Macrophages are professional phagocytes known to play a vital role in controlling Mycobacterium tuberculosis (Mtb) infection and disease progression. Here we compare Mtb growth in mouse alveolar ...(AMs), peritoneal (PMs), and liver (Kupffer cells; KCs) macrophages and in bone marrow-derived monocytes (BDMs). KCs restrict Mtb growth more efficiently than all other macrophages and monocytes despite equivalent infections through enhanced autophagy. A metabolomics comparison of Mtb-infected macrophages indicates that ornithine and imidazole are two top-scoring metabolites in Mtb-infected KCs and that acetylcholine is the top-scoring in Mtb-infected AMs. Ornithine, imidazole and atropine (acetylcholine inhibitor) inhibit Mtb growth in AMs. Ornithine enhances AMPK mediated autophagy whereas imidazole directly kills Mtb by reducing cytochrome P450 activity. Intranasal delivery of ornithine or imidazole or the two together restricts Mtb growth. Our study demonstrates that the metabolic differences between Mtb-infected AMs and KCs lead to differences in the restriction of Mtb growth.
Titanium nitride (TiN) has recently emerged as an attractive alternative material for plasmonics. However, the typical high-temperature deposition of plasmonic TiN using either sputtering or atomic ...layer deposition has greatly limited its potential applications and prevented its integration into existing CMOS device architectures. Here, we demonstrate highly plasmonic TiN thin films and nanostructures by a room-temperature, low-power, and bias-free reactive sputtering process. We investigate the optical properties of the TiN films and their dependence on the sputtering conditions and substrate materials. We find that our TiN possesses one of the largest negative values of the real part of the dielectric function as compared to all other plasmonic TiN films reported to date. Two-dimensional periodic arrays of TiN nanodisks are then fabricated, from which we validate that strong plasmonic resonances are supported. Our room-temperature deposition process can allow for fabricating complex plasmonic TiN nanostructures and be integrated into the fabrication of existing CMOS-based photonic devices to enhance their performance and functionalities.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Despite its prominent role as a C-type lectin (CTL) pattern recognition receptor, mannose receptor (MR, CD206)-specific signaling molecules and pathways are unknown. The MR is highly expressed ...on human macrophages, regulating endocytosis, phagocytosis, and immune responses and mediating Mycobacterium tuberculosis (M.tb) phagocytosis by human macrophages, thereby limiting phagosome-lysosome (P-L) fusion. We identified human MR-associated proteins using phosphorylated and non-phosphorylated MR cytoplasmic tail peptides. We found that MR binds FcRγ-chain, which is required for MR plasma membrane localization and M.tb cell association. Additionally, we discovered that MR-mediated M.tb association triggers immediate MR tyrosine residue phosphorylation and Grb2 recruitment, activating the Rac/Pak/Cdc-42 signaling cascade important for M.tb uptake. MR activation subsequently recruits SHP-1 to the M.tb-containing phagosome, where its activity limits PI(3)P generation at the phagosome and M.tb P-L fusion and promotes M.tb growth. In sum, we identify human MR signaling pathways that temporally regulate phagocytosis and P-L fusion during M.tb infection.
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•MR interaction with FcRγ-chain is essential for MR macrophage surface exposure•MR activation mediates Grb2 recruitment to initiate phagocytosis signaling•MR-dependent SHP-1 recruitment limits PI3K activity and phagosome-lysosome fusion
The human mannose receptor (MR) mediates macrophage phagocytosis and immune regulation. MR-specific signaling remains a major gap in the field. Rajaram et al. identify the importance of FcRγ-chain and Grb2 during MR-mediated phagocytosis and subsequent MR-dependent recruitment of SHP-1 to the M.tb phagosome, thereby limiting PI(3)P generation and phagosome-lysosome fusion.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Over the past two decades, terahertz time-domain spectroscopy and quantum-cascade lasers have been two of the most important developments in terahertz science and technology. These technologies may ...contribute to a multitude of terahertz applications that are currently under investigation globally. However, the devices and components necessary to effectively manipulate terahertz radiation require substantial development beyond what has been accomplished to date. Here we demonstrate an electrically controlled planar hybrid metamaterial device that linearly controls the phase of terahertz radiation with constant insertion loss over a narrow frequency band. Alternatively, our device may operate as a broadband terahertz modulator because of the causal relation between the amplitude modulation and phase shifting. We perform terahertz time-domain spectroscopy, in which our hybrid metamaterial modulator replaces a commercial mechanical optical chopper, demonstrating comparable broadband performance and superior high-speed operation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract
Protonic ceramic fuel cells (PCFCs) have become the most efficient, clean and cost-effective electrochemical energy conversion devices in recent years. While significant progress has been ...made in developing proton conducting electrolyte materials, mechanical strength and durability still need to be improved for efficient applications. We report that adding 5 mol% Zn to the Y-doped barium cerate-zirconate perovskite electrolyte material can significantly improve the sintering properties, mechanical strength, durability and performance. Using same proton conducting material in anodes, electrolytes and cathodes to make a strong structural backbone shows clear advantages in mechanical strength over other arrangements with different materials. Rietveld analysis of the X-ray and neutron diffraction data of BaCe
0.7
Zr
0.1
Y
0.15
Zn
0.05
O
3−δ
(BCZYZn05) revealed a pure orthorhombic structure belonging to the
Pbnm
space group. Structural and electrochemical analyses indicate highly dense and high proton conductivity at intermediate temperature (400–700 °C). The anode-supported single cell, NiO-BCZYZn05|BCZYZn05|BSCF-BCZYZn05, demonstrates a peak power density of 872 mW cm
−2
at 700 °C which is one of the highest power density in an all-protonic solid oxide fuel cell. This observation represents an important step towards commercially viable SOFC technology.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
As the demand for energy increases and fossil fuel resources are depleted, the search for clean sources of energy has intensified worldwide. This is coupled with a strong global desire to reduce CO2 ...emissions to curb global warming. Brunei Darussalam is committed to reduce its CO2 emissions but currently utilizes fossil fuels to meet almost all of its energy requirements. This situation provides good incentives to search for renewable and sustainable resources to produce energy in the country. Acacia species are exotic species that have invaded and spread to natural habitats in Brunei Darussalam. Acacia species are a sustainable source of high quality biomass feedstock to produce bioenergy in the country. Hot tropical weather of the country is highly suitable for the rapid growth of Acacias without requiring any major agricultural input. This study reviews the thermochemical conversion of Acacia species especially; Acacia mangium and Acacia auriculiformis to produce biofuels and bio-products. The prospective of using Acacia biomass as feedstock in pyrolysis, gasification, liquefaction and combustion is also discussed. Acacia biomass is a sustainable and renewable energy resource for Brunei Darussalam to be exploited for energy requirements and can be beneficial for the economy of the country by providing new investment and employment opportunities.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
37.
Space-Time Quantum Metasurfaces Kort-Kamp, Wilton J. M.; Azad, Abul K.; Dalvit, Diego A. R.
Physical review letters,
07/2021, Volume:
127, Issue:
4
Journal Article
Peer reviewed
Open access
Metasurfaces have recently entered the realm of quantum photonics, enabling manipulation of quantum light using a compact nanophotonic platform. Realizing the full potential of metasurfaces at the ...deepest quantum level requires the ability to tune coherent light-matter interactions continuously in space and time. Here, we introduce the concept of space-time quantum metasurfaces for arbitrary control of the spectral, spatial, and spin properties of nonclassical light using a compact photonic platform. We show that space-time quantum metasurfaces allow on-demand tailoring of entanglement among all degrees of freedom of a single photon. We also show that spatiotemporal modulation induces asymmetry at the fundamental level of quantum fluctuations, resulting in the generation of steered and vortex photon pairs out of vacuum. Space-time quantum metasurfaces have the potential to enable novel photonic functionalities, such as encoding quantum information into high-dimensional color qudits using designer modulation protocols, sculpting multispectral and multispatial modes in spontaneous emission, and generating reconfigurable hyperentanglement for high-capacity quantum communications.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
We demonstrated giant optical activity using a chiral metamaterial composed of an array of conjugated bilayer metal structures. The chiral metamaterials were further integrated with photoactive ...inclusions to accomplish a wide tuning range of the optical activity through illumination with near-infrared light. The strong chirality observed in our metamaterials results in a negative refractive index, which can also be well controlled by the near-infrared optical excitation.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The BaCe0.7Zr0.1Y0.2−xZnxO3−δ (x = 0.05, 0.10, 0.15, 0.20) has been synthesized by the conventional solid state reaction method for application in protonic solid oxide fuel cell. The phase purity and ...lattice parameters of the materials have been studied by the room temperature X-ray diffraction (XRD). Scanning electron microscopy (SEM) has been done for check the morphology and grain growth of the samples. The chemical and mechanical stabilities have been done using thermogravimetric analysis (TGA) in pure CO2 environment and thermomechanical analysis (TMA) in Argon atmosphere. The XRD of the materials show the orthorhombic crystal symmetry with Pbnm space group. The SEM images of the pellets show that the samples sintered at 1200 °C are highly dense. The XRD after TGA in CO2 and thermal expansion measurements confirm the stability. The particles of the samples are in micrometer ranges and increasing Zn content decreases the size. The conductivity measurements have been done in 5% H2 with Ar in dry and wet atmospheres. All the materials show high proton conductivity in the intermediate temperature range (400–700 °C). The maximum proton conductivity was found to be 1.0 × 10−2 S cm−1 at 700 °C in wet atmosphere for x = 0.10. From our study, 10 wt % of Zn seems to be optimum at the B-site of the perovskite structure. All the properties studied here suggest it can be a promising candidate of electrolyte for IT-SOFCs.
Rietveld analysis confirms that BaCe0.7Zr0.1Y0.2−xZnxO3−δ (x = 0.05, 0.10, 0.15, 0.20) crystallized in the orthorhombic symmetry after sintering at 1200 °C which are highly dense and good protonic conductors. Insert shows the schematic 3D diagram (left) and high density SEM profile (right). Display omitted
•The materials were in single phase orthorhombic structure at 1200 °C.•Highly dense at 1200 °C and large SEM morphology for IT-SOFC electrolyte.•High chemical stability up to 1000 °C under carbon dioxide.•It shows high conductivity of 1.0 × 10−2 S cm−1 at 700 °C in wet H2.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
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