152 research outputs found

    Vitamin D status including 3-epi-25(OH)D3 among adult patients with thyroid disorders during summer months

    Get PDF
    Introduction: In the context of pleiotropic vitamin D effects, its role has also been investigated in thyroid pathology, in particular autoimmune thyroid diseases (AITD). However, available data concerning vitamin D status in Polish patients with thyroid disorders are inconclusive. In the study we investigated vitamin D status and adequacy of supplementation, as well as sunlight exposure during summer months among adult patients with thyroid diseases.Material and methods: Adults with diagnosed or suspected thyroid disease were recruited almost entirely in an ambulatory setting between June and September in Northern Poland. Questionnaire examinations were performed, and serum concentrations of 25(OH)D2, 25(OH)D3, 3-epi-25(OH)D3, and 24,25(OH)2D3 were determined by LC-MS/MS.Results: Thirty men and 194 women participated in the study, mean age ± standard deviation (SD): 42 ± 15 years, mean ± SD body mass index (BMI) 26 ± 6 kg/m2. Among the participants, 133 declared L-thyroxine treatment, 44 — Hashimoto’s thyroiditis, 40 — nodular goitre, and 20 — hyperthyroidism and/or Graves’ disease. Mean ± SD 25(OH)D level was 26.9 ± 8.2 ng/ml, and deficiency (< 20 ng/ml) was stated in 12%, insufficiency (20 ≤ 25(OH)D < 30 ng/ml) in 50.4% of study participants. Calcidiol was significantly higher in subjects who declared supplementation, mean ± SD: 29.4 ± 7.5 vs. 25.2 ± 8 ng/ml. Among participants without vitamin D supplementation sunlight exposure correlated with 25(OH)D. The C3 epimer of 25(OH)D3 was detected in all subjects; its concentration correlated strongly with that of 25(OH)D3. 24,25(OH)2D3 levels also strongly correlated with those of 25(OH)D3.Conclusions: To our knowledge, the current study is the first in Poland to analyse vitamin D status in summer months among patients with thyroid diseases, as well as serum 3-epi-25(OH)D3 and 24,25(OH)2D3 concentrations. The data presented here indicate that vitamin D sufficiency is not attained even in summer months in patients with thyroid diseases

    Bcc 4^4He as a Coherent Quantum Solid

    Full text link
    In this work we investigate implications of the quantum nature of bcc 4^{4}% He. We show that it is a unique solid phase with both a lattice structure and an Off-Diagonal Long Range Order of coherently oscillating local electric dipole moments. These dipoles arise from the local motion of the atoms in the crystal potential well, and oscillate in synchrony to reduce the dipolar interaction energy. The dipolar ground-state is therefore found to be a coherent state with a well defined global phase and a three-component complex order parameter. The condensation energy of the dipoles in the bcc phase stabilizes it over the hcp phase at finite temperatures. We further show that there can be fermionic excitations of this ground-state and predict that they form an optical-like branch in the (110) direction. A comparison with 'super-solid' models is also discussed.Comment: 12 pages, 8 figure

    Local modes, phonons, and mass transport in solid 4^4He

    Full text link
    We propose a model to treat the local motion of atoms in solid 4^{4}He as a local mode. In this model, the solid is assumed to be described by the Self Consistent Harmonic approximation, combined with an array of local modes. We show that in the bcc phase the atomic local motion is highly directional and correlated, while in the hcp phase there is no such correlation. The correlated motion in the bcc phase leads to a strong hybridization of the local modes with the T1(110)_{1}(110) phonon branch, which becomes much softer than that obtained through a Self Consistent Harmonic calculation, in agreement with experiment. In addition we predict a high energy excitation branch which is important for self-diffusion. Both the hybridization and the presence of a high energy branch are a consequence of the correlation, and appear only in the bcc phase. We suggest that the local modes can play the role in mass transport usually attributed to point defects (vacancies). Our approach offers a more overall consistent picture than obtained using vacancies as the predominant point defect. In particular, we show that our approach resolves the long standing controversy regarding the contribution of point defects to the specific heat of solid 4^{4}He.Comment: 10 pages, 10 figure

    Long-range antiferromagnetic order in the S=1 chain compound LiVGe2O6

    Full text link
    The phase transition in the compound LiVGe2O6 has been proposed as a unique example of a spin-Peierls transition in an S=1 antiferromagnetic chain. We report neutron and x-ray diffraction measurements of LiVGe2O6 above and below the phase transition at T=24 K. No evidence is seen for any structural distortion associated with the transition. The neutron results indicate that the low temperature state is antiferromagnetic, driven by ferromagnetic interchain couplings.Comment: 4 pages, 4 ps figures, REVTEX, submitted to PR

    Large-scale mapping of bioactive peptides in structural and sequence space

    Get PDF
    Health-enhancing potential bioactive peptide (BP) has driven an interest in food proteins as well as in the development of predictive methods. Research in this area has been especially active to use them as components in functional foods. Apparently, BPs do not have a given biological function in the containing proteins and they do not evolve under independent evolutionary constraints. In this work we performed a large-scale mapping of BPs in sequence and structural space. Using well curated BP deposited in BIOPEP database, we searched for exact matches in non-redundant sequences databases. Proteins containing BPs, were used in fold-recognition methods to predict the corresponding folds and BPs occurrences were mapped. We found that fold distribution of BP occurrences possibly reflects sequence relative abundance in databases. However, we also found that proteins with 5 or more than 5 BP in their sequences correspond to well populated protein folds, called superfolds. Also, we found that in well populated superfamilies, BPs tend to adopt similar locations in the protein fold, suggesting the existence of hotspots. We think that our results could contribute to the development of new bioinformatics pipeline to improve BP detection.Fil: Nardo, Agustina Estefania. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Añon, Maria Cristina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Parisi, Gustavo Daniel. Universidad Nacional de Quilmes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Observation of a new excitation in bcc solid 4He by inelastic neutron scattering

    Full text link
    We report neutron scattering measurements of the phonons in bcc solid 4He. In general, only 3 accoustic phonon branches should exist in a monoatomic cubic crystal. In addition to these phonon branches, we found a new ''optic-like'' mode along the [110] direction. One possible interpretation of this new mode is in terms of localized excitations unique to a quantum solid.Comment: Text and 4 figures, to appear in Phys. Rev. Let

    Danger- and pathogen-associated molecular patterns recognition by pattern-recognition receptors and ion channels of the transient receptor potential family triggers the inflammasome activation in immune cells and sensory neurons.

    Get PDF
    An increasing number of studies show that the activation of the innate immune system and inflammatory mechanisms play an important role in the pathogenesis of numerous diseases. The innate immune system is present in almost all multicellular organisms and its activation occurs in response to pathogens or tissue injury via pattern-recognition receptors (PRRs) that recognize pathogen-associated molecular patterns (PAMPs) or danger-associated molecular patterns (DAMPs). Intracellular pathways, linking immune and inflammatory response to ion channel expression and function, have been recently identified. Among ion channels, the transient receptor potential (TRP) channels are a major family of non-selective cation-permeable channels that function as polymodal cellular sensors involved in many physiological and pathological processes.In this review, we summarize current knowledge of interactions between immune cells and PRRs and ion channels of TRP families with PAMPs and DAMPs to provide new insights into the pathogenesis of inflammatory diseases. TRP channels have been found to interfere with innate immunity via both nuclear factor-kB and procaspase-1 activation to generate the mature caspase-1 that cleaves pro-interleukin-1ß cytokine into the mature interleukin-1ß.Sensory neurons are also adapted to recognize dangers by virtue of their sensitivity to intense mechanical, thermal and irritant chemical stimuli. As immune cells, they possess many of the same molecular recognition pathways for danger. Thus, they express PRRs including Toll-like receptors 3, 4, 7, and 9, and stimulation by Toll-like receptor ligands leads to induction of inward currents and sensitization in TRPs. In addition, the expression of inflammasomes in neurons and the involvement of TRPs in central nervous system diseases strongly support a role of TRPs in inflammasome-mediated neurodegenerative pathologies. This field is still at its beginning and further studies may be required.Overall, these studies highlight the therapeutic potential of targeting the inflammasomes in proinflammatory, autoinflammatory and metabolic disorders associated with undesirable activation of the inflammasome by using specific TRP antagonists, anti-human TRP monoclonal antibody or different molecules able to abrogate the TRP channel-mediated inflammatory signals

    Danger- and pathogen-associated molecular patterns recognition by pattern-recognition receptors and ion channels of the transient receptor potential family triggers the inflammasome activation in immune cells and sensory neurons

    Get PDF
    • …
    corecore