Assessment of Size-Dependent Antimicrobial and Cytotoxic Properties of Silver Nanoparticles

Nanoscale silver has been increasingly applied to commercial products for their antimicrobial function as antibiotics and disinfectants. In this work, the different sizes of silver nanoparticles (AgNPs) were studied not only in Methylobacterium spp. for their antimicrobial potential but also in human peripheral blood mononuclear cells (PBMCs) for their cytotoxicity in order to determine responses dependent on their particle size. Size controlled silver particles were prepared by chemical reduction of silver cations (Ag+) and then dispersed in water for their physicochemical characterization using transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potential measurements. To ascertain antimicrobial response, water-soluble silver nanoparticles were mixed into Methylobacterium spp. cultured for two days and the sample from the broth was spread on the agar plate for colony counting. 10 nm nanoparticles showed more antimicrobial activity than 100 nm particles at which concentrations were equivalently controlled. Increased cytotoxic effect of smaller silver nanoparticles was also observed in PBMCs cocultured with particles. Silver ions released from 10 nm particles might be correlated with upregulated antimicrobial and cytotoxic properties of AgNPs

Plasmacytoid Dendritic Cells Contribute to the Protective Immunity Induced by Intranasal Treatment with Fc-fused Interleukin-7 against Lethal Influenza Virus Infection

Developing a novel vaccine that can be applied against multiple strains of influenza virus is of utmost importance to human health. Previously, we demonstrated that the intranasal introduction of Fc-fused IL-7 (IL-7-mFc), a long-acting cytokine fusion protein, confers long-lasting prophylaxis against multiple strains of influenza A virus (IAV) by inducing the development of lung-resident memory-like T cells, called TRM-like cells. Here, we further investigated the mechanisms of IL-7-mFc-mediated protective immunity to IAVs. First, we found that IL-7-mFc treatment augments the accumulation of pulmonary T cells in 2 ways: recruiting blood circulating T cells into the lung and expanding T cells at the lung parenchyma. Second, the blockade of T cell migration from the lymph nodes (LNs) with FTY720 treatment was not required for mounting the protective immunity to IAV with IL-7-mFc, suggesting a more important role of IL-7 in T cells in the lungs. Third, IL-7-mFc treatment also recruited various innate immune cells into the lungs. Among these cells, plasmacytoid dendritic cells (pDCs) play an important role in IL-7-mFc-mediated protective immunity through reducing the immunopathology and increasing IAV-specific cytotoxic T lymphocyte (CTL) responses. In summary, our results show that intranasal treatment with IL-7-mFc modulates pulmonary immune responses to IAV, affecting both innate and adaptive immune cells. ? 2017. The Korean Association of Immunologists.112Ysciescopuskc

3D Cell Printed Tissue Analogues: A New Platform for Theranostics

Stem cell theranostics has received much attention for noninvasively monitoring and tracing transplanted therapeutic stem cells through imaging agents and imaging modalities. Despite the excellent regenerative capability of stem cells, their efficacy has been limited due to low cellular retention, low survival rate, and low engraftment after implantation. Three-dimensional (3D) cell printing provides stem cells with the similar architecture and microenvironment of the native tissue and facilitates the generation of a 3D tissue-like construct that exhibits remarkable regenerative capacity and functionality as well as enhanced cell viability. Thus, 3D cell printing can overcome the current concerns of stem cell therapy by delivering the 3D construct to the damaged site. Despite the advantages of 3D cell printing, the in vivo and in vitro tracking and monitoring of the performance of 3D cell printed tissue in a noninvasive and real-time manner have not been thoroughly studied. In this review, we explore the recent progress in 3D cell technology and its applications. Finally, we investigate their potential limitations and suggest future perspectives on 3D cell printing and stem cell theranostics.116Nsciescopu

Citizen Engagement in Smart City Planning: The Case of Living Labs in South Korea

The smart city is recognized as a new city model for inclusive urban planning. Many local governments are making smart city plans to develop new policies that manage urban issues in South Korea. They identify issues through citizen surveys and decide which issues should be managed with priority. Some governments test developed policies based on citizen engagement. Most local governments use the living labs to encourage citizen engagement in smart city plans since these are public spaces where planners engage citizens to develop innovative and inclusive ideas. This study conducted a content analysis of smart city plans of local government. We analyzed the various approaches to the living lab and examined the stage of the planning process it is utilized in. Additionally, we identified the barrier to the living lab by interviewing people who participated in the smart city plan. According to the analysis, a barrier to citizen engagement exists in smart city plans; most citizen engagement is only used when planners develop ideas for setting visions and goals. It implies that citizen engagement occurs at a limited level in smart city plans and may cause planning to be less inclusive. We suggest that citizen engagement should be considered in the whole planning process to improve the inclusiveness of smart city plans and encourage sustainable citizen engagement

Massive MIMO Systems With Low-Resolution ADCs: Baseband Energy Consumption vs. Symbol Detection Performance

In massive multiple-input multiple-output (MIMO) systems using a large number of antennas, it would be difficult to connect high-resolution analog-to-digital converters (ADCs) to each antenna component due to high cost and energy consumption problems. To resolve these issues, there has been much work on implementing symbol detectors and channel estimators using low-resolution ADCs for massive MIMO systems. Although it is intuitively true that using low-resolution ADCs makes it possible to save a large amount of energy consumption in massive MIMO systems, the relationship between energy consumption using low-resolution ADCs and detection performance has not been properly analyzed yet. In this paper, the tradeoff between different detectors and total baseband energy consumption including flexible ADCs is thoroughly analyzed taking the optimal fixed-point operations performed during the detection processes into account. In order to minimize the energy consumption for the given channel condition, the proposed scheme selects the best mode among various processing options while supporting the target frame error rate. The numerous case studies reveal that the proposed work remarkably saves the energy consumption of the massive MIMO processing compared with the existing schemes.11Ysciescopu

Synergistic Effects of Simvastatin and Irinotecan against Colon Cancer Cells with or without Irinotecan Resistance

Aims. We here investigated whether the combination of simvastatin and irinotecan could induce the synergistic effect on colon cancer cells with or without resistance to irinotecan. Methods. We investigated cell proliferation assay and assessed cell death detection ELISA and caspase-3 activity assay of various concentrations of simvastatin and irinotecan to evaluate the efficacy of drug combination on colon cancer cells with or without irinotecan resistance. Results. The IC50 values of simvastatin alone and irinotecan alone were 115.4±0.14 μM (r=0.98) and 62.5±0.18 μM (r=0.98) in HT-29 cells without resistance to irinotecan. The IC50 values of these two drugs were 221.9±0.22 μM (r=0.98) and 195.9±0.16 μM (r=0.99), respectively, in HT-29 cell with resistance to irinotecan. The results of combinations of the various concentrations of two drugs showed that combined treatment with irinotecan and simvastatin more efficiently suppressed cell proliferation of HT-29 cells even with resistance to irinotecan as well as without resistance. Furthermore, the combination of simvastatin and irinotecan at 2:1 molar ratio showed the best synergistic interaction. Conclusion. Simvastatin could act synergistically with irinotecan to overcome irinotecan resistance of colon cancer

The Design of a Sliding Rectangular Waveguide Array Antenna for Beam Steering

In this paper, we designed a sliding waveguide array antenna that can be beam-steered via mechanical manipulation. This reduces the vulnerability of electronic beam-steering radars mounted on ships or aircraft to electromagnetic pulse (EMP) attacks. The design frequency was 9.375 GHz. First, the proposed antenna was designed to adjust the phase difference between the arrayed waveguide antennas by changing the length of the rectangular waveguide using a slide. Subsequently, a ridge structure with optimized curvature was attached to the aperture of the rectangular waveguide to obtain stable reflection coefficient characteristics. Finally, eight rectangular waveguide antennas and two dummy antennas were E-plane arrayed at intervals of 0.8λ (25.6 mm) to obtain a beam width of nearly 8°. A beam width of 8° was then obtained by adjusting the length of each waveguide. It was possible to orient the beam of the antenna in intervals of 8° using the phase difference of each antenna. The proposed mechanical beam steering technique can replace electronic beam steering for radar antennas, rendering the structures less vulnerable to EMP attacks