6,959 research outputs found
Interplay between Quantum Size Effect and Strain Effect on Growth of Nanoscale Metal Thin Film
We develop a theoretical framework to investigate the interplay between
quantum size effect (QSE) and strain effect on the stability of metal
nanofilms. The QSE and strain effect are shown to be coupled through the
concept of "quantum electronic stress. First-principles calculations reveal
large quantum oscillations in the surface stress of metal nanofilms as a
function of film thickness. This adds extrinsically additional strain-coupled
quantum oscillations to surface energy of strained metal nanofilms. Our theory
enables a quantitative estimation of the amount of strain in experimental
samples, and suggests strain be an important factor contributing to the
discrepancies between the existing theories and experiments
Cardiac Specific Overexpression of Mitochondrial Omi/HtrA2 Induces Myocardial Apoptosis and Cardiac Dysfunction.
Myocardial apoptosis is a significant problem underlying ischemic heart disease. We previously reported significantly elevated expression of cytoplasmic Omi/HtrA2, triggers cardiomyocytes apoptosis. However, whether increased Omi/HtrA2 within mitochondria itself influences myocardial survival in vivo is unknown. We aim to observe the effects of mitochondria-specific, not cytoplasmic, Omi/HtrA2 on myocardial apoptosis and cardiac function. Transgenic mice overexpressing cardiac-specific mitochondrial Omi/HtrA2 were generated and they had increased myocardial apoptosis, decreased systolic and diastolic function, and decreased left ventricular remodeling. Transiently or stably overexpression of mitochondria Omi/HtrA2 in H9C2 cells enhance apoptosis as evidenced by elevated caspase-3, -9 activity and TUNEL staining, which was completely blocked by Ucf-101, a specific Omi/HtrA2 inhibitor. Mechanistic studies revealed mitochondrial Omi/HtrA2 overexpression degraded the mitochondrial anti-apoptotic protein HAX-1, an effect attenuated by Ucf-101. Additionally, transfected cells overexpressing mitochondrial Omi/HtrA2 were more sensitive to hypoxia and reoxygenation (H/R) induced apoptosis. Cyclosporine A (CsA), a mitochondrial permeability transition inhibitor, blocked translocation of Omi/HtrA2 from mitochondrial to cytoplasm, and protected transfected cells incompletely against H/R-induced caspase-3 activation. We report in vitro and in vivo overexpression of mitochondrial Omi/HtrA2 induces cardiac apoptosis and dysfunction. Thus, strategies to directly inhibit Omi/HtrA2 or its cytosolic translocation from mitochondria may protect against heart injury
Synthesis and anticancer activities of diquinazoline diselenides compounds
A series of novel diquinazoline diselenide compounds was designed and synthesized with substituted 4-chloroquinazoline and sodium diselenide. Their structures were confirmed by IR, 1H NMR, 13C NMR, and elemental analyses.The antitumor activity of the new compounds was evaluated by MTT method. Compound 1a, 1c, 1h and 1i were found to have activities against MDA-MB-435, A549,MDA-MB-231, SiHa, and HeLa cells. Moreover, compared with the commercial anticancer drugs Gefitinib, Oxaliplatin,Taxol, 10-Hydroxycamptothec in, and Epirubicin Hydrochloride,1a exerted better antitumor effects on corresponding cell lines at 10 μM
UrbanFM: Inferring Fine-Grained Urban Flows
Urban flow monitoring systems play important roles in smart city efforts
around the world. However, the ubiquitous deployment of monitoring devices,
such as CCTVs, induces a long-lasting and enormous cost for maintenance and
operation. This suggests the need for a technology that can reduce the number
of deployed devices, while preventing the degeneration of data accuracy and
granularity. In this paper, we aim to infer the real-time and fine-grained
crowd flows throughout a city based on coarse-grained observations. This task
is challenging due to two reasons: the spatial correlations between coarse- and
fine-grained urban flows, and the complexities of external impacts. To tackle
these issues, we develop a method entitled UrbanFM based on deep neural
networks. Our model consists of two major parts: 1) an inference network to
generate fine-grained flow distributions from coarse-grained inputs by using a
feature extraction module and a novel distributional upsampling module; 2) a
general fusion subnet to further boost the performance by considering the
influences of different external factors. Extensive experiments on two
real-world datasets, namely TaxiBJ and HappyValley, validate the effectiveness
and efficiency of our method compared to seven baselines, demonstrating the
state-of-the-art performance of our approach on the fine-grained urban flow
inference problem
The correlation between the expression of differentiated embryo-chondrocyte expressed gene l and oral squamous cell carcinoma
BACKGROUND: This study aims to explore the correlation between expression of differentiated embryo-chondrocyte expressed gene l (DEC1) and oral squamous cell carcinoma (OSCC), which could provide the reference for treatment and prognosis assessment of OSCC. METHODS: The expression of DEC1 in tissues from 56 primary OSCC patients and 20 normal oral mucosa samples were detected using real-time polymerase chain reaction and immunohistochemical methods, respectively. RESULTS: The results showed that the positive expression rate of DEC1 in the OSCC group was significantly higher than that in the normal group (P <0.05); further, the expression of DEC1 in different OSCC groups was statistically significant (P <0.05). The expression of DEC1 in the 1-year recurrence OSCC group was significantly higher than other groups. The expression of DEC1 in the 3-years no recurrence OSCC group was the lowest. CONCLUSIONS: The expression of DEC1 was associated with the incidence of OSCC and there was a negative correlation between the expression of DEC1 and the prognosis of OSCC
Electronic analog of chiral metamaterial: Helicity-resolved filtering and focusing of Dirac fermions in thin films of topological materials
Control over the helicity degree of freedom of Dirac fermions is identified in thin films of topological materials which act as a tunable “chiral-metamaterial-like” platform to tame left- and right-handed Dirac fermions in two dimensions. Using topological crystalline insulator SnTe(111) thin films as an example, we perform the first-principles calculations and show that giant helicity splitting in the band structures can be induced under moderate electric field. Based on this result, helicity-resolved functionalities, including pronounced electron dichroism, helicity switching, helical negative refraction, and birefraction, are demonstrated, where the intrahelical scattering always dominates over the interhelical one. Such intriguing control strategy for helical Dirac fermions may hold great promise for the applications of helicity-based electron optics and nanoelectronics.National Natural Science Foundation (China) (Grant 11204154)National Natural Science Foundation (China) (Grant 11334006)Ministry of Science and Technology of the People's Republic of China (Grant 2011CB921901)Ministry of Science and Technology of the People's Republic of China (Grant 2011CB606405
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