219 research outputs found
AN INFRARED PHOTODISSOCIATION SPECTROSCOPIC AND THEORETICAL STUDY OF M(CO)6,7,8+ (M = Ti, Zr, Hf)
Spectroscopic and theoretical study of extreme coordinated metal carbonyl complexes has been a subject of intensive studies.\footnote{Zhou, M. F.; Frenking, G. Angew. Chem. Int. Ed. 2018, 57(21), 6236-6241; Science, 2018, 361(6405), 912-916.} M(CO) (M = Ti, Zr, Hf) ions were produced by ablating a metal target in a pulse of CO seeded helium, and further studied by mass-selected infrared photodissociation spectroscopy in the carbonyl stretching region. Ti(CO) is formed as dominant species in the mass spectrum, while M(CO) ions are of the most abundant species in the mass spectra for zirconium and hafnium. The infrared spectra of M(CO) (M = Ti, Zr, Hf) show good agreement with previous reports.\footnote{Duncan, M. A. J. Phys. Chem. A, 2013, 117(46), 11695–11703.} M(CO) (M = Zr, Hf) ions only dissociate under focused laser irradiation and have one broad band, indicating strongly coordinated complexes. M(CO) (M = Zr, Hf) complexes can fragment by one CO molecule in unfocused light, and each exhibits an infrared band centered at 2084 \wn (Zr) and 2072 \wn (Hf). Theoretical calculations indicate that the M(CO) (M = Zr, Hf) complexes are at doublet ground states with \textit{C} symmetry. The M(CO) (M = Zr, Hf) complexes are identified as 19-electron octacarbonyls. Each of them has \textit{D} symmetry (distorted cubic geometry) and a doublet ground state. The results extend the knowledge of extreme coordinated carbonyl complexes to Group 4 metals, and provide insights into the ion growth mechanisms in the gas phase
HCDG: A Hierarchical Consistency Framework for Domain Generalization on Medical Image Segmentation
Modern deep neural networks struggle to transfer knowledge and generalize
across diverse domains when deployed to real-world applications. Currently,
domain generalization (DG) is introduced to learn a universal representation
from multiple domains to improve the network generalization ability on unseen
domains. However, previous DG methods only focus on the data-level consistency
scheme without considering the synergistic regularization among different
consistency schemes. In this paper, we present a novel Hierarchical Consistency
framework for Domain Generalization (HCDG) by integrating Extrinsic Consistency
and Intrinsic Consistency synergistically. Particularly, for the Extrinsic
Consistency, we leverage the knowledge across multiple source domains to
enforce data-level consistency. To better enhance such consistency, we design a
novel Amplitude Gaussian-mixing strategy into Fourier-based data augmentation
called DomainUp. For the Intrinsic Consistency, we perform task-level
consistency for the same instance under the dual-task scenario. We evaluate the
proposed HCDG framework on two medical image segmentation tasks, i.e., optic
cup/disc segmentation on fundus images and prostate MRI segmentation. Extensive
experimental results manifest the effectiveness and versatility of our HCDG
framework.Comment: this paper is currently not publishe
ABCG2 is associated with HER-2 Expression, lymph node metastasis and clinical stage in breast invasive ductal carcinoma
<p>Abstract</p> <p>Background</p> <p>ABCG2 is an ABC transporter. It has been demonstrated that endogenous ABCG2 expression in certain cancers is a possible reflection of the differentiated phenotype of the cell of origin and likely contributes to intrinsic drug resistance. But little is known about the contribution of ABCG2 to the drug resistance and the clinicopathological characteristics in breast cancer. In the present study, we investigated the expression of ABCG2 and the correlations between ABCG2 expression and patients' clinicopathological and biological characteristics.</p> <p>Methods</p> <p>Immunohistochemistry was employed on the tissue microarray paraffin sections of surgically removed samples from 196 breast cancer patients with clinicopathological data.</p> <p>Results</p> <p>The results showed that ABCG2 was expressed in different intensities and distributions in the tumor cells of the breast invasive ductal carcinoma. A positive stain for ABCG2 was defined as a brown stain observed in the cytoplasm and cytomembrane. A statistically significant correlation was demonstrated between ABCG2 expression and HER-2 expression (p = 0.001), lymph node metastasis (p = 0.049), and clinical stage (p = 0.015) respectively.</p> <p>Conclusion</p> <p>ABCG2 correlated with Her-2 expression, lymph node metastasis and clinical stage in breast invasive ductal carcinoma. It could be a novel potential bio-marker which can predict biological behavior, clinical progression, prognosis and chemotherapy effectiveness.</p
Pro- and Antiinflammatory Cytokine Signaling: Reciprocal Antagonism Regulates Interferon-gamma Production by Human Natural Killer Cells
SummaryActivated monocytes produce proinflammatory cytokines (monokines) such as interleukin (IL)-12, IL-15, and IL-18 for induction of interferon-γ (IFN-γ) by natural killer (NK) cells. NK cells provide the antiinflammatory cytokine transforming growth factor (TGF)-β, an autocrine/negative regulator of IFN-γ. The ability of one signaling pathway to prevail over the other is likely important in controlling IFN-γ for the purposes of infection and autoimmunity, but the molecular mechanism(s) of how this counterregulation occurs is unknown. Here we show that in isolated human NK cells, proinflammatory monokines antagonize antiinflammatory TGF-β signaling by downregulating the expression of the TGF-β type II receptor, and its signaling intermediates SMAD2 and SMAD3. In contrast, TGF-β utilizes SMAD2, SMAD3, and SMAD4 to suppress IFN-γ and T-BET, a positive regulator of IFN-γ. Indeed, activated NK cells from Smad3−/− mice produce more IFN-γ in vivo than NK cells from wild-type mice. Collectively, our data suggest that pro- and antiinflammatory cytokine signaling reciprocally antagonize each other in an effort to prevail in the regulation of NK cell IFN-γ production
The Oncogenic Roles of Nuclear Receptor Coactivator 1 in Human Esophageal Carcinoma
Nuclear receptor coactivator 1 (NCOA1) plays crucial roles in the regulation of gene expression mediated by a wide spectrum of steroid receptors such as androgen receptor (AR), estrogen receptor α (ER α), and estrogen receptor β (ER β). Therefore, dysregulations of NCOA1 have been found in a variety of cancer types. However, the clinical relevance and the functional roles of NCOA1 in human esophageal squamous cell carcinoma (ESCC) are less known. We found in this study that elevated levels of NCOA1 protein and/or mRNA as well as amplification of the NCOA1 gene occur in human ESCC. Elevated levels of NCOA1 due to these dysregulations were not only associated with more aggressive clinic-pathologic parameters but also poorer survival. Results from multiple cohorts of ESCC patients strongly suggest that the levels of NCOA1 could serve as an independent predictor of overall survival. In addition, silencing NCOA1 in ESCC cells remarkably decreased proliferation, migration, and invasion. These findings not only indicate that NCOA1 plays important roles in human ESCC but the levels of NCOA1 also could serve as a potential prognostic biomarker of ESCC and targeting NCOA1 could be an efficacious strategy in ESCC treatment
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
Core-collapse supernova (CCSN) is one of the most energetic astrophysical
events in the Universe. The early and prompt detection of neutrinos before
(pre-SN) and during the SN burst is a unique opportunity to realize the
multi-messenger observation of the CCSN events. In this work, we describe the
monitoring concept and present the sensitivity of the system to the pre-SN and
SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is
a 20 kton liquid scintillator detector under construction in South China. The
real-time monitoring system is designed with both the prompt monitors on the
electronic board and online monitors at the data acquisition stage, in order to
ensure both the alert speed and alert coverage of progenitor stars. By assuming
a false alert rate of 1 per year, this monitoring system can be sensitive to
the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos
up to about 370 (360) kpc for a progenitor mass of 30 for the case
of normal (inverted) mass ordering. The pointing ability of the CCSN is
evaluated by using the accumulated event anisotropy of the inverse beta decay
interactions from pre-SN or SN neutrinos, which, along with the early alert,
can play important roles for the followup multi-messenger observations of the
next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure
Potential of Core-Collapse Supernova Neutrino Detection at JUNO
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve
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