2,438 research outputs found
Skin Story: with critical introduction: âScars left by the commonplace for womenâ.
A creative thesis with a story about themes of domestic violence focused particularly on an aspect of rape culture that does not directly involve rape: blamed femaleness. The critical introduction seeks to make this tie explicit to the text of the story
Two-loop corrections to the decay rate of parapositronium
Order corrections to the decay rate of parapositronium are
calculated. A QED scattering calculation of the amplitude for electron-positron
annihilation into two photons at threshold is combined with the technique of
effective field theory to determine an NRQED Hamiltonian, which is then used in
a bound state calculation to determine the decay rate. Our result for the
two-loop correction is in units of times the
lowest order rate. This is consistent with but more precise than the result
of a previous calculation.Comment: 26 pages, 7 figure
alpha^2 corrections to parapositronium decay: a detailed description
We present details of our recent calculation of alpha^2 corrections to the
parapositronium decay into two photons. These corrections are rather small and
our final result for the parapositronium lifetime agrees well with the most
recent measurement. Implications for orthopositronium decays are briefly
discussed.Comment: 18 pages, late
The soft-energy region in the radiative decay of bound states
The orthopositronium decay to three photons is studied in the phase-space
region where one of the photons has an energy comparable to the relative
three-momentum of the e+e- system (w ~ m alpha). The NRQED computation in this
regime shows that the dominant contribution arises from distances ~
1/(mw)^(1/2), which allows to treat the Coulomb interaction perturbatively. The
small-photon energy expansion of the 1-loop decay spectrum from full QED yields
the same result as the effective theory. By doing the threshold expansion of
the 1-loop QED amplitude we confirm that the leading term arises from a
loop-momentum region where q^0 ~ q^2/m ~ w. This corresponds to a new
non-relativistic loop-momentum region, which has to be taken into account for
the description of a non-relativistic particle-antiparticle system that decays
through soft photon emission.Comment: 28 pages, 5 figures; typos corrected, one reference added, published
versio
Clinical trial data of anti-PD-1/PD-L1 therapy for recurrent or metastatic nasopharyngeal carcinoma: A review
IMPORTANCE: Anti-programmed cell death receptor-1 (PD-1) therapy is standard of care for incurable recurrent or metastatic non-nasopharyngeal head and neck cancer. In contrast, there are no regulatory agency-approved anti-PD-1 agents indicated for the treatment of recurrent or metastatic nasopharyngeal carcinomas (RM-NPC) in the Western hemisphere, and no standard treatment option exists beyond first-line chemotherapy for RM-NPC. The pace of development of novel systemic therapy regimens for RM-NPC has been slow compared to many other advanced tumor types, leaving an unmet clinical need for these patients with a poor prognosis.
OBSERVATIONS: Recent clinical trials have documented the clinical activity of anti-PD-1 therapy in RM-NPC. In particular, randomized clinical trials in the first-line setting have demonstrated significant improvements in progression-free survival (PFS) with the addition of anti-PD-1 therapy to standard chemotherapy. Whether the observed PFS benefits require combination chemoimmunotherapy or can be achieved with chemotherapy followed by crossover to immunotherapy upon progression remains unknown. Ongoing clinical trials are exploring novel anti-PD-1 therapy-based combinations, which may further solidify a role for these agents in RM-NPC.
CONCLUSIONS AND RELEVANCE: Among patients with RM-NPC, anti-PD-1 therapy added to first-line standard-of-care gemcitabine plus cisplatin provides significantly better efficacy outcomes compared to chemotherapy alone, and anti-PD-1 monotherapy appears to have comparable clinical activity and better tolerability than chemotherapy in previously treated disease. Thus, anti-PD-1 therapy is poised to advance standard of care for the treatment of RM-NPC
Ulta-slow relaxation in discontinuous-film based electron glasses
We present field effect measurements on discontinuous 2D thin films which are
composed of a sub monolayer of nano-grains of Au, Ni, Ag or Al. Like other
electron glasses these systems exhibit slow conductance relaxation and memory
effects. However, unlike other systems, the discontinuous films exhibit a
dramatic slowing down of the dynamics below a characteristic temperature .
is typically between 10-50K and is sample dependent. For the
sample exhibits a few other peculiar features such as repeatable conductance
fluctuations in millimeter size samples. We suggest that the enhanced system
sluggishness is related to the current carrying network becoming very dilute in
discontinuous films so that the system contains many parts which are
electrically very weakly connected and the transport is dominated by very few
weak links. This enables studying the glassy properties of the sample as it
transitions from a macroscopic sample to a mesocopic sample, hence, the results
provide new insight on the underlying physics of electron glasses.Comment: 4 pages, 4 figure
SU(2) Skyrme Vortices
A regular method for constructing vortex-like solutions with cylindrical
symmetry to the equations of the SU(2) Skyrme chiral model is proposed. A
numerical estimate for the length density of mass is given
Inhibition of VEGF and Angiopoietin-2 to Reduce Brain Metastases of Breast Cancer Burden
For metastases in the central nervous system, angiogenesis enhances metastatic potential and promotes progression. Primary factors which drive vessel growth are vascular endothelial growth factor (VEGF) and angiopoietin-2. Preclinical models show inhibition of either factor reduces metastases spread and inhibits growth. This work sets out to answer two questions in a preclinical mouse model. First, whether the combined inhibition of VEGF and angiopoietin-2, reduces passive permeability and limits drug uptake into brain metastases; and second, whether this inhibition reduces metastases burden in brain. We observed combinatorial inhibition of VEGF and angiopoietin-2, decreased (p \u3c 0.05) angiogenesis and vascular branching in an aortic ring assay and decreased (p \u3c 0.05) endothelial wound closure times. Using a brain metastases of breast cancer model (induced by intracardiac injections of brain seeking MDA-MB-231Br cells or 4T1Br cells), we observed, similar to VEGF, angiopoetin-2 expression correlates to increased angiogenesis (p \u3c 0.05) and increased lesion permeability. To determine efficacy, animals were administered bevacizumab plus L1-10 (angiopoietin inhibitor) twice per week until neurological symptoms developed. Lesion permeability significantly decreased by âŒ50% (p \u3c 0.05) compared to untreated lesions, but remained âŒ25% greater (p \u3c 0.0%) than brain. In subsequent experiments, animals were administered similar regimens but sacrificed on day 32. The number of metastatic lesions developed was significantly (p \u3c 0.001) reduced in the bevacizumab group (56%) and combination group (86%). Lesionsâ size was reduced in bevacizumab treated lesions (âŒ67%) and bevacizumab and L1-10 treated lesions (âŒ78%) developing area \u3c 0.5 mm2. In summary, combinatorial inhibition of VEGF and angiopoietin reduces lesion permeability and brain metastatic burden
The "recoil" correction of order to hyperfine splitting of positronium ground state
The "recoil" correction of order to the hyperfine splitting of
positronium ground state was found. The formalism employed is based on the
noncovariant perturbation theory in QED. Equation for two-particle component of
full (many-body) wave function is used, in which effective Hamiltonian depends
on the energy of a system. The effective Hamiltonian is not restricted to the
nonrelativistic region, so there is no need in any regularization. To evaluate
integrals over loop momenta, they are divided into "hard" and "soft" parts,
coming from large and small momenta respectively. Soft contributions were found
analytically, and hard ones are evaluated by numerical integration. Some soft
terms due to the retardation cancel each other. To calculate the "hard"
contributions, a great number of noncovariant graphs is replaced by only a few
covariant ones. The hard contribution was found in two ways. The first way is
to evaluate contributions of separate graphs, using the Coulomb gauge. The
second one is to calculate full hard contribution as a whole using the Feynman
gauge. The final result for the "recoil" correction is 0.381(6) m\al^6 and
agrees with those of previous papers. Diagram-to-diagram comparison with the
revised results of Adkins&Sapirstein was done. All the results agree, so the
"recoil" correction is now firmly established. This means a considerable
disagreement with the experimental data.Comment: 28 pages, latex including latex figure
An Expansion Term In Hamilton's Equations
For any given spacetime the choice of time coordinate is undetermined. A
particular choice is the absolute time associated with a preferred vector
field. Using the absolute time Hamilton's equations are
+ (\delta H_{c})/(\delta \pi)=\dot{q}\Theta = V^{a}_{.;a}N\equiv exp(-\int\Theta d \ta)\pi^{N}\pi^N$. Briefly the possibility of a non-standard sympletic form
and the further possibility of there being a non-zero Finsler curvature
corresponding to this are looked at.Comment: 10 page
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