101,825 research outputs found
Using probe electrospray ionization mass spectrometry and machine learning for detecting pancreatic cancer with high performance
A rapid blood-based diagnostic modality to detect pancreatic ductal adenocarcinoma (PDAC) with high accuracy is an unmet medical need. The study aimed to validate a unique diagnosis system using Probe Electrospray Ionization Mass Spectrometry (PESI-MS) and Machine Learning to the diagnosis of PDAC. Peripheral blood samples were collected from a total of 322 consecutive PDAC patients and 265 controls with a family history of PDAC. Five µl of serum samples were analyzed using PESI-MS system. The mass spectra from each specimen were then fed into machine learning algorithms to discriminate between control and cancer cases. A total of 587 serum samples were analyzed. The sensitivity of the machine learning algorithm using PESI-MS profiles to identify PDAC is 90.8% with specificity of 91.7% (95% CI 83.9%-97.4% and 82.8%-97.7% respectively). Combined PESI-MS profiles with age and CA19-9 as predictors, the accuracy for stage 1 or 2 of PDAC is 92.9% and for stage 3 or 4 is 93% (95% CI 86.3-98.2; 87.9-97.4 respectively). The accuracy and simplicity of the PESI-MS profiles combined with machine learning provide an opportunity to detect PDAC at an early stage and must be applicable to the examination of at-risk populations. [Abstract copyright: AJTR Copyright © 2020.
Origin of spin reorientation transitions in antiferromagnetic MnPt-based alloys
Antiferromagnetic MnPt exhibits a spin reorientation transition (SRT) as a
function of temperature, and off-stoichiometric Mn-Pt alloys also display SRTs
as a function of concentration. The magnetocrystalline anisotropy in these
alloys is studied using first-principles calculations based on the coherent
potential approximation and the disordered local moment method. The anisotropy
is fairly small and sensitive to the variations in composition and temperature
due to the cancellation of large contributions from different parts of the
Brillouin zone. Concentration and temperature-driven SRTs are found in
reasonable agreement with experimental data. Contributions from specific
band-structure features are identified and used to explain the origin of the
SRTs.Comment: 6 pages, 8 figure
Structure and correlation effects in semiconducting SrTiO₃
We have investigated the effects of structure change and electron correlation on SrTiO₃ single crystals using angle-resolved photoemission spectroscopy. We show that the cubic to tetragonal phase transition at 105 K is manifested by a charge transfer from in-plane (dyz and dzx) bands to out-of-plane (dxy) band, which is opposite to the theoretical predictions. Along this second-order phase transition, we find a smooth evolution of the quasiparticle strength and effective masses. The in-plane band exhibits a peak-dip-hump lineshape, indicating a high degree of correlation on a relatively large (170 meV) energy scale, which is attributed to the polaron formation
Transforming carbon nanotubes by silylation: An ab initio study
We use ab initio density functional calculations to study the chemical
functionalization of single-wall carbon nanotubes and graphene monolayers by
silyl (SiH3) radicals and hydrogen. We find that silyl radicals form strong
covalent bonds with graphene and nanotube walls, causing local structural
relaxations that enhance the sp3 character of these graphitic nanostructures.
Silylation transforms all carbon nanotubes into semiconductors, independent of
their chirality. Calculated vibrational spectra suggest that specific frequency
shifts can be used as a signature of successful silylation.Comment: 4 pages, 3 figure
Observation of emission from chaotic lasing modes in deformed microspheres: displacement by the stable orbit modes
By combining detailed imaging measurements at different tilt angles with
simulations of ray emission from prolate deformed lasing micro-droplets, we
conclude that the probability density for the lasing modes in a
three-dimensional dielectric microcavity must reside in the chaotic region of
the ray phase space. In particular, maximum emission from such chaotic lasing
modes is not from tangent rays emerging from the highest curvature part of the
rim. The laser emission is observed and calculated to be non-tangent and
displaced from the highest curvature due to the presence of stable orbits. In
this Letter we present the first experimental evidence for this phenomenon of
``dynamical eclipsing''.Comment: 4 figure
A balanced work-life relationship helps boost employee performance
The current Perspective is written for personnel managers and MBA students, aiming to raise the awareness of work-life balance importance in the employee management policies. In the intersection of work and personal life, the work-life balance is the equilibrium between the two; more specifically, work-life balance explains the relationship and interaction between individual job and their private life. In the Perspective, we first introduce the concept and characteristics of work-life balance through relevant literature. We then argue the significance of incorporating work-life balance into employee management practices, as the concept of work-life balance helps managers appreciate individual differences and develop more human-oriented awareness in management. We encourage managers to adopt transformational leadership in their management, in which the concept of work-life balance should be embedded in the design and implementation of employee management policies. By giving more autonomy to the employees through the work-life balance policies and practices, employees are more likely to appreciate the work and make more contribution accordingly. Practitioner points are also recommended
Two-terminal monolithic InP-based tandem solar cells with tunneling intercell ohmic connections
A monolithic two-terminal InP/InGaAsP tandem solar cell was successfully fabricated. This tandem solar cell consists of a p/n InP homojunction top subcell and a 0.95 eV p/n InGaAsP homojunction bottom subcell. A patterned 0.95 eV n(+)/p(+) InGaAsP tunnel diode was employed as an intercell ohmic connection. The solar cell structure was prepared by two-step liquid phase epitaxial growth. Under one sun, AM1.5 global illumination, the best tandem cell delivered a conversion efficiency of 14.8 pct
Phase-locked InGaAsP laser array with diffraction coupling
A phase-locked array of InGaAsP lasers has been fabricated for the first time. This 50-µm-wide array utilized diffraction coupling between adjacent lasers to achieve phase locking. Threshold current as low as 200 mA is obtained for arrays with 250-µm cavity length. Smooth single-lobe far-field patterns with beam divergence as narrow as 3° have been achieved
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Real-time decoding of question-and-answer speech dialogue using human cortical activity.
Natural communication often occurs in dialogue, differentially engaging auditory and sensorimotor brain regions during listening and speaking. However, previous attempts to decode speech directly from the human brain typically consider listening or speaking tasks in isolation. Here, human participants listened to questions and responded aloud with answers while we used high-density electrocorticography (ECoG) recordings to detect when they heard or said an utterance and to then decode the utterance's identity. Because certain answers were only plausible responses to certain questions, we could dynamically update the prior probabilities of each answer using the decoded question likelihoods as context. We decode produced and perceived utterances with accuracy rates as high as 61% and 76%, respectively (chance is 7% and 20%). Contextual integration of decoded question likelihoods significantly improves answer decoding. These results demonstrate real-time decoding of speech in an interactive, conversational setting, which has important implications for patients who are unable to communicate
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