Abstract Background: Glomerular capillary formation is one of the fundamental mysteries in renal developmental biology. However, there are still debates on this issue, and its detailed formation process has not been clarified. Results: To resolve this problem, we performed antibody staining with ultra-thick section on embryonic and postnatal mouse kidneys to detect and analyze the development of glomerular capillaries. We found that blood vessel of the fetal kidneys expanded through proliferation and sprouting. During the comma-stage and S-shaped stages, 3-4 capillaries began to bud and migrate into the glomerular cleft, forming a capillary bed in the Bowman’s capsule. Then, the capillary bed expanded into mature glomerular capillary by intussusceptive angiogenesis. The afferent and efferent arterioles were formed through pruning. The distribution of VEGFA in the nephron epithelial cells but not only in podocytes, induced multiple capillaries sprouted into the glomerular cleft. And CXCR4 played an important role in the differentiation and expansion of capillary bed into glomerular capillary. Conclusions: Immunofluorescence performed with ultra-thick section allowed us to investigate the development of complex structure tissues systematically and comprehensively.
Objective To investigate the effect of stromal cell derived factor-1 (SDF-1) on the proliferation and migration of endothelial progenitor cells (EPCs) and whether such an effect could be blocked with AMD3100. Methods EPCs in 96-well plates were co-cultured with SDF-1α (1, 5, 10 ng/ml), or AMD3100 or 5 ng/ml SDF-1α +AMD3100 (10, 50, 100 ng/ml) for 24 h. EPCs proliferation was assayed with MTT. EPCs was incubated with or without 10 ng/ml AMD3100 for 1 h, then induced by SDF-1α or without to start migration at 37 ℃ for 6 h. EPCs migration was evaluated by using a modified Boyden chamber assay. Results SDF-1α increased EPCs proliferation activity in a dose-dependent manner, but its effect induced by 5 ng/ml SDF-1α was inhibited completely with 10 ng/ml AMD3100. The proliferation of EPCs treated with AMD3100 alone was inhibited. SDF-1α increased EPCs migration, but this effect was completely blocked by AMD3100. The migration of EPCs was reduced by AMD3100 alone. Conclusion SDF-1α can improve EPCs proliferation and migration, and its effect could be blocked with AMD3100. The treatment of AMD3100 alone decreases the proliferation and migration of EPCs.
With the coming of the era of big data, traditional entity recognition technologies have been unable to effectively finish data preprocessing due to large scale of power grid data and complex volume type features. The rising of Hadoop technologies in these years can deal with big data processings better. Therefore, this paper proposes a power big data entity recognition algorithm based on Hadoop. It applies the discretization algorithm to select higher information accuracy discrete points and put forward a discretization evaluation indicator. In the end, we finish entity recognition of the monitoring data of wind turbines on Hadoop platform.Experimental results show that the proposed algorithm performs well in terms of correctness and breakpoint number experiments and it has a good speed-up ratio. The proposed algorithm can apply to power large data entity recognition processing.
A new comprehensive evaluation method for the urgency of medium voltage distribution network project considering correction factors is put forward. Based on the analytic hierarchy process, the 10kV distribution network project evaluation index system is established, influence among evaluating indicators is analyzed and influence matrix of evaluating indicators is built. After that, the calculation methods of correction factors, which are developed from the influence matrix, can make quantitative analysis for the urgency of medium voltage distribution network comprehensively. Not only the evaluating indicator importance degree to the overall evaluation is considered, but also the impact of mutual influence degree between evaluating indicators on the overall evaluation is taken into account. It is possible to give a more accurate evaluation score level for evaluation samples. With analysis of three 10kV lines power lines carrying out, the effectiveness and practicality of the method is demonstrated.
SARS-CoV-2 infection starts from the association of its spike 1 (S1) subunit with sensitive cells. Vesicular endothelial cells and platelets are among the cell types that bind SARS-CoV-2, but the effectors that mediate viral attachment on the cell membrane have not been fully elucidated. Herein, we show that P-selectin (SELP), a biomarker for endothelial dysfunction and platelet activation, can facilitate the attachment of SARS-CoV-2 S1. Since we observe colocalization of SELP with S1 in the lung tissues of COVID-19 patients, we perform molecular biology experiments on human umbilical vein endothelial cells (HUVECs) to confirm the intermolecular interaction between SELP and S1. SELP overexpression increases S1 recruitment to HUVECs and enhances SARS-CoV-2 spike pseudovirion infection. The opposite results are determined after SELP downregulation. As S1 causes endothelial inflammatory responses in a dose-dependent manner, by activating the interleukin (IL)-17 signaling pathway, SELP-induced S1 recruitment may contribute to the development of a "cytokine storm" after viral infection. Furthermore, SELP also promotes the attachment of S1 to the platelet membrane. Employment of PSI-697, a small inhibitor of SELP, markedly decreases S1 adhesion to both HUVECs and platelets. In addition to the role of membrane SELP in facilitating S1 attachment, we also discover that soluble SELP is a prognostic factor for severe COVID-19 through a meta-analysis. In this study, we identify SELP as an adhesive site for the SARS-CoV-2 S1, thus providing a potential drug target for COVID-19 treatment.
On ships, the EMI that promotes motor excitation has a great impact on the safety of the ship's power grid and the service life of the motor. In this paper, bridge Reversible Chopper for the excitation of DC motor has carried out a detailed study of its conducted interference propagation path model and interference noise source, and established a high accuracy EMI model. The EMI model not only analyzes the influence factors of the EMI, but also significantly saves the design cost of subsequent EMI filters, which is of great practical significance.
In order to solve the problem of excessive short-circuit current in the present power system, a fault current limiter has become a new type of power device with high demand and is one of the current research hotspots. The flux-coupling type superconducting fault current limiter (FC-SFCL) generates a current-limiting impedance through decoupling superconducting parallel inductance based on the circuit breakers' fractional interruption. The principle is simple, and the impedance is low during normal operation. It can directly use the existing circuit breaker to open a short circuit that is much higher than its own breaking capacity. Thus, it can be used for large-capacity fault current limiting and effective failure breaking. This paper focused on exploring and studying the implementation scheme of practical products of FC-SFCL. Considering that the quenched-type parallel inductance can limit the first peak value of the fault current, a quenched-type improvement scheme was proposed. Then, an electromagnetic design method based on the simplified calculation of the number of parallel tapes was proposed, which simplified the design process and reduced the design difficulty of the quenched FC-SFCL. Taking a 10 kV/500 A/5 kA quenched prototype as an example, its electromagnetic design was completed, and the performances of the non-quenched and quenched schemes were compared. The results showed that, compared to the non-quenched structure, the technical economics of the quenched one were more prominent, and it can be used preferentially for engineering prototypes. This study about the scheme of the quenched FC-SFCL and its electromagnetic design method is useful for promoting the implementation of the current limiter engineering prototype.
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