202 research outputs found

    One-dimensional dynamics of the d-electrons in α′\alpha'-NaV2_{2}O5_{5}

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    We have studied the electronic properties of the ladder compound α′\alpha'-NaV2_{2}O5_{5}, adopting a joint experimental and theoretical approach. The momentum-dependent loss function was measured using electron energy-loss spectroscopy in transmission. The optical conductivity derived from the loss function by a Kramers-Kronig analysis agrees well with our results from LSDA+U band-structure calculations upon application of an antiferromagnetic alignment of the V~3dxyd_{xy} spins along the legs and an on-site Coulomb interaction U of between 2 and 3 eV. The decomposition of the calculated optical conductivity into contributions from transitions between selected energy regions of the DOS reveals the origin of the observed anisotropy of the optical conductivity. In addition, we have investigated the plasmon excitations related to transitions between the vanadium states within an effective 16 site vanadium cluster model. Good agreement between the theoretical and experimental loss function was obtained using the hopping parameters derived from the tight binding fit to the band-structure and moderate Coulomb interactions between the electrons within the ab plane.Comment: 23 pages, 8 figures; submitted to PR

    Higher blood pressure in normal weight women with PCOS compared to controls

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    Objective: Obesity is considered to be the strongest predictive factor for cardio-metabolic risk in women with polycystic ovary syndrome (PCOS). The aim of the study was to compare blood pressure (BP) in normal weight women with PCOS and controls matched for age and BMI. Methods: From a Nordic cross-sectional base of 2615 individuals of Nordic ethnicity, we studied a sub cohort of 793 normal weight women with BMI = 140/90 mmHg was 11.1% (57/ 512) in women with PCOS vs 1.8% (5/281) in controls, P = 35 years the prevalence of BP >= 140/90 mmHg was comparable in women with PCOS and controls (12.7% vs 9.8%, P = 0.6). Using multiple regression analyses, the strongest association with BP was found for age, waist circumference, and total cholesterol in women with PCOS. Conclusions: Normal weight women with PCOS have higher BP than controls. BP and metabolic screening are relevant also in young normal weight women with PCOS.Peer reviewe

    Spin, charge and orbital ordering in ferrimagnetic insulator YBaMn2_2O5_5

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    The oxygen-deficient (double) perovskite YBaMn2_2O5_5, containing corner-linked MnO5_5 square pyramids, is found to exhibit ferrimagnetic ordering in its ground state. In the present work we report generalized-gradient-corrected, relativistic first-principles full-potential density-functional calculations performed on YBaMn2_2O5_5 in the nonmagnetic, ferromagnetic and ferrimagnetic states. The charge, orbital and spin orderings are explained with site-, angular momentum- and orbital-projected density of states, charge-density plots, electronic structure and total energy studies. YBaMn2_2O5_5 is found to stabilize in a G-type ferrimagnetic state in accordance with experimental results. The experimentally observed insulating behavior appears only when we include ferrimagnetic ordering in our calculation. We observed significant optical anisotropy in this material originating from the combined effect of ferrimagnetic ordering and crystal field splitting. In order to gain knowledge about the presence of different valence states for Mn in YBaMn2_2O5_5 we have calculated KK-edge x-ray absorption near-edge spectra for the Mn and O atoms. The presence of the different valence states for Mn is clearly established from the x-ray absorption near-edge spectra, hyperfine field parameters and the magnetic properties study. Among the experimentally proposed structures, the recently reported description based on PP4/nmmnmm is found to represent the stable structure

    Validation of control genes and a standardised protocol for quantifying gene expression in the livers of C57BL/6 and ApoE−/− mice

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    The liver plays a critical role in food and drug metabolism and detoxification and accordingly influences systemic body homeostasis in health and disease. While the C57BL/6 and ApoE−/− mouse models are widely used to study gene expression changes in liver disease and metabolism, currently there are no validated stably expressed endogenous genes in these models, neither is it known how gene expression varies within and across liver lobes. Here we show regional variations in the expression of Ywhaz, Gak, Gapdh, Hmbs and Act-β endogenous genes across a liver lobe; Using homogeneous samples from the four liver lobes of 6 C57BL/6 mice we tested the stability of 12 endogenous genes and show that Act-β and Eif2-α are the most stably expressed endogenous genes in all four lobes and demonstrate lobular differences in the expression of Abca1 cholesterol efflux gene. These results suggest that sampling from a specified homogeneous powdered liver lobe is paramount in enhancing data reliability and reproducibility. The stability of the 12 endogenous genes was further tested using homogeneous samples of left liver lobes from 20 ApoE−/− mice on standard or high polyphenol diets. Act-β and Ywhaz are suitable endogenous genes for gene expression normalisation in this mouse model

    Potential conservation of circadian clock proteins in the phylum Nematoda as revealed by bioinformatic searches

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    Although several circadian rhythms have been described in C. elegans, its molecular clock remains elusive. In this work we employed a novel bioinformatic approach, applying probabilistic methodologies, to search for circadian clock proteins of several of the best studied circadian model organisms of different taxa (Mus musculus, Drosophila melanogaster, Neurospora crassa, Arabidopsis thaliana and Synechoccocus elongatus) in the proteomes of C. elegans and other members of the phylum Nematoda. With this approach we found that the Nematoda contain proteins most related to the core and accessory proteins of the insect and mammalian clocks, which provide new insights into the nematode clock and the evolution of the circadian system.Fil: Romanowski, Andrés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; ArgentinaFil: Garavaglia, Matías Javier. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ing.genética y Biolog.molecular y Celular. Area Virus de Insectos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Goya, María Eugenia. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ghiringhelli, Pablo Daniel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Ing.genética y Biolog.molecular y Celular. Area Virus de Insectos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Golombek, Diego Andres. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Cronobiología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    Does Jacobson's relaxation technique reduce consumption of psychotropic and analgesic drugsin cancer patients? A multicenter pre-post intervention study

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    Background: Cancer patients often suffer from emotional distress as a result of the oncological process. The purpose of our study was to determine whether practice of Jacobson?s relaxation technique reduced consumption of psychotropic and analgesic drugs in a sample of cancer patients. Methods: This was a multicenter pre?post intervention design. Participants were 272 patients aged over 18 years attending 10 Spanish public hospitals with oncological pathologies and anxiety symptoms. The intervention consisted of a protocol of abbreviated progressive muscle relaxation training developed by Bernstein and Borkovec. This was followed up by telephone calls over a 1-month period. The intervention was performed between November 2014 and October 2015. Sociodemographic variables related to the oncological process, mental health variables, and intervention characteristics were measured. Results: A reduction in the consumption of psychotropic and analgesic drugs was observed throughout the follow-up period. Improvement was observed throughout the 4-week follow-up for all the parameters assessed: anxiety, relaxation, concentration, and mastery of the relaxation technique. Conclusions: The practice of abbreviated Jacobson?s relaxation technique can help to decrease the consumption of psychotropic and analgesic drugs. Patients experienced positive changes in all the evaluated parameters, at least during the 1-month follow-up. To confirm these findings, additional long-term studies are needed that include control groups. Trial registration: ISRCTN 81335752, DOI 10.1186/ISRCTN81335752 17. Date of registration: 22/11/2016 (retrospectively registered)

    The impact of muscle relaxation techniques on the quality of life of cancer patients, as measured by the FACT-G questionnaire

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    Introduction Patients with cancer frequently suffer from emotional distress, characterized by psychological symptoms such as anxiety or depression. The presence of psychological symptoms combined with the complex nature of oncology processes can negatively impact patients' quality of life. We aimed to determine the impact of a relaxation protocol on improving quality of life in a sample of oncological patients treated in the Spanish National Public Health System. Materials and methods We conducted a multicenter interventional study without a control group. In total, 272 patients with different oncologic pathologies and showing symptoms of anxiety were recruited from 10 Spanish public hospitals. The intervention comprised abbreviated progressive muscle relaxation training, according to Bernstein and Borkovec. This was followed by weekly telephone calls to each patient over a 1-month period. We collected sociodemographic variables related to the disease process, including information about mental health and the intervention. Patients' quality of life was assessed using the Functional Assessment of Cancer Therapy-General (FACT-G) questionnaire. Bivariate and univariate analyses were performed, along with an analysis of multiple correspondences to identify subgroups of patients with similar variations on the FACT-G. Results Patients showed statistically significant improvements on the FACT-G overall score (W = 16806; p<0.001), with an initial mean score of 55.33±10.42 and a final mean score of 64.49±7.70. We also found significant improvements for all subscales: emotional wellbeing (W = 13118; p<0.001), functional wellbeing (W = 16155.5; p<0.001), physical wellbeing (W = 8885.5; p<0.001), and social and family context (W = ?1840; p = 0.037). Conclusions Patients with cancer who learned and practiced abbreviated progressive muscle relaxation experienced improvement in their perceived quality of life as measured by the FACT-G. Our findings support a previous assumption that complementary techniques (including relaxation techniques) are effective in improving the quality of life of patients with cancer

    Masking effect of anti-androgens on androgenic activity in European river sediment unveiled by effect-directed analysis

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    This study shows that the androgen receptor agonistic potency is clearly concealed by the effects of androgen receptor antagonists in a total sediment extract, demonstrating that toxicity screening of total extracts is not enough to evaluate the full in vitro endocrine disrupting potential of a complex chemical mixture, as encountered in the environment. The anti-androgenic compounds were masking the activity of androgenic compounds in the extract with relatively high anti-androgenic potency, equivalent to 200 nmol flutamide equivalents/g dry weight. A two-step serial liquid chromatography fractionation of the extract successfully separated anti-androgenic compounds from androgenic compounds, resulting in a total androgenic potency of 3,820 pmol dihydrotestosterone equivalents/g dry weight. The fractionation simplified the chemical identification analysis of the original complex sample matrix. Seventeen chemical structures were tentatively identified. Polyaromatic hydrocarbons, a technical mixture of nonylphenol and dibutyl phthalate were identified to contribute to the anti-androgenic potency observed in the river sediment sample. With the GC/MS screening method applied here, no compounds with AR agonistic disrupting potencies could be identified. Seventy-one unidentified peaks, which represent potentially new endocrine disrupters, have been added to a database for future investigation

    An unbiased ranking of murine dietary models based on their proximity to human metabolic dysfunction-associated steatotic liver disease (MASLD)

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    Metabolic dysfunction-associated steatotic liver disease (MASLD), previously known as non-alcoholic fatty liver disease, encompasses steatosis and metabolic dysfunction-associated steatohepatitis (MASH), leading to cirrhosis and hepatocellular carcinoma. Preclinical MASLD research is mainly performed in rodents; however, the model that best recapitulates human disease is yet to be defined. We conducted a wide-ranging retrospective review (metabolic phenotype, liver histopathology, transcriptome benchmarked against humans) of murine models (mostly male) and ranked them using an unbiased MASLD ‘human proximity score’ to define their metabolic relevance and ability to induce MASH-fibrosis. Here, we show that Western diets align closely with human MASH; high cholesterol content, extended study duration and/or genetic manipulation of disease-promoting pathways are required to intensify liver damage and accelerate significant (F2+) fibrosis development. Choline-deficient models rapidly induce MASH-fibrosis while showing relatively poor translatability. Our ranking of commonly used MASLD models, based on their proximity to human MASLD, helps with the selection of appropriate in vivo models to accelerate preclinical research
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