负载氯喹的骨靶向纳米颗粒打破肿瘤细胞增殖与骨吸收之间的恶性循环

肿瘤细胞增殖与骨吸收之间的恶性循环加剧了骨肿瘤的进展和转移风险.为此,我们设计并制备了聚乙二醇-阿仑膦酸钠修饰的聚多巴胺(PPA)纳米粒子,并在其表面负载自噬抑制剂氯喹(CQ),期望利用该治疗载体(PPA/CQ)打破肿瘤细胞增殖与骨吸收之间的恶性循环,从而有效地治疗骨肿瘤.实验证明,PPA/CQ可以有效地富集到骨组织,...     

新型高效冷渣机的研制和经济分析

循环流化床锅炉是当代燃煤锅炉中脱硫效益最高的设备,本文对国内现有循环流化床锅炉的冷渣方式进行了综合述评,并着重推荐一种简单、高效、耐用,节能的干式冷渣机.该新型冷渣机应用了一种全新旋转抛洒推进技术,运行可靠性大大提高,固体燃料在推进过程中水冷与风冷相结合,可以在较短的筒体中完成必须的冷却,产生非常显著的节能、环保和社会效益.     

Hydrodynamic characteristics and noise reduction mechanism of a wave leading hydrofoil placed in the wake of a cylinder

We have investigated the hydrodynamic and acoustic performance of a hydrofoil with a wave leading edge that is being ingested in a cylindrical wake,to explore the interaction and noise reduction mechanism with the use of near flow field and far field noise decoupled prediction methods of large eddy simulation(LES)and Ffowcs Williams-Hawkings(FW-H).Our results indicate that the wave leading edge has minimal effect on the hydrodynamic performance,however,it has demonstrated the ability to significantly improve the acoustic performance.Through the comparison of sound pressure level(SPL)and acoustic directivity,we have observed that the wave leading edge can significantly reduce the broadband noise in the far field.This is due to its ability to break the large-scale structure of the incoming flow,which weakens the direct impact and therefore reduces the tone noise.Additionally,the interaction between the broken vortex and the boundary layer around the hydrofoil surface is weakened,leading to a reduction in surface pressure pulsation and broadband noise intensity.The wave structure primarily affects the flow structure near the leading edge,resulting in a reduction in flow disturbance and sound source intensity,and an improvement in the acoustic feedback loop between the foil and the fore-cylinder.     

LvBMP-2 gene-modified BMSCs combined with calcium phosphate cement scaffolds for the repair of calvarial defects in rats

The study aims to evaluate the effect of bone marrow stromal cells (BMSCs) expressing bone morphogenic protein-2 (BMP-2) mediated by lentiviral (Lv) gene transduction combined with calcium phosphate cement (CPC) scaffolds for the repair of critical size calvarial defects in rats. BMSCs derived from Fisher 344 rats were transduced with LvBMP-2 or lentivirus encoding enhanced green fluorescent protein (LvEGFP) in vitro. Obvious osteogenic differentiation of BMSCs in the LvBMP-2 group was demonstrated by alkaline phosphatase staining and alizarin red staining. Enzyme-linked immunosorbent assay results show that LvBMP-2 gene expression in vitro can last for at least 8 weeks. Gene-transduced or untransduced BMSCs were seeded onto CPC scaffolds to repair rat calvarial defects with a diameter of 5 mm. Scanning electron microscope analysis indicated that porous CPC scaffolds facilitated initial adhesion and spreading of BMSCs onto its surface. Calvarial defects were successfully repaired with LvBMP-2-transduced BMSCs/CPC constructs 8 weeks postoperatively. The percentage of new bone formation in the LvBMP-2 group was significantly higher than in other control groups. Lentiviral mediated BMP-2 gene therapy together with CPC scaffolds can be used successfully in calvarial repair and bone regeneration.     

超声波三轴压缩试验机及其应用

在单轴压缩试验机的基础上研制了一套超声波三轴压缩试验系统,实现了三轴压缩过程中超声波的全程测试。对一组混凝土试样进行了试验研究,采用小波分析对超声波数据进行处理。在频域范围内提出了三个能反映试样中损伤演化的特征量:归一化第一能量峰值、归一化第二能量峰值、第一能量峰值对应的尺度。本文为研究损伤本构关系提供了新的设备,提出的三个特征量能够反映材料内部结构的变化,特别是第三个特征量具有较强的规律性,可以作为描述材料结构变化的损伤变量。     

死区直接补偿的电液系统BP神经网络控制

为解决电液比例伺服系统无法精确定位的问题,推导了系统的流量动态平衡方程,并设计了一种基于死区直接补偿的BP(DZDC-BP)神经网络控制算法,即在线性化比例阀输入信号与输出流量关系的基础上,利用BP神经网络控制算法逼近非线性系统的特性,弥补系统中的非线性、未知参数、外部干扰和建模误差等问题,使得系统能够时刻跟随期望轨迹。使用MATLAB-AMESim软件对系统进行联合仿真,结果表明:无论系统有无外部干扰,DZDC-BP神经网络控制与有死区比例阀PID控制(PPID)和无死区比例阀PID控制(SPID)相比,系统的稳态误差都有显著的减少。说明DZDC-BP神经网络控制算法在一定程度上解决了系统中的死区和非线性等问题,同时具有良好的抗干扰能力,显著提高了系统的控制性能。     

Targeted Silencing of MART-1 Gene Expression by RNA Interference Enhances the Migration Ability of Uveal Melanoma Cells

Uveal melanoma (UM) is the most common primary intraocular malignancy and the leading potentially fatal primary intraocular disease in adults. Melanoma antigen recognized by T-cells (MART-1) has been studied extensively as a clinically important diagnostic marker for melanoma, however, its biological function remains unclear. In the present study, the UM cell line SP6.5, which showed a high level of MART-1 expression, was subjected to small interfering RNA-mediated silencing of MART-1. Silencing of MART-1 expression increased the migration ability of SP6.5 cells and down-regulated the expression of the metastasis suppressor NM23. Our results suggest that MART-1 is a candidate target for the development of therapeutic strategies for UM and in particular for the suppression of metastasis associated with this malignancy.