
The Ile181Asn variant of human UDP‐xylose synthase (hUXS1), associated with a short‐stature genetic syndrome, has previously been reported as inactive. Our findings demonstrate that Ile181Asn‐hUXS1 retains catalytic activity similar to the wild‐type but exhibits reduced stability, a looser oligomeric state, and an increased tendency to precipitate ...
Tuo Li, Pedro A. Sánchez‐Murcia, Bernd Nidetzky   +2 more
wiley   +1 more source

The Panchromatic Hubble Andromeda Treasury. VI. The reliability of far-ultraviolet flux as a star formation tracer on sub-kpc scales

, 2014
We have used optical observations of resolved stars from the Panchromatic Hubble Andromeda Treasury (PHAT) to measure the recent (< 500 Myr) star formation histories (SFHs) of 33 FUV-bright regions in M31.
Bell, Eric F., Bianchi, Luciana, Dalcanton, Julianne J., Dolphin, Andrew E., Johnson, Benjamin D., Simones, Jacob E., Skillman, Evan D., Weisz, Daniel R., Williams, Benjamin F.   +8 more
core   +3 more sources

Star formation and dust extinction in nearby star forming and starburst galaxies [PDF]

, 2002
We study the star formation rate and dust extinction properties of a sample of nearby star forming galaxies as derived from Halpha and UV (2000 A) observations and we compare them to those of a sample of starburst galaxies.
Bonfanti, C., Boselli, A., Buat, V., Gavazzi, G.   +3 more
core   +3 more sources

The (Glg)ABCs of cyanobacteria: modelling of glycogen synthesis and functional divergence of glycogen synthases in Synechocystis sp. PCC 6803

FEBS Letters, EarlyView.
We reconstituted Synechocystis glycogen synthesis in vitro from purified enzymes and showed that two GlgA isoenzymes produce glycogen with different architectures: GlgA1 yields denser, highly branched glycogen, whereas GlgA2 synthesizes longer, less‐branched chains.
Kenric Lee, Dimitrios Bekiari, Sofia Doello, Karl Forchhammer   +3 more
wiley   +1 more source

External inverse-Compton emission from jetted tidal disruption events

, 2016
The recent discoveries of Swift J1644+57 and J2058+05 show that tidal disruption events (TDEs) can launch relativistic jets. Super-Eddington accretion produces a strong radiation field of order Eddington luminosity.
Kumar, Pawan, Lu, Wenbin
core   +1 more source

Effect of Photometric Redshift Uncertainties on Weak Lensing Tomography [PDF]

, 2005
We perform a systematic analysis of the effects of photometric redshift uncertainties on weak lensing tomography. We describe the photo-z distribution with a bias and Gaussian scatter that are allowed to vary arbitrarily between intervals of dz = 0.1 in ...
Dragan Huterer, Ishak M., Peacock J. A., Van Waerbeke L., Wayne Hu, Zhaoming Ma   +5 more
core   +1 more source

Structural biology of ferritin nanocages

FEBS Letters, EarlyView.
Ferritin is a conserved iron‐storage protein that sequesters iron as a ferric mineral core within a nanocage, protecting cells from oxidative damage and maintaining iron homeostasis. This review discusses ferritin biology, structure, and function, and highlights recent cryo‐EM studies revealing mechanisms of ferritinophagy, cellular iron uptake, and ...
Eloise Mastrangelo, Flavio Di Pisa
wiley   +1 more source