28,684 research outputs found
On the six-dimensional origin of the AGT correspondence
We argue that the six-dimensional (2,0) superconformal theory defined on M
\times C, with M being a four-manifold and C a Riemann surface, can be twisted
in a way that makes it topological on M and holomorphic on C. Assuming the
existence of such a twisted theory, we show that its chiral algebra contains a
W-algebra when M = R^4, possibly in the presence of a codimension-two defect
operator supported on R^2 \times C \subset M \times C. We expect this structure
to survive the \Omega-deformation.Comment: References added. 14 page
Optical properties of in the normal state
We present the optical reflectance and conductivity spectra for non-oxide
antiperovskite superconductor at different temperatures. The
reflectance drops gradually over a large energy scale up to 33,000 cm,
with the presence of several wiggles. The reflectance has slight temperature
dependence at low frequency but becomes temperature independent at high
frequency. The optical conductivity shows a Drude response at low frequencies
and four broad absorption features in the frequency range from 600 to
33,000 . We illustrate that those features can be well understood from
the intra- and interband transitions between different components of Ni 3d
bands which are hybridized with C 2p bands. There is a good agreement between
our experimental data and the first-principle band structure calculations.Comment: 4 pages, to be published in Phys. Rev.
Shoulder recovery for head and neck cancer patients after unilateral neck dissection: a pilot exploratory study
An established side-effect of neck dissection (ND) for head and neck (HNC) tumour management includes shoulder dysfunction (SD), which can impact quality of life (QOL). Shoulder strength and range of movement (ROM) are key parameters to be monitored in SD. However, such evaluations are not routinely conducted in the clinical setting. The aim of this study was to evaluate objectively the impact of ND on shoulder functions.
Methods: This is a pilot exploratory study in a tertiary cancer centre. Five participants with unilateral ND and advanced HNC, completed the study. Outcome measures consisted of self-reported QOL questionnaires, C2–T1 dermatomes and shoulder ROM and strength testing. Data was collected at baseline, 1.5-months after surgery and 6-months after diagnosis (after adjuvant treatment completion).
Results: Most outcome measures on the surgically affected side were negatively impacted post-operatively, with varied recovery seen at follow-up. Sensory loss was noted at C3–4 dermatome levels. Shoulder ROM and strength was reduced on the surficial side for all participants, with some recovery after six months except for two participants.
Conclusion: Results of SD after ND are diverse and unique to each patient. Findings from this pilot study indicate that regular rehabilitation/exercise may facilitate recovery of shoulder function post HNC surgery. However, customised rehabilitation may yield better outcomes. Future studies with a larger sample are indicated to validate the findings of this study
Evolution of InAs branches in InAs/GaAs nanowire heterostructures
Branched nanowireheterostructures of InAs∕GaAs were observed during Au-assisted growth of InAs on GaAsnanowires. The evolution of these branches has been determined through detailed electron microscopy characterization with the following sequence: (1) in the initial stage of InAsgrowth, the Au droplet is observed to slide down the side of the GaAsnanowire, (2) the downward movement of Aunanoparticle later terminates when the nanoparticle encounters InAsgrowing radially on the GaAsnanowire sidewalls, and (3) with further supply of In and As vapor reactants, the Aunanoparticles assist the formation of InAs branches with a well-defined orientation relationship with GaAs∕InAs core/shell stems. We anticipate that these observations advance the understanding of the kink formation in axial nanowireheterostructures.The Australian Research Council is acknowledged for
the financial support of this project. One of the authors
M.P. acknowledges the support of an International Postgraduate
Research Scholarship
Evidence for nodeless superconducting gap in NaFeCoAs from low-temperature thermal conductivity measurements
The thermal conductivity of optimally doped NaFeCoAs
( 20 K) and overdoped NaFeCoAs ( 11 K)
single crystals were measured down to 50 mK. No residual linear term
is found in zero magnetic field for both compounds, which is an
evidence for nodeless superconducting gap. Applying field up to = 9 T
() does not noticeably increase in
NaFeCoAs, which is consistent with multiple isotropic gaps
with similar magnitudes. The of overdoped
NaFeCoAs shows a relatively faster field dependence,
indicating the increase of the ratio between the magnitudes of different gaps,
or the enhancement of gap anisotropy upon increasing doping.Comment: 5 pages, 4 figure
Larotrectinib efficacy and safety in TRK fusion cancer: An expanded clinical dataset showing consistency in an age and tumor agnostic approach
Background: TRK fusion cancer results from gene fusions involving NTRK1, NTRK2 or NTRK3. Larotrectinib, the first selective TRK inhibitor, has demonstrated an overall response rate (ORR) of 75% with a favorable safety profile in the first 55 consecutively enrolled adult and pediatric patients with TRK fusion cancer (Drilon et al.,NEJM2018). Here, we report the clinical activity of larotrectinib in an additional 35 TRK fusion cancer patients and provide updated follow-up of the primary analysis set (PAS) of 55 patients as of 19thFeb 2018. Methods: Patients with TRK fusion cancer detected by molecular profiling from 3 larotrectinib clinical trials (NCT02122913, NCT02637687, and NCT02576431) were eligible.Larotrectinib was administered until disease progression, withdrawal, or unacceptable toxicity. Disease status was assessed using RECIST version 1.1. Results: As of Feb 2018, by independent review, 6 PRs in the PAS deepened to CRs. The median duration of response (DoR) and progression-free survival in the PAS had still not been reached, with 12.9 months median follow-up. At 1 year, 69% of responses were ongoing, 58% of patients remained progression-free and 90% of patients were alive. An additional 19 children and 25 adults (age range, 0.1-78 years) with TRK fusion cancer were enrolled after the PAS, and included cancers of the salivary gland, thyroid, lung, colon, melanoma, sarcoma, GIST and congenital mesoblastic nephroma. In 35 evaluable patients, the ORR by investigator assessment was 74% (5 CR, 21 PR, 6 SD, 2 PD, 1 not determined). In these patients, with median follow-up of 5.5 months, median DoR had not yet been reached, and 88% of responses were ongoing at 6 months, consistent with the PAS. Adverse events (AEs) were predominantly grade 1, with dizziness, increased AST/ALT, fatigue, nausea and constipation the most common AEs reported in ≥ 10% of patients. No AE of grade 3 or 4 related to larotrectinib occurred in more than 5% of patients. Conclusions: TRK fusions are detected in a broad range of tumor types. Larotrectinib is an effective age- and tumor-agnostic treatment for TRK fusion cancer with a positive safety profile. Screening patients for NTRK gene fusions in solid- and brain tumors should be actively considered
Cosmic Rays and Large Extra Dimensions
We have proposed that the cosmic ray spectrum "knee", the steepening of the
cosmic ray spectrum at energy E \gsim 10^{15.5} eV, is due to "new physics",
namely new interactions at TeV cm energies which produce particles undetected
by the experimental apparatus. In this letter we examine specifically the
possibility that this interaction is low scale gravity. We consider that the
graviton propagates, besides the usual four dimensions, into an additional
, compactified, large dimensions and we estimate the graviton
production in collisions in the high energy approximation where graviton
emission is factorized. We find that the cross section for graviton production
rises as fast as , where is the fundamental
scale of gravity in dimensions, and that the distribution of
radiating a fraction of the initial particle's energy into gravitational
energy (which goes undetected) behaves as . The missing
energy leads to an underestimate of the true energy and generates a break in
the {\sl inferred} cosmic ray spectrum (the "kne"). By fitting the cosmic ray
spectrum data we deduce that the favorite values for the parameters of the
theory are TeV and .Comment: 8 pages, 1 figur
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