32 research outputs found
HST-MRF: Heterogeneous Swin Transformer with Multi-Receptive Field for Medical Image Segmentation
The Transformer has been successfully used in medical image segmentation due
to its excellent long-range modeling capabilities. However, patch segmentation
is necessary when building a Transformer class model. This process may disrupt
the tissue structure in medical images, resulting in the loss of relevant
information. In this study, we proposed a Heterogeneous Swin Transformer with
Multi-Receptive Field (HST-MRF) model based on U-shaped networks for medical
image segmentation. The main purpose is to solve the problem of loss of
structural information caused by patch segmentation using transformer by fusing
patch information under different receptive fields. The heterogeneous Swin
Transformer (HST) is the core module, which achieves the interaction of
multi-receptive field patch information through heterogeneous attention and
passes it to the next stage for progressive learning. We also designed a
two-stage fusion module, multimodal bilinear pooling (MBP), to assist HST in
further fusing multi-receptive field information and combining low-level and
high-level semantic information for accurate localization of lesion regions. In
addition, we developed adaptive patch embedding (APE) and soft channel
attention (SCA) modules to retain more valuable information when acquiring
patch embedding and filtering channel features, respectively, thereby improving
model segmentation quality. We evaluated HST-MRF on multiple datasets for polyp
and skin lesion segmentation tasks. Experimental results show that our proposed
method outperforms state-of-the-art models and can achieve superior
performance. Furthermore, we verified the effectiveness of each module and the
benefits of multi-receptive field segmentation in reducing the loss of
structural information through ablation experiments
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Determination of Pb2+ by Colorimetric Method Based on Catalytic Amplification of Ag Nanoparticles Supported by Covalent Organic Frameworks
In this paper, covalent organic frameworks (COFs) are prepared by solvothermal synthesis using 1,3,5-benzenetricarboxaldehyde and benzidine as ligands. Then, using COFs as a template, AgCOFs with high catalytic activity is prepared by in situ loading silver nanoparticles (AgNC) on the surface of COFs by sodium borohydride reduction method. AgCOFs are characterized by TEM, SEM, FTIR and XRD. At the same time, the catalytic ability of AgCOFs for trisodium citrate-AgNO3 nanosilver reaction is studied. The results show that AgCOFs can catalyze the reaction of trisodium citrate-AgNO3 to generate silver nanoparticles (AgNPs). The solution color of the system gradually changes from colorless to yellow, and the absorbance value increases. Based on the catalytic reaction of AgCOFs and the regulation effect of nucleic acid aptamer reaction on AgCOFs, a new “on–off–on” colorimetric analysis platform is constructed and applied to the detection of trace Pb2+ in water samples. This analytical platform is simple, sensitive and selective. Finally, the catalytic mechanism of the system is discussed to verify the feasibility of constructing a colorimetric analysis platform
Multilinear Discriminative Spatial Patterns for Movement-Related Cortical Potential Based on EEG Classification with Tensor Representation
The discriminative spatial patterns (DSP) algorithm is a classical and effective feature extraction technique for decoding of voluntary finger premovements from electroencephalography (EEG). As a purely data-driven subspace learning algorithm, DSP essentially is a spatial-domain filter and does not make full use of the information in frequency domain. The paper presents multilinear discriminative spatial patterns (MDSP) to derive multiple interrelated lower dimensional discriminative subspaces of low frequency movement-related cortical potential (MRCP). Experimental results on two finger movement tasks’ EEG datasets demonstrate the effectiveness of the proposed MDSP method
The expression of hydrogen sulfide-producing enzymes in primary and lung metastatic osteosarcoma
Background. Hydrogen sulfide (H2S) is a
novel gas transmitter signaling molecule. H2S is
synthesized by cystathionine β-synthase (CBS),
cystathionine γ-lyase (CSE), and 3-mercaptopyruvate
sulfurtransferase (MST). There have been no reports
about the roles of these enzymes in osteosarcoma and its
metastases. We detected H2S synthase expression levels
in human primary osteosarcoma and lung metastatic
osteosarcoma.
Methods. Immunohistochemistry was performed in
primary osteosarcoma (n=19), lung metastatic
osteosarcoma (n=11), osteoblastoma (n=10) and bony
callus (n=2). The expression of CBS, CSE, and MST
was defined as negative, moderately positive and
strongly positive.
Results. MST staining was moderately to strongly
positive in all cases. CSE staining was negative in 94.7%
(18/19) of primary osteosarcoma cases and 90.9%
(10/11) of lung metastatic osteosarcoma cases. CBS
staining was strongly positive in 68.4% (13/19) of
primary osteosarcoma cases, moderately positive in
15.8% (3/19) of cases, and negative in 15.8% (3/19) of
cases. In lung metastatic osteosarcoma, the proportions
of negative, moderately positive and strongly positive
cases were 63.6% (7/11), 18.2% (2/11) and 18.2%
(2/11), respectively.
Conclusions. CBS and CSE expression, especially
CSE expression, decreased in both primary
osteosarcoma and lung metastatic osteosarcoma, which
may suggest that CBS and CSE play roles in osteoblast
cell malignant transformation and osteosarcoma
progression. These enzymes could be used as new
prognostic assessment factors and may represent new
therapeutic targets for osteosarcoma and metastasis
preventio
A Face Detector with Adaptive Feature Fusion in Classroom Environment
Face detection in the classroom environment is the basis for student face recognition, sensorless attendance, and concentration analysis. Due to equipment, lighting, and the uncontrollability of students in an unconstrained environment, images include many moving faces, occluded faces, and extremely small faces in a classroom environment. Since the image sent to the detector will be resized to a smaller size, the face information extracted by the detector is very limited. This seriously affects the accuracy of face detection. Therefore, this paper proposes an adaptive fusion-based YOLOv5 method for face detection in classroom environments. First, a very small face detection layer in YOLOv5 is added to enhance the YOLOv5 baseline, and an adaptive fusion backbone network based on multi-scale features is proposed, which has the ability to feature fusion and rich feature information. Second, the adaptive spatial feature fusion strategy is applied to the network, considering the face location information and semantic information. Finally, a face dataset Classroom-Face in the classroom environment is creatively proposed, and it is verified with our method. The experimental results show that, compared with YOLOv5 or other traditional algorithms, our algorithm portrays better performance in WIDER-FACE Dataset and Classroom-Face dataset
Wnt5a/Ror2 promotes vascular smooth muscle cells proliferation via activating PKC
Introduction. Abnormal proliferation of vascular smooth muscle cells (VSMCs) can cause various vascular diseases, such as atherosclerosis, restenosis, and pulmonary hypertension. However, the effect and underlying mechanism of Wnt5a on the proliferation of VSMCs remain unclear. Our study aimed to investigate whether Wnt5a/Ror2 promotes vascular smooth muscle cell proliferation via activating protein kinase C (PKC), thereby effectively alleviating vascular proliferative diseases.Material and methods. The proliferation of HA-VSMC cell line was evaluated by CCK-8, EdU, and Plate clone formation assays. The Wnt5a gene knockdown and overexpression were carried out by standard methods. The interaction between Wnt5a and Ror2 was explored by co-immunoprecipitation. Western blotting and immunofluorescence were used to determine the expression levels of key proteins in VSMCs.Results. The present study found that the expression of Wnt5a protein increased significantly in the proliferation of VSMCs stimulated by 10% serum in a time-dependent manner. Furthermore, the proliferative rate of VSMCs overexpressing Wnt5a was dramatically accelerated, whereas Wnt5a knockdown using siWnt5a reversed thisproliferative effect. Wnt5a up-regulated the expression of receptor tyrosine kinase-like orphan receptor 2 (Ror2) by binding to it. Further studies indicated that Wnt5a induces the PKC expression in VSMCs and knockdown of Wnt5a or Ror2 could inhibit PKC phosphorylation.Conclusions. Wnt5a could effectively promote the proliferation of VSMCs, which might be related to the binding of Wnt5a and Ror2 to activate PKC
Spry1 and Spry4 differentially regulate human aortic smooth muscle cell phenotype via Akt/FoxO/myocardin signaling.
BACKGROUND: Changes in the vascular smooth muscle cell (VSMC) contractile phenotype occur in pathological states such as restenosis and atherosclerosis. Multiple cytokines, signaling through receptor tyrosine kinases (RTK) and PI3K/Akt and MAPK/ERK pathways, regulate these phenotypic transitions. The Spry proteins are feedback modulators of RTK signaling, but their specific roles in VSMC have not been established.
METHODOLOGY/PRINCIPAL FINDINGS: Here, we report for the first time that Spry1, but not Spry4, is required for maintaining the differentiated state of human VSMC in vitro. While Spry1 is a known MAPK/ERK inhibitor in many cell types, we found that Spry1 has little effect on MAPK/ERK signaling but increases and maintains Akt activation in VSMC. Sustained Akt signaling is required for VSMC marker expression in vitro, while ERK signaling negatively modulates Akt activation and VSMC marker gene expression. Spry4, which antagonizes both MAPK/ERK and Akt signaling, suppresses VSMC differentiation marker gene expression. We show using siRNA knockdown and ChIP assays that FoxO3a, a downstream target of PI3K/Akt signaling, represses myocardin promoter activity, and that Spry1 increases, while Spry4 decreases myocardin mRNA levels.
CONCLUSIONS: Together, these data indicate that Spry1 and Spry4 have opposing roles in VSMC phenotypic modulation, and Spry1 maintains the VSMC differentiation phenotype in vitro in part through an Akt/FoxO/myocardin pathway