13,970 research outputs found
PET-CT Principles and Applications in Lung Cancer Management
Lung cancer is the most common malignant cancer throughout the world; the positron emission tomography/computed tomography (PET-CT) combines both the metabolism information from PET and anatomy details from CT, which is the state of the art. This manuscript introduced the PET-CT and applications in lung cancer diagnosing, staging, and treatment. Several aspects including clinical features, classification, grading and pathology of the lung cancer, principles of PET-CT, and evaluation of diagnosing and treatment had been covered. Detailed demonstration of each cancer subtype, staging criteria, and classification was described. The content will benefit the clinical doctors as well as radiologists
Towards Searching for Entangled Photons in the CMB Sky
We explore the possibility of detecting entangled photon pairs from cosmic
microwave background or other cosmological sources coming from two patches of
the sky. The measurements use two detectors with different photon polarizer
directions. When two photon sources are separated by a large angle relative to
the earth, such that each detector has only one photon source in its field of
view, a null test of unentangled photons can be performed. The deviation from
this unentangled background is, in principle, the signature of photon
entanglement. To confirm whether the deviation is consistent with entangled
photons, we derive a photon polarization correlation to compare with, similar
to that in a Bell inequality measurement. However, since photon coincidence
measurement cannot be used to discriminate unentangled cosmic photons, it is
unlikely that the correlation expectation value alone can violate Bell
inequality to provide the signature for entanglement.Comment: 5 pages, 2 figure; references added, typos fixed. v3 revised version
with more discussions on detection possibilities; added references.v4
published version in PR
Frozen Bardeen-Dirac stars and light ball
In this paper, we study solutions of a static spherically symmetric system,
which is composed of the coupling with the Bardeen action and two Dirac fields.
For the case where only the Bardeen action is present, the magnetic charge
can be infinite, then when the magnetic charge is greater than a certain value
, there exists a black hole solution, which is called the Bardeen black
hole (BBH). However, if the Dirac field is introduced, we find that the
magnetic charge can only be smaller than the critical value , in which
there is no black hole solution. Moreover, in the region , we find that
if the magnetic charge exceeds another critical value (i.e.,
), the frequency of the Dirac field can approach zero, and the
solution where a critical horizon appears is similar to an extremal black hole
outside the critical horizon but has a nonsingular interior. The Dirac fields
are also almost concentrated within it. In fact, this is a frozen star
solution, we call such solutions frozen Bardeen-Dirac stars (FBDSs). We analyze
the light rings of FBDSs and find that there exists a ``true" light ring
outside the critical horizon, but inside it, the velocity of photons is very
close to zero, which leads to the formation of a ``light ball" inside the
critical horizon.Comment: 22 pages, 7 figure
Investigation of Cofactor Activities of Endothelial Microparticle- Thrombomodulin with Liposomal Surrogate
Thrombomodulin (TM) is a type I transmembrane glycoprotein mainly expressed on the endothelial cells, where it binds thrombin to form the thrombin-TM complex that can activate protein C and thrombin-activable fibrinolysis inhibitor (TAFI) and induce anticoagulant and anti-fibrinolytic reactions, respec-tively. Cell activation and injury often sheds microparticles that contain membrane TM, which circulate in biofluids like blood. However, the biological function of circulating microparticle-TM is still unknown even though it has been recognized as a biomarker of endothelial cell injury and damage. In comparison with cell membrane, different phospholipids are exposed on the microparticle surface due to cell membrane flip-flop upon cell activation and injury. Liposomes can be used as a microparticle mimetics. In this report, we prepared TM-containing liposomes with different phospholipids as surrogates of endothelial microparticle-TM and investigated their cofactor activities. We found that liposomal TM with phosphatidylethanolamine (PtEtn) showed increased protein C activation but decreased TAFI activation in comparison to liposomal TM with phosphatidylcholine (PtCho). In addition, we investigated whether protein C and TAFI compete for the thrombin/TM complex on the liposomes. We found that protein C and TAFI did not compete for the thrombin/TM complex on the liposomes with PtCho alone and with low concentration (5%) of PtEtn and phosphatidylserine (PtSer), but competed each other on the liposomes with higher concentration (10%) of PtEtn and PtSer. These results indicate that membrane lipids affect protein C and TAFI activation and microparticle-TM may have different cofactor activities in comparison to cell membrane TM.(c) 2023 The Author(s)
Tidal Love numbers of Axion stars
We investigate the tidal deformability of spherically symmetric axion stars
on the stable branches, including the Newtonian and relativistic branches. The
results suggest that on the stable branch, the electric Love numbers of axion
star are positive, while the magnetic Love numbers are negative. On the
Newtonian stable branch, the electric tidal Love numbers are much larger than
the magnetic ones, while on the relativistic stable branch, they are slightly
larger. Furthermore, the relativistic stable branch has much smaller tidal Love
numbers than the Newtonian stable branch, indicating weaker deformability of
axion stars on the relativistic stable branch. This could be attributed to the
fact that on the relativistic branch, axion stars are more compact, resulting
hardly distorted by tidal forces.Comment: 22 pages, 5 figure
PIP2 Activates TRPV5 and Releases Its Inhibition by Intracellular Mg2+
The transient receptor potential type V5 channel (TRPV5) is a Ca2+-selective TRP channel important for epithelial Ca2+ transport. Intracellular Mg2+ causes a fast voltage-dependent block of the TRPV5 channel by binding to the selectivity filter. Here, we report that intracellular Mg2+ binding to the selectivity filter of TRPV5 also causes a slower reversible conformational change leading to channel closure. We further report that PIP2 activates TRPV5. Activation of TRPV5 by PIP2 is independent of Mg2+. Yet, PIP2 decreases sensitivity of the channel to the Mg2+-induced slow inhibition. Mutation of aspartate-542, a critical Mg2+-binding site in the selectivity filter, abolishes Mg2+-induced slow inhibition. PIP2 has no effects on Mg2+-induced voltage-dependent block. Thus, PIP2 prevents the Mg2+-induced conformational change without affecting Mg2+ binding to the selectivity filter. Hydrolysis of PIP2 via receptor activation of phospholipase C sensitizes TRPV5 to the Mg2+-induced slow inhibition. These results provide a novel mechanism for regulation of TRP channels by phospholipase C–activating hormones via alteration of the sensitivity to intracellular Mg2+
Excited Dirac stars with higher azimuthal harmonic index
In this paper, we investigate the properties of the first excited state Dirac
stars (DSs) with higher azimuthal harmonic index (specifically, the azimuthal
harmonic indexes = , , ), as well as the relationship
between the ADM mass and angular momentum of Dirac stars with respect to
frequency. Moreover, We find that the ergospheres of DSs appear at lower spinor
field frequencies, and both the ergospheres and the distribution of the spinor
field functions are asymmetric about the equatorial plane. Furthermore, we
introduce the ground state scalar field and examine its impact on this system,
which is known as the multi-state Dirac-boson stars (DBSs) model. We show
various types of solution families for DBSs under both synchronized frequency
and nonsynchronized frequencies and find that similar to DSs, the
spinor field and the ergospheres of DBSs are also asymmetric about the
equatorial plane, but the ergospheres appear at higher spinor field
frequencies.Comment: 22 pages, 8 figure
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