| 1. |
- Abadie, J., et al.
(author)
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Implementation and testing of the first prompt search for gravitational wave transients with electromagnetic counterparts
- 2012
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In: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 539
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Journal article (peer-reviewed)abstract
- Aims. A transient astrophysical event observed in both gravitational wave (GW) and electromagnetic (EM) channels would yield rich scientific rewards. A first program initiating EM follow-ups to possible transient GW events has been developed and exercised by the LIGO and Virgo community in association with several partners. In this paper, we describe and evaluate the methods used to promptly identify and localize GW event candidates and to request images of targeted sky locations. Methods. During two observing periods (Dec. 17, 2009 to Jan. 8, 2010 and Sep. 2 to Oct. 20, 2010), a low-latency analysis pipeline was used to identify GW event candidates and to reconstruct maps of possible sky locations. A catalog of nearby galaxies and Milky Way globular clusters was used to select the most promising sky positions to be imaged, and this directional information was delivered to EM observatories with time lags of about thirty minutes. A Monte Carlo simulation has been used to evaluate the low-latency GW pipeline's ability to reconstruct source positions correctly. Results. For signals near the detection threshold, our low-latency algorithms often localized simulated GW burst signals to tens of square degrees, while neutron star/neutron star inspirals and neutron star/black hole inspirals were localized to a few hundred square degrees. Localization precision improves for moderately stronger signals. The correct sky location of signals well above threshold and originating from nearby galaxies may be observed with similar to 50% or better probability with a few pointings of wide-field telescopes.
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| 2. |
- Abadie, J., et al.
(author)
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Search for Gravitational Waves Associated with Gamma-Ray Bursts during LIGO Science Run 6 and Virgo Science Runs 2 and 3
- 2012
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In: Astrophysical Journal. - 0004-637X. ; 760:1
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Journal article (peer-reviewed)abstract
- We present the results of a search for gravitational waves associated with 154 gamma-ray bursts (GRBs) that were detected by satellite-based gamma-ray experiments in 2009-2010, during the sixth LIGO science run and the second and third Virgo science runs. We perform two distinct searches: a modeled search for coalescences of either two neutron stars or a neutron star and black hole, and a search for generic, unmodeled gravitational-wave bursts. We find no evidence for gravitational-wave counterparts, either with any individual GRB in this sample or with the population as a whole. For all GRBs we place lower bounds on the distance to the progenitor, under the optimistic assumption of a gravitational-wave emission energy of 10(-2) M-circle dot c(2) at 150 Hz, with a median limit of 17 Mpc. For short-hard GRBs we place exclusion distances on binary neutron star and neutron-star-black-hole progenitors, using astrophysically motivated priors on the source parameters, with median values of 16 Mpc and 28 Mpc, respectively. These distance limits, while significantly larger than for a search that is not aided by GRB satellite observations, are not large enough to expect a coincidence with a GRB. However, projecting these exclusions to the sensitivities of Advanced LIGO and Virgo, which should begin operation in 2015, we find that the detection of gravitational waves associated with GRBs will become quite possible.
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| 3. |
- Abadie, J., et al.
(author)
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All-sky search for periodic gravitational waves in the full S5 LIGO data
- 2012
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In: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 85:2
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Journal article (peer-reviewed)abstract
- We report on an all-sky search for periodic gravitational waves in the frequency band 50-800 Hz and with the frequency time derivative in the range of 0 through -6 x 10(-9) Hz/s. Such a signal could be produced by a nearby spinning and slightly nonaxisymmetric isolated neutron star in our Galaxy. After recent improvements in the search program that yielded a 10x increase in computational efficiency, we have searched in two years of data collected during LIGO's fifth science run and have obtained the most sensitive all-sky upper limits on gravitational-wave strain to date. Near 150 Hz our upper limit on worst-case linearly polarized strain amplitude h(0) is 1 x 10(-24), while at the high end of our frequency range we achieve a worst-case upper limit of 3.8 x 10(-24) for all polarizations and sky locations. These results constitute a factor of 2 improvement upon previously published data. A new detection pipeline utilizing a loosely coherent algorithm was able to follow up weaker outliers, increasing the volume of space where signals can be detected by a factor of 10, but has not revealed any gravitational-wave signals. The pipeline has been tested for robustness with respect to deviations from the model of an isolated neutron star, such as caused by a low-mass or long-period binary companion.
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| 4. |
- Abadie, J., et al.
(author)
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Search for gravitational waves from low mass compact binary coalescence in LIGO's sixth science run and Virgo's science runs 2 and 3
- 2012
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In: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 85:8
-
Journal article (peer-reviewed)abstract
- We report on a search for gravitational waves from coalescing compact binaries using LIGO and Virgo observations between July 7, 2009, and October 20, 2010. We searched for signals from binaries with total mass between 2 and 25M(circle dot); this includes binary neutron stars, binary black holes, and binaries consisting of a black hole and neutron star. The detectors were sensitive to systems up to 40 Mpc distant for binary neutron stars, and further for higher mass systems. No gravitational-wave signals were detected. We report upper limits on the rate of compact binary coalescence as a function of total mass, including the results from previous LIGO and Virgo observations. The cumulative 90% confidence rate upper limits of the binary coalescence of binary neutron star, neutron star-black hole, and binary black hole systems are 1.3 x 10(-4), 3.1 x 10(-5), and 6.4 x 10(-6) Mpc(-3) yr(-1), respectively. These upper limits are up to a factor 1.4 lower than previously derived limits. We also report on results from a blind injection challenge.
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| 5. |
- Abadie, J., et al.
(author)
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All-sky search for gravitational-wave bursts in the second joint LIGO-Virgo run
- 2012
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In: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 85:12
-
Journal article (peer-reviewed)abstract
- We present results from a search for gravitational-wave bursts in the data collected by the LIGO and Virgo detectors between July 7, 2009 and October 20, 2010: data are analyzed when at least two of the three LIGO-Virgo detectors are in coincident operation, with a total observation time of 207 days. The analysis searches for transients of duration less than or similar to 1 s over the frequency band 64-5000 Hz, without other assumptions on the signal waveform, polarization, direction or occurrence time. All identified events are consistent with the expected accidental background. We set frequentist upper limits on the rate of gravitational-wave bursts by combining this search with the previous LIGO-Virgo search on the data collected between November 2005 and October 2007. The upper limit on the rate of strong gravitational-wave bursts at the Earth is 1.3 events per year at 90% confidence. We also present upper limits on source rate density per year and Mpc(3) for sample populations of standard-candle sources. As in the previous joint run, typical sensitivities of the search in terms of the root-sum-squared strain amplitude for these waveforms lie in the range similar to 5 x 10(-22) Hz(-1/2) to similar to 1 x 10(-20) Hz(-1/2). The combination of the two joint runs entails the most sensitive all-sky search for generic gravitational-wave bursts and synthesizes the results achieved by the initial generation of interferometric detectors.
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| 6. |
- Abadie, J., et al.
(author)
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First low-latency LIGO plus Virgo search for binary inspirals and their electromagnetic counterparts
- 2012
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In: Astronomy & Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 541
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Journal article (peer-reviewed)abstract
- Aims. The detection and measurement of gravitational-waves from coalescing neutron-star binary systems is an important science goal for ground-based gravitational-wave detectors. In addition to emitting gravitational-waves at frequencies that span the most sensitive bands of the LIGO and Virgo detectors, these sources are also amongst the most likely to produce an electromagnetic counterpart to the gravitational-wave emission. A joint detection of the gravitational-wave and electromagnetic signals would provide a powerful new probe for astronomy. Methods. During the period between September 19 and October 20, 2010, the first low-latency search for gravitational-waves from binary inspirals in LIGO and Virgo data was conducted. The resulting triggers were sent to electromagnetic observatories for followup. We describe the generation and processing of the low-latency gravitational-wave triggers. The results of the electromagnetic image analysis will be described elsewhere. Results. Over the course of the science run, three gravitational-wave triggers passed all of the low-latency selection cuts. Of these, one was followed up by several of our observational partners. Analysis of the gravitational-wave data leads to an estimated false alarm rate of once every 6.4 days, falling far short of the requirement for a detection based solely on gravitational-wave data.
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| 7. |
- Abadie, J., et al.
(author)
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Search for gravitational waves from intermediate mass binary black holes
- 2012
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In: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 85:10
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Journal article (peer-reviewed)abstract
- We present the results of a weakly modeled burst search for gravitational waves from mergers of nonspinning intermediate mass black holes in the total mass range 100-450 M-circle dot and with the component mass ratios between 1: and 4:1. The search was conducted on data collected by the LIGO and Virgo detectors between November of 2005 and October of 2007. No plausible signals were observed by the search which constrains the astrophysical rates of the intermediate mass black holes mergers as a function of the component masses. In the most efficiently detected bin centered on 88 + 88 M-circle dot, for nonspinning sources, the rate density upper limit is 0.13 per Mpc(3) per Myr at the 90% confidence level.
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| 8. |
- Abadie, J., et al.
(author)
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Upper limits on a stochastic gravitational-wave background using LIGO and Virgo interferometers at 600-1000 Hz
- 2012
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In: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 85:12
-
Journal article (peer-reviewed)abstract
- A stochastic background of gravitational waves is expected to arise from a superposition of many incoherent sources of gravitational waves, of either cosmological or astrophysical origin. This background is a target for the current generation of ground-based detectors. In this article we present the first joint search for a stochastic background using data from the LIGO and Virgo interferometers. In a frequency band of 600-1000 Hz, we obtained a 95% upper limit on the amplitude of Omega(GW)(f) = Omega(3)(f/900 Hz)(3), of Omega(3) < 0.32, assuming a value of the Hubble parameter of h(100) = 0.71. These new limits are a factor of seven better than the previous best in this frequency band.
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| 9. |
- Campbell, PJ, et al.
(author)
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Pan-cancer analysis of whole genomes
- 2020
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In: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 578:7793, s. 82-
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Journal article (peer-reviewed)abstract
- Cancer is driven by genetic change, and the advent of massively parallel sequencing has enabled systematic documentation of this variation at the whole-genome scale1–3. Here we report the integrative analysis of 2,658 whole-cancer genomes and their matching normal tissues across 38 tumour types from the Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium of the International Cancer Genome Consortium (ICGC) and The Cancer Genome Atlas (TCGA). We describe the generation of the PCAWG resource, facilitated by international data sharing using compute clouds. On average, cancer genomes contained 4–5 driver mutations when combining coding and non-coding genomic elements; however, in around 5% of cases no drivers were identified, suggesting that cancer driver discovery is not yet complete. Chromothripsis, in which many clustered structural variants arise in a single catastrophic event, is frequently an early event in tumour evolution; in acral melanoma, for example, these events precede most somatic point mutations and affect several cancer-associated genes simultaneously. Cancers with abnormal telomere maintenance often originate from tissues with low replicative activity and show several mechanisms of preventing telomere attrition to critical levels. Common and rare germline variants affect patterns of somatic mutation, including point mutations, structural variants and somatic retrotransposition. A collection of papers from the PCAWG Consortium describes non-coding mutations that drive cancer beyond those in the TERT promoter4; identifies new signatures of mutational processes that cause base substitutions, small insertions and deletions and structural variation5,6; analyses timings and patterns of tumour evolution7; describes the diverse transcriptional consequences of somatic mutation on splicing, expression levels, fusion genes and promoter activity8,9; and evaluates a range of more-specialized features of cancer genomes8,10–18.
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| 10. |
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| 11. |
- Alava, Mikko, et al.
(author)
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Circumspect descent prevails in solving random constraint satisfaction problems
- 2008
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In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 105:40, s. 15253-15257
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Journal article (peer-reviewed)abstract
- We study the performance of stochastic local search algorithms for random instances of the K-satisfiability (K-SAT) problem. We present a stochastic local search algorithm, ChainSAT, which moves in the energy landscape of a problem instance by never going upwards in energy. ChainSAT is a focused algorithm in the sense that it focuses on variables occurring in unsatisfied clauses. We show by extensive numerical investigations that ChainSAT and other focused algorithms solve large K-SAT instances almost surely in linear time, up to high clause-to-variable ratios a; for example, for K = 4 we observe linear-time performance well beyond the recently postulated clustering and condensation transitions in the solution space. The performance of ChainSAT is a surprise given that by design the algorithm gets trapped into the first local energy minimum it encounters, yet no such minima are encountered. We also study the geometry of the solution space as accessed by stochastic local search algorithms.
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| 12. |
- Krishnamurthy, A, et al.
(author)
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ACPA-INDUCED PAIN-BEHAVIOR, BONE LOSS AND TENDON INFLAMMATION IN MICE: A NOVEL MODEL FOR THE PRE-DISEASE PHASES OF ACPA-POSITIVE RHEUMATOID ARTHRITIS
- 2020
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In: ANNALS OF THE RHEUMATIC DISEASES. - : BMJ. - 0003-4967 .- 1468-2060. ; 79, s. 200-201
-
Conference paper (other academic/artistic)abstract
- In rheumatoid arthritis (RA), anti-citrullinated protein antibodies (ACPAs) are associated with bone loss and pain. Recently, tenosynovitis has been suggested as a predicting factor for arthritis progression in individuals at-risk for RA.Objectives:We aimed to investigate if transfer of human ACPAs into mice could induce tenosynovitis and/or subclinical inflammation.Methods:Monoclonal ACPA (1325:04C03 and 1325:01B09) and control (1362:01E02) antibodies (mAbs) were generated from synovial plasma or memory B cells of RA patients. 2mg of combination of monoclonal ACPAs or control antibody were injected in BALB/c female mice (age 12-16 weeks) (n= 9). Pain-like behavior was monitored by measuring mechanical hypersensitivity using von Frey filaments every 3 days and estimation by up-down Dixon method. Bone morphometrics was analyzed by micro-CT. Using specially designed mobilization casts, dedicated mouse MRI coils, and gadolinium enhanced contrast medium, the hind limbs of these mice were scanned in a 9.4 T scanner and resulting T1-weighted images were evaluated for signs of soft tissue joint inflammation. The MRI images were scored for the presence of joint involvement and tendon inflammatory changes by 3 readers in a blinded manner.Figure 1.NAPA performed on healthy donor mo-DCs incubated with native, PAD2-citrullinated, and PAD4-citrullinated fibrinogen. Alpha, beta, and gamma chains of fibrinogen are shown separately. Each colored line represents a unique peptide. Nested peptides with a common core motif are shown in the same color. Grey bar denotes peptides with identical core motif between samples.Results:ACPAs (1325:04C03 and 1325:01B09) induced pain-like behavior (lasting for at least 4 weeks) and reduction of the trabecular and cortical bone thickness in the hind limbs as compared to control monoclonal antibodies (p<0.05). While no macroscopic or MRI signs of synovial inflammation were detected, MRI subclinical inflammation of the tendon sheaths was present in mice injected with ACPAs, but not in those injected with control mAb. Semi-quantitative scoring of the inflammatory tendon changes showed significant higher values in mice injected with ACPA (median of 1, range 0 to 2) than those injected with control mAb (median of 0, range 0 to 1).Conclusion:We show that ACPA induces pain-like behavior, bone loss and tendon sheath inflammation in mice, a model that mimics the preclinical state of ACPA positive RA.References:[1]Harre, U. et al. J Clin Invest (2012)[2]Krishnamurthy, A. et al. Ann Rheum Dis (2016, 2019), JI 2019[3]Wigerblad, G. et al. Ann Rheum Dis (2016, 2019)[4]KleyerA, Seminars in Arthritis and Rheumatism (2016)Disclosure of Interests:Akilan Krishnamurthy: None declared, Yogan Kisten: None declared, Alexandra Circiumaru: None declared, Koji Sakurabas: None declared, Patrik Jarvolli: None declared, Juan Jimenez Jimenez Andrade: None declared, Peter Damberg: None declared, Heidi Wähämaa: None declared, Vivianne Malmström Grant/research support from: VM has had research grants from Janssen Pharmaceutica, Lars Klareskog: None declared, Camilla Svensson: None declared, Bence Réthi: None declared, Anca Catrina: None declared
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| 13. |
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Kuzuhara, Masayuki, et al.
(author)
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Gliese 12 b: A Temperate Earth-sized Planet at 12 pc Ideal for Atmospheric Transmission Spectroscopy
- 2024
-
In: Astrophysical Journal Letters. - 2041-8213 .- 2041-8205. ; 969:1
-
Journal article (peer-reviewed)abstract
- Recent discoveries of Earth-sized planets transiting nearby M dwarfs have made it possible to characterize the atmospheres of terrestrial planets via follow-up spectroscopic observations. However, the number of such planets receiving low insolation is still small, limiting our ability to understand the diversity of the atmospheric composition and climates of temperate terrestrial planets. We report the discovery of an Earth-sized planet transiting the nearby (12 pc) inactive M3.0 dwarf Gliese 12 (TOI-6251) with an orbital period (P(or)b) of 12.76 days. The planet, Gliese 12 b, was initially identified as a candidate with an ambiguous P-orb from TESS data. We confirmed the transit signal and P-orb using ground-based photometry with MuSCAT2 and MuSCAT3, and validated the planetary nature of the signal using high-resolution images from Gemini/NIRI and Keck/NIRC2 as well as radial velocity (RV) measurements from the InfraRed Doppler instrument on the Subaru 8.2 m telescope and from CARMENES on the CAHA 3.5 m telescope. X-ray observations with XMM-Newton showed the host star is inactive, with an X-ray-to-bolometric luminosity ratio of log L-X/L-bol approximate to - 5.7. Joint analysis of the light curves and RV measurements revealed that Gliese 12 b has a radius of 0.96 +/- 0.05 R-circle plus, a 3 sigma mass upper limit of 3.9M(circle plus), and an equilibrium temperature of 315 +/- 6 K assuming zero albedo. The transmission spectroscopy metric (TSM) value of Gliese 12 b is close to the TSM values of the TRAPPIST-1 planets, adding Gliese 12 b to the small list of potentially terrestrial, temperate planets amenable to atmospheric characterization with JWST.
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| 18. |
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| 19. |
- Morello, Giuseppe, 1989, et al.
(author)
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TOI-1442 b and TOI-2445 b: Two potentially rocky ultra-short period planets around M dwarfs
- 2023
-
In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 673
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Journal article (peer-reviewed)abstract
- Context. Exoplanets with orbital periods of less than one day are known as ultra-short period (USP) planets. They are relatively rare products of planetary formation and evolution processes, but especially favourable for characterisation with current planet detection methods. At the time of writing, 125 USP planets have already been confirmed. Aims. Our aim is to validate the planetary nature of two new transiting planet candidates around M dwarfs announced by the NASA Transiting Exoplanet Survey Satellite (TESS), registered as TESS Objects of Interest (TOIs) TOI-1442.01 and TOI-2445.01. Methods. We used TESS data, ground-based photometric light curves, and Subaru/IRD spectrograph radial velocity (RV) measurements to validate both planetary candidates and to establish their physical properties. Results. TOI-1442 b is a validated exoplanet with an orbital period of P = 0.4090682 ± 0.0000004 day, a radius of Rp = 1.15 ± 0.06 R☉, and equilibrium temperature of Tp,eq = 1357+−4942 K. TOI-2445 b is also validated with an orbital period of P = 0.3711286 ± 0.0000004 day, a radius of Rp = 1.33 ± 0.09 R☉, and equilibrium temperature of Tp,eq = 1330+−6156 K. Their physical properties align with current empirical trends and formation theories of USP planets. Based on the RV measurements, we set 3σ upper mass limits of 8 M☉ and 20 M☉, thus confirming the non-stellar, sub-Jovian nature of both transiting objects. More RV measurements will be needed to constrain the planetary masses and mean densities, and the predicted presence of outer planetary companions. These targets extend the small sample of USP planets orbiting around M dwarfs up to 21 members. They are also among the 20 most suitable terrestrial planets for atmospheric characterisation via secondary eclipse with the James Webb Space Telescope, according to a widespread emission spectroscopy metric.
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| 20. |
- ONNERUD, P, et al.
(author)
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A MAGNETIC-STRUCTURE INVESTIGATION OF TETRAGONAL (FE1-XCOX)(2)AS
- 1995
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In: JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS. - : ELSEVIER SCIENCE BV. - 0304-8853. ; 147:3, s. 346-354
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Journal article (peer-reviewed)abstract
- The crystal and magnetic structures of tetragonal (Fe1-xCox)(2) As have been investigated using magnetization measurements, Mossbauer spectroscopy and neutron powder diffraction. Mossbauer and magnetisation measurements were performed on compositions with
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| 21. |
- Bruederle, Daniel, et al.
(author)
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A comprehensive workflow for general-purpose neural modeling with highly configurable neuromorphic hardware systems
- 2011
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In: Biological Cybernetics. - : Springer Science and Business Media LLC. - 0340-1200 .- 1432-0770. ; 104:4-5, s. 263-296
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Journal article (peer-reviewed)abstract
- In this article, we present a methodological framework that meets novel requirements emerging from upcoming types of accelerated and highly configurable neuromorphic hardware systems. We describe in detail a device with 45 million programmable and dynamic synapses that is currently under development, and we sketch the conceptual challenges that arise from taking this platform into operation. More specifically, we aim at the establishment of this neuromorphic system as a flexible and neuroscientifically valuable modeling tool that can be used by non-hardware experts. We consider various functional aspects to be crucial for this purpose, and we introduce a consistent workflow with detailed descriptions of all involved modules that implement the suggested steps: The integration of the hardware interface into the simulator-independent model description language PyNN; a fully automated translation between the PyNN domain and appropriate hardware configurations; an executable specification of the future neuromorphic system that can be seamlessly integrated into this biology-to-hardware mapping process as a test bench for all software layers and possible hardware design modifications; an evaluation scheme that deploys models from a dedicated benchmark library, compares the results generated by virtual or prototype hardware devices with reference software simulations and analyzes the differences. The integration of these components into one hardware-software workflow provides an ecosystem for ongoing preparative studies that support the hardware design process and represents the basis for the maturity of the model-to-hardware mapping software. The functionality and flexibility of the latter is proven with a variety of experimental results.
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| 22. |
- Dalui, Malay, et al.
(author)
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Mass selection in laser-plasma ion accelerator on nanostructured surfaces
- 2017
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In: Physics of Plasmas. - : AIP Publishing. - 1070-664X .- 1089-7674. ; 24:1
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Journal article (peer-reviewed)abstract
- When an intense laser pulse interacts with a solid surface, ions get accelerated in the laser-plasma due to the formation of transient longitudinal electric field along the target normal direction. However, the acceleration is not mass-selective. The possibility of manipulating such ion acceleration scheme to enhance the energy of one ionic species (either proton or carbon) selectively over the other species is investigated experimentally using nanopore targets. For an incident laser intensity of approximately 5×1017 W/cm2, we show that the acceleration is optimal for protons when the pore diameter is about 15-20 nm, while carbon ions are optimally accelerated when the pore diameter is close to 40-50 nm. The observed effect is due to tailoring targetry by the pulse pedestal of the laser prior to the arrival of the main pulse.
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| 23. |
- Grandhi, G. Krishnamurthy, et al.
(author)
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Wide-Bandgap Perovskite-Inspired Materials: Defect-Driven Challenges for High-Performance Optoelectronics
- 2023
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In: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028.
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Research review (peer-reviewed)abstract
- The remarkable success of lead halide perovskites (LHPs) in photovoltaics and other optoelectronics is significantly linked to their defect tolerance, although this correlation remains not fully clear. The tendency of LHPs to decompose into toxic lead-containing compounds in the presence of humid air calls for the need of low-toxicity LHP alternatives comprising of cations with stable oxidation states. To this aim, a plethora of low-dimensional and wide-bandgap perovskite-inspired materials (PIMs) are proposed. Unfortunately, the optoelectronic performance of PIMs currently lags behind that of their LHP-based counterparts, with a key limiting factor being the high concentration of defects in PIMs, whose rich and complex chemistry is still inadequately understood. This review discusses the defect chemistry of relevant PIMs belonging to the halide elpasolite, vacancy-ordered double perovskite, pnictogen-based metal halide, Ag-Bi-I, and metal chalcohalide families of materials. The defect-driven optical and charge-carrier transport properties of PIMs and their device performance within and beyond photovoltaics are especially discussed. Finally, a view on potential solutions for advancing the research on wide-bandgap PIMs is provided. The key insights of this review will help to tackle the commercialization challenges of these emerging semiconductors with low toxicity and intrinsic air stability.
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| 24. |
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| 25. |
- Hirano, T., et al.
(author)
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An Earth-sized Planet around an M5 Dwarf Star at 22 pc
- 2023
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In: Astronomical Journal. - : American Astronomical Society. - 1538-3881 .- 0004-6256. ; 165:3
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Journal article (peer-reviewed)abstract
- We report on the discovery of an Earth-sized transiting planet (R p = 1.015 ± 0.051 R ⊕) in a P = 4.02 day orbit around K2-415 (EPIC 211414619), an M5V star at 22 pc. The planet candidate was first identified by analyzing the light-curve data obtained by the K2 mission, and it is here shown to exist in the most recent data from TESS. Combining the light curves with the data secured by our follow-up observations, including high-resolution imaging and near-infrared spectroscopy with IRD, we rule out false-positive scenarios, finding a low false-positive probability of 2 × 10−4. Based on IRD’s radial velocities of K2-415, which were sparsely taken over three years, we obtain a planet mass of 3.0 ± 2.7 M ⊕ (M p < 7.5 M ⊕ at 95% confidence) for K2-415b. Being one of the lowest-mass stars (≈0.16 M ⊙) known to host an Earth-sized transiting planet, K2-415 will be an interesting target for further follow-up observations, including additional radial velocity monitoring and transit spectroscopy.
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| 26. |
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| 27. |
- Kawauchi, K., et al.
(author)
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Validation and atmospheric exploration of the sub-Neptune TOI-2136b around a nearby M3 dwarf
- 2022
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In: Astronomy and Astrophysics. - : EDP Sciences. - 0004-6361 .- 1432-0746. ; 666
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Journal article (peer-reviewed)abstract
- Context. The NASA space telescope TESS is currently in the extended mission of its all-sky search for new transiting planets. Of the thousands of candidates that TESS is expected to deliver, transiting planets orbiting nearby M dwarfs are particularly interesting targets since they provide a great opportunity to characterize their atmospheres by transmission spectroscopy. Aims. We aim to validate and characterize the new sub-Neptune-sized planet candidate TOI-2136.01 orbiting a nearby M dwarf (d = 33.36 +/- 0.02 pc, T-eff = 3373 +/- 108 K) with an orbital period of 7.852 days. Methods. We use TESS data, ground-based multicolor photometry, and radial velocity measurements with the InfraRed Doppler (IRD) instrument on the Subaru Telescope to validate the planetary nature of TOI-2136.01, and estimate the stellar and planetary parameters. We also conduct high-resolution transmission spectroscopy to search for helium in its atmosphere. Results. We confirm that TOI-2136.01 (now named TOI-2136b) is a bona fide planet with a planetary radius of R-p = 2.20 +/- 0.07 R-circle plus and a mass of M-p = 4.7(-2.6)(+3.1) M-circle plus. We also search for helium 10830 angstrom absorption lines and place an upper limit on the equivalent width of <7.8 m angstrom and on the absorption signal of <1.44% with 95% confidence. Conclusions. TOI-2136b is a sub-Neptune transiting a nearby and bright star (J = 10.8 mag), and is a potentially hycean planet, which is a new class of habitable planets with large oceans under a H-2-rich atmosphere, making it an excellent target for atmospheric studies to understand the formation, evolution, and habitability of the small planets.
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| 32. |
- Krishnamurthy, Narayanan, et al.
(author)
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Studies on low-intensity oxy-fuel burner
- 2009
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In: PROCEEDINGS OF THE COMBUSTION INSTITUTE. - : Elsevier BV. - 1540-7489. ; 32, s. 3139-3146
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Journal article (peer-reviewed)abstract
- This paper presents experimental and computational results of oxy-fuel burner operating on classical flame and flameless mode for heat release rate of 26 kW/m(3). The uniqueness of the burner arises from a slight asymmetric injection of oxygen at near sonic velocities. Measurements of temperature, species, total heat flux, radiative heat flux and NOx emission were carried out inside the furnace and the flow field was computationally analyzed. The flame studies were carried Out for coaxial flow of oxygen and fuel jets with similar inlet velocities. This configuration results in slow mixing between fuel and oxygen and the flame is developed at distance away from the burner and the flame is bright/white in colour. In the flameless mode a slight asymmetric injection of the high velocity oxygen jet leads to a large asymmetric recirculation pattern with the recirculation ratio of 25 and the resulting flame is weak bluish in colour with little soot and acetylene formation. The classical flame in comparison is characterised by soot and acetylene formation, higher NOx and noise generation. The distribution of temperature and heat flux in the furnace is more uniform with flameless mode than with flame mode.
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| 33. |
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| 34. |
- Krishnamurthy, S, et al.
(author)
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Soft-x-ray spectroscopic investigation of ferromagnetic Co-doped ZnO
- 2006
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In: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 99:8
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Journal article (peer-reviewed)abstract
- The electronic properties of cobalt-doped ZnO were investigated through site-selective and element-sensitive x-ray-absorption spectroscopy in the vicinity of the Co L-2,L-3 edge, the oxygen K edge, and at the Zn L-3 edge. The spectroscopic measurements of the ferromagnetic cobalt-doped ZnO films appear to have additional components in the O K edge x-ray-absorption spectrum not observed in the undoped films. The observed features may derive from both hybridization with unoccupied Co 3d states and also from lattice defects such as oxygen vacancies. Only minor changes in the Zn L-3 edge spectra were observed. These observations are consistent with a polaron percolation model in which the ferromagnetic coupling is mediated by shallow donor electrons trapped in oxygen vacancies and couples the Co atoms substituted on Zn sites in the hexagonal wurtzite ZnO structure.
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| 35. |
- Mehta, Manan, et al.
(author)
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Synthesis of MoS2-TiO2 nanocomposite for enhanced photocatalytic and photoelectrochemical performance under visible light irradiation
- 2018
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In: Vacuum. - : Elsevier BV. - 0042-207X. ; 155, s. 675-681
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Journal article (peer-reviewed)abstract
- In this work, we have prepared MoS2 nanoflakes modified TiO2 nanoparticles (MoS2-TiO2 nanocomposite) with varying concentration of MoS2 (2.5–10 wt.%) by a two-step hydrothermal synthesis method involving specific preparation conditions for the TiO2 nanoparticles and MoS2 nanoflakes. The prepared samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS) techniques. The photocatalytic activity of the pristine TiO2 nanoparticles and MoS2-TiO2 nanocomposite samples were evaluated by examining the photocatalytic degradation of Rhodamine B (RhB). The photoelectrochemical activity of these samples were measured by performing solar water splitting experiments under visible light irradiation. It was observed that the MoS2-TiO2 nanocomposite with 7.5 wt.% MoS2 exhibits highest photocatalytic and photoelectrochemical activity as it has the optimum amount of MoS2 nanoflakes which probably minimizes the recombination of photogenerated charge carriers as compared to other concentrations of MoS2 in MoS2-TiO2 nanocomposite and pristine TiO2 nanoparticles. In addition, a rather high photocatalytic reaction rate constant was observed for MoS2-TiO2 nanocomposite with 7.5 wt.% MoS2 nanoflakes.
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| 36. |
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| 37. |
- Nik-Zainal, Serena, et al.
(author)
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Landscape of somatic mutations in 560 breast cancer whole-genome sequences
- 2016
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In: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 534:7605, s. 47-54
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Journal article (peer-reviewed)abstract
- We analysed whole-genome sequences of 560 breast cancers to advance understanding of the driver mutations conferring clonal advantage and the mutational processes generating somatic mutations. We found that 93 protein-coding cancer genes carried probable driver mutations. Some non-coding regions exhibited high mutation frequencies, but most have distinctive structural features probably causing elevated mutation rates and do not contain driver mutations. Mutational signature analysis was extended to genome rearrangements and revealed twelve base substitution and six rearrangement signatures. Three rearrangement signatures, characterized by tandem duplications or deletions, appear associated with defective homologous-recombination-based DNA repair: one with deficient BRCA1 function, another with deficient BRCA1 or BRCA2 function, the cause of the third is unknown. This analysis of all classes of somatic mutation across exons, introns and intergenic regions highlights the repertoire of cancer genes and mutational processes operating, and progresses towards a comprehensive account of the somatic genetic basis of breast cancer.
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| 38. |
- Patridge, Erik V., et al.
(author)
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7-Nitro-4-(phenylthio)benzofurazan is a potent generator of superoxide and hydrogen peroxide
- 2012
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In: Archives of Toxicology. - : Springer Science and Business Media LLC. - 0340-5761 .- 1432-0738. ; 86:10, s. 1613-1625
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Journal article (peer-reviewed)abstract
- Here, we report on 7-nitro-4-(phenylthio)benzofurazan (NBF-SPh), the most potent derivative among a set of patented anticancer 7-nitrobenzofurazans (NBFs), which have been suggested to function by perturbing protein-protein interactions. We demonstrate that NBF-SPh participates in toxic redox-cycling, rapidly generating reactive oxygen species (ROS) in the presence of molecular oxygen, and this is the first report to detail ROS production for any of the anticancer NBFs. Oxygraph studies showed that NBF-SPh consumes molecular oxygen at a substantial rate, rivaling even plumbagin, menadione, and juglone. Biochemical and enzymatic assays identified superoxide and hydrogen peroxide as products of its redox-cycling activity, and the rapid rate of ROS production appears to be sufficient to account for some of the toxicity of NBF-SPh (LC50 = 12.1 mu M), possibly explaining why tumor cells exhibit a sharp threshold for tolerating the compound. In cell cultures, lipid peroxidation was enhanced after treatment with NBF-SPh, as measured by 2-thiobarbituric acid-reactive substances, indicating a significant accumulation of ROS. Thioglycerol rescued cell death and increased survival by 15-fold to 20-fold, but pyruvate and uric acid were ineffective protectants. We also observed that the redox-cycling activity of NBF-SPh became exhausted after an average of approximately 19 cycles per NBF-SPh molecule. Electrochemical and computational analyses suggest that partial reduction of NBF-SPh enhances electrophilicity, which appears to encourage scavenging activity and contribute to electrophilic toxicity.
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| 39. |
- SRIVASTAVA, BK, et al.
(author)
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REENTRANT SPIN-GLASS-LIKE BEHAVIOR OF (FE0.90CR0.05NI0.05)2P
- 1994
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In: Journal of Magnetism and Magnetic Materials. - : Elsevier BV. - 0304-8853 .- 1873-4766. ; 132, s. 124-130
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Journal article (peer-reviewed)abstract
- Di-iron phosphide with small substitutions of iron with Cr and Ni, (Fe0.90Cr0.05Ni0.05)2P, has been investigated by SQUID-magnetometry. The sample exhibits a first order ferromagnetic transition at T(c) almost-equal-to 180 K and a re-entrant spin glass transition at T(g) almost-equal-to 125 K. The ferromagnetic transition is severely smeared by weak applied magnetic fields. The re-entrant transition is evidenced from both dc-magnetisation and ac-susceptibility measurements. An aging phenomenon is observed at temperatures below T(g) and the freezing temperatures, T(f), and their corresponding relaxation times, tau scale according to conventional critical slowing down: tau/tau0 = ((T(f) - T(g))/T(g))-znu, with an exponent znu almost-equal-to 9, a value that is found also at ordinary paramagnetic to spin glass transitions.
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| 40. |
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| 41. |
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| 42. |
- Wigerblad, G., et al.
(author)
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Autoantibodies to citrullinated proteins induce joint pain independent of inflammation via a chemokine-dependent mechanism
- 2016
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In: Annals of the Rheumatic Diseases. - : BMJ. - 0003-4967 .- 1468-2060. ; 75:4, s. 730-738
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Journal article (peer-reviewed)abstract
- OBJECTIVE: An interesting and so far unexplained feature of chronic pain in autoimmune disease is the frequent disconnect between pain and inflammation. This is illustrated well in rheumatoid arthritis (RA) where pain in joints (arthralgia) may precede joint inflammation and persist even after successful anti-inflammatory treatment. In the present study, we have addressed the possibility that autoantibodies against citrullinated proteins (ACPA), present in RA, may be directly responsible for the induction of pain, independent of inflammation. METHODS: Antibodies purified from human patients with RA, healthy donors and murinised monoclonal ACPA were injected into mice. Pain-like behaviour was monitored for up to 28 days, and tissues were analysed for signs of pathology. Mouse osteoclasts were cultured and stimulated with antibodies, and supernatants analysed for release of factors. Mice were treated with CXCR1/2 (interleukin (IL) 8 receptor) antagonist reparixin. RESULTS: Mice injected with either human or murinised ACPA developed long-lasting pronounced pain-like behaviour in the absence of inflammation, while non-ACPA IgG from patients with RA or control monoclonal IgG were without pronociceptive effect. This effect was coupled to ACPA-mediated activation of osteoclasts and release of the nociceptive chemokine CXCL1 (analogue to human IL-8). ACPA-induced pain-like behaviour was reversed with reparixin. CONCLUSIONS: The data suggest that CXCL1/IL-8, released from osteoclasts in an autoantibody-dependent manner, produces pain by activating sensory neurons. The identification of this new pain pathway may open new avenues for pain treatment in RA and also in other painful diseases associated with autoantibody production and/or osteoclast activation.
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