ABSTRACT
The rapid spread of monkeypox in multiple countries has resulted in a global public health threat and has caused international concerns since May 2022. Poxvirus encoded M2 protein is a member of the poxvirus immune evasion family and plays roles in host immunomodulation via the regulation of innate immune response mediated by the NF-κB pathway and adaptive immune response mediated by B7 ligands. However, the interaction of monkeypox virus (MPXV) M2 with B7 ligands and structural insight into poxviral M2 function have remained elusive. Here we reveal that MPXV M2, co-existing as a hexamer and a heptamer, recognizes human B7.1 and B7.2 (hB7.1/2) with high avidities. The binding of oligomeric MPXV M2 interrupts the interactions of hB7.1/2 with CD28 and CTLA4 and subverts T cell activation mediated by B7.1/2 costimulatory signals. Cryo-EM structures of M2 in complex with hB7.1/2 show that M2 binds to the shallow concave face of hB7.1/2 and displays sterically competition with CD28 and CTLA4 for the binding to hB7.1/2. Our findings provide structural mechanisms of poxviral M2 function and immune evasion deployed by poxviruses.
Subject(s)
Mpox (monkeypox) , Poxviridae , Humans , Monkeypox virus , CTLA-4 Antigen , CD28 Antigens , Ligands , T-LymphocytesABSTRACT
Objective@#To explore the impact of tennis on the visual health of primary school students, so as to provide a basis for myopia prevention.@*Methods@#In September 2021, a total of 202 third grade students from Fengtai Affiliated School of Renmin University of China in Beijing were recruited, with 75 students in the intervention group and 127 students in the control group. In addition to attending the same cultural and physical education courses, the intervention group added a tennis course twice a week and tested their vision before the intervention (September 2021), middle (January 2022) and later (June 2022). Data collected at different time points in the two groups were analyzed by using independent sample t-test for comparison between blocks, and single factor repeated measurement ANOVA for analysis of time point factors.@*Results@#After intervention, among male subjects, the average visual acuity of the left and right eyes in the intervention group were higher than that in the control group at the third visual acuity test (left eye:5.00±0.13,4.88±0.29, right eye:5.00±0.12,4.88±0.30, t =2.33, 2.36, P <0.05). Among female subjects, the second visual acuity test (left eye:5.03±0.17, 4.86±0.21, right eye:5.03±0.15, 4.85±0.23) and the third visual acuity test (left eye:4.97±0.13, 4.81±0.23, right eye:4.97±0.14, 4.82±0.24) showed that the average visual acuity of the left and right eyes in the intervention group were higher than that in the control group among females (second: t =3.84, 3.87, third: t =3.70, 3.46, P < 0.01 ). After intervention, the detection rate of visual impairment in both males and females control groups increased at three tests, with statistically significant differences ( χ 2=17.86, 34.77, P <0.01). In the first visual acuity test, there was no statistically significant difference in the detection rate of visual impairment between the control group and the intervention group for both males and females ( χ 2=0.01, 0.10, P >0.05). The third visual impairment detection rate of males in the intervention group was lower than that of the control group (20.00% vs 45.45%), while the second and third visual impairment detection rates of female students in the intervention group were lower than those of the control group (22.86% vs 54.00%; 28.57% vs 70.00%) ( χ 2=7.34, 8.24, 14.18, P < 0.01).@*Conclusions@#Tennis can alleviate and prevent the occurrence of myopia in primary school students to a certain extent. Sports such as tennis should be actively promoted to protect the visual health of primary school students.
ABSTRACT
In terms of small objects in traffic scenes, general object detection algorithms have low detection accuracy, high model complexity, and slow detection speed. To solve the above problems, an improved algorithm (named YOLO-MXANet) is proposed in this paper. Complete-Intersection over Union (CIoU) is utilized to improve loss function for promoting the positioning accuracy of the small object. In order to reduce the complexity of the model, we present a lightweight yet powerful backbone network (named SA-MobileNeXt) that incorporates channel and spatial attention. Our approach can extract expressive features more effectively by applying the Shuffle Channel and Spatial Attention (SCSA) module into the SandGlass Block (SGBlock) module while increasing the parameters by a small number. In addition, the data enhancement method combining Mosaic and Mixup is employed to improve the robustness of the training model. The Multi-scale Feature Enhancement Fusion (MFEF) network is proposed to fuse the extracted features better. In addition, the SiLU activation function is utilized to optimize the Convolution-Batchnorm-Leaky ReLU (CBL) module and the SGBlock module to accelerate the convergence of the model. The ablation experiments on the KITTI dataset show that each improved method is effective. The improved algorithm reduces the complexity and detection speed of the model while improving the object detection accuracy. The comparative experiments on the KITTY dataset and CCTSDB dataset with other algorithms show that our algorithm also has certain advantages.
Subject(s)
Algorithms , Research DesignABSTRACT
BACKGROUND:Bilateral ovariectomy is a most commonly used method to establish an animal model of postmenopausal osteoporosis.Up to now,little is reported on the C57 mouse model of osteoporosis with calvarial critical-size defects.OBJECTIVE:To establish the C57 mouse model of osteoporosis with calvarial critical-size defects.METHODS:Thirty-six C57 mice aged 8 weeks were randomly divided into two groups:the mice in model group received bilateral ovariectomy,and the same weight of fat tissues around the ovaries of the other mice were cut as control group.At 6 weeks after modeling,the mouse femur was removed for micro-CT scan and hematoxylin-eosin staining to testify whether there is a success or failure in animal modeling.Afterwards,six mice were respectively selected from each group,and two round calvarial defects with a diameter of 4 mm were symmetrically made on the parietal bone.The defect healing was evaluated by micro-CT scan at 8 weeks after modeling.RESULTS AND CONCLUSION:At 6 weeks after modeling,the bone volume fraction,bone surface to volume ratio,trabecular thickness,trabecular number,trabecular spacing and bone mineral density in the modeling group were significantly lower than those in the control group (P ＜ 0.05).In the model group,there were loosen or fractured trabeculae,and enlarged medullary cavity.At 8 weeks after bone defects,showed no significant micro-CT changes in the defect region in both two groups.These findings implicate a success in establishing the C57 mouse model of osteoporosis with calvarial critical-size defects.
ABSTRACT
·Age-related macular degeneration (AMD) and retinitis pigmentosa (RP) are common outer retinal degenerative problems, which are also the predominant causes of most blinding retinal diseases. Retinal prosthesis is a promising solution for such photoreceptor degeneration diseases.Most of current concepts for a retinal prosthesis are based on neuronal electrical stimulation. In the past twenty years, retinal prosthesis has been developed in two different directions: epiretinal prosthesis and subretinal prosthesis. Each prosthesis technique has its advantages and disadvantages. For epiretinal prosthesis, it is easier to be implanted and has the advantage of keeping most of the electronics in the vitreous cavity, off the retinal surface, which greatly helps in dissipating the heat generated by the implant device. In this paper, a brief overview of retinal prostheses concepts is introduced. After that, several important aspects of epiretinal electrical stimulation will be discussed. Moreover, some practical epiretinal prosthesis devices developed by researchers in United States, Germany and Japan in the past have been reviewed. We hope that the devices will be used widely in the near future.
ABSTRACT
This paper introduces the working principle of the blood circle treatment system outside the body. A monitoring instrument of plasma leakage suited for the blood circle treatment system outside the body is developed based on the absorption spectrum experiments of plasma leakage. Photoelectric detection technology and virtual instrumentation are utilized in the development. A series of detecting experiments of waste solution containing plasma with continuously changing concentration show the monitoring system possesses a relatively high sensitivity. Moreover, the experiments of continual detection with plasma concentration at one certain point indicate the monitoring system has a quite good stability. The monitoring instrument is adapted to dynamically detecting the plasma leakage when the blood circle treatment system outside the body is working.
ABSTRACT
Virtual instrumentation makes great progress in instrument development. LabVIEW is a graphical programming language that uses icons instead of lines of text to create applications. It has been used widely in developing virtual instrument. The application of virtual instrument to medical equipments presented, this paper introduces how to drive common DAQ system and its several implement methods, builds a shared library adapting to AC6010, and develops a low-cost and good-capability DAQ system, which has been utilized to detect biomedical signal with a optic-electric detecting system.
