Overview of Position Servo Control Technology and Development of Voice Coil Motor

Voice coil motor(VCM) is a special direct drive linear motor, which can convert electric energy directly into mechanical energy without the use of transmission mechanism. VCM has the advantages of simple structure, good rigidity, fast response, silence, high linearity, no cogging force, no pulsation et al. It is widely used in the field of high-precision control. This paper reviews and summarizes the results of VCM research conducted by scholars from various countries, and summarizes the general situation of VCM servo control technology. Firstly, a basic description of VCM’s mathematical model and common control mechanisms is provided. The benefits, drawbacks, and application of control techniques in the field of VCM are all explored in detail;At the same time, the methods to improve control strategy are proposed;Then, combined with the analysis and research of scholars in various countries on VCM, the problems of difficult to establish accurate model, friction disturbance and mechanical vibration of VCM and the solutions to the corresponding problems are summarized;Finally, a summary of VCM’s application fields is provided.

A positive feedback loop between PLD1 and NF-κB signaling promotes tumorigenesis of nasopharyngeal carcinoma

Phospholipase D(PLD)lipid-signaling enzyme superfamily has been widely implicated in various human malignancies,but its role and underlying mechanism remain unclear in nasopharyngeal carcinoma(NPC).Here,we analyze the expressions of 6 PLD family members between 87 NPC and 10 control samples through transcriptome analysis.Our findings reveal a notable upregulation of PLD1 in both NPC tumors and cell lines,correlating with worse disease-free and overall survival in NPC patients.Functional assays further elucidate the oncogenic role of PLD1,demonstrating its pivotal promotion of critical tumorigenic processes such as cellproliferation and migration in vitro,as well as tumor growth in vivo.Notably,our study uncovers a positive feedback loop between PLD1 and the NF-κB signaling pathway to render NPC progression.Specifically,PLD1 enhances NF-kB activity by facilitating the phosphorylation and nuclear translocation of RELA,which in turn binds to the promoter of PLD1,augmenting its expression.Moreover,RELA over-expression markedly rescues the inhibitory effects in PLD1-depleted NPC cells.Importantly,the application of the PLD1 inhibitor,VU0155069,substantially inhibits NPC tumorigenesis in a patient-derived xenograft model.Together,our findings identify PLD1/NF-κB signaling as a positive feedback loop with promising therapeutic and prognostic potential in NPC.

作为开环系统的高精度定位装置

作者分析了闭环及开环控制系统各自的优缺点，提出了利用计算机高速大容量的特点进行离线检测、在线补偿的可能性，以及在实施过程中必须解决的关键问题。最后附有实测数据。该系统在２５ｍｍ行程中示值误差≤１μｍ、回程误差≤０．３μｍ、分辨率为０．１μｍ，结构简单、可靠、价格低廉。已获得专利。

部分行程测试在海洋平台的应用研究

针对关断阀延长检修周期引起的安全完整性等级降低的问题,通过对改善关断阀安全完整性等级的方法进行分析研究,以及对现有部分行程测试方式的综合比较,并结合海洋平台应急关断系统的设计要求,给出了关断阀气动回路式和定位器式部分行程测试在海洋平台的应用方案。同时,对关断阀采用部分行程测试前后的安全完整性等级进行了计算。验证结果表明,部分行程测试能够提高关断阀的安全完整性等级,对海洋平台延长停产检修周期和提高生产能力具有一定帮助。

An HGF-dependent positive feedback loop between bladder cancer cells and fibroblasts mediates lymphangiogenesis and lymphatic metastasis

Background Cancer-associated fibroblasts (CAFs) play a vital role in facilitating tumor progression through extensive reciprocal interplay with cancer cells. Tumor-derived extracellular vesicles (EVs) are the critical mediators involved in the crosstalk between cancer cells and stromal cells, contributing to the metastasis of cancers. Yet, the biological mechanisms of tumor-derived EVs in triggering CAFs phenotype to stimulate the lymph node (LN) metastasis of bladder cancer (BCa) are largely unknown. Here, we aimed to explore the effects and molecular mechanisms of tumor-derived EV-mediated CAFs phenotype in regulating BCa LN metastasis. Methods The high-throughput sequencing was utilized to identify the crucial long non-coding RNA (lncRNA) associated with CAF enrichment in BCa. The functional role of the transition of fibroblasts to CAFs induced by LINC00665-mediated EVs was investigated through the in vitro and in vivo assays. Chromatin isolation by RNA purification assays, fluorescence resonance energy transfer assays, cytokine profiling and patient-derived xenograft (PDX) model were performed to explore the underlying mechanism of LINC00665 in the LN metastasis of BCa. Results We found that CAFs are widely enriched in the tumor microenvironment of BCa, which correlated with BCa lymphangiogenesis and LN metastasis. We then identified a CAF-associated long non-coding RNA, LINC00665, which acted as a crucial mediator of CAF infiltration in BCa. Clinically, LINC00665 was associated with LN metastasis and poor prognosis in patients with BCa. Mechanistically, LINC00665 transcriptionally upregulated RAB27B expression and induced H3K4me3 modification on the promoter of RAB27B through the recruitment of hnRNPL. Moreover, RAB27B-induced EVs secretion endowed fibroblasts with the CAF phenotype, which reciprocally induced LINC00665 overexpression to form a RAB27B-HGF-c-Myc positive feedback loop, enhancing the lymphangiogenesis and LN metastasis of BCa. Importantly, we demonstrated that blocking EV-transmitted LINC00665 or HGF broke this loop and impaired BCa lymphangiogenesis in a PDX model. Conclusion Our study uncovers a precise mechanism that LINC00665 sustains BCa LN metastasis by inducing a RAB27B-HGF-c-Myc positive feedback loop between BCa cells and fibroblasts, suggesting that LINC00665 could be a promising therapeutic target for patients with LN metastatic BCa.

Network Modeling of Inammatory Dynamics Induced by Biomass Smoke Leading to Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease(COPD) is a chronic inflammatory disorder characterized by airflow obstruction and progressive damage of lung tissues. As currently more than 3 billion people use biomass fuel for cooking and heating worldwide, exposure to biomass smoke(BS) is recognized as a significant risk factor for COPD. Recent clinical data have shown that BS-COPD patients have a Th2-type inflammatory profile significantly different from that in COPD induced by cigarette smoke. As COPD is essentially proinflammatory,however, the mechanism underlying this Th2-type anti-inflammatory profile remains elusive.In this work, a network model is applied to study BS-induced inflammatory dynamics. The network model involves several positive feedback loops, activations of which are responsible for different mechanisms by which clinical phenotypes of COPD are produced. Our modeling study in this work has identified a subset of BS-COPD patients with a mixed M1-and Th2-type inflammatory profile. The model’s prediction is in good agreement with clinical experiments and our in silico knockout simulations have demonstrated several important network components that play an important role in the disease. Our modeling study provides novel insight into BS-COPD progression, offering a rationale for targeted therapy and personalized medicine for treatment of the disease in future.

PLEK2 promotes cancer stemness and tumorigenesis of head and neck squamous cell carcinoma via the c-Myc-mediated positive feedback loop

Background:Head and neck squamous cell carcinoma(HNSCC)is one of the most frequent malignancies worldwide and is characterized by unfavorable prognosis,high lymph node metastasis and early recurrence.However,the molecular events regulating HNSCC tumorigenesis remain poorly understood.Therefore,uncovering the underlying mechanisms is urgently needed to identify novel and promising therapeutic targets for HNSCC.In this study,we aimed to explore the role of pleckstrin-2(PLEK2)in regulating HNSCC tumorigenesis.Methods:The expression pattern of PLEK2 and its clinical significance in HNSCC were determined by analyzing publicly assessable datasets and our own independent HNSCC cohort.In vitro and in vivo experiments,including cell proliferation,colony formation,Matrigel invasion,tumor sphere formation,ALDEFLUOR,Western blotting assays and xenograft mouse models,were used to investigate the role of PLEK2 in regulating the malignant behaviors of HNSCC cells.The underlying molecular mechanisms for the tumor-promoting role of PLEK2 were elucidated using co-immunoprecipitation,cycloheximide chase analysis,ubiquitination assays,chromatin immunoprecipitation-quantitative polymerase chain reaction,luciferase reporter assays and rescue experiments.Results:The expression levels of PLEK2 mRNA and protein were significantly increased in HNSCC tissues,and PLEK2 overexpression was strongly associated with poor overall survival and therapeutic resistance.Additionally,PLEK2 was important for maintaining the proliferation,invasion,epithelial-mesenchymal transition,cancer stemness and tumorigenesis of HNSCC cells and could alter the cellular metabolism of the cancer cells.Mechanistically,PLEK2 interacted with c-Myc and reduced the association of F-box and WD repeat domain containing 7(FBXW7)with c-Myc,thereby avoiding ubiquitination and subsequent proteasome-mediated degradation of c-Myc.Moreover,the c-Myc signaling activated by PLEK2 was important for sustaining the aggressive malignant phenotypes and tumorigenesis of HNSCC cells.c-Myc also directly bounded to the PLEK2 promoter and activated its transcription,forming a positive feedback loop.Conclusions:Collectively,these findings uncover a previously unknown molecular basis of PLEK2-enhanced c-Myc signaling in HNSCC,suggesting that PLEK2 may represent a promising therapeutic target for treating HNSCC.

Meiotic nuclear divisions 1(MND1)fuels cell cycle progression by activating a KLF6/E2F1 positive feedback loop in lung adenocarcinoma

Background:Considering the increase in the proportion of lung adenocarcinoma(LUAD)cases among all lung cancers and its considerable contribution to cancer-related deaths worldwide,we sought to identify novel oncogenes to provide potential targets and facilitate a better understanding of the malignant progression of LUAD.Methods:The results from the screening of transcriptome and survival analyses according to the integrated Gene Expression Omnibus(GEO)datasets and The Cancer Genome Atlas(TCGA)data were combined,and a promising risk biomarker called meiotic nuclear divisions 1(MND1)was selectively acquired.Cell viability assays and subcutaneous xenograftmodelswere used to validate the oncogenic role ofMND1 in LUADcell proliferation and tumor growth.Aseries of assays,including mass spectrometry,co-immunoprecipitation(Co-IP),and chromatin immunoprecipitation(ChIP),were performed to explore the underlying mechanism.Results:MND1 up-regulation was identified to be an independent risk factor for overall survival in LUAD patients evaluated by both tissue microarray staining and third party data analysis.In vivo and in vitro assays showed that MND1 promoted LUAD cell proliferation by regulating cell cycle.The results of the Co-IP,ChIP and dual-luciferase reporter assays validated that MND1 competitively bound to tumor suppressor Kruppel-like factor 6(KLF6),and thereby protecting E2F transcription factor 1(E2F1)from KLF6-induced transcriptional repression.Luciferase reporter and ChIP assays found that E2F1 activated MND1 transcription by binding to its promoter in a feedback manner.Conclusions:MND1,KLF6,and E2F1 form a positive feedback loop to regulate cell cycle and confer DDP resistance in LUAD.MND1 is crucial for malignant progression and may be a potential therapeutic target in LUAD patients.

Substrate concentration effect on gene expression in genetic circuits with additional positive feedback

In gene regulatory networks, gene regulation loops often occur with multiple positive feedback, multiple negative feedback and coupled positive and negative feedback forms. In above gene regulation loops, auto-activation loops are ubiquitous regulatory motifs. This paper aims to investigate a two-component dual-positive feedback genetic circuit, which consists of a double negative feedback circuit and an additional positive feedback loop(APFL). We study effect of substrate concentration on gene expression in the single and the networked systems with APFLs, respectively. We find that substrate concentration can tune stochastic switch behavior in the signal system and then we explore relationship of substrate concentration with positive feedback strength in aspect of stochastic switch behavior. Furthermore, we also discuss gene expression and stochastic switch behavior in the networked systems with APFLs. Based on analysis in the networked systems, we discover that genes express in some specific cells and do not express in the other cells when the expression achieves its steady state. These results can be used to well explain the character of regionalization in the expression of genes and the phenomenon of gene differentiation.

A"three musketeers"tactic for inclining interferon-γ as a comrade-in-arm to reinforce the synergistic-tumoricidal therapy

Interferon-γ(IFN-γ),secreted by activated T cells predominantly,plays a crucial performance in the tumoricidal immune response.Unfortunately,a high level of IFN-γseverely ignites the immunosuppressive response,especially by increasing the expression of immune checkpoint programmed death-ligand 1(PD-L1)and immunoregulatory enzyme indoleamine 2,3-dioxygenase 1(IDO-1).Herein,we have explored a versatile IFN-γ-nano-integrator(aPD-L1-SH@Ce6@NLG919-PEG,simplified as CNDP)to establish a positive anti-tumor feedback loop to amplify the IFN-γ-mediated tumoricidal effect.In this nanointegrator,photosensitizer chlorin e6(Ce6)mediates photodynamic therapy(PDT)to re-shape immunogenicity and activate the adaptive immune response,followed by the secretion of high-level IFN-γto struggle tumor cells.IDO-1 inhibitor(NLG919)afterwards mitigates the immunosuppressive behavior of IFN-γby neutralizing the function of IDO-1.To turn“waste”into wealth,anti-PD-L1(aPD-L1)antibodies are technically integrated into the nano-integrator to propel the precise attack of breast cancer through ascending PD-L1 blockade.Together,this“three musketeers”nano-integrator tumoricidal tactic may give a unique insight into the clinical anti-tumor therapy.