| 1. |
- Ching, Tao-Chung, et al.
(författare)
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The JCMT BISTRO-2 Survey: Magnetic Fields of the Massive DR21 Filament
- 2022
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 941:2
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Tidskriftsartikel (refereegranskat)abstract
- We present 850 mu m dust polarization observations of the massive DR21 filament from the B-fields In STar-forming Region Observations (BISTRO) survey, using the POL-2 polarimeter and the SCUBA-2 camera on the James Clerk Maxwell Telescope. We detect ordered magnetic fields perpendicular to the parsec-scale ridge of the DR21 main filament. In the subfilaments, the magnetic fields are mainly parallel to the filamentary structures and smoothly connect to the magnetic fields of the main filament. We compare the POL-2 and Planck dust polarization observations to study the magnetic field structures of the DR21 filament on 0.1-10 pc scales. The magnetic fields revealed in the Planck data are well-aligned with those of the POL-2 data, indicating a smooth variation of magnetic fields from large to small scales. The plane-of-sky magnetic field strengths derived from angular dispersion functions of dust polarization are 0.6-1.0 mG in the DR21 filament and similar to 0.1 mG in the surrounding ambient gas. The mass-to-flux ratios are found to be magnetically supercritical in the filament and slightly subcritical to nearly critical in the ambient gas. The alignment between column density structures and magnetic fields changes from random alignment in the low-density ambient gas probed by Planck to mostly perpendicular in the high-density main filament probed by James Clerk Maxwell Telescope. The magnetic field structures of the DR21 filament are in agreement with MHD simulations of a strongly magnetized medium, suggesting that magnetic fields play an important role in shaping the DR21 main filament and subfilaments.
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| 2. |
- Kwon, Woojin, et al.
(författare)
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B-fields in Star-forming Region Observations (BISTRO): Magnetic Fields in the Filamentary Structures of Serpens Main
- 2022
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 926:2
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Tidskriftsartikel (refereegranskat)abstract
- We present 850 mu m polarimetric observations toward the Serpens Main molecular cloud obtained using the POL-2 polarimeter on the James Clerk Maxwell Telescope as part of the B-fields In STar-forming Region Observations survey. These observations probe the magnetic field morphology of the Serpens Main molecular cloud on about 6000 au scales, which consists of cores and six filaments with different physical properties such as density and star formation activity. Using the histogram of relative orientation (HRO) technique, we find that magnetic fields are parallel to filaments in less-dense filamentary structures where NH2 < 0.93 x 10(22) cm(-2) (magnetic fields perpendicular to density gradients), while they are perpendicular to filaments (magnetic fields parallel to density gradients) in dense filamentary structures with star formation activity. Moreover, applying the HRO technique to denser core regions, we find that magnetic field orientations change to become perpendicular to density gradients again at NH2 approximate to 4.6 x 10(22) NH2 approximate to 16 x 10(22) cm(-2), magnetic fields change back to being parallel to density gradients once again, which can be understood to be due to magnetic fields being dragged in by infalling material. In addition, we estimate the magnetic field strengths of the filaments (B-POS = 60-300 mu G)) using the Davis-Chandrasekhar-Fermi method and discuss whether the filaments are gravitationally unstable based on magnetic field and turbulence energy densities.
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| 3. |
- Hwang, Jihye, et al.
(författare)
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The JCMT BISTRO Survey: A Spiral Magnetic Field in a Hub-filament Structure, Monoceros R2
- 2022
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Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 941:1
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Tidskriftsartikel (refereegranskat)abstract
- We present and analyze observations of polarized dust emission at 850 μm toward the central 1 × 1 pc hub-filament structure of Monoceros R2 (Mon R2). The data are obtained with SCUBA-2/POL-2 on the James Clerk Maxwell Telescope (JCMT) as part of the B-fields in Star-forming Region Observations survey. The orientations of the magnetic field follow the spiral structure of Mon R2, which are well described by an axisymmetric magnetic field model. We estimate the turbulent component of the magnetic field using the angle difference between our observations and the best-fit model of the underlying large-scale mean magnetic field. This estimate is used to calculate the magnetic field strength using the Davis–Chandrasekhar–Fermi method, for which we also obtain the distribution of volume density and velocity dispersion using a column density map derived from Herschel data and the C18O (J = 3 - 2) data taken with HARP on the JCMT, respectively. We make maps of magnetic field strengths and mass-to-flux ratios, finding that magnetic field strengths vary from 0.02 to 3.64 mG with a mean value of 1.0 ± 0.06 mG, and the mean critical mass-to-flux ratio is 0.47 ± 0.02. Additionally, the mean Alfvén Mach number is 0.35 ± 0.01. This suggests that, in Mon R2, the magnetic fields provide resistance against large-scale gravitational collapse, and the magnetic pressure exceeds the turbulent pressure. We also investigate the properties of each filament in Mon R2. Most of the filaments are aligned along the magnetic field direction and are magnetically subcritical.
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| 4. |
- Kim, Min Seo, et al.
(författare)
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Comparative effectiveness of N95, surgical or medical, and non-medical facemasks in protection against respiratory virus infection: A systematic review and network meta-analysis
- 2022
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Ingår i: Reviews in Medical Virology. - : WILEY. - 1052-9276 .- 1099-1654. ; 32:5
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Forskningsöversikt (refereegranskat)abstract
- The aim of this systematic review and network meta-analysis is to evaluate the comparative effectiveness of N95, surgical/medical and non-medical facemasks as personal protective equipment against respiratory virus infection. The study incorporated 35 published and unpublished randomized controlled trials and observational studies investigating specific mask effectiveness against influenza virus, SARS-CoV, MERS-CoV and SARS-CoV-2. We searched PubMed, Google Scholar and medRxiv databases for studies published up to 5 February 2021 (PROSPERO registration: CRD42020214729). The primary outcome of interest was the rate of respiratory viral infection. The quality of evidence was estimated using the GRADE approach. High compliance to mask-wearing conferred a significantly better protection (odds ratio [OR], 0.43; 95% confidence interval [CI], 0.23-0.82) than low compliance. N95 or equivalent masks were the most effective in providing protection against coronavirus infections (OR, 0.30; CI, 0.20-0.44) consistently across subgroup analyses of causative viruses and clinical settings. Evidence supporting the use of medical or surgical masks against influenza or coronavirus infections (SARS, MERS and COVID-19) was weak. Our study confirmed that the use of facemasks provides protection against respiratory viral infections in general; however, the effectiveness may vary according to the type of facemask used. Our findings encourage the use of N95 respirators or their equivalents (e.g., P2) for best personal protection in healthcare settings until more evidence on surgical and medical masks is accrued. This study highlights a substantial lack of evidence on the comparative effectiveness of mask types in community settings.
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| 5. |
- Ugawa, Masashi, et al.
(författare)
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Reduced acoustic resonator dimensions improve focusing efficiency of bacteria and submicron particles
- 2022
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Ingår i: Analyst. - : Royal Society of Chemistry (RSC). - 1364-5528. ; 147:2, s. 274-281
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we demonstrate an acoustofluidic device that enables single-file focusing of submicron particles and bacteria using a two-dimensional (2D) acoustic standing wave. The device consists of a 100 μm × 100 μm square channel that supports 2D particle focusing in the channel center at an actuation frequency of 7.39 MHz. This higher actuation frequency compared with conventional bulk acoustic systems enables radiation-force-dominant motion of submicron particles and overcomes the classical size limitation (≈2 μm) of acoustic focusing. We present acoustic radiation force-based focusing of particles with diameters less than 0.5 μm at a flow rate of 12 μL min−1, and 1.33 μm particles at flow rates up to 80 μL min−1. The device focused 0.25 μm particles by the 2D acoustic radiation force while undergoing a channel cross-section centered, single-vortex acoustic streaming. A suspension of bacteria was also investigated to evaluate the biological relevance of the device, which demonstrated the alignment of bacteria in the channel at aflow rate of up to 20 μL min−1. The developed acoustofluidic device can align submicron particles within a narrow flow stream in a highly robust manner, validating its use as a flow-through focusing chamber to perform high-throughput and accurate flow cytometry of submicron objects
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| 6. |
- Jeong, Heesu, et al.
(författare)
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Room-Temperature-Grown amorphous Indium-Tin-Silicon-Oxide thin film as a new electron transporting layer for perovskite solar cells
- 2022
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Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 581
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Tidskriftsartikel (refereegranskat)abstract
- We report the amorphous quaternary oxide, indium-tin-silicon-oxide (ITSO), thin film as a new electron transport layer (ETL) for perovskite solar cells (PSCs). ITSO thin films are grown by magnetron co-sputtering indium-tin-oxide (ITO) and silicon oxide (SiO2) on commercial transparent conducting oxide (TCO) thin films at room temperature. As Si content increases (0-53.8 at%) the optical bandgap increases by approximately 1.3 eV and the electrical resistivity increases by six orders mainly because of the carrier concentration decrease. Consequently, the ITSO electronic structure depends largely on Si content. PSCs employing ITSO thin films as ETLs were fabricated to evaluate the effect of Si content on device performances. Si content influenced the shunt and series resistance. The optimized device was obtained using an ITSO film with 33.0 at% Si content, exhibiting 14.50% power-conversion efficiency. These results demonstrate that ITSO films are promising for developing efficient PSCs by optimizing the growing process and/or In/Sn/Si/O compositions. This approach can reduce PSC manufacturing process time and costs if ITO and ITSO are grown together by continuous sequential sputtering in a dual gun (ITO and SiO2) chamber.
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| 7. |
- Song, Byong-Sop, et al.
(författare)
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Mitoribosomal defects aggravate liver cancer via aberrant glycolytic flux and T cell exhaustion
- 2022
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Ingår i: Journal for ImmunoTherapy of Cancer. - : BMJ. - 2051-1426. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Background Mitochondria are involved in cancer energy metabolism, although the mechanisms underlying the involvement of mitoribosomal dysfunction in hepatocellular carcinoma (HCC) remain poorly understood. Here, we investigated the effects of mitoribosomal impairment-mediated alterations on the immunometabolic characteristics of liver cancer.Methods We used a mouse model of HCC, liver tissues from patients with HCC, and datasets from The Cancer Genome Atlas (TCGA) to elucidate the relationship between mitoribosomal proteins (MRPs) and HCC. In a mouse model, we selectively disrupted expression of the mitochondrial ribosomal protein CR6-interacting factor 1 (CRIF1) in hepatocytes to determine the impact of hepatocyte-specific impairment of mitoribosomal function on liver cancer progression. The metabolism and immunophenotype of liver cancer was assessed by glucose flux assays and flow cytometry, respectively.Results Single-cell RNA-seq analysis of tumor tissue and TCGA HCC transcriptome analysis identified mitochondrial defects associated with high-MRP expression and poor survival outcomes. In the mouse model, hepatocyte-specific disruption of the mitochondrial ribosomal protein CRIF1 revealed the impact of mitoribosomal dysfunction on liver cancer progression. Crif1 deficiency promoted programmed cell death protein 1 expression by immune cells in the hepatic tumor microenvironment. A [U-13C6]-glucose tracer demonstrated enhanced glucose entry into the tricarboxylic acid cycle and lactate production in mice with mitoribosomal defects during cancer progression. Mice with hepatic mitoribosomal defects also exhibited enhanced progression of liver cancer accompanied by highly exhausted tumor-infiltrating T cells. Crif1 deficiency induced an environment unfavorable to T cells, leading to exhaustion of T cells via elevation of reactive oxygen species and lactate production.Conclusions Hepatic mitoribosomal defects promote glucose partitioning toward glycolytic flux and lactate synthesis, leading to T cell exhaustion and cancer progression. Overall, the results suggest a distinct role for mitoribosomes in regulating the immunometabolic microenvironment during HCC progression.
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| 8. |
- Cholewa, Marian, et al.
(författare)
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Investigating the Secondary Electron Emission of Nanomaterials Induced by a High-Resolution Proton Beam
- 2022
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Ingår i: Physica Status Solidi (B). - : Wiley. - 0370-1972 .- 1521-3951.
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Tidskriftsartikel (refereegranskat)abstract
- Herein, the secondary electron emission (SEE) from 1D nanomaterials in the form of nanorods is investigated. The small beam of a 1.5 MeV +H2 hydrogen with a sub 70 nm in diameter allows studying the SEE with a very high resolution. A wide range of nanomaterials from various laboratories are studied, including thin ZnO and ZnO/GaN nanostructures grown on 1 μm thick Si3N4 membranes and thick InP, GaN and GaN/AlN nanorod structures grown on bulk Si substrates. By virtue of the small size of the exciting nanobeams, high-resolution maps could be created presenting an SEE yield from various parts of the structures. This allows us to show that the top parts of nanorods in ZnO, ZnO/GaN, GaN, InP, and GaN/AlN nanostructures emit secondary electrons much more efficiently than the valley areas between nanorods. These results indicate that by a proper design and growth of 1D nanostructures, SEE properties could be improved over those of the traditionally used Au and CsI thin films. This work has been undertaken to find materials with the highest achievable SEE emission, which is a figure of merit for the detection efficiency relevant for the development and application of novel radiation detectors.
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