3,676 research outputs found
Empirical Evidence of the Metacognitive Model of Rumination and Depression in Clinical and Nonclinical Samples: A Systematic Review and Meta-Analysis
Rumination is considered a cognitive vulnerability factor in the development and maintenance of depression. The metacognitive model of rumination and depression suggests that the development of rumination and its association with depression partly depends on metacognitive beliefs. Two metacognitive beliefs about rumination have been identified: positive beliefs about its utility and negative beliefs about the uncontrollability and its negative social consequences. We conducted a systematic review and meta-analysis aimed: (1) to analyze the associations between metacognitive beliefs and rumination and depression; (2) to test the metacognitive model, using a Two-Stage Structural Equation Modeling approach (TSSEM). Literature search retrieved 41 studies. These 41 studies (N = 10,607) were included in the narrative synthesis and meta-analysis, and 16 studies (N = 4477) were comprised for the TSSEM. Results indicated metacognitive beliefs are associated with rumination and depression. Measures on metacognitive beliefs about rumination indicated that positive beliefs showed moderate associations with rumination (r = 0.50), and low with depression (r = 0.27); whereas negative beliefs showed moderate associations with both rumination (r = 0.46) and depression (r = 0.49). These results were consistent across studies using different instruments to measure metacognitive beliefs, and in both clinical and nonclinical samples. Moreover, results of the TSSEM analyses showed that the metacognitive model had a good fit. In sum, our results are in line with the metacognitive model of rumination and depression, highlighting that metacognitive beliefs are relevant factors to understand why people ruminate and get depressed. Future directions and clinical implications are discussed
Clear cell sarcoma mimicking a breast tumor in an elderly man: a rare case report and a literature review
Objective: Clear Cell Sarcoma (CCS) is a rare tumor of mesenchymal origin accounting for 1% of soft tissue sarcomas (STS)1. Often misdiagnosed as malignant melanoma2 (MM), it has only one curative treatment: radical surgery and an extensive postoperative follow-up program2. Herein, we present a case of CCS mimicking a right breast tumor, where the patient´s age, gender, growth and localization of the neoplasm render it uncommon.
Case presentation: A 70-year-old male was admitted to the Surgery Department complaining about a 3-month right breast tumor. Ultrasound evidenced a nodular formation (2.29 cm-1.91 cm) and mammography showed a hyperdense image, projected 35 mm from the nipple, surrounded by calcifications. No signs of systemic disease were present. Core needle biopsy expressed histological characteristics compatible with both MM and CCS.
Results: After multidisciplinary team meeting, a wide resection surgery was performed followed by lymphadenectomy. The immunohistochemistry and pathology report led to the diagnosis: CCS.
Conclusions: CCS is a rare sarcoma with poor prognosis. This case is exceptional due to its epidemiology, unusual clinical manifestations and appearance, setting CCS up as a new differential diagnosis to keep in mind regarding breast tumors. Its extreme rarity could help other colleagues deal with this infrequent presentation
A Single Amino Acid Substitution, Found in Mammals with Low Susceptibility to Prion Diseases, Delays Propagation of Two Prion Strains in Highly Susceptible Transgenic Mouse Models
Specific variations in the amino acid sequence of prion protein (PrP) are key determinants of susceptibility to prion diseases. We previously showed that an amino acid substitution specific to canids confers resistance to prion diseases when expressed in mice and demonstrated its dominant-negative protective effect against a variety of infectious prion strains of different origins and characteristics. Here, we show that expression of this single amino acid change significantly increases survival time in transgenic mice expressing bank vole cellular prion protein (PrP C ), which is inherently prone to misfolding, following inoculation with two distinct prion strains (the CWD-vole strain and an atypical strain of spontaneous origin). This amino acid substitution hinders the propagation of both prion strains, even when expressed in the context of a PrP C uniquely susceptible to a wide range of prion isolates. Non-inoculated mice expressing this substitution experience spontaneous prion formation, but showing an increase in survival time comparable to that observed in mutant mice inoculated with the atypical strain. Our results underscore the importance of this PrP variant in the search for molecules with therapeutic potential against prion diseases
Antioxidant effects of insulin-like growth factor-I (IGF-I) in rats with advanced liver cirrhosis
BACKGROUND: The exogenous administration of Insulin-like Growth Factor-I (IGF-I) induces hepatoprotective and antifibrogenic actions in experimental liver cirrhosis. To better understand the possible pathways behind the beneficial effect of IGF-I, the aim of this work was to investigate severe parameters involved in oxidative damage in hepatic tissue from cirrhotic animals treated with IGF-I (2 μg. 100 g(-1). day(-1)). Iron and copper play an important role in oxidative mechanisms, producing the deleterious hydroxyl radical (*OH) that peroxides lipid membranes and damages DNA. Myeloperoxidase (MPO) and nitric oxide (NO) are known sources of free radicals and induce reduction of ferritin-Fe(3+ )into free Fe(2+), contributing to oxidative damage. METHODS: Liver cirrhosis was induced by CCl(4 )inhalation in Wistar male rats for 30 weeks. Healthy controls were studied in parallel (n = 10). Fe and Cu were assessed by atomic absoption spectrometry and iron content was also evaluated by Perls' staining. MPO was measured by ELISA and transferrin and ferritin by immunoturbidimetry. iNOS expression was studied by immuno-histochemistry. RESULTS: Liver cirrhosis was histologically proven and ascites was observed in all cirrhotic rats. Compared to controls untreated cirrhotic rats showed increased hepatic levels of iron, ferritin, transferrin (p < 0.01), copper, MPO and iNOS expression (p < 0.01). However, IGF-treatment induced a significant reduction of all these parameters (p < 0.05). CONCLUSION: the hepatoprotective and antifibrogenic effects of IGF-I in cirrhosis are associated with a diminution of the hepatic contents of several factors all of them involved in oxidative damage
Fast degrading polymer networks based on carboxymethyl chitosan
[EN] In this work macroporous membrane for mesenchymal stem cells, MSCs, transplant has been developed. The membranes support cell seeding and proliferation and completely degrade in less than one week in "in vitro" culture. The biodegradable material is a polymer network based on carboxymethyl chitosan( a water soluble modification of chitosan) crosslinked by poly(epsilon-caprolactone) PCL, fragments which are susceptible to hydrolytic degradation. Synthesis was performed in solution in a common solvent for the two components of the network. The gel fraction was assessed by extraction in selective solvents. Physical characterization of networks of varying composition included water sorption capacity and the crystallinity of poly(epsilon-caprolactone) in the network. In this way polymer networks are synthesized that lose between 66 +/- 5% and 89 +/- 1% of their mass when immersed in water for 28 days. The same weight loss is attained in enzymatic medium in only 4 days. Porcine bone marrow MSCs were seeded in macroporous membranes to show cell viability, and proliferation up to 7 days culture when the biomaterial is completely dissolved in the medium.Gamiz Gonzalez, MA.; Guldrís-Prada, P.; Antolinos Turpín, CM.; Ródenas Rochina, J.; Vidaurre, A.; Gómez Ribelles, JL. (2017). Fast degrading polymer networks based on carboxymethyl chitosan. Materials Today Communications. 10:54-66. doi:10.1016/j.mtcomm.2017.01.005S54661
A construção de uma arena ambiental para a conservação da biodiversidade marinha no Chile
Effect of Solution Composition on the Energy Production by Capacitive Mixing in Membrane-Electrode Assembly
The final edited version of the paper can be found at: http://pubs.acs.org/articlesonrequest/AOR-c9UMxSzGY3eiU5SENNgT The complete citation is: Ahualli, S.; et al. Effect of Solution Composition on the Energy Production by Capacitive Mixing in Membrane-Electrode Assembly. Journal of Physical Chemistry, 118(29): 15590-15599 (2014). DOI:10.1021/jp504461mOpen access in the Journal on May 26, 2015In this work we consider the extent to which the presence of multi-valent ions in solution modifies the equilibrium and dynamics of the energy production in a capacitive cell built with ion-exchange membranes in contact with high surface area electrodes. The cell potential in open circuit (OCV) is controlled by the difference between both membrane potentials, simulated as constant volume charge regions. A theoretical model is elaborated for steady state OCV, first in the case of monovalent solutions, as a reference. This is compared to the results in multi-ionic systems, containing divalent cations in concentrations similar to those in real sea water. It is found that the OCV is reduced by about 25 % (as compared to the results in pure NaCl solutions) due to the presence of the divalent ions, even in low concentrations. Interestingly, this can be related to the “uphill” transport of such ions against their concentration gradients. On the contrary, their effect on the dynamics of the cell potential is negligible in the case of highly charged membranes. The comparison between model predictions and experimental results shows a very satisfactory agreement, and gives clues for the practical application of these recently introduced energy production methods.The research leading to these results received funding from the European Union 7th
Framework Programme (FP7/2007-2013) under agreement No. 256868. Further financial
support from Junta de Andalucia, Spain (PE2012-FQM 694) is also acknowledged. One of us, M.M.F., received financial support throughan FPU grant from the Universityof Granada
Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV
The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8 TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
- …