| 731. |
- Mikhaylushkin, A. S., et al.
(författare)
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Structural and magnetic properties of FeHx (x=0.25; 0.50; 0.75)
- 2006
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Ingår i: AIP Conf. Proc.. - : AIP. - 0735403295 - 9780735403291 ; , s. 161-167
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Konferensbidrag (refereegranskat)abstract
- The structural and magnetic properties of the FeHx (x=0.25; 0.50; 0.75) compounds have been studied using the projector augmented wave (PAW) method within the generalized gradient approximation (GGA). We compare the hcp, dhcp and fcc structures and find that for the considered concentrations of hydrogen the hcp structure is most stable in a wide pressure range. The magnetic behavior of iron is crucially influenced by hydrogen. In particular, the local moment on a Fe atom depends on the number of hydrogen atoms in the atom surroundings. Iron atoms, which are crystallographically equivalent in their original structures (hcp, fcc) but have different number of hydrogen neighbors, are shown to have different local magnetic moments. This finding suggests that the experimental observations of two magnetic moments in iron hydride can be explained by nonstoichiometry of the hydride and might not be a direct evidence for the presence of the dhcp phase.
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| 732. |
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| 733. |
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| 734. |
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| 735. |
- Mountzias, Alexander, et al.
(författare)
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Inflammatory response markers and survival prediction in patients with renal cell carcinoma
- 2022
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Ingår i: Scandinavian journal of urology. - : Taylor & Francis Group. - 2168-1805 .- 2168-1813. ; 56:1, s. 47-52
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Many factors influence the clinical course of patients with renal cell carcinoma (RCC). The most commonly used prognostic indicators are TNM stage, tumor size and RCC type. In this study we evaluated the prognostic relevance of albumin and C-reactive protein (CRP), and Glasgow Prognostic scores (GPS), in patients with primary RCC.Methods: We retrospectively reviewed all patients surgically treated for primary RCC between 1982 and 2018 at Umeå University Hospital. There were 872 patients, 527 males and 345 females. Data on albumin, CRP and GPS points before surgery were extracted, as well as TNM stage, RCC type, tumor grade, tumor size, and primary treatment. The patients were followed for recurrence and death for up to 37.2 years. We used Kaplan-Meier estimators, Cox-proportional hazards models, to assess the relation between potentially prognostic indicators and RCC-specific death, and all-cause mortality.Results: Of 872 patients, 708 had clear-cell RCC, 114 papillary RCC, 36 chromophobe RCC and 9 undefined RCC type while 5 patients had missing RCC type data. Except that, women had a significantly (p = 0.002) lower proportion of pRCC, no difference in RCC types and levels of albumin and CRP was observed between genders. Albumin, CRP, and GPSs were all univariately associated to RCC survival (p < 0.001). CRP demonstrated the strongest prognostic association (HR 1.67 95% Ci (1.53–1.83, overriding both albumin and GPS in multivariable models. The AUC for CRP was 0.77 (95% CI: 0.74-0.80).Conclusion: Elevated CRP, low albumin levels, and elevated GPSs were all associated to poor survival in patients with RCC, Only CRP remained independent in multivariate analysis.
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| 736. |
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| 737. |
- Muller, David C., et al.
(författare)
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Circulating 25-Hydroxyvitamin D-3 in Relation to Renal Cell Carcinoma Incidence and Survival in the EPIC Cohort
- 2014
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Ingår i: American Journal of Epidemiology. - : Oxford University Press (OUP). - 0002-9262 .- 1476-6256. ; 180:8, s. 810-820
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Tidskriftsartikel (refereegranskat)abstract
- Normal renal function is essential for vitamin D metabolism, but it is unclear whether circulating vitamin D is associated with risk of renal cell carcinoma (RCC). We assessed whether 25-hydroxyvitamin D-3 (25(OH)D-3) was associated with risk of RCC and death after RCC diagnosis in the European Prospective Investigation into Cancer and Nutrition (EPIC). EPIC recruited 385,747 participants with blood samples between 1992 and 2000. The current study included 560 RCC cases, 557 individually matched controls, and 553 additional controls. Circulating 25(OH)D-3 was assessed by mass spectrometry. Conditional and unconditional logistic regression models were used to calculate odds ratios and 95% confidence intervals. Death after RCC diagnosis was assessed using Cox proportional hazards models and flexible parametric survival models. A doubling of 25(OH)D-3 was associated with 28% lower odds of RCC after adjustment for season of and age at blood collection, sex, and country of recruitment (odds ratio = 0.72, 95% confidence interval: 0.60, 0.86; P = 0.0004). This estimatewas attenuated somewhat after additional adjustment for smoking status at baseline, circulating cotinine, body mass index (weight (kg)/height (m)(2)), and alcohol intake (odds ratio = 0.82, 95% confidence interval: 0.68, 0.99; P = 0.038). There was also some indication that both low and high 25(OH)D-3 levels were associated with higher risk of death from any cause among RCC cases.
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| 738. |
- Music, Denis
(författare)
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Boron Suboxide Based Thin Films
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Boron suboxide (BOx, x< 1.5) is a promising material for a wide range of applications. The elastic modulus (E) of 473 GPa has been reported for crystalline BO0.17, which tends to exhibit ultra-low friction as a direct consequence of boric acid (H3BO3) formation. When thin films are formed, they are reported to be amorphous with E<300 GPa. The objective of this work was to understand the formation of crystalline BOx based films. The methodology applied was to study the correlation between composition, structure, and properties of this material with experimental and theoretical means. The growth technique used was reactive RF magnetron sputtering in an Ar/O2 ambient and the characterization included a wide range of analytical techniques. The theoretical tools employed were classical molecular dynamics and ab initio calculations. Two distinctive approaches were used to find a pathway for crystalline film synthesis: firstly extensive ion bombardment during film growth and secondly control of chemical composition as well as quantum design. When films were bombarded with Ar+ ions, they remained amorphous and E (55-248 GPa) was found to be a strong function of film density (p=1.5-2.3 g/cm3) at constant chemical composition. On the other hand, when the chemical composition was varied, the behavior of E was more complex. Firstly, it was established that the role of O in amorphous films is different than in crystalline BO0.17, where O shortens the chemical bonds. As x in BOx increased from 0.08 to 0.60, the fraction of long B-O bonds increased resulting in E decreasing from 273 to 15 GPa. Secondly, H incorporation (up to 4.7 at.%) reduced E, most likely due to a H3BO3 formation. Thirdly, C incorporation (up to 0.6 at.%) shortened the average bond length, increasing p and E, but decreasing the relative dielectric constant (19.2-0.9). Based on ab initio calculations investigating the effect of alloying metals with BO0.17, the formation of a crystalline Y containing phase was predicted. This so-called BOY phase was calculated to be 0.36 eV/atom more stable than BO0.17 and B-B were 4.9% shorter. Experimentally, this phase was synthesized and properties were determined. The measured E of 316 GPa was consistent with the prediction based on elastic constants. Moreover, the BOY phase was found to be thermally stable at temperatures up to 1000 °C and exhibited a resistivity of 3.8 Ωcm.
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| 739. |
- Månsson, Kristofer
(författare)
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Essays on Nonlinearities and Time Scales in Macroeconomics and Finance
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis consists of four chapters concerning the topics of nonlinearities and time scales in economics. The focus is on market frictions and price rigidities that may cause nonlinearities and different relationships between economic variables over time. It also focuses on applying robust econometrical methods. Chapter two evaluates the size and power of some nonlinear tests for panel unit roots in the presence of cross-sectional dependency and spatial dependency. Based on the simulated results some robust tests for nonlinear panel unit roots have been found.Chapter three applies robust linear and nonlinear tests for panel unit roots in order to investigate the purchasing power parity theory in developing regions. The main finding is that nonlinearities is an important phenomenon in the real effective exchange rates in developing regions and that support for several regions may be found by applying the nonlinear panel unit root test. Chapter four investigates if positive asymmetric price transmission (APT) exists in the Swedish mortgage loan market. Here robust quantile regression is used on data for the Swedish SEB bank. The main contribution is that positive APT effects are found, which implies that there is a higher propensity for the bank to rapidly increase its mortgage interest rates for customers following an increase in its borrowing costs, compared with the propensity for the bank to decrease its customers’ mortgage rates subsequent to a corresponding borrowing cost decrease.Chapter five investigates the causal relations between exchange rates and interest rate differentials using wavelets. Also the sign of the relationship between the two variables is studied using impulse response functions. The data used is for seven country pairs in which Sweden is included in all of the different combinations. In this chapter one key empirical finding is that the causal relationship between the two variables becomes stronger as the time scale increases. The other key empirical finding is that more evidence of negative relationships is found at the shorter time scales and more positive relationships at the longer time scales.
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| 740. |
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