| 51. |
- Ahlund, John, et al.
(författare)
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Molecular growth determined by surface domain patterns
- 2008
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 112:17, s. 6887-6890
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Tidskriftsartikel (refereegranskat)abstract
- The growth of iron phthalocyanine (FePc) on InSb(001) c(8 x 2) at submonolayer coverage has been investigated with scanning tunneling microscopy (STM). FePc adsorbs flat centered on the In rows both at 70 K and at room temperature (RT). However, the shapes of the two-dimensional molecular islands are fundamentally different; while the RT growth results in chainlike structures along the [I 10] direction, as already observed for other Pc's adsorbed on the same surface, the islands are prolonged along [110], i.e., perpendicular to the substrate rows, at 70 K. These observations are explained on the basis of a recently observed new surface phase at low temperature, resulting in structural domains on the surface. The molecular growth front follows the propagating domain boundary that freezes at low temperature.
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| 52. |
- Ahnesjö, Anders, et al.
(författare)
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Beam modeling and verification of a photon beam multisource model.
- 2005
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Ingår i: Medical Physics. - : Wiley. - 0094-2405. ; 32:6, s. 1722-37
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Tidskriftsartikel (refereegranskat)abstract
- Dose calculations for treatment planning of photon beam radiotherapy require a model of the beam to drive the dose calculation models. The beam shaping process involves scattering and filtering that yield radiation components which vary with collimator settings. The necessity to model these components has motivated the development of multisource beam models. We describe and evaluate clinical photon beam modeling based on multisource models, including lateral beam quality variations. The evaluation is based on user data for a pencil kernel algorithm and a point kernel algorithm (collapsed cone) used in the clinical treatment planning systems Helax-TMS and Nucletron-Oncentra. The pencil kernel implementations treat the beam spectrum as lateral invariant while the collapsed cone involves off axis softening of the spectrum. Both algorithms include modeling of head scatter components. The parameters of the beam model are derived from measured beam data in a semiautomatic process called RDH (radiation data handling) that, in sequential steps, minimizes the deviations in calculated dose versus the measured data. The RDH procedure is reviewed and the results of processing data from a large number of treatment units are analyzed for the two dose calculation algorithms. The results for both algorithms are similar, with slightly better results for the collapsed cone implementations. For open beams, 87% of the machines have maximum errors less than 2.5%. For wedged beams the errors were found to increase with increasing wedge angle. Internal, motorized wedges did yield slightly larger errors than external wedges. These results reflect the increased complexity, both experimentally and computationally, when wedges are used compared to open beams.
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| 53. |
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| 54. |
- Albertsson, Maria, et al.
(författare)
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Phase II studies on docetaxel alone every third week, or weekly in combination with gemcitabine in patients with primary locally advanced, metastatic, or recurrent esophageal cancer
- 2007
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Ingår i: Medical Oncology. - : Springer Science and Business Media LLC. - 1357-0560 .- 1559-131X. ; 24:4, s. 407-412
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The purpose of these studies was to compare efficacy and toxicity of docetaxel alone with the combination of gemcitabine and docetaxel for treatment of metastatic esophageal carcinoma. PATIENTS AND METHODS: These studies enrolled patients with histopathologically verified squamous cell carcinoma or adenocarcinoma of the esophagus or cardia. Between March 1997 and June 1999, 52 patients were enrolled in the initial Phase II study (Study 1). They were scheduled for treatment with docetaxel 100 mg/m2 every third week as a 1-h infusion. The second Phase II study between September 2000 and March 2003 included 65 patients (Study II). They were given docetaxel 30 mg/m2, administered as a 30-min i.v. infusion weekly for four times, followed by 2 weeks of rest, and gemcitabine starting with a dose of 750 mg/m2 (if well-tolerated 1,000 mg/m2) on days 1 and 15, followed by 3 weeks of rest. A new cycle began on day 36. Patients were premedicated with betamethasone 8 mg p.o. on the evening before, and 8 mg i.v. 30-60 min before the docetaxel infusion. Response was confirmed by computed tomography and assessed at 12 and 24 weeks. Toxicity was assessed according to WHO scales. RESULTS: In study I, 38 out of the 52 enrolled patients were valuable. Two patients experienced complete remission (CR) (5%), 10 patients partial remission (PR) (26%), nine patients stable disease (SD) (24%), and 17 patients showed progressive disease (PD) (45%). Toxicity mainly involved leukopenia, which in some cases required hospitalization and treatment with antibiotics. In Study II, 46 out of the 65 enrolled patients (70%) were assessable. Out of these, three patients (7%) had CR, eight patients (17%) had PR, 10 patients (22%) had SD, and 25 (54%) PD. Overall response was 24% while an additional 22% showed stable disease. Toxicity mainly consisted of leucopenia and pain. CONCLUSION: Docetaxel as a single agent is active in esophageal cancer, both in treatment naive and in previously treated patients with recurrent disease. The overall response rate was 31%, with a good-safety profile. The addition of gemcitabine is well tolerated, but adds no efficacy. Weekly administration of docetaxel may be less effective. It demonstrates moderate efficacy and the doses used provide an acceptable safety profile.
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| 55. |
- Albertsson-Wikland, Kerstin, 1947, et al.
(författare)
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Dose-dependent effect of growth hormone on final height in children with short stature without growth hormone deficiency
- 2008
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : The Endocrine Society. - 0021-972X .- 1945-7197. ; 93:11, s. 4342-4350
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Tidskriftsartikel (refereegranskat)abstract
- CONTEXT: The effect of GH therapy in short non-GH-deficient children, especially those with idiopathic short stature (ISS), has not been clearly established owing to the lack of controlled trials continuing until final height (FH).OBJECTIVE: The aim of the study was to investigate the effect on growth to FH of two GH doses given to short children, mainly with ISS, compared with untreated controls.DESIGN AND SETTING: A randomized, controlled, long-term multicenter trial was conducted in Sweden.INTERVENTION: Two doses of GH (Genotropin) were administered, 33 or 67 microg/kg.d; control subjects were untreated.SUBJECTS: A total of 177 subjects with short stature were enrolled. Of these, 151 were included in the intent to treat (AllITT) population, and 108 in the per protocol (AllPP) population. Analysis of ISS subjects included 126 children in the ITT (ISSITT) population and 68 subjects in the PP (ISSPP) population.MAIN OUTCOME MEASURES: We measured FH sd score (SDS), difference in SDS to midparenteral height (diff MPHSDS), and gain in heightSDS.RESULTS: After 5.9+/-1.1 yr on GH therapy, the FHSDS in the AllPP population treated with GH vs. controls was -1.5+/-0.81 (33 microg/kg.d, -1.7+/-0.70; and 67 microg/kg.d, -1.4+/-0.86; P<0.032), vs. -2.4+/-0.85 (P<0.001); the diff MPHSDS was -0.2+/-1.0 vs. -1.0+/-0.74 (P<0.001); and the gain in heightSDS was 1.3+/-0.78 vs. 0.2+/-0.69 (P<0.001). GH therapy was safe and had no impact on time to onset of puberty. A dose-response relationship identified after 1 yr remained to FH for all growth outcome variables in all four populations.CONCLUSION: GH treatment significantly increased FH in ISS children in a dose-dependent manner, with a mean gain of 1.3 SDS (8 cm) and a broad range of response from no gain to 3 SDS compared to a mean gain of 0.2 SDS in the untreated controls.
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| 56. |
- Alfredsson, Ylvi, et al.
(författare)
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Electronic structure of a vapor-deposited metal-free phthalocyanine thin film
- 2005
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 122:21
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Tidskriftsartikel (refereegranskat)abstract
- The electronic structure of a vapor-sublimated thin film of metal-free phthalocyanine (H2Pc) is studied experimentally and theoretically. An atom-specific picture of the occupied and unoccupied electronic states is obtained using x-ray-absorption spectroscopy (XAS), core- and valence-level x-ray photoelectron spectroscopy (XPS), and density-functional theory (DFT) calculations. The DFT calculations allow for an identification of the contributions from individual nitrogen atoms to the experimental N1s XAS and valence XPS spectra. This comprehensive study of metal-free phthalocyanine is relevant for the application of such molecules in molecular electronics and provides a solid foundation for identifying modifications in the electronic structure induced by various substituent groups.
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| 57. |
- Alm, Per, 1963-
(författare)
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Stuttering and sensory gating : a study of acoustic startle prepulse inhibition
- 2006
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Ingår i: Brain and Language. - : Elsevier. - 0093-934X .- 1090-2155. ; 97:3, s. 317-321
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Tidskriftsartikel (refereegranskat)abstract
- It was hypothesized that stuttering may be related to impaired sensory gating, leading to overflow of superfluous disturbing auditory feedback and breakdown of the speech sequence. This hypothesis was tested using the acoustic startle prepulse inhibition (PPI) paradigm. A group of 22 adults with developmental stuttering were compared with controls regarding the degree of PPI. No significant differences were found between the stuttering adults and the control group; the groups showed similar means and distribution. Likewise, no relation between the degree of PPI and the effect of altered auditory feedback on stuttering was found. In summary, the results of the study indicate that there is no relation between stuttering and PPI.
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| 58. |
- Alm, Per, et al.
(författare)
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Stuttering in adults: the acoustic startle response, temperamental traits, and biological factors
- 2007
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Ingår i: Journal of Communication Disorders. - : Elsevier BV. - 0021-9924 .- 1873-7994. ; 40:1, s. 1-41
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Tidskriftsartikel (refereegranskat)abstract
- The purpose of this study was to investigate the relation between stuttering and a range of variables of possible relevance, with the main focus on neuromuscular reactivity, and anxiety. The explorative analysis also included temperament, biochemical variables, heredity, preonset lesions, and altered auditory feedback (AAF). An increased level of neuromuscular reactivity in stuttering adults has previously been reported by [Guitar, B. (2003). Acoustic startle responses and temperament in individuals who stutter. Journal of Speech Language and Hearing Research, 46, 233-240], also indicating a link to anxiety and temperament. The present study included a large number of variables in order to enable analysis of subgroups and relations between variables. Totally 32 stuttering adults were compared with nonstuttering controls. The acoustic startle eyeblink response was used as a measure of neuromuscular reactivity. No significant group difference was found regarding startle, and startle was not significantly correlated with trait anxiety, stuttering severity, or AAF. Startle was mainly related to calcium and prolactin. The stuttering group had significantly higher scores for anxiety and childhood ADHD. Two subgroups of stuttering were found, with high versus low traits of childhood ADHD, characterized by indications of preonset lesions versus heredity for stuttering. The study does not support the view that excessive reactivity is a typical characteristic of stuttering. The increased anxiety is suggested to mainly be an effect of experiences of stuttering. Learning outcomes: As a result of reading this article, the reader will be able to: (a) critically discuss the literature regarding stuttering in relation to acoustic startle, anxiety, and temperament; (b) describe the effect of calcium on neuromuscular reactivity; (c) discuss findings supporting the importance of early neurological incidents in some cases of stuttering, and the relation between such incidents and traits of ADHD or ADD; and (d) discuss the role of genetics in stuttering.
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| 59. |
- Almgren, Mats, et al.
(författare)
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Dispersed lipid liquid crystalline phases stabilized by a hydrophobically modified cellulose
- 2007
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 23:5, s. 2768-2777
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Tidskriftsartikel (refereegranskat)abstract
- Aqueous dispersions of monoolein (MO) with a commercial hydrophobically modified ethyl hydroxyethyl cellulose ether (HMEHEC) have been investigated with respect to the morphologies of the liquid crystalline nanoparticles. Only very low proportions of HMEHEC are accepted in the cubic and lamellar phases of the monoolein−water system. Due to the broad variation of composition and size of the commercial polymer, no other single-phase regions were found in the quasi-ternary system. Interactions of MO with different fractions of the HMEHEC sample induced the formation of lamellar and reversed hexagonal phases, identified from SAXD, polarization microscopy, and cryogenic TEM examinations. In excess water (more than 90 wt %) coarse dispersions are formed more or less spontaneously, containing particles of cubic phase from a size visible by the naked eye to small particles observed by cryoTEM. At high polymer/MO ratios, vesicles were frequently observed, often oligo-lamellar with inter-lamellar connections. After homogenization of the coarse dispersions in a microfluidizer, the large particles disappeared, apparently replaced by smaller cubic particles, often with vesicular attachments on the surfaces, and by vesicles or vesicular particles with a disordered interior. At the largest polymer contents no proper cubic particles were found directly after homogenization but mainly single-walled defected vesicles with a peculiar edgy appearance. During storage for 2 weeks, the dispersed particles changed toward more well-shaped cubic particles, even in dispersions with the highest polymer contents. In some of the samples with low polymer/MO ratio, dispersed particles of the reversed hexagonal type were found. A few of the homogenized samples were freeze-dried and rehydrated. Particles of essentially the same types, but with a less well-developed cubic character, were found after this treatment.
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| 60. |
- Ameur, Yacin, et al.
(författare)
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Interpolation classes and matrix monotone functions
- 2007
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Ingår i: Journal of operator theory. - 0379-4024 .- 1841-7744. ; 57:2, s. 409-427
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Tidskriftsartikel (refereegranskat)abstract
- An interpolation function of order n is a positive function -/+ on (0, infinity) such that vertical bar vertical bar -/+ (A)(1/2) T -/+ (A)-(1/2) vertical bar vertical bar <= max(vertical bar vertical bar T vertical bar vertical bar, vertical bar A(1/2)TA(-1/2) vertical bar vertical bar) for all n x ii matrices T and A such that A is positive definite. By a theorem of Donoghue, the class C-n of interpolation functions of order n coincides with the class of functions -/+ such that for each n-subset S = {lambda i}(n)(i=1)of (0,infinity) there exists a positive Pick function h on (0, co) interpolating -/+ at S. This note comprises a study of the classes C-n and their relations to matrix monotone functions of finite order. We also consider interpolation functions on general unital C*-algebras.
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