6,917 research outputs found
Multi-microjoule GaSe-based mid-infrared optical parametric amplifier with an ultra-broad idler spectrum covering 4.2-16 {\mu}m
We report a multi-microjoule, ultra-broadband mid-infrared optical parametric
amplifier based on a GaSe nonlinear crystal pumped at ~2 {\mu}m. The generated
idler pulse has a flat spectrum spanning from 4.5 to 13.3 {\mu}m at -3 dB and
4.2 to 16 {\mu}m in the full spectral range, with a central wavelength of 8.8
{\mu}m. The proposed scheme supports a sub-cycle Fourier-transform-limited
pulse width. A (2+1)-dimensional numerical simulation is employed to reproduce
the obtained idler spectrum. To our best knowledge, this is the broadest -3 dB
spectrum ever obtained by optical parametric amplifiers in this spectral
region. The idler pulse energy is ~3.4 {\mu}J with a conversion efficiency of
~2% from the ~2 {\mu}m pump to the idler pulse.Comment: 5 pages, 5 figure
Automated Segmentation of Pulmonary Lobes using Coordination-Guided Deep Neural Networks
The identification of pulmonary lobes is of great importance in disease
diagnosis and treatment. A few lung diseases have regional disorders at lobar
level. Thus, an accurate segmentation of pulmonary lobes is necessary. In this
work, we propose an automated segmentation of pulmonary lobes using
coordination-guided deep neural networks from chest CT images. We first employ
an automated lung segmentation to extract the lung area from CT image, then
exploit volumetric convolutional neural network (V-net) for segmenting the
pulmonary lobes. To reduce the misclassification of different lobes, we
therefore adopt coordination-guided convolutional layers (CoordConvs) that
generate additional feature maps of the positional information of pulmonary
lobes. The proposed model is trained and evaluated on a few publicly available
datasets and has achieved the state-of-the-art accuracy with a mean Dice
coefficient index of 0.947 0.044.Comment: ISBI 2019 (Oral
Examining Scientific Writing Styles from the Perspective of Linguistic Complexity
Publishing articles in high-impact English journals is difficult for scholars
around the world, especially for non-native English-speaking scholars (NNESs),
most of whom struggle with proficiency in English. In order to uncover the
differences in English scientific writing between native English-speaking
scholars (NESs) and NNESs, we collected a large-scale data set containing more
than 150,000 full-text articles published in PLoS between 2006 and 2015. We
divided these articles into three groups according to the ethnic backgrounds of
the first and corresponding authors, obtained by Ethnea, and examined the
scientific writing styles in English from a two-fold perspective of linguistic
complexity: (1) syntactic complexity, including measurements of sentence length
and sentence complexity; and (2) lexical complexity, including measurements of
lexical diversity, lexical density, and lexical sophistication. The
observations suggest marginal differences between groups in syntactical and
lexical complexity.Comment: 6 figure
Ethyl 2-(4-chlorophenyl)-3-(2,4-difluorophenoxy)acrylate
In the molecule of the title compound, C17H13ClF2O3, the dihedral angles formed by the aromatic rings of the chlorobenzene and difluorobenzene groups with the plane of the acrylate unit are 48.85 (12) and 9.07 (14)°, respectively. In the crystal structure, molecules are linked by weak intermolecular C—H⋯O hydrogen-bond interactions, forming chains along the c axis
Diisopropylammonium nitrite
In the title molecular salt, C6H16N+·NO2
−, the cation forms two N—H⋯O hydrogen bonds to nearby nitrite anions which link the ionic units into chains propagating along the b-axis direction
A cell-free system toward deciphering the post-translational modification barcodes of Oct4 in different cellular contexts
AbstractThe octamer-binding transcription factor 4 (Oct4) is essential for maintaining the self-renewal and pluripotency of embryonic stem cells (ESCs). Post-translational modifications (PTMs) of Oct4 critically control its structure, function and intracellular localization. However, determination of Oct4 PTM profiles has largely been restricted by the quantity and purity of the Oct4 protein samples required for mass spectrometric analyses. In this study, by incubating the Escherichia coli-derived His-tagged Oct4 proteins with the whole cell lysates of a variety of human cells followed by retrieving the reacted Oct4 proteins with the Ni–NTA beads, we developed a labor- and cost-effective in vitro PTM method that allowed for mass spectrometric determination of the phosphorylation profiles of Oct4 proteins exposed to various cell-free systems. A number of Oct4 phosphorylation sites that were commonly present in all the cell-free systems or specifically present in a particular cellular context were identified, indicating that Oct4 is controlled by both common and distinct PTM regulatory pathways. Our work provided a proof-of-concept that such a cell-free system-based in vitro PTM approach can be applied to systematically map out the physiologically-relevant PTM sites in Oct4 proteins, which opened up an avenue to fully decipher the Oct4 PTM barcodes in various cellular contexts
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