| 11. |
- Aktas, A, et al.
(författare)
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Search for single top quark production in ep collisions at HERA
- 2004
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Ingår i: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 33:1, s. 9-22
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Tidskriftsartikel (refereegranskat)abstract
- A search for single top quark production is performed in e(+/-) pcollisions at HERA. The search exploits data corresponding to an integrated luminosity of 118.3 pb(-1). A model for the anomalous production of top quarks in a flavour changing neutral current process involving a tugamma coupling is investigated. Decays of top quarks into a b quark and a W boson are considered in the leptonic and the hadronic decay channels of the W. Both a cut-based analysis and a multivariate likelihood analysis are performed to discriminate anomalous top quark production from Standard Model background processes. In the leptonic channel, 5 events are found while 1.31 +/- 0.22 events are expected from the Standard Model background. In the hadronic channel, no excess above the expectation for Standard Model processes is found. These observations lead to a cross section (ep --> e t X) = 0.29(-0.14)(+0.15) pb at roots = 319 GeV. Alternatively, assuming that the observed events are due to a statistical fluctuation, upper limits of 0.55 pb on the anomalous top production cross section and of 0.27 on the tugamma coupling k(tugamma) are established at the 95% confidence level.
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| 12. |
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| 13. |
- Benisty, H., et al.
(författare)
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Low-loss photonic-crystal and monolithic InP integration : Bands, bends, lasers, filters
- 2004
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Ingår i: Photonic Crystal Materials and Devices II. - : SPIE - International Society for Optical Engineering. - 0819452688 ; , s. 119-128
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Konferensbidrag (refereegranskat)abstract
- Practical realizations of 2D (planar) photonics crystal (PhC) are either on a membrane or etched through a conventional heterostructure. While fascinating objects can emerge from the first approach, only the latter approach lends itself to a progressive integration of more compact PhC's towards monolithic PICs based on InP. We describe in this talk the various aspects from technology to functions and devices, as emerged from the European collaboration "PCIC". The main technology tour de force is deep-etching with aspect ratio of about 10 and vertical sidewall, achieved by three techniques (CAIBE, ICP-RIE, ECR-RIE). The basic functions explored are bends, splitters/combiners, mirrors, tapers, and the devices are filters and lasers. At the end of the talk, I will emphasize some positive aspects of "broad" multimode PhC waveguides, in view of compact add-drop filtering action, notably.
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| 14. |
- Briggs, Ewan P, et al.
(författare)
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Formation of highly adherent nano-porous alumina on Ti-based substrates : a novel bone implant coating
- 2004
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Ingår i: Journal of materials science. Materials in medicine. - 0957-4530 .- 1573-4838. ; 15:9, s. 1021-1029
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Tidskriftsartikel (refereegranskat)abstract
- Thin, nano-porous, highly adherent layers of anodised aluminium formed on the surface of titanium alloys are being developed as coatings for metallic surgical implants. The layers are formed by anodisation of a 1–5 m thick layer of aluminium which has been deposited on substrate material by electron beam evaporation. The surface ceramic layer so produced is alumina with 6–8 wt % phosphate ions and contains 5×108 cm–2 pores with a 160 nm average diameter, running perpendicular to the surface. Mechanical testing showed the coatings'' shear and tensile strength to be at least 20 and 10 MPa, respectively. Initial cell/material studies show promising cellular response to the nano-porous alumina. A normal osteoblastic growth pattern with cell number increasing from day 1 to 21 was shown, with slightly higher proliferative activity on the nano-porous alumina compared to the Thermanox control. Scanning electron microscopy (SEM) examination of the cells on the porous alumina membrane showed normal osteoblast morphology. Flattened cells with filopodia attaching to the pores and good coverage were also observed. In addition, the pore structure produced in these ceramic coatings is expected to be suitable for loading with bioactive material to enhance further their biological properties.
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| 15. |
- Burmeister, F., et al.
(författare)
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A study of the inner-valence ionization region in HCl and DCl
- 2004
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Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 37:6, s. 1173-1183
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Tidskriftsartikel (refereegranskat)abstract
- An in-depth photoionization study of the inner-valence electrons in HCl and DCl has been performed using synchrotron radiation. A series of photoelectron spectra of HCl were obtained at a resolution of 23 meV over the binding energy range 25-30.5 eV at various excitation energies and at two different electron collection angles relative to the plane of polarization of the undulator radiation. In addition, photoelectron spectra of DCl were recorded at two different excitation energies. These spectra were compared directly with the threshold photoelectron spectra of HCl and DCl that were recorded previously under similar resolution conditions (similar to30 meV). This comparative study reveals new information on the nature of the numerous band systems observed in this binding energy region. In addition, we present the experimental confirmation of the theoretical prediction given by Andersson et al (2001 Phys. Rev. A 65 012705) that a vibrational progression showing interference structure would appear in the main inner-valence ionization band in the photoelectron spectrum of DCl at a resolution of 10 meV.
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| 16. |
- Ejerhed, L., et al.
(författare)
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The effect of anterior cruciate ligament surgery on bone mineral in the calcaneus: a prospective study with a 2-year follow-up evaluation
- 2004
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Ingår i: Arthroscopy. - 1526-3231. ; 20:4, s. 352-9
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The goal of this study was to evaluate the effect of anterior cruciate ligament (ACL) reconstruction on the bone mineral area mass (BMA) in the calcaneus on the injured and noninjured sides. TYPE OF STUDY: A prospective cohort study with sequential assessments of bone mineral in the calcaneus before and after ACL reconstruction. METHODS: Thirty-four consecutive patients with a unilateral ACL rupture underwent arthroscopic reconstruction using patellar tendon autografts. The BMA was assessed bilaterally in the calcaneus using a gamma camera according to the dual-energy photon absorptiometry technique, before surgery and after 6 and 26 months. RESULTS: Thirty-one of 34 patients (20 men and 11 women) underwent all BMA measurements. The median age at index surgery was 27 (16 to 50) years, and the reconstruction was performed 12 (2 to 192) months after the injury. The median preoperative Tegner activity level increased from 3 (2 to 8) to 7 (2 to 9) at 26 months (P <.0001). The BMA in the calcaneus on both the injured and noninjured side decreased by 16% and 17% respectively from the preoperative measurement to the 26-month control (P =.0014; P =.0006). On all occasions, the BMA was lower on the injured side than on the noninjured side (P =.012). CONCLUSIONS: Patients with a unilateral ACL rupture had a lower BMA in the calcaneus on the injured side compared with the noninjured side. Although patients increased activity levels after reconstruction, the BMA in the calcaneus decreased on both the injured and the noninjured side up to 2 years after surgery. LEVEL OF EVIDENCE: Level II-1, prospective cohort study.
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| 17. |
- Karlsson, Håkan K R, et al.
(författare)
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Branched-chain amino acids increase p70S6k phosphorylation in human skeletal muscle after resistance exercise.
- 2004
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Ingår i: American Journal of Physiology. Endocrinology and Metabolism. - : American Physiological Society. - 0193-1849 .- 1522-1555. ; 287:1, s. E1-7
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Tidskriftsartikel (refereegranskat)abstract
- The aim of the study was to investigate the effect of resistance exercise alone or in combination with oral intake of branched-chain amino acids (BCAA) on phosphorylation of the 70-kDa S6 protein kinase (p70(S6k)) and mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (ERK1/2), and p38 MAPK in skeletal muscle. Seven male subjects performed one session of quadriceps muscle resistance training (4 x 10 repetitions at 80% of one repetition maximum) on two occasions. In a randomized order, double-blind, crossover test, subjects ingested a solution of BCAA or placebo during and after exercise. Ingestion of BCAA increased plasma concentrations of isoleucine, leucine, and valine during exercise and throughout recovery after exercise (2 h postexercise), whereas no change was noted after the placebo trial. Resistance exercise led to a robust increase in p70(S6k) phosphorylation at Ser(424) and/or Thr(421), which persisted 1 and 2 h after exercise. BCAA ingestion further enhanced p70(S6k) phosphorylation 3.5-fold during recovery. p70(S6k) phosphorylation at Thr(389) was unaltered directly after resistance exercise. However, during recovery, Thr(389) phosphorylation was profoundly increased, but only during the BCAA trial. Furthermore, phosphorylation of the ribosomal protein S6 was also increased in the recovery period only during the BCAA trial. Exercise led to a marked increase in ERK1/2 and p38 MAPK phosphorylation, which was completely suppressed upon recovery and unaltered by BCAA. In conclusion, BCAA, ingested during and after resistance exercise, mediate signal transduction through p70(S6k) in skeletal muscle.
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| 18. |
- Ristinmaa Sörensen, Stacey, et al.
(författare)
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Application of an atomic relaxation model for the interpretation of O1s to Rydberg excited Auger electron spectra of molecular oxygen
- 2004
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Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 398:1-3, s. 168-174
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Tidskriftsartikel (refereegranskat)abstract
- Resonant and normal Auger electron spectra associated with an O1s initial vacancy of the O-2 molecule have been recorded using photon energies of 541.80, 541.97 and 650 eV. The resonant Auger spectra obtained at 541.80 and 541.97 eV are interpreted as composed essentially of two characteristic parts, one between 10 and 35 eV binding energy reminiscent to direct photoionisation, and another, above 35 eV, associated primarily with spectator decay of the intermediate core-hole state. The spectra above 35 eV owe some similarity to the ordinary Auger electron spectrum recorded at 650 eV, and an interpretation is made in terms of Rydberg series in the cation converging towards the dicationic ionisation limits. The interpretation is based on a relaxation model introduced earlier for atomic resonant Auger spectra. The assignments of the resonant spectra assume that the relevant intermediate neutral states at 541.80 and 541.97 eV governing the Auger decay are essentially the v = 0 and 1 vibrational components of the (O1s) ((4)Sigma(u)(-)) 4psigma Rydberg state. Arguments for this interpretation are given.
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| 19. |
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| 20. |
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