| 221. |
- Laakso, H., et al.
(author)
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Multi-point electric field observations in the high-latitude magnetosphere
- 2001
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In: European Space Agency, (Special Publication) ESA SP. ; , s. 27-34
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Conference paper (peer-reviewed)abstract
- We use multi-point electric field observations from the four Cluster satellites to study the dynamical behavior of the high-latitude magnetosphere on February 13-14, 2001, 20-02 UT. At 20:00 UT the vehicles enter the cusp where three satellites observe a 500-volt potential drop. It implies that at lower altitudes there likely exist some parallel electric fields that accelerate electrons downward and ions upward. In the following 2-3 hours the satellites move over the southern polar cap where all four satellites pass through a number of stationary, large-scale density enhancements that are associated with 200-volt potential drops. The observed events are possibly ionospheric ion outflows, triggered by geomagnetic activity. At 23:20 UT, the satellites move in the distant plasma sheet, and an hour later they have a brief encounter with the auroral region where a density cavity of a few degrees wide is observed. At the equatorward edge of the cavity, large electric fields of 100 mV/m are observed, which are likely related to an auroral arc. Similar observations are collected from all four satellites within a few minutes, but a detailed comparison reveals plenty of differences, apparently due to small spatial and temporal scale sizes. Near the perigee pass, the vehicles traverse the plasma trough near local midnight, where they all detect a ULF wave event. A preliminary analysis of the event shows that it is a resonant mode of a 120-sec period. Surprisingly the observations from four satellites are not well correlated, which suggests a short spatial and temporal scale for the event. A possible source mechanism for ULF waves at this local time sector is drifting ring current protons.
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| 222. |
- Laakso, M, et al.
(author)
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Cytokeratin 5/14-positive breast cancer: true basal phenotype confined to BRCA1 tumors
- 2005
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In: Modern Pathology. - : Elsevier BV. - 1530-0285 .- 0893-3952. ; 18:10, s. 1321-1328
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Journal article (peer-reviewed)abstract
- Breast ducts contain two types of epithelial cells, inner luminal cells and outer basal/ myoepithelial cells. These cells can be distinguished by their immunophenotype. Cytokeratins ( CKs) 8 and 18 are expressed in the luminal layer, whereas CK5/ 14 and the transcription factor p63 characterize the basal epithelial layer. We studied a population- based cohort of 288 sporadic ductal invasive cancers and found 9% positive for CK5/ 14 and 4% positive for p63. Using a highly sensitive polymer- based immunohistochemical staining, all sporadic tumors were positive for the luminal CK8/ 18, including those positive for CK5/ 14. Pairs of primary tumors and metastases ( n = 38) were always concordant for CK5/ 14 expression. The majority of the CK5/ 14- positive cases were of histologic grade III ( P = 0.0007) and steroid hormone receptor negative ( P < 0.0001). CK5/ 14 expression was inversely associated with HER- 2 oncogene amplification, but only in the subgroup of estrogen receptor-negative tumors ( P = 0.007). In a separate set of 42 hereditary breast cancers, the majority ( 78%) of the BRCA1-associated tumors, but only one of 15 BRCA2- associated tumors was positive for CK5/ 14. In contrast to sporadic CK5/ 14- positive tumors, BRCA1- associated tumors displayed less intense CK8/ 18 staining, including some truly CK5/ 14- positive CK8/ 18- negative cases. These results suggest that CK5/ 14- positive sporadic breast cancers arise from glandularly committed progenitor cells rather than true CK8/ 18- negative basal cells.
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| 224. |
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| 225. |
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| 226. |
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| 227. |
- Laakso, S, et al.
(author)
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Testicular Function and Bone in Young Men with Severe Childhood-Onset Obesity
- 2018
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In: Hormone research in paediatrics. - : S. Karger AG. - 1663-2826 .- 1663-2818. ; 89:6, s. 442-449
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Journal article (peer-reviewed)abstract
- <b><i>Background:</i></b> Previous studies suggest increased risk for hypoandrogenism and fractures in men with obesity. We aimed to describe the effects of severe childhood-onset obesity on the cross talk between metabolic state, testes, and skeleton at late puberty. <b><i>Methods:</i></b> A cohort of adolescent and young adult males with severe childhood-onset obesity (<i>n</i> = 21, mean age 18.5 years) and an age-matched control group were assessed for testicular hormones and X-ray absorptiometry-derived bone mass. <b><i>Results:</i></b> Current median body mass indexes for the obese and control subjects were 37.4 and 22.9. Severe early-onset obesity manifested with lower free testosterone (median [interquartile range] 244 [194–332] vs. 403 [293–463] pmol/L, <i>p</i> = 0.002). Lower insulin-like 3 (1.02 [0.82–1.23] vs. 1.22 [1.01–1.46] ng/mL, <i>p</i> = 0.045) and lower ratio of testosterone to luteinizing hormone (2.81 [1.96–3.98] vs. 4.10 [3.03–5.83] nmol/IU, <i>p</i> = 0.008) suggested disrupted Leydig cell function. The degree of current obesity inversely correlated with free testosterone (τ = –0.516, <i>p</i> = 0.003), which in turn correlated positively with bone area at all measurement sites in males with childhood-onset obesity. <b><i>Conclusions:</i></b> Severe childhood-onset obesity is associated with impaired Leydig cell function in young men and lower free testosterone may contribute to impaired skeletal characteristics.
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| 228. |
- Laakso, S.V.A., et al.
(author)
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Too Sharp for its Own Good – Tool Edge Deformation Mechanisms in the Initial Stages of Metal Cutting
- 2017
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In: Procedia Manufacturing. - : Elsevier BV. - 2351-9789. ; 11, s. 449-456
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Journal article (peer-reviewed)abstract
- © 2017 Metal cutting simulations have become an important part of cutting tool design and the research in the field in general. One of the most important aspects of modeling is the accuracy of the tool geometry. 3D microscopy is used for measuring the tool edge radius with good accuracy. However, especially with sharp tools, i.e. small tool edge radii, the measurements, no matter how accurate, are not much of a use, since the initial wear, or deformation is so fast in the first 1-30 seconds into the cutting, that the tool geometry is significantly different than the one measured from the new tool. The average tool life is often set to 15 minutes. Therefore, the cutting simulations that only predict the tool behavior in the first seconds of its lifetime are not very useful in predicting the process variables throughout the tool life. Simulations with creep and elastic-plastic material model however, can predict the initial deformation of the tool. This tool shape can be then used in rigid tool model to predict the process variables in the steady wear region of the tool life. This paper presents simulation model for predicting the initial tool edge deformation for WC-10%Co tool while machining AISI 304 stainless steel. The novelty in this approach is the simultaneous coupled calculation of contact surface temperature and stress and change of the tool shape.
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| 229. |
- Lankinen, Maria A., et al.
(author)
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Dietary carbohydrate modification alters serum metabolic profiles in individuals with the metabolic syndrome
- 2010
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In: NMCD. Nutrition Metabolism and Cardiovascular Diseases. - : Elsevier. - 0939-4753 .- 1590-3729. ; 20:4, s. 249-57
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Journal article (peer-reviewed)abstract
- BACKGROUND AND AIMS: Whole-grain cereals and diets with a low glycemic index may protect against the development of type 2 diabetes and heart disease, but the mechanisms are poorly understood. We studied the effect of carbohydrate modification on serum metabolic profiles, including lipids and branched chain amino acids, and dependencies between these and specific gene expression pathways in adipose tissue.METHODS AND RESULTS: Twenty subjects with metabolic syndrome were selected from the larger FUNGENUT study population, randomized either to a diet high in oat and wheat bread and potato (OWP) or rye bread and pasta (RP). Serum metabolomics analyses were performed using ultra-performance liquid chromatography coupled to electrospray ionization mass spectrometry (UPLC/MS), gas chromatography (GC) and UPLC. In the OWP group multiple proinflammatory lysophosphatidylcholines increased, while in the RP group docosahexaenoic acid (DHA 22:6n-3) increased and isoleucine decreased. mRNA expression of stress reactions- and adipose tissue differentiation-related genes were up-regulated in adipose tissue in the OWP group. In the RP group, however, pathways related to stress reactions and insulin signaling and energy metabolism were down-regulated. The lipid profiles had the strongest association with the changes in the adipose tissue differentiation pathway when using the elastic net regression model of the lipidomic profiles on selected pathways.CONCLUSION: Our results suggest that the dietary carbohydrate modification alters the serum metabolic profile, especially in lysoPC species, and may, thus, contribute to proinflammatory processes which in turn promote adverse changes in insulin and glucose metabolism.
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