Effect of hydrofracking fluid on colloid transport in the unsaturated zone

Hydraulic fracturing is expanding rapidly in the US to meet increasing energy demand and requires high volumes of hydrofracking fluid to displace natural gas from shale. Accidental spills and deliberate land application of hydrofracking fluids, which return to the surface during hydrofracking, are common causes of environmental contamination. Since the chemistry of hydrofracking fluids favors transport of colloids and mineral particles through rock cracks, it may also facilitate transport of in situ colloids and associated pollutants in unsaturated soils. We investigated this by subsequently injecting deionized water and flowback fluid at increasing flow rates into unsaturated sand columns containing colloids. Colloid retention and mobilization was measured in the column effluent and visualized in situ with bright field microscopy. While <5% of initial colloids were released by flushing with deionized water, 32–36% were released by flushing with flowback fluid in two distinct breakthrough peaks. These peaks resulted from 1) surface tension reduction and steric repulsion and 2) slow kinetic disaggregation of colloid flocs. Increasing the flow rate of the flowback fluid mobilized an additional 36% of colloids, due to the expansion of water filled pore space. This study suggests that hydrofracking fluid may also indirectly contaminate groundwater by remobilizing existing colloidal pollutants

Replication-Competent Recombinant Porcine Reproductive and Respiratory Syndrome (PRRS) Viruses Expressing Indicator Proteins and Antiviral Cytokines

Porcine reproductive and respiratory syndrome virus (PRRSV) can subvert early innate immunity, which leads to ineffective antimicrobial responses. Overcoming immune subversion is critical for developing vaccines and other measures to control this devastating swine virus. The overall goal of this work was to enhance innate and adaptive immunity following vaccination through the expression of interferon (IFN) genes by the PRRSV genome. We have constructed a series of recombinant PRRS viruses using an infectious PRRSV cDNA clone (pCMV-P129). Coding regions of exogenous genes, which included Renilla luciferase (Rluc), green and red fluorescent proteins (GFP and DsRed, respectively) and several interferons (IFNs), were constructed and expressed through a unique subgenomic mRNA placed between ORF1b and ORF2 of the PRRSV infectious clone. The constructs, which expressed Rluc, GFP, DsRed, efficiently produced progeny viruses and mimicked the parental virus in both MARC-145 cells and porcine macrophages. In contrast, replication of IFN-expressing viruses was attenuated, similar to the level of replication observed after the addition of exogenous IFN. Furthermore, the IFN expressing viruses inhibited the replication of a second PRRS virus co-transfected or co-infected. Inhibition by the different IFN subtypes corresponded to their anti-PRRSV activity, i.e., IFNω5 ° IFNα1 > IFN-β > IFNδ3. In summary, the indicator-expressing viruses provided an efficient means for real-time monitoring of viral replication thus allowing high‑throughput elucidation of the role of host factors in PRRSV infection. This was shown when they were used to clearly demonstrate the involvement of tumor susceptibility gene 101 (TSG101) in the early stage of PRRSV infection. In addition, replication‑competent IFN-expressing viruses may be good candidates for development of modified live virus (MLV) vaccines, which are capable of reversing subverted innate immune responses and may induce more effective adaptive immunity against PRRSV infection

Highly reflective subtractive color filters capitalizing on a silicon metasurface integrated with nanostructured aluminum mirrors

Metasurface-based color filters have been recently applied for the creation of imaging devices and color printing in a subwavelength scale. In this work, a highly reflective subtractive color filter featuring an excellent color contrast is conceived and demonstrated, by exploiting a crystalline-silicon nanopillar (NP)-based dielectric metasurface integrated with an aluminum disk mirror (DM) and holey mirror (HM) at the top and bottom, respectively. A deep suppression in reflection is acquired through a magnetic dipole (MD) resonance that is supported by the constituent NP, and can be effectively tailored via the control of the NP diameter. The cooperation of the nanostructured DM and HM plays a dual role of dramatically boosting the efficiency and reinforcing the confinement of the MD in the NP, which is primarily accountable for the reduction in the spectral bandwidth. For the manufactured filters, both a high reflection efficiency reaching ∼70% and relatively small bandwidth of ∼55 nm are attained, thus leading to a broad palette of vivid and bright colors. The proposed devices are supposed to exhibit a polarization-insensitive operation and a relaxed angular tolerance, thereby facilitating the implementation of miniaturized display/imaging devices with a high resolution and excellent color fidelity.This work was supported by a National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (No. 2016R1A2B2010170 and 2011– 0030079) and by the Research Grant of Kwangwoon University in 2017. The work was partly supported by the Australian Research Council Future Fellowship (FT110100853, Dr. Duk-Yong Choi) and was performed in part at the ACT node of the Australian National Fabrication Facility

Synthesis of large-area multilayer hexagonal boron nitride for high material performance

Although hexagonal boron nitride (h-BN) is a good candidate for gate-insulating materials by minimizing interaction from substrate, further applications to electronic devices with available two-dimensional semiconductors continue to be limited by flake size. While monolayer h-BN has been synthesized on Pt and Cu foil using chemical vapour deposition (CVD), multilayer h-BN is still absent. Here we use Fe foil and synthesize large-area multilayer h-BN film by CVD with a borazine precursor. These films reveal strong cathodoluminescence and high mechanical strength (Young’s modulus: 1.16±0.1 TPa), reminiscent of formation of high-quality h-BN. The CVD-grown graphene on multilayer h-BN film yields a high carrier mobility of ~24,000 cm[superscript 2] V[superscript −1] s[superscript −1] at room temperature, higher than that (~13,000 [superscript 2] V[superscript −1] s[superscript −1]) with exfoliated h-BN. By placing additional h-BN on a SiO[subscript 2]/Si substrate for a MoS[subscript 2] (WSe[subscript 2]) field-effect transistor, the doping effect from gate oxide is minimized and furthermore the mobility is improved by four (150) times.Korea Institute of Science and Technology. Institutional ProgramNational Science Foundation (U.S.) (STC Center for Integrated Quantum Materials Grant DMR-1231319)Massachusetts Institute of Technology. Institute for Soldier Nanotechnologie

High-Throughput Sequencing Analysis of Endophytic Bacteria Diversity in Fruits of White and Red Pitayas from Three Different Origins

Pitaya contains various types of polyphenols, flavonoid and vitamins which are beneficial for health and it is among the most important commercial tropical fruits worldwide. Endophytic bacteria might be beneficial for plant growth and yield. However, bacterial diversity in pitaya is poorly characterized. In this study, fruits of white and red pitayas from three different origins (Thailand, Vietnam and China) were chosen for endophytic bacteria diversity investigation by using Illumina HiSeq second-generation high-throughput sequencing technology. Large number of endophytic bacteria were detected and 22 phyla, 56 classes, 81 orders, 122 families and 159 genera were identified. Endophytic bacteria diversity was uneven among pitaya fruits from different origins and bacteria structure was different between white pitaya group and red pitaya group. Phylum Bacteroidetes, classes Bacteroidia and Coriobacteriia, orders Bacteroidales and Coriobacteriales, families Prevotellaceae, Bacteroidaceae, Ruminococcaceae, Paraprevotellaceae, Rikenellaceae, Alcaligenaceae and Coriobacteriaceae, genera Prevotella, Bacteroides, Roseburia, Faecalibacterium and Sutterella were statistically significant different species (P < 0.05) between white and red pitayas. These findings might be useful for growth improvement, fruit preservation and processing of different pitaya species from different origins

Differential expression of type I interferons in fetal tissues and the maternal-fetal interface in response to PRRSV infection

Master of ScienceDepartment of Diagnostic Medicine/PathobiologyRaymond R. R. RowlandInterferons (IFNs) comprise a group of antiviral cytokines; however, their expression at the porcine maternal-fetal interface and in fetal tissues has not previously been investigated. The purpose of this study was to analyze the expression of type I IFNs and their receptors in maternal and fetal tissues from sows infected with PRRSV. The approach was to use real-time RT-PCR to identify the expression of different subtypes of type I IFN genes. The results show that the constitutive gene expression of some subtypes including IFN-[alpha] and IFN-[alpha][omega] were detected in fetal lymphoid nodes (IFN-[alpha][omega]), placenta (several IFN-[alpha] subtypes and IFN-[omega]5) and particularly, thymus (multiple IFN-[alpha], IFN-[delta] and IFN-[omega]5). The results demonstrate that porcine type I IFNs are differentially expressed at the maternal-fetal interface and in fetal tissues in response to PRRSV infection