Publications

The hybrid combination of superconductors and low-dimensional semiconductors offers a versatile ground for novel device concepts, such as sources of spin-entangled electrons, nanoscale superconducting magnetometers, or recently proposed qubits based on topologically protected Majorana fermions. The underlying physics behind such hybrid devices ultimately rely on the magnetic properties of sub-gap excitations, known as Andreev levels. Here we report the Zeeman effect on the Andreev levels of a semiconductor nanowire quantum dot (QD) strongly coupled to a conventional superconductor. The combination of the large QD g-factor with the large superconductor critical magnetic field allows spin degeneracy to be lifted without suppressing superconductivity. We show that a Zeeman-split Andreev level crossing the Fermi energy signals a quantum phase transition in the ground state of the superconductivity-induced QD, denoting a change in the fermionic parity of the system. This transition manifests itself as a zero-bias conductance anomaly appearing at a finite magnetic field, with properties that resemble those expected for Majorana fermions in a topological superconductor. Although the herein reported zero-bias anomalies do not hold any relation with topological superconductivity, the observed parity transitions can be regarded as precursors of Majorana modes in the long-wire limit.

BACKGROUND This study examines cognitive functioning in adults born across the range of prematurity with appropriate or small for gestational age (SGA) birth weight compared with full-term controls. METHODS ESTER Preterm Birth Study participants without severe disabilities, comprising 133 early preterm (<34 weeks, 17% SGA), 241 late preterm (34 + 0-36 + 6 weeks, 13% SGA), and 348 full-term subjects, performed the Cogstate® test at a mean age of 23.3 (SD = 1.2) years. Subtests measured paired associate learning, psychomotor function, executive function, spatial memory efficiency, visual memory, attention, working memory, visual learning, and emotional cognition. Data were analyzed with linear regression, full models adjusted for prenatal and postnatal factors and socioeconomic position. RESULTS Early preterm, late preterm, and full-term participants showed similar abilities in almost all subtests. Early preterm participants had 0.6 fewer moves/10 s (95% CI: -1.0; -0.2, full model) and late preterm and SGA participants had 1.3 fewer moves/10 s (95% CI: -2.1; -0.4) than full-term controls in the Groton Maze Learning Test, indicating weaker spatial memory efficiency. CONCLUSIONS Adults born across the range of prematurity on average lack major defects in cognitive abilities. Cognitive problems may persist to adulthood only among those born the smallest: very preterm or preterm and SGA. IMPACT Although preterm birth is a risk for the developing brain, adults born preterm as a group showed similar cognitive performance to their full-term peers. Children born preterm across gestational ages show defects in cognitive domains. With a supportive environment, many of them have the potential to catch up with those born at term. The unfavorable effect of late preterm birth on cognitive functions in childhood may not persist to adulthood; in this study, adults born late preterm showed similar cognitive functioning to adults born full-term. The deficits in cognitive function in adults born preterm detected by earlier studies mainly concern those born the smallest, i.e., very preterm or preterm and small for gestational age.

Objective: To examine the association between urinary excretions of isoflavonoids and risk of type 2 diabetes (T2D). Methods: Urinary excretions of daidzein and genistein, as well as their metabolites desmethylangolensin (DMA), dihydrogenistein (DHGE), dihydrodaidzein (DHDE) were assayed by liquid chromatography mass spectrometry among 1,111 T2D nested case-control pairs identified during 1995 - 2008 in the Nurses’ Health Study (NHS; aged 54 - 80y, 99% postmenopausal) and NHSII (aged 33 - 52y, 22% postmenopausal) who were free of diabetes, cardiovascular disease, and cancer at urine sample collection in 1995-2001. Incident self-reported T2D cases were confirmed using a validated supplementary questionnaire. Results: Total urinary isoflavones and all individual metabolites except DMA were associated with a lower risk of T2D in the NHS but not in the younger women of the NHSII. Compared to the lowest tertile of total urinary isoflavones, the odds ratios (ORs) of T2D in the middle and high tertile of NHS wer...

Self-assembled monolayers (SAMs) formed from alkanethiols on thin films of gold were exposed to a beam of metastable argon atoms through a stencil mask. The changes in the organizational structure of the alkyl chains in the SAM that resulted from exposure were characterized using reflection−absorption infrared spectroscopy. All spectroscopic evidence suggested that the SAMs become disordered after exposure to metastable argon atoms and that no apparent oxidation of the alkane chain occurred. The alkanethiolates in the regions of a SAM of dodecanethiolate damaged by the atom beam exchanged readily upon immersion in a solution of 16-mercaptohexadecanoic acid. The exchange reaction was selective for the regions of the SAM exposed to metastable argon atoms with patterns containing critical dimensions of <50 nm. A thin (<5 nm) polymeric multilayer was covalently linked to the carboxylic acid groups in the exposed regions of the SAM. The polymeric layer served as an improved resist against a commercial KI/I2-based etchant used to transfer the pattern into the thin film of gold.

Abstract Genetic research utilizes a decomposition of trait variances and covariances into genetic and environmental parts. Our software package biMM is a computationally efficient implementation of a bivariate linear mixed model for settings where hundreds of traits have been measured on partially overlapping sets of individuals. Availability Implementation in R freely available at www.iki.fi/mpirinen .

The association between single-parent family background and physical illness in early adulthood was studied in a sample of an unselected, general population: the Northern Finland 1966 Birth Cohort. Between the ages of 16 and 28 years, women of single-parent family background were more commonly treated (61% versus 57%) for any physical condition in hospital wards compared with women of two-parent family background. Spontaneous abortions (odds ratio; OR = 1.4, 95% CI 1.0-2.0), complications of pregnancy (OR = 1.1, 95% CI 1.0-1.3), and intracranial injuries (OR = 2.0, 95% CI 1.0-3.8) were more common among women with single-parent family background. They also had a clearly higher risk for induced abortions (OR = 1.6. 95% CI 1.4-1.9), and a higher incidence of deliveries than did other women. The risk of hospital-treated physical illness did not differ between men of single-parent and two-parent family background. Poisonings and injuries were, however, more common reasons for hospital admission among men with single-parent family background than among other men. In conclusion, our main finding was that, among women, an association between overall hospital-treated physical illness and single-parent family background does exist. However, offspring of single-parent families are mostly in as good physical health as others.

Low high-density lipoprotein cholesterol (HDL-C) is associated with cardiometabolic pathologies. In this study, we investigate the biological pathways and individual genes behind low HDL-C by integrating results from 3 high-throughput data sources: adipose tissue transcriptomics, HDL lipidomics, and dense marker genotypes from Finnish individuals with low or high HDL-C (n=450).In the pathway analysis of genetic data, we demonstrate that genetic variants within inflammatory pathways were enriched among low HDL-C associated single-nucleotide polymorphisms, and the expression of these pathways upregulated in the adipose tissue of low HDL-C subjects. The lipidomic analysis highlighted the change in HDL particle quality toward putatively more inflammatory and less vasoprotective state in subjects with low HDL-C, as evidenced by their decreased antioxidative plasmalogen contents. We show that the focal point of these inflammatory pathways seems to be the HLA region with its low HDL-associated alleles also associating with more abundant local transcript levels in adipose tissue, increased plasma vascular cell adhesion molecule 1 (VCAM1) levels, and decreased HDL particle plasmalogen contents, markers of adipose tissue inflammation, vascular inflammation, and HDL antioxidative potential, respectively. In a population-based look-up of the inflammatory pathway single-nucleotide polymorphisms in a large Finnish cohorts (n=11 211), no association of the HLA region was detected for HDL-C as quantitative trait, but with extreme HDL-C phenotypes, implying the presence of low or high HDL genes in addition to the population-genomewide association studies-identified HDL genes.Our study highlights the role of inflammation with a genetic component in subjects with low HDL-C and identifies novel cis-expression quantitative trait loci (cis-eQTL) variants in HLA region to be associated with low HDL-C.