基于PIC16F716的PWM恒流控制器

0引言本控制器为结合铅酸蓄电池充放电特性和太阳能电池伏安特性,专为负载LED灯具设计的一款充放电控制器。选用美国MICROCHIP公司生产的     

面向融合的移动通信网络安全关键技术研究

随着我国社会经济和科学技术的快速发展，移动通信网络已经深入到各行各业中，人们对移动通信网络的要求越来越高。在人们的众多要求中，安全方面的需求最为重要。在固定移动融合（Fix Mobile Convergence，FMC）体系的框架下，可以为移动通信网络提供更多的对外接口，使移动通信网络更具开放性，同时原有体系中的不安全因素逐渐暴露出来，成了重要的安全威胁，降低了移动通信网络整体的安全性。在这种情况下，需要注重面向融合的移动通信网络安全关键技术的研究工作，并提出切实可行的方案，这对我国整体的移动通信网络发展具有重要的作用和价值。     

A Biomimetic Peptide Functions as Specific Extracellular Matrix for Quiescence of Stem Cells against Intervertebral Disc Degeneration

Maintaining quiescence of stem cells is a potential way to decrease cell nutrition demand for restoring the organization. Herein, a biomimetic peptide to maintain quiescence of stem cells through C-X-C motif chemokine ligand 8 (CXCL8)-C-X-C motif chemokine receptor 1 (CXCR1) pathway against intervertebral disc degeneration (IVDD) is developed. First, it is confirmed that quiescence can be induced via inhibiting phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway in nucleus pulposus stem cells (NPSCs). Meanwhile, it is well known that CXCR1, a chemokine receptor, can be targeted by CXCL8, resulting in cell proliferation via activating PI3K/Akt/mTOR pathway. Second, a biomimetic peptide (OAFF) that can bind to CXCR1 and form fibrous networks on NPSCs, mimicking extracellular matrix formation is developed. The multivalent effect and long-term binding to CXCR1 on NPSCs of OAFF fibers offer forcefully competitive inhibition with natural CXCL8, which induces NPSCs quiescence and ultimately overcomes obstacle in intradiscal injection therapy. In rat caudal disc puncture model, OAFF nanofibers still maintain at 5 weeks after operation and inhibit degeneration process of intervertebral disc in terms of histopathology and imageology. In situ fibrillogenesis of biomimetic peptide on NPSCs provides promising stem cells for intradiscal injection therapy against IVDD.