3,656 research outputs found
Moving boundary and photoelastic coupling in GaAs optomechanical resonators
Chip-based cavity optomechanical systems are being considered for
applications in sensing, metrology, and quantum information science. Critical
to their development is an understanding of how the optical and mechanical
modes interact, quantified by the coupling rate . Here, we develop GaAs
optomechanical resonators and investigate the moving dielectric boundary and
photoelastic contributions to . First, we consider coupling between the
fundamental radial breathing mechanical mode and a 1550 nm band optical
whispering gallery mode in microdisks. For decreasing disk radius from
m to m, simulations and measurements show that changes
from being dominated by the moving boundary contribution to having an equal
photoelastic contribution. Next, we design and demonstrate nanobeam
optomechanical crystals in which a GHz mechanical breathing mode couples
to a 1550 nm optical mode predominantly through the photoelastic effect. We
show a significant (30 ) dependence of on the device's in-plane
orientation, resulting from the difference in GaAs photoelastic coefficients
along different crystalline axes, with fabricated devices exhibiting
as high as 1.1 MHz for orientation along the [110] axis.
GaAs nanobeam optomechanical crystals are a promising system which can combine
the demonstrated large optomechanical coupling strength with additional
functionality, such as piezoelectric actuation and incorporation of optical
gain media
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Current status of hepatocellular carcinoma detection: screening strategies and novel biomarkers.
Hepatocellular carcinoma (HCC) remains a major cause of cancer-related mortality worldwide. Delayed diagnosis is a major factor responsible for the poor prognosis of HCC. Several advances have been made in the field of liver imaging with the use of novel imaging contrasts, improving current imaging techniques with contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI), introduction of new technologies such as contrast liver ultrasound, and development of novel biomarkers with the goal of early detection of HCC and improving outcomes of patients with HCC. This review focuses on current surveillance strategies and development of biomarkers with the goal of early detection of HCC
Cyclin D1-mediated microRNA expression signature predicts breast cancer outcome
Background: Genetic classification of breast cancer based on the coding mRNA suggests the evolution of distinct subtypes. Whether the non-coding genome is altered concordantly with the coding genome and the mechanism by which the cell cycle directly controls the non-coding genome is poorly understood.
Methods: Herein, the miRNA signature maintained by endogenous cyclin D1 in human breast cancer cells was defined. In order to determine the clinical significance of the cyclin D1-mediated miRNA signature, we defined a miRNA expression superset from 459 breast cancer samples. We compared the coding and non-coding genome of breast cancer subtypes.
Results: Hierarchical clustering of human breast cancers defined four distinct miRNA clusters (G1-G4) associated with distinguishable relapse-free survival by Kaplan-Meier analysis. The cyclin D1-regulated miRNA signature included several oncomirs, was conserved in multiple breast cancer cell lines, was associated with the G2 tumor miRNA cluster, ERα+ status, better outcome and activation of the Wnt pathway. The coding and non-coding genome were discordant within breast cancer subtypes. Seed elements for cyclin D1-regulated miRNA were identified in 63 genes of the Wnt signaling pathway including DKK. Cyclin D1 restrained DKK1 via the 3\u27UTR. In vivo studies using inducible transgenics confirmed cyclin D1 induces Wnt-dependent gene expression.
Conclusion: The non-coding genome defines breast cancer subtypes that are discordant with their coding genome subtype suggesting distinct evolutionary drivers within the tumors. Cyclin D1 orchestrates expression of a miRNA signature that induces Wnt/β-catenin signaling, therefore cyclin D1 serves both upstream and downstream of Wnt/β-catenin signaling
Cellular preservation of excysting developmental stages of new eukaryotes from the early Ediacaran Weng'an Biota
Calorimetric Evidence for Nodes in the Overdoped Ba(FeCo)As
We present low-temperature specific heat of the electron-doped
Ba(FeCo)As, which does not show any indication of
an upturn down to 400 mK, the lowest measuring temperature. The lack of a
Schottky-like feature at low temperatures or in magnetic fields up to 9 Tesla
enables us to identify enhanced low-temperature quasiparticle excitations and
to study anisotropy in the linear term of the specific heat. Our results can
not be explained by a single or multiple isotropic superconducting gap, but are
consistent with multi-gap superconductivity with nodes on at least one Fermi
surface sheet.Comment: 5 pages 4 figure
KMT-2016-BLG-1107: A New Hollywood-Planet Close/Wide Degeneracy
We show that microlensing event KMT-2016-BLG-1107 displays a new type of
degeneracy between wide-binary and close-binary Hollywood events in which a
giant-star source envelops the planetary caustic. The planetary anomaly takes
the form of a smooth, two-day "bump" far out on the falling wing of the light
curve, which can be interpreted either as the source completely enveloping a
minor-image caustic due to a close companion with mass ratio , or
partially enveloping a major-image caustic due to a wide companion with
. The best estimates of the companion masses are both in the planetary
regime ( and ) but differ by an even larger factor than the mass ratios due to
different inferred host masses. We show that the two solutions can be
distinguished by high-resolution imaging at first light on next-generation
("30m") telescopes. We provide analytic guidance to understand the conditions
under which this new type of degeneracy can appear.Comment: 23 pages, 7 figures, accepted for publication in A
KMT-2018-BLG-1990Lb: A Nearby Jovian Planet From A Low-Cadence Microlensing Field
We report the discovery and characterization of KMT-2018-BLG-1990Lb, a Jovian
planet orbiting a late M dwarf
, at a distance
(D_L=1.23_{-0.43}^{+1.06}\,\kpc), and projected at times the
snow line distance, i.e., a_{\rm snow}\equiv 2.7\,\au (M/M_\odot), This is
the second Jovian planet discovered by KMTNet in its low cadence () fields, demonstrating that this population will be well
characterized based on survey-only microlensing data.Comment: 24 pages, 7 figures, 4 table
Health-related quality of life in KEYNOTE-010 : a phase II/III study of pembrolizumab versus docetaxel in patients with previously treated advanced, programmed death ligand 1-expressing NSCLC
Introduction: In the phase II/III KEYNOTE-010 study (ClinicalTrials.gov, NCT01905657), pembrolizumab significantly prolonged overall survival over docetaxel in patients with previously treated, programmed death ligand 1-expressing (tumor proportion score >= 1%), advanced NSCLC. Health-related quality of life (HRQoL) results are reported here. Methods: Patients were randomized 1:1:1 to pembrolizumab 2 or 10 mg/kg every 3 weeks or docetaxel 75 mg/m(2) every 3 weeks. HRQoL was assessed using European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLC) Core 30 (C30), EORTC QLQ-Lung Cancer 13 (LC13), and EuroQoL-5D. Key analyses included mean baseline-to-week-12 change in global health status (GHS)/quality of life (QoL) score, functioning and symptom domains, and time to deterioration in a QLQ-LC13 composite endpoint of cough, dyspnea, and chest pain. Results: Patient reported outcomes compliance was high across all three instruments. Pembrolizumab was associated with better QLQ-C30 GHS/QoL scores from baseline to 12 weeks than docetaxel, regardless of pembrolizumab dose or tumor proportion score status (not significant). Compared with docetaxel, fewer pembrolizumab-treated patients had "deteriorated" status and more had "improved" status in GHS/QoL. Nominally significant improvement was reported in many EORTC symptom domains with pembrolizumab, and nominally significant worsening was reported with docetaxel. Significant prolongation in true time to deterioration for the QLQ-LC13 composite endpoint emerged for pembrolizumab 10 mg/kg compared to docetaxel (nominal two-sided p = 0.03), but not for the 2-mg/kg dose. Conclusions: These findings suggest that HRQoL and symptoms are maintained or improved to a greater degree with pembrolizumab than with docetaxel in this NSCLC patient population. (C) 2019 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.
KMT-2018-BLG-1292: A Super-Jovian Microlens Planet in the Galactic Plane
We report the discovery of KMT-2018-BLG-1292Lb, a super-Jovian planet orbiting an F or G dwarf , which lies physically within {\cal O}(10\,\pc) of the
Galactic plane. The source star is a heavily extincted luminous
giant that has the lowest Galactic latitude, , of any planetary
microlensing event. The relatively blue blended light is almost certainly
either the host or its binary companion, with the first explanation being
substantially more likely. This blend dominates the light at band and
completely dominates at and bands. Hence, the lens system can be probed
by follow-up observations immediately, i.e., long before the lens system and
the source separate due to their relative proper motion. The system is well
characterized despite the low cadence -- of
observations and short viewing windows near the end of the bulge season. This
suggests that optical microlensing planet searches can be extended to the
Galactic plane at relatively modest cost.Comment: 35 pages, 3 Tables, 8 figure
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