267 research outputs found
A study of Pt-/alpha-Fe2O3 nanocomposites by XPS
alpha-Fe2O3 matrices were deposited on Fluorine-doped Tin Oxide (FTO) substrates by Plasma Enhanced-
Chemical Vapor Deposition (PE-CVD) from Fe(hfa)_2TMEDA (hfa = 1,1,1,5,5,5-hexafluoro-2,4-pentanedionate; TMEDA =
N,N,N’,N’-tetramethylethylenediamine). The obtained nanosystems were subsequently functionalized by platinum nanoparticles (NPs) via Radio Frequency (RF)-sputtering, exposing samples either to a pre- or post-sputtering thermal treatment at 650°C for one hour in air. Interestingly, Pt oxidation state in the final composite systems strongly depended on the adopted processing conditions. In this work, a detailed X-ray Photoelectron Spectroscopy (XPS) analysis was carried out in order to investigate the material chemical composition, with particular regard to the relative Pt(0)/Pt(II)/Pt(IV) content. The obtained results evidenced that, when annealing is performed prior to sputtering, only PtO and PtO2 are revealed in the final Pt/alpha-Fe2O3 nanocomposite. In a different way, annealing after sputtering results in the co-presence of Pt(0), Pt(II) and Pt(IV) species, the former arising from the thermal decomposition of PtO2 to metallic platinum
Nonlinear resonance in a three-terminal carbon nanotube resonator
The RF-response of a three-terminal carbon nanotube resonator coupled to
RF-transmission lines is studied by means of perturbation theory and direct
numerical integration. We find three distinct oscillatory regimes, including
one regime capable of exhibiting very large hysteresis loops in the frequency
response. Considering a purely capacitive transduction, we derive a set of
algebraic equations which can be used to find the output power (S-parameters)
for a device connected to transmission lines with characteristic impedance
.Comment: 16 pages, 8 figure
Occurrence and predictors of retinopathy and visual acuity in type 2 diabetic patients and control subjects 10-year follow-up from the diagnosis
Rozwój retinopatii i zaburzeń ostrości widzenia oraz czynniki ryzyka ich wystąpienia u pacjentów z nowo rozpoznaną cukrzycą i w grupie kontrolnej u osób bez cukrzycy.
Prospektywne, 10-letnie badanie objęło reprezentatywną grupę 133 chorych (70
mężczyzn i 63 kobiety) na cukrzycę typu 2, świeżo rozpoznaną w latach 1979-1981, oraz 144 osoby (62 mężczyzn i 82 kobiety) z grupy kontrolnej bez cukrzycy, wyłonione z populacji ogólnej. Częstość retinopatii oraz stopień jej zaawansowania oceniano
na podstawie 45o zdjęć dna oka wykonywanych na początku badania oraz po 5 i 10 latach. Po 10 latach obserwacji u chorych na cukrzycę stwierdzono gorszą ostrość wzroku niż u osób z grupy kontrolnej. Upośledzenie ostrości widzenia wykazywało odwrotną korelację z wartościami HbA1c oznaczonymi po 5 latach. Częstość retinopatii u chorych na cukrzycę typu 2 wzrastała gwałtownie po 5 latach, a po 10 latach obserwacji już u 55% stwierdzano cechy retinopatii. Natomiast u osób z grupy kontrolnej częstość retinopatii była niewielka, lecz wykrywalna. Zła kontrola glikemii była u chorych na cukrzycę najistotniejszym czynnikiem pozwalającym przewidywać rozwój retinopatii. Wartości ciśnienia tętniczego były wyższe, a mikroalbuminuria częstsza u osób z grupy kontrolnej, u których stwierdzano retinopatię. U chorych ze świeżo rozpoznaną cukrzycą typu 2 ostrość widzenia ulegała pogorszeniu, a częstość retinopatii rosła wraz z czasem trwania choroby oraz złą kontrolą glikemii. Wyższe ciśnienie tętnicze oraz mikroalbuminuria pozwalały przewidywać rozwój retinopatii u osób z grupy kontrolnej.The evolution of visual acuity and retinopathy and their risk factors in patients with newly diagnosed type 2 diabetes and in control subjects. A 10-year prospective study consisting of a representative group of 133 (70 men, 63 women) newly diagnosed type 2 diabetic patients diagnosed at health centers between 1979 and 1981 and 144 (62 men, 82 women) non-diabetic control subjects recruited from the population register. The frequency of retinopathy was determined by grading of 45° fundus
photographs at baseline and after 5 and 10 years. By the 10-year follow-up the
diabetic patients had lower visual acuity than the control subjects. The im-pairment of the visual acuity correlated inversely to HbA1c value of the 5-year examination. The frequency of retinopathy in type 2 diabetic patients increased sharply after 5 years and at 10-year 55% of diabetic patients had signs of retinopathy. The frequency of retinopathy in the control subjects was low, but detectable. In the diabetic patients poor glycemic control was the most important predictive factor
for the development of retinopathy. In the control subjects blood pressure levels were higher and microalbuminuria more common in those with than in those without retinopathy. The visual acuity deteriorated and the frequency of retinopathy increased in newly diagnosed type 2 diabetic patients with duration of disease and poor glycemic control. Interestingly, higher blood pressure levels and microalbuminuria
predicted retinopathy in control subjects
Extensive sampling and thorough taxonomic assessment of Afrotropical Rhyssinae (Hymenoptera, Ichneumonidae) reveals two new species and demonstrates the limitations of previous sampling efforts
Tropical forest invertebrates, such as the parasitoid wasp family Ichneumonidae, are poorly known. This
work reports some of the first results of an extensive survey implemented in Kibale National Park, Uganda. A total of 456 individuals was caught of the subfamily Rhyssinae Morley, 1913, which in the Afrotropical region was previously known from only 30 specimens. Here, the six species found at the site are
described and the Afrotropical Rhyssinae are reviewed. Two new species, Epirhyssa johanna Hopkins, sp.
nov. and E. quagga sp. nov., are described and a key, diagnostic characters, and descriptions for all 13
known Afrotropical species are provided, including the first description of the male of Epirhyssa overlaeti
Seyrig, 1937. Epirhyssa gavinbroadi Rousse & van Noort, 2014, syn. nov. is proposed to be a synonym of
E. uelensis Benoit, 1951. Extensive sampling with Malaise traps gave an unprecedented sample size, and
the method is recommended for other poorly known tropical areas.</p
Cryptic biodiversity of tropical hesperiid caterpillar-attacking parasitoid wasps: three new species of Creagrura Townes (Hymenoptera, Ichneumonidae, Cremastinae) from Costa Rica and Peru
We describe three new species of the previously monotypic genus Creagrura Townes from Central and South America: C. alejandromasisi sp. n. and C. rogerblancoi sp. n. from Costa Rica and C. allpahuaya sp. n. from Peru, all of which emphasise the unknown parasitoid insect diversity yet to be revealed in the tropics. New information Host relationships of the two Costa Rican species are described in detail. In addition, it is inferred that the Creagrura wasps find and oviposit in the caterpillar when it is exposed at night, rather than when it is concealed during daylight hours
Genetic Risk Score for Serum 25-Hydroxyvitamin D Concentration Helps to Guide Personalized Vitamin D Supplementation in Healthy Finnish Adults
Background Genetic factors modify serum 25-hydroxyvitamin D [25(OH)D] concentration and can affect the optimal intake of vitamin D. Objectives We aimed to personalize vitamin D supplementation by applying knowledge of genetic factors affecting serum 25(OH)D concentration. Methods We performed a genome-wide association study of serum 25(OH)D concentration in the Finnish Health 2011 cohort (n = 3339) using linear regression and applied the results to develop a population-matched genetic risk score (GRS) for serum 25(OH)D. This GRS was used to tailor vitamin D supplementation for 96 participants of a longitudinal Digital Health Revolution (DHR) Study. The GRS, serum 25(OH)D concentrations, and personalized supplementation and dietary advice were electronically returned to participants. Serum 25(OH)D concentrations were assessed using immunoassays and vitamin D intake using FFQs. In data analyses, cross-sectional and repeated-measures statistical tests and models were applied as described in detail elsewhere. Results GC vitamin D-binding protein and cytochrome P450 family 2 subfamily R polypeptide 1 genes showed genome-wide significant associations with serum 25(OH)D concentration. One single nucleotide polymorphism from each locus (rs4588 and rs10741657) was used to develop the GRS. After returning data to the DHR Study participants, daily vitamin D supplement users increased from 32.6% to 60.2% (P = 6.5 x 10(-6)) and serum 25(OH)D concentration from 64.4 +/- 20.9 nmol/L to 68.5 +/- 19.2 nmol/L (P = 0.006) between August and November. Notably, the difference in serum 25(OH)D concentrations between participants with no risk alleles and those with 3 or 4 risk alleles decreased from 20.7 nmol/L to 8.0 nmol/L (P = 0.0063). Conclusions We developed and applied a population-matched GRS to identify individuals genetically predisposed to low serum 25(OH)D concentration. We show how the electronic return of individual genetic risk, serum 25(OH)D concentrations, and factors affecting vitamin D status can be used to tailor vitamin D supplementation. This model could be applied to other populations and countries.Peer reviewe
Genetic Risk Score for Serum 25-Hydroxyvitamin D Concentration Helps to Guide Personalized Vitamin D Supplementation in Healthy Finnish Adults
Background Genetic factors modify serum 25-hydroxyvitamin D [25(OH)D] concentration and can affect the optimal intake of vitamin D. Objectives We aimed to personalize vitamin D supplementation by applying knowledge of genetic factors affecting serum 25(OH)D concentration. Methods We performed a genome-wide association study of serum 25(OH)D concentration in the Finnish Health 2011 cohort (n = 3339) using linear regression and applied the results to develop a population-matched genetic risk score (GRS) for serum 25(OH)D. This GRS was used to tailor vitamin D supplementation for 96 participants of a longitudinal Digital Health Revolution (DHR) Study. The GRS, serum 25(OH)D concentrations, and personalized supplementation and dietary advice were electronically returned to participants. Serum 25(OH)D concentrations were assessed using immunoassays and vitamin D intake using FFQs. In data analyses, cross-sectional and repeated-measures statistical tests and models were applied as described in detail elsewhere. Results GC vitamin D-binding protein and cytochrome P450 family 2 subfamily R polypeptide 1 genes showed genome-wide significant associations with serum 25(OH)D concentration. One single nucleotide polymorphism from each locus (rs4588 and rs10741657) was used to develop the GRS. After returning data to the DHR Study participants, daily vitamin D supplement users increased from 32.6% to 60.2% (P = 6.5 x 10(-6)) and serum 25(OH)D concentration from 64.4 +/- 20.9 nmol/L to 68.5 +/- 19.2 nmol/L (P = 0.006) between August and November. Notably, the difference in serum 25(OH)D concentrations between participants with no risk alleles and those with 3 or 4 risk alleles decreased from 20.7 nmol/L to 8.0 nmol/L (P = 0.0063). Conclusions We developed and applied a population-matched GRS to identify individuals genetically predisposed to low serum 25(OH)D concentration. We show how the electronic return of individual genetic risk, serum 25(OH)D concentrations, and factors affecting vitamin D status can be used to tailor vitamin D supplementation. This model could be applied to other populations and countries.Peer reviewe
Polygenic risk provides biological validity for the ICHD-3 criteria among Finnish migraine families
Background Migraine is diagnosed using the extensively field-tested International Classification of Headache Disorders (ICHD-3) consensus criteria derived by the International Headache Society. To evaluate the criteria in respect to a measurable biomarker, we studied the relationship between the main ICHD-3 criteria and the polygenic risk score, a measure of common variant burden in migraine. Methods We used linear mixed models to study the correlation of ICHD-3 diagnostic criteria, underlying symptoms, and main diagnoses with the polygenic risk score of migraine in a cohort of 8602 individuals from the Finnish Migraine Genome Project. Results Main diagnostic categories and all underlying diagnostic criteria formed a consistent continuum along the increasing polygenic burden. Polygenic risk was associated with the heterogeneous clinical picture starting from the non-migraine headache (mean 0.07; 95% CI 0.02-0.12; p = 0.008 compared to the non-headache group), to probable migraine (mean 0.13; 95% CI 0.08-0.18; p < 0.001), migraine headache (mean 0.17; 95% CI 0.14-0.21; p < 0.001) and migraine with typical visual aura (mean 0.29; 95% CI 0.26-0.33; p < 0.001), all the way to the hemiplegic aura (mean 0.37; 95% CI 0.31-0.43; p < 0.001). All individual ICHD-3 symptoms and the total number of reported symptoms, a surrogate of migraine complexity, demonstrated a clear inclination with an increasing polygenic risk. Conclusions The complex migraine phenotype progressively follows the polygenic burden from individuals with no headache to non-migrainous headache and up to patients with attacks manifesting all the features of the ICHD-3 headache and aura. Results provide further biological support for the ICHD-3 diagnostic criteria.Peer reviewe
Direct transmission detection of tunable mechanical resonance in an individual carbon nanofiber relay
A direct on-chip transmission measurement of the resonance frequency of an individual singly clamped carbon nanofiber relay is reported.
The experimental results are in good agreement with a small signal model and show the expected tuning of the resonance frequency with
changing bias voltage
Immunohistochemical detection of macrophage migration inhibitory factor in fetal and adult bovine epididymis: Release by the apocrine secretion mode?
Originally defined as a lymphokine inhibiting the random migration of macrophages, the macrophage migration inhibitory factor (MIF) is an important mediator of the host response to infection. Beyond its function as a classical cytokine, MIF is currently portrayed as a multifunctional protein with growth-regulating properties present in organ systems beyond immune cells. In previous studies, we detected substantial amounts of MIF in the rat epididymis and epididymal spermatozoa, where it appears to play a role during post-testicular sperm maturation and the acquisition of fertilization ability. To explore its presence in other species not yet examined in this respect, we extended the range of studies to the bull. Using a polyclonal antibody raised against MIF purified from bovine eye lenses, we detected MIF in the epithelium of the adult bovine epididymis with the basal cells representing a prominently stained cell type. A distinct accumulation of MIF at the apical cell pole of the epithelial cells and in membranous vesicles localized in the lumen of the epididynnal duct was obvious. In the fetal bovine epididymis, we also detected MIF in the epithelium, whereas MIF accumulation was evident at the apical cell surface and in apical protrusions. By immuno-electron microscopy of the adult bovine epididymis, we localized MIF in apical protrusions of the epithelial cells and in luminal membrane-bound vesicles that were found in close proximity to sperm cells. Although the precise origin of the MIF-containing vesicles remains to be delineated, our morphological observations support the hypothesis that they become detached from the apical surface of the epididymal epithelial cells. Additionally, an association of MIF with the outer dense fibers of luminal spermatozoa was demonstrated. Data obtained in this study suggest MIF release by an apocrine secretion mode in the bovine epididymis. Furthermore, MIF localized in the basal cells of the epithelium and in the connective tissue could be responsible for regulating the migration of macrophages in order to avoid contact of immune cells with spermatozoa that carry a wide range of potent antigens. Copyright (c) 2006 S. Karger AG, Basel
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