155 research outputs found
Effect of Rydberg-atom-based sensor performance on different Rydberg atom population at one atomic-vapor cell
The atomic-vapor cell is a vital component for Rydberg atomic microwave
sensors, and impacts on overall capability of Rydberg sensor. However, the
conventional analysis approach on effect of vapor-cell length contains two
implicit assumptions, that is, the same atomic population density and buffer
gas pressure, which make it unable to accurately capture actual response about
effect of Rydberg-atom-based sensor performance on different Rydberg atom
population. Here, utilizing a stepped cesium atomic-vapor cell with five
different dimensions at the same atomic population density and buffer gas
pressure, the height and full width at half maximum of Electromagnetically
Induced Transparency(EIT) signal, and the sensitivity of the atomic
superheterodyne sensor are comprehensively investigated at the same Rabi
frequences(saturated laser power) conditions. It is identified that EIT signal
height is proportional to the cell length, full width at half maximum and
sensitivity grow with the increment of cell length to a certain extent. Based
on the coherent integration signal theory and atomic linear expansion
coefficient method, theoretical analysis of the EIT height and sensitivity are
further investigated. The results could shed new light on the understanding and
design of ultrahigh-sensitivity Rydberg atomic microwave sensors and find
promising applications in quantum measurement, communication, and imaging
SK-Net: Deep Learning on Point Cloud via End-to-end Discovery of Spatial Keypoints
Since the PointNet was proposed, deep learning on point cloud has been the
concentration of intense 3D research. However, existing point-based methods
usually are not adequate to extract the local features and the spatial pattern
of a point cloud for further shape understanding. This paper presents an
end-to-end framework, SK-Net, to jointly optimize the inference of spatial
keypoint with the learning of feature representation of a point cloud for a
specific point cloud task. One key process of SK-Net is the generation of
spatial keypoints (Skeypoints). It is jointly conducted by two proposed
regulating losses and a task objective function without knowledge of Skeypoint
location annotations and proposals. Specifically, our Skeypoints are not
sensitive to the location consistency but are acutely aware of shape. Another
key process of SK-Net is the extraction of the local structure of Skeypoints
(detail feature) and the local spatial pattern of normalized Skeypoints
(pattern feature). This process generates a comprehensive representation,
pattern-detail (PD) feature, which comprises the local detail information of a
point cloud and reveals its spatial pattern through the part district
reconstruction on normalized Skeypoints. Consequently, our network is prompted
to effectively understand the correlation between different regions of a point
cloud and integrate contextual information of the point cloud. In point cloud
tasks, such as classification and segmentation, our proposed method performs
better than or comparable with the state-of-the-art approaches. We also present
an ablation study to demonstrate the advantages of SK-Net
BPTF Is Essential for T Cell Homeostasis and Function
Bromodomain PHD Finger Transcription Factor (BPTF), a ubiquitously expressed ATP-dependent chromatin-remodeling factor, is critical for epigenetically regulating DNA accessibility and gene expression. While BPTF is important for the development of thymocytes, its function in mature T cells remains largely unknown. By specifically deleting BPTF from late DN3/DN4 stage of developing T cells, we found that BPTF was critical for the homeostasis of T cells via a cell intrinsic manner. In addition, BPTF was essential for the maintenance and function of Treg cells. Treg cell-specific BPTF deletion led to reduced Foxp3 expression, increased lymphocyte infiltration in the non-lymphoid organs and a systemic autoimmune syndrome. These findings therefore reveal a vital role for BPTF in T and Treg cell function and immune homeostasis
Nano-Subsidence Assisted Precise Integration of Patterned Two-Dimensional Materials for High-Performance Photodetector Arrays
The spatially precise integration of arrays of micro-patterned
two-dimensional (2D) crystals onto three-dimensionally structured Si/SiO
substrates represents an attractive strategy towards the low-cost
system-on-chip integration of extended functions in silicon microelectronics.
However, the reliable integration of the arrays of 2D materials on non-flat
surfaces has thus far proved extremely challenging due to their poor adhesion
to underlying substrates as ruled by weak van der Waals interactions. Here we
report on a novel fabrication method based on nano-subsidence which enables the
precise and reliable integration of the micro-patterned 2D materials/silicon
photodiode arrays exhibiting high uniformity. Our devices display peak
sensitivity as high as 0.35 A/W and external quantum efficiency (EQE) of ca.
90%, outperforming most commercial photodiodes. The nano-subsidence technique
opens a viable path to on-chip integrate 2D crystals onto silicon for
beyond-silicon microelectronics.Comment: 41 pages, 5 figures, with S
Relationship between motor performance and cortical activity of older neurological disorder patients with dyskinesia using fNIRS: A systematic review
Background: Neurological disorders with dyskinesia would seriously affect older people’s daily activities, which is not only associated with the degeneration or injury of the musculoskeletal or the nervous system but also associated with complex linkage between them. This study aims to review the relationship between motor performance and cortical activity of typical older neurological disorder patients with dyskinesia during walking and balance tasks.Methods: Scopus, PubMed, and Web of Science databases were searched. Articles that described gait or balance performance and cortical activity of older Parkinson’s disease (PD), multiple sclerosis, and stroke patients using functional near-infrared spectroscopy were screened by the reviewers. A total of 23 full-text articles were included for review, following an initial yield of 377 studies.Results: Participants were mostly PD patients, the prefrontal cortex was the favorite region of interest, and walking was the most popular test motor task, interventional studies were four. Seven studies used statistical methods to interpret the relationship between motor performance and cortical activation. The motor performance and cortical activation were simultaneously affected under difficult walking and balance task conditions. The concurrent changes of motor performance and cortical activation in reviewed studies contained the same direction change and different direction change.Conclusion: Most of the reviewed studies reported poor motor performance and increased cortical activation of PD, stroke and multiple sclerosis older patients. The external motor performance such as step speed were analyzed only. The design and results were not comprehensive and profound. More than 5 weeks walking training or physiotherapy can contribute to motor function promotion as well as cortices activation of PD and stroke patients. Thus, further study is needed for more statistical analysis on the relationship between motor performance and activation of the motor-related cortex. More different type and program sports training intervention studies are needed to perform
Patterns of Convergence and Divergence Between Bipolar Disorder Type I and Type II: Evidence From Integrative Genomic Analyses
Aim: Genome-wide association studies (GWAS) analyses have revealed genetic evidence of bipolar disorder (BD), but little is known about the genetic structure of BD subtypes. We aimed to investigate the genetic overlap and distinction of bipolar type I (BD I) & type II (BD II) by conducting integrative post-GWAS analyses.
Methods: We utilized single nucleotide polymorphism (SNP)-level approaches to uncover correlated and distinct genetic loci. Transcriptome-wide association analyses (TWAS) were then approached to pinpoint functional genes expressed in specific brain tissues and blood. Next, we performed cross-phenotype analysis, including exploring the potential causal associations between two BD subtypes and lithium responses and comparing the difference in genetic structures among four different psychiatric traits.
Results: SNP-level evidence revealed three genomic loci, SLC25A17, ZNF184, and RPL10AP3, shared by BD I and II, and one locus (MAD1L1) and significant gene sets involved in calcium channel activity, neural and synapsed signals that distinguished two subtypes. TWAS data implicated different genes affecting BD I and II through expression in specific brain regions (nucleus accumbens for BD I). Cross-phenotype analyses indicated that BD I and II share continuous genetic structures with schizophrenia and major depressive disorder, which help fill the gaps left by the dichotomy of mental disorders.
Conclusion: These combined evidences illustrate genetic convergence and divergence between BD I and II and provide an underlying biological and trans-diagnostic insight into major psychiatric disorders
Repair of fingertip defect with reverse digital artery island flap and repair of donor site with digital dorsal advancement flap
ObjectiveThe reverse digital artery island flap (RDAF) is widely used in repairing fingertip skin defects based on its good appearance and practicability. However, the donor area of the flap needs skin grafting, which can lead to complications. This retrospective study explored the clinical application of digital dorsal advance flap (DDAF) in repairing the donor site of the reverse digital artery island flap.MethodFrom June 2019 to February 2022, 17 patients with a soft tissue defect of the finger had been restored with the reverse digital artery island flap, and at the same time, the donor area was repaired with digital dorsal advance flap (DDAF). The sensitivity, the active range of motion (ROM) and patient satisfaction were assessed after the operation.ResultsAll flaps survived completely without skin grafting with only one linear scar. The sensory and motor functions of all patients recovered well. Assessment based on the Michigan Hand Outcomes Questionnaire (MHQ) showed satisfactory functional recovery for all patients.ConclusionsReconstruction using RDAF combined with DDAF represents an effective alternative for repairing fingertip skin defects
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