| 1. |
- Cho, Nam-Hyuk, et al.
(författare)
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The Orientia tsutsugamushi genome reveals massive proliferation of conjugative type IV secretion system and host–cell interaction genes
- 2007
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 104:19, s. 7981-7986
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Tidskriftsartikel (refereegranskat)abstract
- Scrub typhus is caused by the obligate intracellular rickettsia Orientia tsutsugamushi (previously called Rickettsia tsutsugamushi). The bacterium is maternally inherited in trombicuid mites and transmitted to humans by feeding larvae. We report here the 2,127,051-bp genome of the Boryong strain, which represents the most highly repeated bacterial genome sequenced to date. The repeat density of the scrub typhus pathogen is 200-fold higher than that of its close relative Rickettsia prowazekii, the agent of epidemic typhus. A total of 359 tra genes for components of conjugative type IV secretion systems were identified at 79 sites in the genome. Associated with these are >200 genes for signaling and host–cell interaction proteins, such as histidine kinases, ankyrin-repeat proteins, and tetratrico peptide-repeat proteins. Additionally, the O. tsutsugamushi genome contains >400 transposases, 60 phage integrases, and 70 reverse transcriptases. Deletions and rearrangements have yielded unique gene combinations as well as frequent pseudogenization in the tra clusters. A comparative analysis of the tra clusters within the genome and across strains indicates sequence homogenization by gene conversion, whereas complexity, diversity, and pseudogenization are acquired by duplications, deletions, and transposon integrations into the amplified segments. The results suggest intragenomic duplications or multiple integrations of a massively proliferating conjugative transfer system. Diversifying selection on host–cell interaction genes along with repeated population bottlenecks may drive rare genome variants to fixation, thereby short-circuiting selection for low complexity in bacterial genomes.
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| 2. |
- Kim, Shin, et al.
(författare)
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Development of boron doped diamond electrodes material for heavy metal ion sensor with high sensitivity and durability
- 2023
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Ingår i: JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY. - : Elsevier BV. - 2238-7854 .- 2214-0697. ; 23, s. 1375-1385
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Tidskriftsartikel (refereegranskat)abstract
- We report on the optimized substrate pretreatment and deposition process conditions for boron-doped diamond (BDD) electrodes fabricated by hot-filament chemical vapor deposition (HFCVD). The optimized BDD electrode with a doping concentration of 8000 ppm showed high accuracy and precision in detecting Cd(II), Pb(II), and Cu(II) ions. In addition, this demonstrates excellent selectivity against external metal ions under the optimized stripping voltammetry measurement conditions. The detection limits of the target ions of Cd(II), Pb(II), and Cu(II) were 0.55 (+/- 0.05), 0.43 (+/- 0.04), and 0.74 (+/- 0.06) mg/L (S/N = 3), respectively. In real samples spiked with 100 mg/L Cd(II), Pb(II), and Cu(II), both the accuracy and precision of the BDD electrode were within 5%; the interference with organic matter was also negligible. The excellent selectivity and long-term stability indicate that the BDD electrode developed in this study are potentially useful for online water environment monitoring systems.
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| 3. |
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| 4. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 5. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 6. |
- Khairy, Kholida Tul, et al.
(författare)
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Thermochromic properties of vanadium oxide thin films prepared by reactive magnetron sputtering at different oxygen concentrations
- 2023
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Ingår i: Vacuum. - : Elsevier. - 0042-207X .- 1879-2715. ; 210
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Tidskriftsartikel (refereegranskat)abstract
- Vanadium dioxide (VO2) is a thermochromic (TC) material, exhibits a reversible transmittance change in the near-infrared (NIR) region upon heating above a critical temperature tic, due to an insulator-to-metal phase transition. Numerous studies on the V-O system can be found in the literature, including the synthesis of VO2 films. The phase diagram of the V-O system involves complicated suboxide phases that prevent pure VO2 for-mation and obscures quantitative analysis. Here, VO2 thin films were systematically prepared with various ox-ygen flow ratios (r) using reactive magnetron sputtering. Thin films prepared with r = 4.1% show dominant VO2 phase and the highest TC performance. The r -range producing dominant VO2 phase is found to be narrow: 3.7% < r<4.2%. At lower and higher r, TC characteristics are shown to be accompanied, as expected, by electrical conductivity changes, but also by microstructure transformations. The latter producing textured films that gradually develop upon cycling around tic. In particular, a change of texture, yielding oriented VO2 crystallites, is observed by in-situ XRD around tic. Our results shed light on the VO2 formation and associated structural, chemical and electrical properties under various oxidizing conditions during magnetron sputtering, which calls for careful preparation and strategies to stabilize the VO2 phase.
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| 7. |
- Kim, Hyeong Seok, et al.
(författare)
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Development, validation, and comparison of a nomogram based on radiologic findings for predicting malignancy in intraductal papillary mucinous neoplasms of the pancreas : An international multicenter study
- 2021
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Ingår i: Journal of hepato-biliary-pancreatic sciences. - : Wiley-Blackwell. - 1868-6974 .- 1868-6982.
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Although we previously proposed a nomogram to predict malignancy in intraductal papillary mucinous neoplasms (IPMN) and validated it in an external cohort, its application is challenging without data on tumor markers. Moreover, existing nomograms have not been compared. This study aimed to develop a nomogram based on radiologic findings and to compare its performance with previously proposed American and Korean/Japanese nomograms.METHODS: We recruited 3708 patients who underwent surgical resection at 31 tertiary institutions in eight countries, and patients with main pancreatic duct >10 mm were excluded. To construct the nomogram, 2606 patients were randomly allocated 1:1 into training and internal validation sets, and area under the receiver operating characteristics curve (AUC) was calculated using 10-fold cross validation by exhaustive search. This nomogram was then validated and compared to the American and Korean/Japanese nomograms using 1102 patients.RESULTS: Among the 2606 patients, 90 had main-duct type, 900 had branch-duct type, and 1616 had mixed-type IPMN. Pathologic results revealed 1628 low-grade dysplasia, 476 high-grade dysplasia, and 502 invasive carcinoma. Location, cyst size, duct dilatation, and mural nodule were selected to construct the nomogram. AUC of this nomogram was higher than the American nomogram (0.691 vs 0.664, P = .014) and comparable with the Korean/Japanese nomogram (0.659 vs 0.653, P = .255).CONCLUSIONS: A novel nomogram based on radiologic findings of IPMN is competitive for predicting risk of malignancy. This nomogram would be clinically helpful in circumstances where tumor markers are not available. The nomogram is freely available at http://statgen.snu.ac.kr/software/nomogramIPMN.
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| 8. |
- Kim, Seohan, et al.
(författare)
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Embedded nanopattern for selectively suppressed thermal conductivity and enhanced transparency in a transparent conducting oxide film
- 2022
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Ingår i: Nano Energy. - : Elsevier. - 2211-2855 .- 2211-3282. ; 103:Part A
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Tidskriftsartikel (refereegranskat)abstract
- Transparent conductive oxide (TCO) thin films are cornerstones in many optoelectronic applications including displays, photovoltaics and touchscreens. In these devices, thin films with simultaneous high optical transparency and electrical conductivity are needed. Ideally, heat generated during normal device operation must ideally be compensated for to achieve optimum functionality. One possible way to address the thermal management problem is adding thermoelectric (TE) properties to TCO films. However, improving TE properties while maintaining optimal electrical conductivity and optical transparency is challenging: thermal and electrical transport properties are deeply intertwined. Here, we demonstrate an approach allowing for independent optimization of optical transparency, electrical conductivity and thermal conductivity. An embedded nanopattern structure is filled with indium tin oxide (ITO) and sandwiched between two ITO layers. The resulting triplelayered structure exhibits reduced thermal conductivity and excellent electrical conductivity. This is made possible by electron channels in the embedded ITO nanopattern that electrically connect top and bottom layers, while at the same time limiting phonon-mediated heat conduction. The filling fraction and thickness of the nanopattern are adjusted to improve optical transmission, achieving transparency higher than bare ITO film. The result is a transparent TCO triple layer film with simultaneous high TCO and thermoelectric figures of merit.
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