3,924 research outputs found
Destination Deimos: A Design Reference Architecture for Initial Human Exploration of the Mars System
The two biggest challenges to successful human operations in interplanetary space are flight dynamics, constrained by the cold hard physics of the rocket equation, and bioastronautics, the psychophysiological realities of human adaptation, or lack thereof, to the deep space environment. Without substantial innovation in project/mission architecture and vehicle design, human exploration of the Mars system could be problematic for decades. Although a human landing on Mars is inevitable, humans-in-the-loop telerobotic exploration from the outer Martian moon Deimos is the best way to begin. Precursor robotic missions for reconnaissance and local site preparation will be required
Localized excited charge carriers generate ultrafast inhomogeneous strain in the multiferroic BiFeO
We apply ultrafast X-ray diffraction with femtosecond temporal resolution to
monitor the lattice dynamics in a thin film of multiferroic BiFeO after
above-bandgap photoexcitation. The sound-velocity limited evolution of the
observed lattice strains indicates a quasi-instantaneous photoinduced stress
which decays on a nanosecond time scale. This stress exhibits an inhomogeneous
spatial profile evidenced by the broadening of the Bragg peak. These new data
require substantial modification of existing models of photogenerated stresses
in BiFeO: the relevant excited charge carriers must remain localized to be
consistent with the data
Optical Properties of (SrMnO3)n/(LaMnO3)2n superlattices: an insulator-to-metal transition observed in the absence of disorder
We measure the optical conductivity of (SrMnO3)n/(LaMnO3)2n superlattices
(SL) for n=1,3,5, and 8 and 10 < T < 400 K. Data show a T-dependent insulator
to metal transition (IMT) for n \leq 3, driven by the softening of a polaronic
mid-infrared band. At n = 5 that softening is incomplete, while at the
largest-period n=8 compound the MIR band is independent of T and the SL remains
insulating. One can thus first observe the IMT in a manganite system in the
absence of the disorder due to chemical doping. Unsuccessful reconstruction of
the SL optical properties from those of the original bulk materials suggests
that (SrMnO3)n/(LaMnO3)2n heterostructures give rise to a novel electronic
state.Comment: Published Online in Nano Letters, November 8, 2010;
http://pubs.acs.org/doi/abs/10.1021/nl1022628; 5 pages, 3 figure
Triple-Negative Breast Cancer: An Update on Neoadjuvant Clinical Trials
Triple-negative breast cancer (TNBC) is an aggressive malignancy with a poor prognosis despite the high rates of response to chemotherapy. This scenario highlights the need to develop novel therapies and/or treatment strategies to reduce the mortality associated with TNBC. The neoadjuvant setting provides a model for rapid assessment of treatment efficacy with smaller patient accruals and over shorter periods of time compared to the traditional adjuvant setting. In addition, a clear surrogate endpoint of improved survival, known as pathologic complete response, already exists in this setting. Here, we review current data from completed and ongoing neoadjuvant clinical trials for TNBC
Oral autoimmune vesicobullous diseases: Classification, clinical presentations, molecular mechanisms, diagnostic algorithms, and management
Mucocutaneous blistering autoimmune diseases are a group of systemic, rare, chronic disorders characterized by humoral-mediated immunologic mechanisms against epithelial, basement membrane, and subepithelial tissues. Morbidity and mortality can be completely different among these diseases, with outcome being dependent on an early and accurate diagnosis, systemic comorbidities, and the patient's response to treatment. Definitive diagnosis is based on clinical and histopathologic findings. Because clinical presentations among these diseases are often similar, different immunofluorescence tests and ELISAs are used to confirm the specific diagnosis. Oral mucosa may often be the first site of clinical manifestation from which the disease spreads to other mucosal surfaces and skin. Thus, often dentists and oral medicine specialists may be the first to encounter patients with such diseases. In this review we discuss the most frequent autoimmune vesicobullous disorders, namely pemphigus vulgaris, mucous membrane pemphigoid, bullous pemphigoid, and linear IgA disease
Robust Batch Process Scheduling in Pharmaceutical Industries: A Case Study
none4openT Adamo, G Ghiani, AD Grieco, E GuerrieroAdamo, T; Ghiani, G; Grieco, Ad; Guerriero,
Spin and lattice excitations of a BiFeO3 thin film and ceramics
We present a comprehensive study of polar and magnetic excitations in BiFeO3
ceramics and a thin film epitaxially grown on an orthorhombic (110) TbScO3
substrate. Infrared reflectivity spectroscopy was performed at temperatures
from 5 to 900 K for the ceramics and below room temperature for the thin film.
All 13 polar phonons allowed by the factor-group analysis were observed in
theceramic samples. The thin-film spectra revealed 12 phonon modes only and an
additional weak excitation, probably of spin origin. On heating towards the
ferroelectric phase transition near 1100 K, some phonons soften, leading to an
increase in the static permittivity. In the ceramics, terahertz transmission
spectra show five low-energy magnetic excitations including two which were not
previously known to be infrared active; at 5 K, their frequencies are 53 and 56
cm-1. Heating induces softening of all magnetic modes. At a temperature of 5 K,
applying an external magnetic field of up to 7 T irreversibly alters the
intensities of some of these modes. The frequencies of the observed spin
excitations provide support for the recently developed complex model of
magnetic interactions in BiFeO3 (R.S. Fishman, Phys. Rev. B 87, 224419 (2013)).
The simultaneous infrared and Raman activity of the spin excitations is
consistent with their assignment to electromagnons
Deep near-infrared imaging of W3 Main: constraints on stellar cluster formation
Embedded clusters like W3 Main are complex and dynamically evolving systems
that represent an important phase of the star formation process. We aim at the
characterization of the entire stellar content of W3 Main in a statistical
sense to identify possible differences in evolutionary phase of the stellar
populations and find clues about the formation mechanism of this massive
embedded cluster. Methods. Deep JHKs imaging is used to derive the disk
fraction, Ks-band luminosity functions and mass functions for several
subregions in W3 Main. A two dimensional completeness analysis using artificial
star experiments is applied as a crucial ingredient to assess realistic
completeness limits for our photometry. We find an overall disk fraction of 7.7
2.3%, radially varying from 9.4 3.0 % in the central 1 pc to 5.6
2.2 % in the outer parts of W3 Main. The mass functions derived for three
subregions are consistent with a Kroupa and Chabrier mass function. The mass
function of IRSN3 is complete down to 0.14 Msun and shows a break at M
0.5 Msun. We interpret the higher disk fraction in the center as evidence for a
younger age of the cluster center. We find that the evolutionary sequence
observed in the low-mass stellar population is consistent with the observed age
spread among the massive stars. An analysis of the mass function variations
does not show evidence for mass segregation. W3 Main is currently still
actively forming stars, showing that the ionizing feedback of OB stars is
confined to small areas ( 0.5 pc). The FUV feedback might be influencing
large regions of the cluster as suggested by the low overall disk fraction.Comment: 15 pages, 13 figures, accepted by A&
When orofacial pain needs a heart repair
Objectives: The association of chronic orofacial pain (COFP) and congenital heart disease has never previously been reported. We report the first case of COFP secondary to a right-to-left shunt (RLS) due to asymptomatic patent foramen ovale (PFO) in a patient with prothrombotic states. Materials and methods: A 48-year-old female patient presented with a 10-month history of left-sided facial pain who was initially diagnosed with persistent idiopathic facial pain (PIFP) on account of its similar characteristics. Magnetic resonance imaging (MRI) of the brain revealed gliosis and carotid siphon tortuosity; in addition, hyperhomocysteinaemia due to the homozygosis mutation for 5,10 MethyleneTetraHydroFolate Reductase was identified. Transcranial doppler ultrasonography was requested from a neurology consultant which revealed a high degree of RLS. Subsequently, a cardiological evaluation was performed; the specialist requested a transesophageal echocardiography that detected an interatrial septum aneurysm with PFO. Results: Based on the analysis of the patient's high degree of RLS, prothrombotic state and gliosis in relation to age, the cardiological consultant chose to perform a percutaneous closure of the PFO to avoid the risk of a cryptogenic stroke. After PFO closure, a complete remission of the pain was obtained. Conclusions: The disappearance of the pain supports the possible association between RLS and COFP. PFO with RLS has been suggested as a risk factor for cryptogenic stroke, especially in association with other thromboembolic risk factors. Therefore, the early detection, in this case, could be considered a possible lifesaver. Communication between different care providers is essential when the patient presents symptoms of facial pain which are of an atypical nature
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