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1.	Aartsen, M. G., et al. (författare) Multipole analysis of IceCube data to search for dark matter accumulated in the Galactic halo 2015 Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 75:1 Tidskriftsartikel (refereegranskat)abstract Dark matter which is bound in the Galactic halo might self-annihilate and produce a flux of stable final state particles, e. g. high energy neutrinos. These neutrinos can be detected with IceCube, a cubic-kilometer sized Cherenkov detector. Given IceCube's large field of view, a characteristic anisotropy of the additional neutrino flux is expected. In this paper we describe a multipole method to search for such a large-scale anisotropy in IceCube data. This method uses the expansion coefficients of a multipole expansion of neutrino arrival directions and incorporates signal-specific weights for each expansion coefficient. We apply the technique to a high-purity muon neutrino sample from the Northern Hemisphere. The final result is compatible with the null-hypothesis. As no signal was observed, we present limits on the self-annihilation cross-section averaged over the relative velocity distribution down to 1.9x10(-23) cm(3) s(-1) for a dark matter particle mass of 700-1,000 GeV and direct annihilation into nu(nu) over bar. The resulting exclusion limits come close to exclusion limits from gamma-ray experiments, that focus on the outer Galactic halo, for high dark matter masses of a few TeV and hard annihilation channels.
2.	Aartsen, M. G., et al. (författare) Observation of High-Energy Astrophysical Neutrinos in Three Years of IceCube Data 2014 Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 113:10, s. 101101- Tidskriftsartikel (refereegranskat)abstract A search for high-energy neutrinos interacting within the IceCube detector between 2010 and 2012 provided the first evidence for a high-energy neutrino flux of extraterrestrial origin. Results from an analysis using the same methods with a third year (2012-2013) of data from the complete IceCube detector are consistent with the previously reported astrophysical flux in the 100 TeV-PeV range at the level of 10(-8) GeV cm(-2) s(-1) sr(-1) per flavor and reject a purely atmospheric explanation for the combined three-year data at 5.7 sigma. The data are consistent with expectations for equal fluxes of all three neutrino flavors and with isotropic arrival directions, suggesting either numerous or spatially extended sources. The three-year data set, with a live time of 988 days, contains a total of 37 neutrino candidate events with deposited energies ranging from 30 to 2000 TeV. The 2000-TeV event is the highest-energy neutrino interaction ever observed.
3.	Aartsen, M. G., et al. (författare) SEARCHES FOR EXTENDED AND POINT-LIKE NEUTRINO SOURCES WITH FOUR YEARS OF ICECUBE DATA 2014 Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 796:2, s. 109- Tidskriftsartikel (refereegranskat)abstract We present results on searches for point-like sources of neutrinos using four years of IceCube data, including the first year of data from the completed 86 string detector. The total livetime of the combined data set is 1373 days. For an E-2 spectrum, the observed 90% C. L. flux upper limits are similar to 10(-12) TeV-1 cm(-2) s(-1) for energies between 1 TeV and 1 PeV in the northern sky and similar to 10(-11) TeV-1 cm(-2) s(-1) for energies between 100 TeV and 100 PeV in the southern sky. This represents a 40% improvement compared to previous publications, resulting from both the additional year of data and the introduction of improved reconstructions. In addition, we present the first results from an all-sky search for extended sources of neutrinos. We update the results of searches for neutrino emission from stacked catalogs of sources and test five new catalogs; two of Galactic supernova remnants and three of active galactic nuclei. In all cases, the data are compatible with the background-only hypothesis, and upper limits on the flux of muon neutrinos are reported for the sources considered.
4.	Aartsen, M. G., et al. (författare) Atmospheric and astrophysical neutrinos above 1 TeV interacting in IceCube 2015 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:2, s. 022001- Tidskriftsartikel (refereegranskat)abstract The IceCube Neutrino Observatory was designed primarily to search for high-energy (TeV-PeV) neutLrinos produced in distant astrophysical objects. A search for. greater than or similar to 100 TeV neutrinos interacting inside the instrumented volume has recently provided evidence for an isotropic flux of such neutrinos. At lower energies, IceCube collects large numbers of neutrinos from the weak decays of mesons in cosmic-ray air showers. Here we present the results of a search for neutrino interactions inside IceCube's instrumented volume between 1 TeV and 1 PeV in 641 days of data taken from 2010-2012, lowering the energy threshold for neutrinos from the southern sky below 10 TeV for the first time, far below the threshold of the previous high-energy analysis. Astrophysical neutrinos remain the dominant component in the southern sky down to a deposited energy of 10 TeV. From these data we derive new constraints on the diffuse astrophysical neutrino spectrum, Phi(v) = 2.06(-0.3)(+0.4) x 10(-18) (E-v = 10(5) GeV)-2.46 +/- 0.12GeV-1 cm(-2) sr(-1) s(-1) for 25 TeV < E-v < 1.4 PeV, as well as the strongest upper limit yet on the flux of neutrinos from charmed-meson decay in the atmosphere, 1.52 times the benchmark theoretical prediction used in previous IceCube results at 90% confidence.
5.	Aartsen, M. G., et al. (författare) Determining neutrino oscillation parameters from atmospheric muon neutrino disappearance with three years of IceCube DeepCore data 2015 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 91:7 Tidskriftsartikel (refereegranskat)abstract We present a measurement of neutrino oscillations via atmospheric muon neutrino disappearance with three years of data of the completed IceCube neutrino detector. DeepCore, a region of denser IceCube instrumentation, enables the detection and reconstruction of atmospheric muon neutrinos between 10 and 100 GeV, where a strong disappearance signal is expected. The IceCube detector volume surrounding DeepCore is used as a veto region to suppress the atmospheric muon background. Neutrino events are selected where the detected Cherenkov photons of the secondary particles minimally scatter, and the neutrino energy and arrival direction are reconstructed. Both variables are used to obtain the neutrino oscillation parameters from the data, with the best fit given by Delta m(32)(2) = 2.72(-0.20)(+0.19) x 10(-3) eV(2) and sin(2)theta(23) = 0.53(-0.12)(+0.09) (normal mass ordering assumed). The results are compatible, and comparable in precision, to those of dedicated oscillation experiments.
6.	Aartsen, M. G., et al. (författare) Development of a general analysis and unfolding scheme and its application to measure the energy spectrum of atmospheric neutrinos with IceCube 2015 Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 75:3 Tidskriftsartikel (refereegranskat)abstract We present the development and application of a generic analysis scheme for the measurement of neutrino spectra with the IceCube detector. This scheme is based on regularized unfolding, preceded by an event selection which uses a Minimum Redundancy Maximum Relevance algorithm to select the relevant variables and a random forest for the classification of events. The analysis has been developed using IceCube data from the 59-string configuration of the detector. 27,771 neutrino candidates were detected in 346 days of livetime. A rejection of 99.9999 % of the atmospheric muon background is achieved. The energy spectrum of the atmospheric neutrino flux is obtained using the TRUEE unfolding program. The unfolded spectrum of atmospheric muon neutrinos covers an energy range from 100 GeV to 1 PeV. Compared to the previous measurement using the detector in the 40-string configuration, the analysis presented here, extends the upper end of the atmospheric neutrino spectrum by more than a factor of two, reaching an energy region that has not been previously accessed by spectral measurements.
7.	Aartsen, M. G., et al. (författare) Flavor Ratio of Astrophysical Neutrinos above 35 TeV in IceCube 2015 Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 114:17 Tidskriftsartikel (refereegranskat)abstract A diffuse flux of astrophysical neutrinos above 100 TeV has been observed at the IceCube Neutrino Observatory. Here we extend this analysis to probe the astrophysical flux down to 35 TeV and analyze its flavor composition by classifying events as showers or tracks. Taking advantage of lower atmospheric backgrounds for showerlike events, we obtain a shower-biased sample containing 129 showers and 8 tracks collected in three years from 2010 to 2013. We demonstrate consistency with the (f(e) : f(mu) : f(tau))(circle plus) approximate to (1 : 1 : 1)(circle plus) flavor ratio at Earth commonly expected from the averaged oscillations of neutrinos produced by pion decay in distant astrophysical sources. Limits are placed on nonstandard flavor compositions that cannot be produced by averaged neutrino oscillations but could arise in exotic physics scenarios. A maximally tracklike composition of (0 : 1 : 0)(circle plus) is excluded at 3.3 sigma, and a purely showerlike composition of (1 : 0 : 0)(circle plus) is excluded at 2.3 sigma.
8.	Aartsen, M. G., et al. (författare) Search for a diffuse flux of astrophysical muon neutrinos with the IceCube 59-string configuration 2014 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:6, s. 062007- Tidskriftsartikel (refereegranskat)abstract A search for high-energy neutrinos was performed using data collected by the IceCube Neutrino Observatory from May 2009 to May 2010, when the array was running in its 59-string configuration. The data sample was optimized to contain muon neutrino induced events with a background contamination of atmospheric muons of less than 1%. These data, which are dominated by atmospheric neutrinos, are analyzed with a global likelihood fit to search for possible contributions of prompt atmospheric and astrophysical neutrinos, neither of which have yet been identified. Such signals are expected to follow a harder energy spectrum than conventional atmospheric neutrinos. In addition, the zenith angle distribution differs for astrophysical and atmospheric signals. A global fit of the reconstructed energies and directions of observed events is performed, including possible neutrino flux contributions for an astrophysical signal and atmospheric backgrounds as well as systematic uncertainties of the experiment and theoretical predictions. The best fit yields an astrophysical signal flux for nu(mu) + (nu) over bar (mu) of E-2. Phi(E) = 0.25 x 10(-8) GeV cm(-2) s(-1) sr(-1), and a zero prompt component. Although the sensitivity of this analysis for astrophysical neutrinos surpasses the Waxman and Bahcall upper bound, the experimental limit at 90% confidence level is a factor of 1.5 above at a flux of E-2 . Phi(E) = 1.44 x 10(-8) GeV cm(-2) s(-1) sr(-1).
9.	Aartsen, M. G., et al. (författare) Search for neutrino-induced particle showers with IceCube-40 2014 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:10, s. 102001- Tidskriftsartikel (refereegranskat)abstract We report on the search for neutrino-induced particle showers, so-called cascades, in the IceCube-40 detector. The data for this search were collected between April 2008 and May 2009 when the first 40 IceCube strings were deployed and operational. Three complementary searches were performed, each optimized for different energy regimes. The analysis with the lowest energy threshold (2 TeV) targeted atmospheric neutrinos. A total of 67 events were found, consistent with the expectation of 41 atmospheric muons and 30 atmospheric neutrino events. The two other analyses targeted a harder, astrophysical neutrino flux. The analysis with an intermediate threshold of 25 TeV leads to the observation of 14 cascadelike events, again consistent with the prediction of 3.0 atmospheric neutrino and 7.7 atmospheric muon events. We hence set an upper limit of E-2 Phi(lim) <= 7.46 x 10(-8) GeV sr(-1) s(-1) cm(-2) (90% C.L.) on the diffuse flux from astrophysical neutrinos of all neutrino flavors, applicable to the energy range 25 TeV to 5 PeV, assuming an E-nu(-2) spectrum and a neutrino flavor ratio of 1: 1: 1 at the Earth. The third analysis utilized a larger and optimized sample of atmospheric muon background simulation, leading to a higher energy threshold of 100 TeV. Three events were found over a background prediction of 0.04 atmospheric muon events and 0.21 events from the flux of conventional and prompt atmospheric neutrinos. Including systematic errors this corresponds to a 2.7 sigma excess with respect to the background-only hypothesis. Our observation of neutrino event candidates above 100 TeV complements IceCube's recently observed evidence for high-energy astrophysical neutrinos.
10.	Aartsen, M. G., et al. (författare) Search for Prompt Neutrino Emission from Gamma-Ray Bursts with IceCube 2015 Ingår i: Astrophysical Journal Letters. - 2041-8205 .- 2041-8213. ; 805:1 Tidskriftsartikel (refereegranskat)abstract We present constraints derived from a search of four years of IceCube data for a prompt neutrino flux from gammaray bursts (GRBs). A single low-significance neutrino, compatible with the atmospheric neutrino background, was found in coincidence with one of the 506 observed bursts. Although GRBs have been proposed as candidate sources for ultra-high-energy cosmic rays, our limits on the neutrino flux disfavor much of the parameter space for the latest models. We also find that no more than similar to 1% of the recently observed astrophysical neutrino flux consists of prompt emission from GRBs that are potentially observable by existing satellites.
11.	Aartsen, M. G., et al. (författare) Searches for small-scale anisotropies from neutrino point sources with three years of IceCube data 2015 Ingår i: Astroparticle physics. - : Elsevier BV. - 0927-6505 .- 1873-2852. ; 66, s. 39-52 Tidskriftsartikel (refereegranskat)abstract Recently, IceCube found evidence for a diffuse signal of astrophysical neutrinos in an energy range of similar to 60 TeV to the PeV-scale [1]. The origin of those events, being a key to understanding the origin of cosmic rays, is still an unsolved question. So far, analyses have not succeeded to resolve the diffuse signal into point-like sources. Searches including a maximum-likelihood-ratio test, based on the reconstructed directions and energies of the detected down- and up-going neutrino candidates, were also performed on IceCube data leading to the exclusion of bright point sources. In this paper, we present two methods to search for faint neutrino point sources in three years of IceCube data, taken between 2008 and 2011. The first method is an autocorrelation test, applied separately to the northern and southern sky. The second method is a multipole analysis, which expands the measured data in the northern hemisphere into spherical harmonics and uses the resulting expansion coefficients to separate signal from background. With both methods, the results are consistent with the background expectation with a slightly more sparse spatial distribution, corresponding to an underfluctuation. Depending on the assumed number of sources, the resulting upper limit on the flux per source in the northern hemisphere for an E-2 energy spectrum ranges from similar to 1.5. 10(-8) GeV/cm(2) s(-1), in the case of one assumed source, to similar to 4. 10(-10) GeV/cm(2) s(-1), in the case of 3500 assumed sources.
12.	Aartsen, M. G., et al. (författare) SEARCHES FOR TIME-DEPENDENT NEUTRINO SOURCES WITH ICECUBE DATA FROM 2008 TO 2012 2015 Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 807:1 Tidskriftsartikel (refereegranskat)abstract In this paper searches for flaring astrophysical neutrino sources and sources with periodic emission with the IceCube neutrino telescope are presented. In contrast to time-integrated searches, where steady emission is assumed, the analyses presented here look for a time-dependent signal of neutrinos using the information from the neutrino arrival times to enhance the discovery potential. A search was performed for correlations between neutrino arrival times and directions, as well as neutrino emission following time-dependent light curves, sporadic emission, or periodicities of candidate sources. These include active galactic nuclei, soft gamma-ray repeaters, supernova remnants hosting pulsars, microquasars, and X-ray binaries. The work presented here updates and extends previously published results to a longer period that covers 4 years. of data from 2008 April 5 to 2012 May 16, including the first year of operation of the completed 86 string detector. The analyses did not find any significant time-dependent point sources of neutrinos, and the results were used to set upper limits on the neutrino flux from source candidates.
13.	Aartsen, M. G., et al. (författare) Evidence for High-Energy Extraterrestrial Neutrinos at the IceCube Detector 2013 Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 342:6161, s. 947- Tidskriftsartikel (refereegranskat)abstract We report on results of an all-sky search for high-energy neutrino events interacting within the IceCube neutrino detector conducted between May 2010 and May 2012. The search follows up on the previous detection of two PeV neutrino events, with improved sensitivity and extended energy coverage down to about 30 TeV. Twenty-six additional events were observed, substantially more than expected from atmospheric backgrounds. Combined, both searches reject a purely atmospheric origin for the 28 events at the 4 sigma level. These 28 events, which include the highest energy neutrinos ever observed, have flavors, directions, and energies inconsistent with those expected from the atmospheric muon and neutrino backgrounds. These properties are, however, consistent with generic predictions for an additional component of extraterrestrial origin.
14.	Aartsen, M. G., et al. (författare) IceCube search for dark matter annihilation in nearby galaxies and galaxy clusters 2013 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:12 Tidskriftsartikel (refereegranskat)abstract We present the results of a first search for self-annihilating dark matter in nearby galaxies and galaxy clusters using a sample of high-energy neutrinos acquired in 339.8 days of live time during 2009/10 with the IceCube neutrino observatory in its 59-string configuration. The targets of interest include the Virgo and Coma galaxy clusters, the Andromeda galaxy, and several dwarf galaxies. We obtain upper limits on the cross section as a function of the weakly interacting massive particle mass between 300 GeV and 100 TeV for the annihilation into b (b) over bar, W+(W) over bar (-), tau(+)tau(-), mu(+)mu(-) , and nu(nu) over bar. A limit derived for the Virgo cluster, when assuming a large effect from subhalos, challenges the weakly interacting massive particle interpretation of a recently observed GeV positron excess in cosmic rays.
15.	Aartsen, M. G., et al. (författare) Improvement in fast particle track reconstruction with robust statistics 2014 Ingår i: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 736, s. 143-149 Tidskriftsartikel (refereegranskat)abstract The IceCube project has transformed 1 km(3) of deep natural Antarctic ice into a Cherenkov detector Muon neutrinos are detected and their direction is inferred by mapping the light produced by the secondary muon track inside the volume instrumented with photomultipliers. Reconstructing the muon track from the observed light is challenging due to noise, light scattering in the ice medium, and the possibility of simultaneously having multiple muons inside the detector, resulting from the large flux of cosmic ray muons. This paper describes work on two problems: (1) the truck reconstruction problem, in which, given a set of observations, the goal is to recover the track of a muon; and (2) the coincident event problem, which is to determine how many muons are active in the detector during a time window. Rather than solving these problems by developing more complex physical models that are applied at later stages of the analysis, our approach is to augment the detector's early reconstruction with data filters and robust statistical techniques. These can be implemented at the level of on-line reconstruction and, therefore, improve all subsequent reconstructions. Using the metric of median angular resolution, a standard metric for track reconstruction, we improve the accuracy in the initial reconstruction direction by 13%. We also present improvements in measuring the number of muons in coincident events: we can accurately determine the number of muons 98% of the time.
16.	Aartsen, M. G., et al. (författare) Measurement of Atmospheric Neutrino Oscillations with IceCube 2013 Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 111:8, s. 081801- Tidskriftsartikel (refereegranskat)abstract We present the first statistically significant detection of neutrino oscillations in the high-energy regime (> 20 GeV) from an analysis of IceCube Neutrino Observatory data collected in 2010 and 2011. This measurement is made possible by the low-energy threshold of the DeepCore detector (similar to 20 GeV) and benefits from the use of the IceCube detector as a veto against cosmic-ray-induced muon background. The oscillation signal was detected within a low-energy muon neutrino sample (20-100 GeV) extracted from data collected by DeepCore. A high-energy muon neutrino sample (100 GeV-10 TeV) was extracted from IceCube data to constrain systematic uncertainties. The disappearance of low-energy upward-going muon neutrinos was observed, and the nonoscillation hypothesis is rejected with more than 5 sigma significance. In a two-neutrino flavor formalism, our data are best described by the atmospheric neutrino oscillation parameters vertical bar Delta m(32)(2)vertical bar = (2.3(-0.5)(+0.6)) x 10(-3) eV(2) and sin(2) (2 theta(23)) > 0.93, and maximum mixing is favored.
17.	Aartsen, M. G., et al. (författare) Measurement of the cosmic ray energy spectrum with IceTop-73 2013 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:4, s. 042004- Tidskriftsartikel (refereegranskat)abstract We report on the measurement of the all-particle cosmic ray energy spectrum with the IceTop air shower array in the energy range from 1.58 PeV to 1.26 EeV. The IceTop air shower array is the surface component of the IceCube Neutrino Observatory at the geographical South Pole. The analysis was performed using only information from IceTop. The data used in this work were taken from June 1, 2010 to May 13, 2011. During that period the IceTop array consisted of 73 stations, compared to 81 in its final configuration. The measured spectrum exhibits a clear deviation from a single power law above the knee around 4 PeV and below 1 EeV. We observe spectral hardening around 18 PeV and steepening around 130 PeV.
18.	Aartsen, M. G., et al. (författare) Observation of the cosmic-ray shadow of the Moon with IceCube 2014 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 89:10, s. 102004- Tidskriftsartikel (refereegranskat)abstract We report on the observation of a significant deficit of cosmic rays from the direction of the Moon with the IceCube detector. The study of this "Moon shadow" is used to characterize the angular resolution and absolute pointing capabilities of the detector. The detection is based on data taken in two periods before the completion of the detector: between April 2008 and May 2009, when IceCube operated in a partial configuration with 40 detector strings deployed in the South Pole ice, and between May 2009 and May 2010 when the detector operated with 59 strings. Using two independent analysis methods, the Moon shadow has been observed to high significance (> 6 sigma) in both detector configurations. The observed location of the shadow center is within 0.2 degrees of its expected position when geomagnetic deflection effects are taken into account. This measurement validates the directional reconstruction capabilities of IceCube.
19.	Aartsen, M. G., et al. (författare) Search for non-relativistic magnetic monopoles with IceCube 2014 Ingår i: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 74:7, s. 2938- Tidskriftsartikel (refereegranskat)abstract The IceCube Neutrino Observatory is a large Cherenkov detector instrumenting of Antarctic ice. The detector can be used to search for signatures of particle physics beyond the Standard Model. Here, we describe the search for non-relativistic, magnetic monopoles as remnants of the Grand Unified Theory (GUT) era shortly after the Big Bang. Depending on the underlying gauge group these monopoles may catalyze the decay of nucleons via the Rubakov-Callan effect with a cross section suggested to be in the range of to . In IceCube, the Cherenkov light from nucleon decays along the monopole trajectory would produce a characteristic hit pattern. This paper presents the results of an analysis of first data taken from May 2011 until May 2012 with a dedicated slow-particle trigger for DeepCore, a subdetector of IceCube. A second analysis provides better sensitivity for the brightest non-relativistic monopoles using data taken from May 2009 until May 2010. In both analyses no monopole signal was observed. For catalysis cross sections of the flux of non-relativistic GUT monopoles is constrained up to a level of at a 90 % confidence level, which is three orders of magnitude below the Parker bound. The limits assume a dominant decay of the proton into a positron and a neutral pion. These results improve the current best experimental limits by one to two orders of magnitude, for a wide range of assumed speeds and catalysis cross sections.
20.	Aartsen, M. G., et al. (författare) SEARCH FOR TIME-INDEPENDENT NEUTRINO EMISSION FROM ASTROPHYSICAL SOURCES WITH 3 yr OF IceCube DATASearch for time-independent neutrino emission from astrophysical sources with 3 yr of icecube data 2013 Ingår i: Astrophysical Journal. - 0004-637X .- 1538-4357. ; 779:2, s. 132- Tidskriftsartikel (refereegranskat)abstract We present the results of a search for neutrino point sources using the IceCube data collected between 2008 April and 2011 May with three partially completed configurations of the detector: the 40-, 59-, and 79-string configurations. The live-time of this data set is 1040 days. An unbinned maximum likelihood ratio test was used to search for an excess of neutrinos above the atmospheric background at any given direction in the sky. By adding two more years of data with improved event selection and reconstruction techniques, the sensitivity was improved by a factor of 3.5 or more with respect to the previously published results obtained with the 40-string configuration of IceCube. We performed an all-sky survey and a dedicated search using a catalog of a priori selected objects observed by other telescopes. In both searches, the data are compatible with the background-only hypothesis. In the absence of evidence for a signal, we set upper limits on the flux of muon neutrinos. For an E-2 neutrino spectrum, the observed limits are (0.9-5) x 10(-12) TeV-1 cm(-2) s(-1) for energies between 1 TeV and 1 PeV in the northern sky and (0.9-23.2) x 10(-12) TeV-1 cm(-2) s(-1) for energies between 10(2) TeV and 10(2) PeV in the southern sky. We also report upper limits for neutrino emission from groups of sources that were selected according to theoretical models or observational parameters and analyzed with a stacking approach. Some of the limits presented already reach the level necessary to quantitatively test current models of neutrino emission.
21.	Pedersen, TR, et al. (författare) Cholesterol lowering and the use of healthcare resources. Results of the Scandinavian Simvastatin Survival Study 1996 Ingår i: Circulation. - 0009-7322. ; 93:10, s. 1796-1802 Tidskriftsartikel (refereegranskat)
22.	Aartsen, M. G., et al. (författare) Energy reconstruction methods in the IceCube neutrino telescope 2014 Ingår i: Journal of Instrumentation. - 1748-0221. ; 9, s. P03009- Tidskriftsartikel (refereegranskat)abstract Accurate measurement of neutrino energies is essential to many of the scientific goals of large-volume neutrino telescopes. The fundamental observable in such detectors is the Cherenkov light produced by the transit through a medium of charged particles created in neutrino interactions. The amount of light emitted is proportional to the deposited energy, which is approximately equal to the neutrino energy for v(e) and v(mu) charged-current interactions and can be used to set a lower bound on neutrino energies and to measure neutrino spectra statistically in other channels. Here we describe methods and performance of reconstructing charged-particle energies and topologies from the observed Cherenkov light yield, including techniques to measure the energies of uncontained muon tracks, achieving average uncertainties in electromagnetic-equivalent deposited energy of similar to 15% above 10 TeV.
23.	Aartsen, M. G., et al. (författare) First Observation of PeV-Energy Neutrinos with IceCube 2013 Ingår i: Physical Review Letters. - 0031-9007 .- 1079-7114. ; 111:2, s. 021103- Tidskriftsartikel (refereegranskat)abstract We report on the observation of two neutrino-induced events which have an estimated deposited energy in the IceCube detector of 1.04 +/- 0.16 and 1.14 +/- 0.17 PeV, respectively, the highest neutrino energies observed so far. These events are consistent with fully contained particle showers induced by neutral-current nu(e,mu,tau) ((nu) over bar (e,mu,tau)) or charged-current nu(e) ((nu) over bar (e)) interactions within the IceCube detector. The events were discovered in a search for ultrahigh energy neutrinos using data corresponding to 615.9 days effective live time. The expected number of atmospheric background is 0.082 +/- 0.004(stat)(-0.057)(+0.041)(syst). The probability of observing two or more candidate events under the atmospheric background-only hypothesis is 2.9 x 10(-3) (2.8 sigma) taking into account the uncertainty on the expected number of background events. These two events could be a first indication of an astrophysical neutrino flux; the moderate significance, however, does not permit a definitive conclusion at this time.
24.	Aartsen, M. G., et al. (författare) Probing the origin of cosmic rays with extremely high energy neutrinos using the IceCube Observatory 2013 Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 88:11 Tidskriftsartikel (refereegranskat)abstract We have searched for extremely high energy neutrinos using data taken with the IceCube detector between May 2010 and May 2012. Two neutrino-induced particle shower events with energies around 1 PeV were observed, as reported previously. In this work, we investigate whether these events could originate from cosmogenic neutrinos produced in the interactions of ultrahigh energy cosmic rays with ambient photons while propagating through intergalactic space. Exploiting IceCube's large exposure for extremely high energy neutrinos and the lack of observed events above 100 PeV, we can rule out the corresponding models at more than 90% confidence level. The model-independent quasidifferential 90% C. L. upper limit, which amounts to E-2 phi(nu e)+(nu mu)+(nu tau) = 1.2 x 10(-7) GeV cm(-2) s(-1) sr(-1) at 1 EeV, provides the most stringent constraint in the energy range from 10 PeV to 10 EeV. Our observation disfavors strong cosmological evolution of the highest energy cosmic-ray sources such as the Fanaroff-Riley type II class of radio galaxies.
25.	Aartsen, M. G., et al. (författare) South Pole glacial climate reconstruction from multi-borehole laser particulate stratigraphy 2013 Ingår i: Journal of Glaciology. - 0022-1430 .- 1727-5652. ; 59:218, s. 1117-1128 Tidskriftsartikel (refereegranskat)abstract The IceCube Neutrino Observatory and its prototype, AMANDA, were built in South Pole ice, using powerful hot-water drills to cleanly bore >100 holes to depths up to 2500 m. The construction of these particle physics detectors provided a unique opportunity to examine the deep ice sheet using a variety of novel techniques. We made high-resolution particulate profiles with a laser dust logger in eight of the boreholes during detector commissioning between 2004 and 2010. The South Pole laser logs are among the most clearly resolved measurements of Antarctic dust strata during the last glacial period and can be used to reconstruct paleoclimate records in exceptional detail. Here we use manual and algorithmic matching to synthesize our South Pole measurements with ice-core and logging data from Dome C, East Antarctica. We derive impurity concentration, precision chronology, annual-layer thickness, local spatial variability, and identify several widespread volcanic ash depositions useful for dating. We also examine the interval around similar to 74 ka recently isolated with radiometric dating to bracket the Toba (Sumatra) supereruption.
26.	Aartsen, M. G., et al. (författare) The IceProd framework : Distributed data processing for the IceCube neutrino observatory 2015 Ingår i: Journal of Parallel and Distributed Computing. - : Elsevier BV. - 0743-7315 .- 1096-0848. ; 75, s. 198-211 Tidskriftsartikel (refereegranskat)abstract IceCube is a one-gigaton instrument located at the geographic South Pole, designed to detect cosmic neutrinos, identify the particle nature of dark matter, and study high-energy neutrinos themselves. Simulation of the IceCube detector and processing of data require a significant amount of computational resources. This paper presents the first detailed description of IceProd, a lightweight distributed management system designed to meet these requirements. It is driven by a central database in order to manage mass production of simulations and analysis of data produced by the IceCube detector. IceProd runs as a separate layer on top of other middleware and can take advantage of a variety of computing resources, including grids and batch systems such as CREAM, HTCondor, and PBS. This is accomplished by a set of dedicated daemons that process job submission in a coordinated fashion through the use of middleware plugins that serve to abstract the details of job submission and job management from the framework. (C) 2014 Elsevier Inc. All rights reserved.
27.	Yndigegn, T., et al. (författare) Beta-Blockers after Myocardial Infarction and Preserved Ejection Fraction 2024 Ingår i: New England Journal of Medicine. - : MASSACHUSETTS MEDICAL SOC. - 0028-4793 .- 1533-4406. Tidskriftsartikel (refereegranskat)abstract Background Most trials that have shown a benefit of beta-blocker treatment after myocardial infarction included patients with large myocardial infarctions and were conducted in an era before modern biomarker-based diagnosis of myocardial infarction and treatment with percutaneous coronary intervention, antithrombotic agents, high-intensity statins, and renin-angiotensin-aldosterone system antagonists.Methods In a parallel-group, open-label trial performed at 45 centers in Sweden, Estonia, and New Zealand, we randomly assigned patients with an acute myocardial infarction who had undergone coronary angiography and had a left ventricular ejection fraction of at least 50% to receive either long-term treatment with a beta-blocker (metoprolol or bisoprolol) or no beta-blocker treatment. The primary end point was a composite of death from any cause or new myocardial infarction.Results From September 2017 through May 2023, a total of 5020 patients were enrolled (95.4% of whom were from Sweden). The median follow-up was 3.5 years (interquartile range, 2.2 to 4.7). A primary end-point event occurred in 199 of 2508 patients (7.9%) in the beta-blocker group and in 208 of 2512 patients (8.3%) in the no-beta-blocker group (hazard ratio, 0.96; 95% confidence interval, 0.79 to 1.16; P=0.64). Beta-blocker treatment did not appear to lead to a lower cumulative incidence of the secondary end points (death from any cause, 3.9% in the beta-blocker group and 4.1% in the no-beta-blocker group; death from cardiovascular causes, 1.5% and 1.3%, respectively; myocardial infarction, 4.5% and 4.7%; hospitalization for atrial fibrillation, 1.1% and 1.4%; and hospitalization for heart failure, 0.8% and 0.9%). With regard to safety end points, hospitalization for bradycardia, second- or third-degree atrioventricular block, hypotension, syncope, or implantation of a pacemaker occurred in 3.4% of the patients in the beta-blocker group and in 3.2% of those in the no-beta-blocker group; hospitalization for asthma or chronic obstructive pulmonary disease in 0.6% and 0.6%, respectively; and hospitalization for stroke in 1.4% and 1.8%.Conclusions Among patients with acute myocardial infarction who underwent early coronary angiography and had a preserved left ventricular ejection fraction (>= 50%), long-term beta-blocker treatment did not lead to a lower risk of the composite primary end point of death from any cause or new myocardial infarction than no beta-blocker use. (Funded by the Swedish Research Council and others; REDUCE-AMI ClinicalTrials.gov number, NCT03278509.) Hospitalized patients with acute myocardial infarction and preserved EF were assigned to receive open-label long-term beta-blocker therapy or not. Beta-blockers did not lead to a lower risk of death or MI.
28.	Bratus, V. Y., et al. (författare) Vacancy-related defects in ion-beam and electron irradiated 6H-SiC 2001 Ingår i: Applied Surface Science. - 0169-4332 .- 1873-5584. ; 184:04-jan, s. 229-236 Tidskriftsartikel (refereegranskat)abstract A brief review is given on EPR study of irradiation-induced defects in SiC. The results of low-temperature study of Ky1 and Ky2 centers reveal for both of them the C-S symmetry, spin S = 1/2 and close coincidence of the g-tensor components. For Ky2 defect the principal values of g-tensor have been determined as g(z) = 2.0048, g(x) = 2.0022 and g(y) = 2.0037, where z and x directions reside in the (11 (2) over bar0) plane and the z-axis makes up an angle 65 degrees with the c-axis. The same residence of z- and x-axis and an angle 59 degrees are found for Ky1 center, g(z) = 2.0058, g(x) = 2.0025 and g(y) = 2.0023. A comparison of experimental and calculated hyperfine (HF) parameters is presented which suggests that Ky2 and Ky1 defects can be assigned to the positively charged carbon vacancy in 6H-SiC. The EPR study of defects created along the Al+ ion track in n-type 6H-SiC shows that lineshape, linewidth and integral intensity of the EPR signal reflect the state of damaged layer generated by ion implantation. A variation of defect density with annealing is reported and defect origin is discussed.
29.	Hall, TS, et al. (författare) Obstructive sleep apnea: no independent association to troponins 2014 Ingår i: Sleep & breathing = Schlaf & Atmung. - : Springer Science and Business Media LLC. - 1522-1709. ; 18:2, s. 351-358 Tidskriftsartikel (refereegranskat)
30.	Hammarstrand, Casper, 1990, et al. (författare) Higher glucocorticoid replacement doses are associated with increased mortality in patients with pituitary adenoma 2017 Ingår i: European Journal of Endocrinology. - 1479-683X. ; 177:3, s. 251-256 Tidskriftsartikel (refereegranskat)abstract OBJECTIVE: Patients with secondary adrenal insufficiency (AI) have an excess mortality. The objective was to investigate the impact of the daily glucocorticoid replacement dose on mortality in patients with hypopituitarism due to non-functioning pituitary adenoma (NFPA). METHODS: Patients with NFPA were followed between years 1997 and 2014 and cross-referenced with the National Swedish Death Register. Standardized mortality ratio (SMR) was calculated with the general population as reference and Cox-regression was used to analyse the mortality. RESULTS: The analysis included 392 patients (140 women) with NFPA. Mean±s.d. age at diagnosis was 58.7±14.6 years and mean follow-up was 12.7±7.2 years. AI was present in 193 patients, receiving a mean daily hydrocortisone equivalent (HCeq) dose of 20±6mg. SMR (95% confidence interval (CI)) for patients with AI was similar to that for patients without, 0.88 (0.68-1.12) and 0.87 (0.63-1.18) respectively. SMR was higher for patients with a daily HCeq dose of >20mg (1.42 (0.88-2.17)) than that in patients with a daily HCeq dose of 20mg (0.71 (0.49-0.99)), P=0.017. In a Cox-regression analysis, a daily HCeq dose of >20mg was independently associated with a higher mortality (HR: 1.88 (1.06-3.33)). Patients with daily HCeq doses of ≤20mg had a mortality risk comparable to patients without glucocorticoid replacement and to the general population. CONCLUSION: Patients with NFPA and AI receiving more than 20mg HCeq per day have an increased mortality. Our data also show that mortality in patients substituted with 20mg HCeq per day or less is not increased. © 2017 European Society of Endocrinology.
31.	Hanssen, K. E., et al. (författare) The effect of strength training volume on satellite cells, myogenic regulatory factors, and growth factors 2013 Ingår i: Scandinavian Journal of Medicine and Science in Sports. - Hoboken, USA : Wiley-Blackwell. - 0905-7188 .- 1600-0838. ; 23:6, s. 728-739 Tidskriftsartikel (refereegranskat)abstract The aim of this work was to study the effect of training volume on activation of satellite cells. Healthy untrained men were randomly assigned into two groups. The 3L-1UB group (n = 10) performed three-set leg exercises and single-set upper body exercises, and the 1L-3UB group (n = 11) performed single-set leg exercises and three-set upper body exercises. Both groups performed three sessions (80-90 min) per week for 11 weeks. Biopsies were taken from m. vastus lateralis and m. trapezius. The number of satellite cells, satellite cells positive for myogenin and MyoD, and the number of myonuclei were counted. Homogenized muscle was analyzed for myogenin and MyoD, and extracted ribonucleic acid (RNA) was monitored for selected growth factor transcripts. Knee extensor strength increased more in the 3L-1UB group than in the 1L-3UB group (48 ± 4% vs 29 ± 4%), whereas the strength gain in shoulder press was similar in both training groups. The number of satellite cells in m. vastus lateralis increased more in the 3L-1UB group than in the 1L-3UB group. The number of myonuclei increased similarly in both groups. The messenger RNA expression of growth factors peaked after 2 weeks of training. In conclusion, increasing training volume enhanced satellite cell numbers in the leg muscle, but not in the upper body muscle.
32.	Andersson, Roland, et al. (författare) Akut gastroenterologi i fokus 2002 Ingår i: Svensk kirurgi. - 0346-847X. ; 60, s. 336-336 Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
33.	Azarov, A. Yu., et al. (författare) Dopant distribution in high fluence Fe implanted GaN 2008 Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 104:5, s. 053509- Tidskriftsartikel (refereegranskat)abstract Undoped wurtzite GaN epilayers implanted at room temperature with 50-325 keV Fe+ ions in the fluence range of 10(15)-10(17) ions/cm(2) are studied by a combination of Rutherford backscattering/channeling spectrometry and time-of-flight elastic recoil detection analysis. The results show an enhanced Fe concentration close to the surface for high ion fluences (>1 X 10(16) cm(-2)), which increases with the ion fluence. Annealing at 800 degrees C for 30 min has a negligible effect on the Fe distribution in the material bulk, but further increases the Fe concentration near the surface. Our findings can be understood by radiation enhanced diffusion during ion implantation and an increased Fe diffusivity in the near surface region with distorted stoichiometry, or formation of secondary phases and precipitates for the highest doses. The simulation shows that, if enhanced diffusion is the reason for Fe buildup at the surface, both radiation enhanced diffusion and the thermal diffusion of Fe atoms near the surface, need to be at least five times larger than ordinary bulk diffusion to explain the increased Fe surface concentration.
34.	Blank, T. V., et al. (författare) Temperature dependence of the photoelectric conversion quantum efficiency of 4H-SiC Schottky UV photodetectors 2005 Ingår i: Semiconductor Science and Technology. - : IOP Publishing. - 0268-1242 .- 1361-6641. ; 20:8, s. 710-715 Tidskriftsartikel (refereegranskat)abstract Ultraviolet Schottky photodetectors based on n-4H-SiC (N-d - N-a = 4 x 10(15) cm(-3)) epitaxial layers of high purity have been fabricated. Their spectral sensitivity range is 3.2-5.3 eV peaking at 4.9 eV (quantum efficiency is about similar to 0.3 electron/photon), which is close to the bactericidal ultraviolet radiation spectrum. The temperature dependence of the quantum efficiency of 4H-SiC Schottky structure has been investigated to determine the temperature stability and the mechanism of the photoelectric conversion process. At low temperatures (78-175 K) the quantum efficiency increases with increasing temperature for all photon energy values and then tends to saturate. We suppose that some imperfections in the space-charge region act as traps that capture both photoelectrons and photoholes. After some time the trapped electron-hole pairs recombine due to the tunnelling effect. At high temperatures (more than 300 K), the second enhancement region of the quantum efficiency is observed in the photon energy range of 3.2-4.5 eV. It is connected with a phonon contribution to indirect optical transitions between the valence band and the M-point of the conduction band. When the photon energy is close to a direct optical transition threshold this enhancement region disappears. This threshold is estimated to be 4.9 eV. At photon energies more than 5 eV a drastic fall of the quantum efficiency has been observed throughout the temperature interval. We propose that in this case the photoelectrons and photoholes are bound to form hot excitons in the space-charge region due to the Brillouin zone singularity, and do not contribute to the following photoelectroconversion process.
35.	Blank, T. V., et al. (författare) Temperature dependence of the quantum efficiency of 4H-SiC-Based Schottky photodiodes 2001 Ingår i: Technical physics letters. - : Pleiades Publishing Ltd. - 1063-7850 .- 1090-6533. ; 27:9, s. 776-778 Tidskriftsartikel (refereegranskat)abstract Using metal-semiconductor structures based on a pure epitaxial layer of n-4H-SiC (N-d - N-a = 4 x 10(15) cm(-3)), UV photodetectors were created with a maximum photosensitivity at 4.9 eV and a quantum efficiency up to 0.3 el/ph. The photosensitivity spectrum of the base structure is close to the spectrum of bactericidal action of the UV radiation. For photon energies in the 3.4 - 4.7 eV range, the quantum efficiency of the photoelectric conversion exhibits rapid growth with the temperature above 300 K, which is explained by the participation of photons in indirect interband transitions. This growth is not manifested when the photon energy is close to the threshold energy of direct optical transitions in the nondirect-bandgap semiconductor, which allows the threshold energy to be evaluated (similar to4.9 eV).
36.	Borseth, T. M., et al. (författare) Annealing study of Sb+ and Al+ ion-implanted ZnO 2005 Ingår i: Superlattices and Microstructures. - : Elsevier BV. - 0749-6036 .- 1096-3677. ; 38:4-6, s. 464-471 Tidskriftsartikel (refereegranskat)abstract In this work we have studied diffusion and electrical activation in Al+ and Sb+ implanted ZnO samples using secondary ion mass spectrometry (SIMS), scanning spreading resistance microscopy (SSRM) and scanning capacitance microscopy (SCM). The samples were hydrothermally grown and post-implant annealing was performed at 800, 900 and 1000 degrees C in pure oxygen atmosphere, After each annealing step the samples were characterized with SSRM/SCM and SIMS. The thermal treatments did not induce any significant impurity redistribution as measured by SIMS, while electrical compensation is observed by SSRM/SCM for the Sb-implanted sample yielding less n-doping than in the as-grown samples. In the Al-implanted samples, an increase in carrier concentration is observed; we ascribe this to Al-related donors and possibly interstitial lithium, a common residual impurity in the samples that have been shown to be very mobile by SIMS.
37.	Chulapakorn, Thawatchart, 1988-, et al. (författare) MeV ion irradiation effects on the luminescence properties of Si-implanted SiO2-thin films 2016 Ingår i: Physica Status Solidi (C) Current Topics in Solid State Physics. - : Wiley-VCH Verlagsgesellschaft. - 1862-6351 .- 1610-1634 .- 1610-1642. ; 13:10-12, s. 921-926 Tidskriftsartikel (refereegranskat)abstract The effects of MeV heavy ion irradiation at varying fluence and flux on excess Si, introduced in SiO2 by keV ion implantation, are investigated by photoluminescence (PL). From the PL peak wavelength (λ) and decay lifetime (τ), two PL sources are distinguished: i) quasi-direct recombination of excitons of Si-nanoparticles (SiNPs), appearing after thermal annealing (λ > 720 nm, τ ∼ μs), and ii) fast-decay PL, possibly due to oxide-related defects (λ ∼ 575-690 nm, τ ∼ ns). The fast-decay PL (ii) observed before and after ion irradiation is induced by ion implantation. It is found that this fast-decay luminescence decreases for higher irradiation fluence of MeV heavy ions. After thermal annealing (forming SiNPs), the SiNP PL is reduced for samples irradiated by MeV heavy ions but found to stabilize at higher level for higher irradiation flux; the (ii) band vanishes as a result of annealing. The results are discussed in terms of the influence of electronic and nuclear stopping powers.
38.	Damgaard, T., et al. (författare) Coordinating supply chains, interfacing production networks, and creating markets : the case of global integrators and sourcing in China 2005 Ingår i: Proceedings of the 21st IMP-conference, Rotterdam, September 1-3, 2005. Konferensbidrag (övrigt vetenskapligt/konstnärligt)
39.	Domeika, Marius, et al. (författare) Guidelines for the laboratory diagnosis of Chlamydia trachomatis infections in East European countries 2009 Ingår i: Journal of the European Academy of Dermatology and Venereology. - : Wiley. - 0926-9959 .- 1468-3083. ; 23:12, s. 1353-1363 Forskningsöversikt (refereegranskat)abstract The present guidelines aim to provide comprehensive information regarding the laboratory diagnosis of infections caused by Chlamydia trachomatis in East European countries. These recommendations contain important information for laboratory staff working with sexually transmitted infections (STIs) and/or STI-related issues. Individual East European countries may be required to make minor national adjustments to these guidelines as a result of lack of accessibility to some reagents or equipment, or laws in a specific country.
40.	Domeika, M, et al. (författare) Prevalence of Chlamydia trachomatis infections in women attending six women's healthcare units in Kaunas, Lithuania 2001 Ingår i: Sex Transm Infect. ; 77, s. 459- Tidskriftsartikel (refereegranskat)
41.	Fredriksson, F., et al. (författare) Haemangiopericytoma presenting with acute intracerebral haemorrhage - a case report and literature review 2013 Ingår i: Acta Oncologica. - : Informa UK Limited. - 0284-186X .- 1651-226X. ; 52:4, s. 753-758 Tidskriftsartikel (refereegranskat)abstract Background. Intracranial haemangiopericytoma (HPC), a rare malignant tumour, should be
42.	Hagg, S, et al. (författare) The Stockholm atherosclerosis gene expression (stage) study - Multiorgan expression profiling in well-characterized coronary artery disease patients 2006 Ingår i: ATHEROSCLEROSIS SUPPLEMENTS. - 1567-5688. ; 7:3, s. 357-357 Konferensbidrag (övrigt vetenskapligt/konstnärligt)
43.	Hall, TS, et al. (författare) Changes in diagnosing non-ST-segment elevation myocardial infarction after the introduction of a new high-sensitivity cardiac troponin T assay: a single-centre experience 2012 Ingår i: Clinical laboratory. - 1433-6510. ; 58:9-10, s. 1029-1036 Tidskriftsartikel (refereegranskat)
44.	Hall, TS, et al. (författare) Myeloid-related protein-8/14 and C-reactive protein in individuals evaluated for obstructive sleep apnea 2014 Ingår i: Sleep medicine. - : Elsevier BV. - 1878-5506 .- 1389-9457. ; 15:7, s. 762-768 Tidskriftsartikel (refereegranskat)
45.	Hallen, M, et al. (författare) A comparison of two different assays for determining S-100B in serum and urine 2008 Ingår i: Clinical chemistry and laboratory medicine. - 1434-6621. ; 46:7, s. 1025-1029 Tidskriftsartikel (refereegranskat)
46.	Hallen, M, et al. (författare) S-100B in serum and urine after traumatic head injury in children 2010 Ingår i: The Journal of trauma. - 1529-8809. ; 69:2, s. 284-289 Tidskriftsartikel (refereegranskat)
47.	Hallen, T., et al. (författare) Cranioplasty without Periosteal Dissection Reduces Blood Loss in Pi-Plasty Surgery for Sagittal Synostosis 2017 Ingår i: Pediatric Neurosurgery. - : S. Karger AG. - 1016-2291 .- 1423-0305. ; 52:4, s. 284-287 Tidskriftsartikel (refereegranskat)abstract Background/Aims: Cranioplasty is often accompanied by a substantial oozing bleeding from the bone surface and bone edges. Our aim was to measure if strict subgaleal dissection without any periosteal release reduces blood loss during pi-plasty surgery for sagittal synostosis. Method: A group of 32 children who underwent pi-plasty surgery at the Sahlgrenska University Hospital between 2010 and 2014 for premature sagittal synostosis with traditional subgaleal dissection combined with incision and release of the periosteum adjacent to the osteotomy lines was compared to a group of 7 children who underwent pi-plasty with strict subgaleal dissection and osteotomy through the bone with the periosteum attached. Information about blood loss and body weight was extracted from medical records. Results: The blood loss in the group of 7 children with strict subgaleal dissection was 102 +/- 86 mL (mean +/- SD) (10 +/- 7 mL/kg) compared to 320 +/- 119 mL (32 +/- 12 mL/kg) in the control group with traditional periosteal release (p < 0.001). Conclusion: Intact periosteum at the osteotomy lines significantly reduces blood loss in pi-plasty surgery for sagittal synostosis. The mechanism is likely because of preserved veins between the bone surface and periosteum.
48.	Intarasiri, S., et al. (författare) Characterization of the crystalline quality of B-SiC formed by ion beam synthesis 2006 Ingår i: Nucl. Instr. Meth. in Phys. Res.. ; :249, s. 851-855 Tidskriftsartikel (refereegranskat)
49.	Intarasiri, S., et al. (författare) Characterization of the crystalline quality of beta-SiC formed by ion beam synthesis 2006 Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 249, s. 851-855 Tidskriftsartikel (refereegranskat)abstract The ion beam synthesis (IBS) technique is applied to form crystalline silicon carbide (SiC) for future optoelectronics applications. Carbon ions at 80 and 40 keV were implanted into (100) high-purity p-type silicon wafers at room temperature and 400 degrees C, respectively, to doses in excess of 10(17) ions/cm(2). Subsequent thermal annealing of the implanted samples was performed in a vacuum furnace at temperatures of 800, 900 and 1000 degrees C, respectively. Elastic recoil detection analysis was used to investigate depth distributions of the implanted ions and infrared transmittance (IR) measurement was used to characterize formation of SiC in the implanted Si substrate. Complementary to IR, Raman scattering measurements were also carried out. Levels of the residual damage distribution of the samples annealed at different temperatures were compared with that of the as-implanted one by Rutherford backscattering spectrometry (RBS) in the channeling mode. The results show that C-ion implantation at the elevated temperature, followed by high-temperature annealing, enhances the synthesis of crystalline SiC.
50.	Intarasiri, S., et al. (författare) RBS and ERDA determinations of depth distributions of high-dose carbon ions implanted in silicon for silicon-carbide synthesis study 2006 Ingår i: Nuclear Instruments and Methods in Physics Research Section B. - : Elsevier BV. - 0168-583X .- 1872-9584. ; 249, s. 859-864 Tidskriftsartikel (refereegranskat)abstract For ion beam synthesis of silicon carbide (SiC), a knowledge of the depth distribution of implanted carbon ions in silicon is crucial for successful development. Based on its simplicity and availability, we selected Rutherford backscattering spectrometry (RBS) as an analysis technique for this purpose. A self-developed computer program dedicated to extract depth profiles of lighter impurities in heavier matrix is established. For control, calculated results are compared with an other ion beam analysis (IBA) technique superior for studying lighter impurity in heavier substrate i.e. elastic recoil detection analysis (ERDA). The RBS was performed with a 1.7-MV Tandetron accelerator using He2+ as the probe ions. The ERDA was performed with a 5-MV Pelletron accelerator using I8+ as the probe ions. This work shows that the RBS-extracted data had no significant deviations from those of ERDA and simulations by SRIM2003 and SIMPL computer codes. We also found that annealing at temperatures as high as 1000 degrees C had quite limited effect on the redistribution of carbon in silicon.

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