864 research outputs found
Exposure of the Hidden Anti-Ferromagnetism in Paramagnetic CdSe:Mn Nanocrystals
We present theoretical and experimental investigations of the magnetism of
paramagnetic semiconductor CdSe:Mn nanocrystals and propose an efficient
approach to the exposure and analysis of the underlying anti-ferromagnetic
interactions between magnetic ions therein. A key advance made here is the
build-up of an analysis method with the exploitation of group theory technique
that allows us to distinguish the anti-ferromagnetic interactions between
aggregative Mn2+ ions from the overall pronounced paramagnetism of magnetic ion
doped semiconductor nanocrystals. By using the method, we clearly reveal and
identify the signatures of anti-ferromagnetism from the measured temperature
dependent magnetisms, and furthermore determine the average number of Mn2+ ions
and the fraction of aggregative ones in the measured CdSe:Mn nanocrystals.Comment: 26 pages, 5 figure
Effects of Trehalose, Bovine Serum Albumin, and Sucrose, on the Integrity of the Plasma Membrane of Pseudosciaena crocea Semen after Cryopreservation
Cryopreservation and the effect of additives on the plasma membrane stability, motility, enzyme activity, membrane lipid composition, and ultrastructural injury of sperm of Pseudosciaena crocea, were examined in this study. Results indicated that the addition of trehalose (TH) and bovine serum albumin (BSA) provided significantly better results in the motility test compared to sucrose. Some BSA groups, showed significantly increased semen motility and effective enzyme activity. There were no significant differences between the cholesterol (CHO) composition for fresh sperm and cryopreserved sperm stored in 3 g/L BSA or 8.56 g/L TH+3 g/L BSA. Ultrastructural injury included damaged membrane, lost mitochondria, or broken flagella, whereas the majority of the freeze-thawed sperm remained morphologically normal. In conclusion, the addition of 3 g/L BSA and 8.56 g/L TH+3 g/L BSA significantly increased semen quality
CommonScenes: Generating Commonsense 3D Indoor Scenes with Scene Graphs
Controllable scene synthesis aims to create interactive environments for
various industrial use cases. Scene graphs provide a highly suitable interface
to facilitate these applications by abstracting the scene context in a compact
manner. Existing methods, reliant on retrieval from extensive databases or
pre-trained shape embeddings, often overlook scene-object and object-object
relationships, leading to inconsistent results due to their limited generation
capacity. To address this issue, we present CommonScenes, a fully generative
model that converts scene graphs into corresponding controllable 3D scenes,
which are semantically realistic and conform to commonsense. Our pipeline
consists of two branches, one predicting the overall scene layout via a
variational auto-encoder and the other generating compatible shapes via latent
diffusion, capturing global scene-object and local inter-object relationships
while preserving shape diversity. The generated scenes can be manipulated by
editing the input scene graph and sampling the noise in the diffusion model.
Due to lacking a scene graph dataset offering high-quality object-level meshes
with relations, we also construct SG-FRONT, enriching the off-the-shelf indoor
dataset 3D-FRONT with additional scene graph labels. Extensive experiments are
conducted on SG-FRONT where CommonScenes shows clear advantages over other
methods regarding generation consistency, quality, and diversity. Codes and the
dataset will be released upon acceptance
Numb regulates cellâcell adhesion and polarity in response to tyrosine kinase signalling
Epithelial-mesenchymal transition (EMT), which can be caused by aberrant tyrosine kinase signalling, marks epithelial tumour progression and metastasis, yet the underlying molecular mechanism is not fully understood. Here, we report that Numb interacts with E-cadherin (E-cad) through its phosphotyrosine-binding domain (PTB) and thereby regulates the localization of E-cad to the lateral domain of epithelial cellâcell junction. Moreover, Numb engages the polarity complex Par3âaPKCâPar6 by binding to Par3 in polarized Madin-Darby canine kidney cells. Intriguingly, after Src activation or hepatocyte growth factor (HGF) treatment, Numb decouples from E-cad and Par3 and associates preferably with aPKCâPar6. Binding of Numb to aPKC is necessary for sequestering the latter in the cytosol during HGF-induced EMT. Knockdown of Numb by small hairpin RNA caused a basolateral-to-apicolateral translocation of E-cad and ÎČ-catenin accompanied by elevated actin polymerization, accumulation of Par3 and aPKC in the nucleus, an enhanced sensitivity to HGF-induced cell scattering, a decrease in cellâcell adhesion, and an increase in cell migration. Our work identifies Numb as an important regulator of epithelial polarity and cellâcell adhesion and a sensor of HGF signalling or Src activity during EMT
Dynamic Hyperbolic Attention Network for Fine Hand-object Reconstruction
Reconstructing both objects and hands in 3D from a single RGB image is
complex. Existing methods rely on manually defined hand-object constraints in
Euclidean space, leading to suboptimal feature learning. Compared with
Euclidean space, hyperbolic space better preserves the geometric properties of
meshes thanks to its exponentially-growing space distance, which amplifies the
differences between the features based on similarity. In this work, we propose
the first precise hand-object reconstruction method in hyperbolic space, namely
Dynamic Hyperbolic Attention Network (DHANet), which leverages intrinsic
properties of hyperbolic space to learn representative features. Our method
that projects mesh and image features into a unified hyperbolic space includes
two modules, ie. dynamic hyperbolic graph convolution and image-attention
hyperbolic graph convolution. With these two modules, our method learns mesh
features with rich geometry-image multi-modal information and models better
hand-object interaction. Our method provides a promising alternative for fine
hand-object reconstruction in hyperbolic space. Extensive experiments on three
public datasets demonstrate that our method outperforms most state-of-the-art
methods.Comment: Accpeted by ICCV 202
The serum matrix metalloproteinase-9 level is an independent predictor of recurrence after ablation of persistent atrial fibrillation
OBJECTIVES: This study investigated whether the serum matrix metalloproteinase-9 level is an independent predictor of recurrence after catheter ablation for persistent atrial fibrillation. METHODS: Fifty-eight consecutive patients with persistent atrial fibrillation were enrolled and underwent catheter ablation. The serum matrix metalloproteinase-9 level was detected before ablation and its relationship with recurrent arrhythmia was analyzed at the end of the follow-up. RESULTS: After a mean follow-up of 12.1±7.2 months, 21 (36.2%) patients had a recurrence of their arrhythmia after catheter ablation. At baseline, the matrix metalloproteinase-9 level was higher in the patients with recurrence than in the non-recurrent group (305.77±88.90 vs 234.41±93.36 ng/ml, respectively, p=0.006). A multivariate analysis showed that the matrix metalloproteinase-9 level was an independent predictor of arrhythmia recurrence, as was a history of atrial fibrillation and the diameter of the left atrium. CONCLUSION: The serum matrix metalloproteinase-9 level is an independent predictor of recurrent arrhythmia after catheter ablation in patients with persistent atrial fibrillation
Epidemiology and Clinical Peculiarities of Norovirus and Rotavirus Infection in Hospitalized Young Children with Acute Diarrhea in Taiwan, 2009
Background/PurposeAcute diarrhea is one of the most common morbidities in pediatrics worldwide. We conducted a study to investigate the incidence of norovirus in young children hospitalized with acute diarrhea in Taiwan and its clinical peculiarity compared with rotavirus gastroenteritis.MethodsBetween January and December, 2009, patients younger than 5 years and admitted to hospital with acute diarrhea were randomly selected; and their stool samples were collected and tested for presence of rotavirus and norovirus by enzyme immunoassay and reverse transcription-polymerase chain reaction, respectively. The clinical manifestations and laboratory findings of the enrolled patients were analyzed.ResultsA total of 989 cases were enrolled with a mean age of 21.6 ± 13.7 months and a male proportion of 56.0%. Rotavirus and norovirus was detected in 20.2% and 14.6% of all patients, respectively. Genogroup II was the predominant strain of norovirus (80.6%). Children aged 6-36 months accounted for the majority of patients positive for rotavirus and norovirus (73.0% and 81.3%, respectively). The incidences of norovirus and rotavirus infection were higher during winter and early spring. Most patients with rotavirus and norovirus diarrhea experienced vomiting (74.9% vs. 74.8%, respectively) and fever (94.7% vs. 71.3%, respectively).ConclusionMost young diarrheal patients presenting with vomiting were likely to have norovirus or rotavirus infection. Patients with norovirus diarrhea experienced an absence of, or low-grade fever and longer duration of vomiting compared with those positive for rotavirus infection. A family history of current gastroenteritis may suggest the possibility of norovirus infection
Enhanced Performance of Dye-Sensitized Solar Cells with Nanostructure Graphene Electron Transfer Layer
The utilization of nanostructure graphene thin films as electron transfer layer in dye-sensitized solar cells (DSSCs) was demonstrated. The effect of a nanostructure graphene thin film in DSSC structure was examined. The nanostructure graphene thin films provides a great electron transfer channel for the photogenerated electrons from TiO2 to indium tin oxide (ITO) glass. Obvious improvements in short-circuit current density of the DSSCs were observed by using the graphene electron transport layer modified photoelectrode. The graphene electron transport layer reduces effectively the back reaction in the interface between the ITO transparent conductive film and the electrolyte in the DSSC
Precise dd excitations and commensurate intersite Coulomb interactions in the dissimilar cuprate YBa_2Cu_3O_(7-x) and La_(2-x)Sr_xCuO_4
Using high-resolution extreme ultraviolet resonant inelastic X-ray scattering
(EUVRIXS) spectroscopy at Cu M-edge, we observed the doping dependent spectral
shifts of inter-orbital (dd) excitations of YBa_2Cu_3O_(7-x) and
La_(2-x)Sr_xCuO_4. With increasing hole doping level from undoped to optimally
doped superconducting compositions, the leading edge of dd excitations is found
to shift towards lower energy loss in a roughly linear trend that is
irrespective to the cuprate species. The magnitude of energy shift can be
explained by including a 0.15 eV Coulomb attraction between Cu 3d_(x^2-y^2)
electrons and the doped holes on the surrounding oxygens in the atomic
multiplet calculations. The consistent energy shift between distinct cuprate
families suggests that this inter-site Coulomb interaction energy scale is
relatively material-independent, and provides an important reference point for
understanding charge density wave phenomena in the cuprate phase diagram.Comment: 29 pages; 8 figures. Physical Review B, in press. This paper reveals
a Cu 3d-O 2p intersite interaction energy for the first time experimentally.
It also explains why Tc of YBCO is higher than that of LSC
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