160 research outputs found
Atomic-scale identification of novel planar defect phases in heteroepitaxial YBaCuO thin films
We have discovered two novel types of planar defects that appear in
heteroepitaxial YBaCuO (YBCO123) thin films, grown by
pulsed-laser deposition (PLD) either with or without a
LaCaMnO (LCMO) overlayer, using the combination of
high-angle annular dark-field scanning transmission electron microscopy
(HAADF-STEM) imaging and electron energy loss spectroscopy (EELS) mapping for
unambiguous identification. These planar lattice defects are based on the
intergrowth of either a BaO plane between two CuO chains or multiple Y-O layers
between two CuO planes, resulting in non-stoichiometric layer sequences
that could directly impact the high- superconductivity
Different responsiveness to a high-fat/cholesterol diet in two inbred mice and underlying genetic factors: a whole genome microarray analysis
<p>Abstract</p> <p>Background</p> <p>To investigate different responses to a high-fat/cholesterol diet and uncover their underlying genetic factors between C57BL/6J (B6) and DBA/2J (D2) inbred mice.</p> <p>Methods</p> <p>B6 and D2 mice were fed a high-fat/cholesterol diet for a series of time-points. Serum and bile lipid profiles, bile acid yields, hepatic apoptosis, gallstones and atherosclerosis formation were measured. Furthermore, a whole genome microarray was performed to screen hepatic genes expression profile. Quantitative real-time PCR, western blot and TUNEL assay were conducted to validate microarray data.</p> <p>Results</p> <p>After fed the high-fat/cholesterol diet, serum and bile total cholesterol, serum cholesterol esters, HDL cholesterol and Non-HDL cholesterol levels were altered in B6 but not significantly changed in D2; meanwhile, biliary bile acid was decreased in B6 but increased in D2. At the same time, hepatic apoptosis, gallstones and atherosclerotic lesions occurred in B6 but not in D2. The hepatic microarray analysis revealed distinctly different genes expression patterns between B6 and D2 mice. Their functional pathway groups included lipid metabolism, oxidative stress, immune/inflammation response and apoptosis. Quantitative real time PCR, TUNEL assay and western-blot results were consistent with microarray analysis.</p> <p>Conclusion</p> <p>Different genes expression patterns between B6 and D2 mice might provide a genetic basis for their distinctive responses to a high-fat/cholesterol diet, and give us an opportunity to identify novel pharmaceutical targets in related diseases in the future.</p
Spatiotemporal expression of histone acetyltransferases, p300 and CBP, in developing embryonic hearts
Histone acetyltransferases (HATs), p300 and cAMP response element binding protein (CREB)-binding protein (CBP) are two structurally related transcriptional co-activators that activate expression of many eukaryotic genes involved in cellular growth and signaling, muscle differentiation and embryogenesis. However, whether these proteins play important and different roles in mouse cardiogenesis is not clear. Here, we investigate the protein distributions and mRNA expression of the two HATs in embryonic and adult mouse heart during normal heart development by using immunohistochemical and RT-PCR techniques. The data from immunohistochemical experiments revealed that p300 was extensively present in nearly every region of the hearts from embryonic stages to the adulthood. However, no CBP expression was detected in embryonic hearts at day E7.5. CBP expression appeared at the later stages, and the distribution of CBP was less than that of p300. In the developmental hearts after E10.5, both for p300 and CBP, the mRNA expression levels reached a peak on day E10.5, and then were gradually decreased afterwards. These results reveal that both p300 and CBP are related to embryonic heart development. The dynamic expression patterns of these two enzymes during mouse heart development indicate that they may play an important role on heart development. However, there is a difference in spatiotemporal expression patterns between these two enzymes during heart development. The expression of p300 is earlier and more predominate, suggesting that p300 may play a more important role in embryonic heart development especially during cardiac precursor cell induction and interventricular septum formation
Influence of Humidity on Adsorption Performance of Activated Carbon
Activated carbon filter is the main equipment used to remove pollutants in the ventilation system in a nuclear power plant. Its main function is to remove radioactive iodine to minimize radioactive hazards against workers in the ventilation area. Periodic evaluation is a key step for verifying its operation effectiveness, further to ensure the safety and long-term operation. In this paper, by changing the micropore structure and surface chemical properties of activated carbon, its physicochemical properties and adsorption performance against methyl iodide under the high humidity working environment are studied. The results show that the adsorption performance of activated carbon on organic compound decreases significantly under the high humidity conditions; however, the combination of potassium iodide, triethylene diamine and functional groups on the activated carbon surface form stable chemical bonds and a new surface structure, which enhances the adsorption performance and stability of activated carbon against pollutants and makes it difficult to remove pollutants. The adsorption capacity of nuclear activated carbon can be restored to 80.7% of the initial capacity, and the adsorption performance can be obviously improved
DPL: Decoupled Prompt Learning for Vision-Language Models
Prompt learning has emerged as an efficient and effective approach for
transferring foundational Vision-Language Models (e.g., CLIP) to downstream
tasks. However, current methods tend to overfit to seen categories, thereby
limiting their generalization ability for unseen classes. In this paper, we
propose a new method, Decoupled Prompt Learning (DPL), which reformulates the
attention in prompt learning to alleviate this problem. Specifically, we
theoretically investigate the collaborative process between prompts and
instances (i.e., image patches/text tokens) by reformulating the original
self-attention into four separate sub-processes. Through detailed analysis, we
observe that certain sub-processes can be strengthened to bolster robustness
and generalizability by some approximation techniques. Furthermore, we
introduce language-conditioned textual prompting based on decoupled attention
to naturally preserve the generalization of text input. Our approach is
flexible for both visual and textual modalities, making it easily extendable to
multi-modal prompt learning. By combining the proposed techniques, our approach
achieves state-of-the-art performance on three representative benchmarks
encompassing 15 image recognition datasets, while maintaining
parameter-efficient. Moreover, our DPL does not rely on any auxiliary
regularization task or extra training data, further demonstrating its
remarkable generalization ability.Comment: 11 pages, 5 figures, 8 table
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