180 research outputs found
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The influence of anisotropic F region ion velocity distributions on ionospheric ion outflows into the magnetosphere
The contribution to the field-aligned ionospheric ion momentum equation, due to coupling between pressure anisotropy and the inhomogeneous geomagnetic field, is investigated. We term this contribution the “hydrodynamic mirror force” and investigate its dependence on the ion drift and the resulting deformations of the ion velocity distribution function from an isotropic form. It is shown that this extra upforce increases rapidly with ion drift relative to the neutral gas but is not highly dependent on the ion-neutral collision model employed. An example of a burst of flow observed by EISCAT, thought to be the ionospheric signature of a flux transfer event at the magnetopause, is studied in detail and it is shown that the nonthermal plasma which results is subject to a hydrodynamic mirror force which is roughly 10% of the gravitational downforce. In addition, predictions by the coupled University College London-Sheffield University model of the ionosphere and thermosphere show that the hydrodynamic mirror force in the auroral oval is up to 3% of the gravitational force for Kp of about 3, rising to 10% following a sudden increase in cross-cap potential. The spatial distribution of the upforce shows peaks in the cusp region and in the post-midnight auroral oval, similar to that of observed low-energy heavy ion flows from the ionosphere into the magnetosphere. We suggest the hydrodynamic mirror force may modulate these outflows by controlling the supply of heavy ions to regions of ion acceleration and that future simulations of the effects of Joule heating on ion outflows should make allowance for it
The impact of orthodontic treatment on choosing a career in dentistry
Introduction Many studies, globally, have aimed at elucidating reasons to choose a career in dentistry. The most common motives found are reasonable working hours and aspiration to help. The aim of this study was to explore whether eventual past personal experience of orthodontic treatment and particularly the interpersonal skills of the treating orthodontist are of significance in this respect. Materials and methods An electronic questionnaire, consisting of multiple choice and descriptive questions about dental history and experiences in dental care, was sent to dental and, as controls, psychology students within the same Faculty of Medicine, University of Helsinki, Finland. The answers between the two groups were compared and differences tested statistically. Results The questionnaire was answered by 143 (46.0%) dental students and 94 (17.6%) psychology students. Dental students, compared to psychology students, had more positive views of their dentition and dental treatment in general (p = 0.000). Amongst participants, 47.9% of dental students and 57.4% of psychology students had received orthodontic treatment. Of those, dental students had perceived their orthodontic treatment as less painful (p = 0.001) and less uncomfortable (p = 0.000) than psychology students. Moreover, dental students reported more often experiences of orthodontist taking into account their situation in life during treatment (p = 0.011) and gave more positive descriptions of the orthodontist's interpersonal skills (p = 0.031). Conclusions Dental students, compared to psychology students, had statistically significantly more positive personal experiences related to dentistry and orthodontics, supporting our hypothesis that positive experiences with orthodontic treatment likely increase the probability of choosing dentistry as the future career.Peer reviewe
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Observations of nonthermal plasmas at different aspect angles
Data are presented from the EISCAT (European Incoherent Scatter (Facility)) CP-3-E experiment which show large increases in the auroral zone convection velocities (>2 km s−1) over a wide range of latitudes. These are larger than the estimated neutral thermal speed and allow a study of the plasma in a nonthermal state over a range of observing angles. Spectra are presented which show a well-defined central peak, consistent with an ion velocity distribution function which significantly departs from a Maxwellian form. As the aspect angle decreases, the central peak becomes less obvious. Simulated spectra, derived using theoretical expressions for the O+ ion velocity distribution function based on the generalized relaxation collision model, are compared with the observations and show good first-order, qualitative agreement. It is shown that ion temperatures derived from the observations, with the assumption of a Maxwellian distribution function, are an overestimate of the true ion temperature at large aspect angles and an underestimate at low aspect angles. The theoretical distribution functions have been included in the “standard” incoherent scatter radar analysis procedure, and attempts have been made to derive realistic ionospheric parameters from nonthermal plasma observations. If the expressions for the distribution function are extended to include mixed ion composition, a significant improvement is found in fitting some of the observed spectra, and estimates of the ion composition can be made. The non-Maxwellian analysis of the data revealed that the spectral shape distortion parameter, D*, was significantly higher in this case for molecular ions than for atomic ions in a thin height slab roughly 40 km thick. This would seem unlikely if the main molecular ions present were NO+. We therefore suggest that N2+ formed a significant proportion of the molecular ions present during these observations
Evaluation of Innotrac Aio! Second-Generation Cardiac Troponin I Assay: The Main Characteristics for Routine Clinical Use
The availability of a simple, sensitive, and rapid test using whole blood to facilitate processing and to
reduce the turnaround time could improve the management of patients presenting with
chest pain. The aim of this study was an evaluation of the Innotrac Aio! second-generation
cardiac troponin I (cTnI) assay. The Innotrac Aio! second-generation cTnI assay was
compared with the Abbott AxSYM first-generation cTnI, Beckman Access AccuTnI, and Innotrac
Aio! first-generation cTnI assays. We studied serum samples from 15 patients with positive
rheumatoid factor but with no indication of myocardial infarction (MI). Additionally, the stability
of the sample with different matrices and the influence of hemodialysis on the cTnI
concentration were evaluated. Within-assay CVs were 3.2%–10.9%, and
between-assay precision ranged from 4.0% to 17.2% for cTnI. The functional sensitivity
(CV = 20 %) and the concentration giving CV of 10% were approximated to be 0.02 and 0.04,
respectively. The assay was found to be linear within the tested range of 0.063–111.6
μ g/L. The correlations between the second-generation Innotrac Aio!, Access,
and AxSYM cTnI assays were good (r coefficients 0.947–0.966), but
involved differences in the measured
concentrations, and the biases were highest with cTnI at low concentrations. The
second-generation Innotrac Aio! cTnI assay was found to be superior to the first-generation assay
with regard to precision in the low concentration range. The stability of the cTnI level was best in the
serum, lithium-heparin plasma, and lithium-heparin whole blood samples (n = 10 , decrease
< 10 % in 24 hours at +20°C and at +4°C.
There was no remarkable influence of hemodialysis on the cTnI release. False-positive
cTnI values occurred in the presence of very high rheumatoid factor values, that is, over 3000 U/L.
The 99th percentile of the apparently healthy reference group was ≤ 0.03
μ g/L. The results demonstrate the very good analytical performance of the second-generation
Innotrac Aio! cTnI assay
Antibacterial Activity of Electrodeposited Copper and Zinc on Metal Injection Molded (MIM) Micropatterned WC-CO Hard Metals
Antibacterial activity of electrodeposited copper and zinc both on flat and micropatterned hard metal tungsten carbide-cobalt (WC-Co) specimens was studied. Tribological wear was applied on electrodeposited specimens: coatings were completely removed from flat surfaces whereas only top of the micropillars was exposed to wear for the micropatterned specimens protecting the functional metal coating in between the micropillars. The growth of Staphylococcus aureus (S. aureus) Gram-positive bacterial species was studied on the specimens using a touch test mimicking bacterial transfer from the surfaces. Copper coated specimens prevented bacterial growth completely independent of wear or surface structure, i.e., even residual traces of copper were sufficient to prevent bacterial growth. Zinc significantly suppressed the bacterial growth both on flat and micropatterned specimens. However, adhesion of zinc was low resulting in an easy removal from the surface by wear. The micropatterned zinc specimens showed antibacterial activity as electrodeposited zinc remained intact on the sample surface between the micropillars. This was sufficient to suppress the growth of S. aureus. On the contrary, the flat zinc coated surfaces did not show any antibacterial activity after wear. Our results show that micropatterned hard metal specimens can be used to preserve antibacterial activity under tribological wear
SNPs in lncRNA Regions and Breast Cancer Risk
Long non-coding RNAs (lncRNAs)
play crucial roles in human physiology, and have been found to be
associated with various cancers. Transcribed ultraconserved regions
(T-UCRs) are a subgroup of lncRNAs conserved in several species, and are
often located in cancer-related regions. Breast cancer is the most
common cancer in women worldwide and the leading cause of female cancer
deaths. We investigated the association of genetic variants in lncRNA
and T-UCR regions with breast cancer risk to uncover candidate loci for
further analysis. Our focus was on low-penetrance variants that can be
discovered in a large dataset. We selected 565 regions of lncRNAs and
T-UCRs that are expressed in breast or breast cancer tissue, or show
expression correlation to major breast cancer associated genes. We
studied the association of single nucleotide polymorphisms (SNPs) in
these regions with breast cancer risk in the 122970 case samples and
105974 controls of the Breast Cancer Association Consortium’s
genome-wide data, and also by in silico functional analyses using Integrated Expression Quantitative trait and in silico
prediction of GWAS targets (INQUISIT) and expression quantitative trait
loci (eQTL) analysis. The eQTL analysis was carried out using the
METABRIC dataset and analyses from GTEx and ncRNA eQTL databases. We
found putative breast cancer risk variants (p –5) targeting the lncRNA GABPB1-AS1 in INQUISIT and eQTL analysis. In addition, putative breast cancer risk associated SNPs (p –5) in the region of two T-UCRs, uc.184 and uc.313, located in protein coding genes CPEB4 and TIAL1,
respectively, targeted these genes in INQUISIT and in eQTL analysis.
Other non-coding regions containing SNPs with the defined p-value and
highly significant false discovery rate (FDR) for breast cancer risk
association were discovered that may warrant further studies. These
results suggest candidate lncRNA loci for further research on breast
cancer risk and the molecular mechanisms.</strong
Variability in the production of tannins and other polyphenols in cell cultures of 12 Nordic plant species
MAIN CONCLUSION: The polyphenol profiles of 18 cell cultures from 12 plant species were screened. The detected polyphenol fingerprints were diverse and differed from polyphenol profiles typically found in corresponding plant species. Cell cultures originating from 12 different plant species growing or grown in the Nordic countries were screened for their ability to synthesize polyphenols to assess their suitability for future studies and applications. The focus was on plant families Rosaceae and Ericaceae. On average, the Rosaceae cultures were the most efficient to produce hydrolysable tannins and the Ericaceae cultures were the most efficient to produce proanthocyanidins. This is in line with the general trend of polyphenols found in Rosaceae and Ericaceae leaves and fruits, even though several individual cell cultures differed from natural plants in their polyphenolic composition. Overall, several of the studied cell cultures exhibited capability in producing a large variety of polyphenols, including tannins with a high molecular weight, thus also showing promise for further studies concerning, for example, the accumulation of specific polyphenols or biosynthesis of polyphenols in the cell cultures.</p
Ellagitannins Inhibit the Exsheathment of Haemonchus contortus and Trichostrongylus colubriformis Larvae: The Efficiency Increases Together with the Molecular Size
Worldwide, parasitic gastrointestinal nematodes continue to threaten animal health, welfare, and production in outdoor breeding systems of small ruminants. For more than 50 years, the control of these parasitic worms has relied on the use of commercial synthetic anthelmintics. However, anthelmintic resistance in worm populations is nowadays widespread and requires novel solutions. The use of tannin-rich plants has been suggested as an alternative to synthetic anthelmintics to control gastrointestinal nematodes. The majority of previous studies have focused on the activity of proanthocyanidins (syn condensed tannins), and less is known about ellagitannins. In this study, the effects of 30 structurally unique ellagitannins on the exsheathment of third-stage infective larvae were examined on Haemonchus contortus and Trichostrongylus colubriformis by the in vitro larval exsheathment inhibition assay. Ellagitannins were found to be promising natural anthelmintics as they showed direct inhibition on larval exsheathment for both nematode species. In general, ellagitannins were more efficient at inhibiting the exsheathment of H. contortus larvae than those of T. colubriformis. The efficiency of inhibition increased as the degree of oligomerization or the molecular weight of the ellagitannin increased. Otherwise, we found no other structural features of ellagitannins that significantly affected the anthelmintic activity on the third-stage infective larvae. The effective concentrations were physiologically relevant and should be achievable in the gastrointestinal tract also in in vivo conditions
Antidepressants during and after Menopausal Transition: A Systematic Review and Meta-Analysis
To assess the therapeutic benefits of antidepressants in depressive women during and after menopausal transition, PubMed, Cochrane Library, EMBASE and Science Direct were systematically searched from inception to February 1, 2020 for randomized controlled trials examining antidepressants compared to placebo. Primary outcome was change in depressive symptom severity, while secondary outcomes were rates of response/remission rates and dropout/discontinuation due to adverse events. Seven trials involving 1,676 participants (mean age = 52.6 years) showed significant improvement in depressive symptoms (k = 7, Hedges’ g = 0.44, 95% confidence interval (CI) = 0.32 to 0.57, p < 0.001) relative to that in controls. Furthermore, response (k = 3, odds ratio (OR) = 2.53, 95% CI = 1.24 to 5.15, p = 0.01) and remission (k = 3, OR = 1.84, 95% CI = 1.32 to 2.57, p < 0.001) rates were significantly higher in antidepressant-treated groups compared to those with controls. Although dropout rates did not differ between antidepressant and control groups (k = 6, OR = 0.93, 95% CI = 0.70 to 1.26, p = 0.68), the rate of discontinuation due to adverse events was significantly higher in antidepressant-treated groups (k = 6, OR = 0.55, 95% CI = 0.35 to 0.86, p = 0.01). Subgroup analysis indicated that antidepressants were also efficacious for depressive symptoms in those without diagnosis of MDD. The results demonstrated that antidepressants were efficacious for women with depressive syndromes during and after menopausal transition but associated with a higher risk of discontinuation due to adverse events
The phylodynamics of SARS-CoV-2 during 2020 in Finland
Finland has had a low incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infections as compared to most European countries. Here we report the origins and turnover of SARS-CoV-2 lineages circulating in Finland in 2020. SARS-CoV-2 introduced to Finland in January 2020 and spread rapidly across southern Finland during spring. We observed rapid turnover among Finnish lineages during this period. Clade 20C became the most prevalent among sequenced cases and was replaced by other strains in fall 2020. Bayesian phylogeographic reconstructions suggested 42 independent introductions into Finland during spring 2020, mainly from Italy, Austria, and Spain, which might have been the source for a third of cases. The investigations of the original introductions of SARS-CoV-2 to Finland during the early stages of the pandemic and of the subsequent lineage dynamics could be utilized to assess the role of transboundary movements and effects of early intervention and public health measures.Peer reviewe
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