大肠杆菌O157:H7压电免疫传感器研究及表征

构建了一种可以快速检测大肠杆菌O157:H7的石英微天平(QCM)压电免疫传感器,并用原子力显微镜(AFM)和电化学方法分别对传感的各个步骤进行了表征,整个检测系统均由实验室自己构建。利用QCM的金电极自组装膜特性、抗原抗体的特异性结合和结合后的频差改变(Δf)来检测溶液中O157:H7含量,最后对传感器的再生性进行了初步探索。结果显示,该检测系统可以在1.5h内检测2.0×102~2.0×108CFU/mL的目标菌,并可重复再生使用。     

Dynamic cell sleeping mechanism: An energy-efficient approach for Mobile 5G HetCN

The paper proposes a novel cell sleeping mechanism for enhancing network energy-efficiency and to combat dynamic downlink interferences linked with mobile Small Cells (mSCs) in a 5G Heterogeneous Cellular Network (HetCN). The proposed Dynamic Mobile Cell Sleeping Mechanism (DMCSM) allows deployed vehicle-mounted mSCs to dynamically go into sleep based on the calculated distances of users from its serving mSCs BS. With this mechanism, vehicular mSCs during mobility dynamically calculate their distances with the Macrocell (MC) users. The mSCs go into sleep or get deactivated for a while based on the calculated distance and the cell radius defined for mSCs. The mSCs will get active and starts to provide services to the users that are found within their coverage radius. The setup 5G HetCN is investigated with a MC superimpose with fixed SCs (fSCs) and mobile SCs (mSCs). The proficiency of DMCSM is investigated with the exploitation of existing sub 6 GHz groups at MCs and the millimeter wave (mmWave) spectrums at deployed fSCs and mSCs. The network downlink performance metrics: user throughput, sumrate, energy-efficiency, and outage probability, have been explored. The work also depicts a comparison of the proposed DMCSM mechanism with the author's previously proposed ICI mitigation techniques.     

Temperature‐Responsive Substrates: Adhesion and Mechanical Properties of PNIPAM Microgel Films and Their Potential Use as Switchable Cell Culture Substrates (Adv. Funct. Mater. 19/2010)

Thermoresponsive poly(N‐isopropylacrylamide) (PNIPAM) microgel films are shown to allow controlled detachment of adsorbed cells via temperature stimuli. Cell response occurs on the timescale of several minutes, is reversible, and allows for harvesting of cells in a mild fashion. The fact that microgels are attached non‐covalently allows using them on a broad variety of (charged) surfaces and is a major advantage as compared to approaches relying on covalent attachment of active films. In the following, the microgels’ physico‐chemical parameters in the adsorbed state and their changes upon temperature variation are studied in order to gain a deeper understanding of the involved phenomena. By means of atomic force microscopy (AFM), the water content, mechanical properties, and adhesion forces of the microgel films are studied as a function of temperature. The analysis shows that these properties change drastically when crossing the critical temperature of the polymer film, which is the basis of the fast cell response upon temperature changes. Furthermore, nanoscale mechanical analysis shows that the films posses a nanoscopic gradient in mechanical properties.     

Tissue Engineered Bio‐Blood‐Vessels Constructed Using a Tissue‐Specific Bioink and 3D Coaxial Cell Printing Technique: A Novel Therapy for Ischemic Disease

Endothelial progenitor cells (EPCs) are a promising cell source for the treatment of several ischemic diseases for their potentials in neovascularization. However, the application of EPCs in cell‐based therapy has shown low therapeutic efficacy due to hostile tissue conditions after ischemia. In this study, a bio‐blood‐vessel (BBV) is developed, which is produced using a novel hybrid bioink (a mixture of vascular‐tissue‐derived decellularized extracellular matrix (VdECM) and alginate) and a versatile 3D coaxial cell printing method for delivering EPC and proangiogenic drugs (atorvastatin) to the ischemic injury sites. The hybrid bioink not only provides a favorable environment to promote the proliferation, differentiation, and neovascularization of EPCs but also enables a direct fabrication of tubular BBV. By controlling the printing parameters, the printing method allows to construct BBVs in desired dimensions, carrying both EPCs and atorvastatin‐loaded poly(lactic‐co‐glycolic) acid microspheres. The therapeutic efficacy of cell/drug‐laden BBVs is evaluated in an ischemia model at nude mouse hind limb, which exhibits enhanced survival and differentiation of EPCs, increased rate of neovascularization, and remarkable salvage of ischemic limbs. These outcomes suggest that the 3D‐printed ECM‐mediated cell/drug implantation can be a new therapeutic approach for the treatment of various ischemic diseases.