59 research outputs found

    Event-plane dependent di-hadron correlations with harmonic vnv_n subtraction in a hydrodynamic model

    Full text link
    In this work, a hydrodynamic study of the di-hadron azimuthal correlations for the Au+Au collisions at 200 GeV is carried out. The correlations are evaluated using the ZYAM method for the centrality windows as well as the transverse momentum range in accordance with the existing data. Event-plane dependence of the correlation is obtained after the subtraction of contributions from the most dominant harmonic coefficients. In particular, the contribution from the triangular flow, v3v_3, is removed from the proper correlations following the procedure implemented by the STAR collaboration. The resultant structure observed in the correlations was sometimes attributed to the mini-jet dynamics, but the present calculations show that a pure hydrodynamic model gives a reasonable agreement with the main feature of the published data. A brief discussion on the physical content of the present findings is presented.Comment: 9 pages, 2 figure

    A conserved dimorphism-regulating histidine kinase controls the dimorphic switching in Paracoccidioides brasiliensis

    Get PDF
    Paracoccidioides brasiliensis and P. lutzii, thermally dimorphic fungi, are the causative agents of paracoccidioidomycosis (PCM). Paracoccidioides infection occurs when conidia or mycelium fragments are inhaled by the host, which causes the Paracoccidioides cells to transition to the yeast form. The development of disease requires conidia inside the host alveoli to differentiate into yeast cells in a temperature-dependent manner. We describe the presence of a two-component signal transduction system in P. brasiliensis, which we investigated by expression analysis of a hypothetical protein gene (PADG_07579) that showed high similarity with the dimorphism-regulating histidine kinase (DRK1) gene of Blastomyces dermatitidis and Histoplasma capsulatum. This gene was sensitive to environmental redox changes, which was demonstrated by a dose-dependent decrease in transcript levels after peroxide stimulation and a subtler decrease in transcript levels after NO stimulation. Furthermore, the higher PbDRK1 levels after treatment with increasing NaCl concentrations suggest that this histidine kinase can play a role as osmosensing. In the mycelium-yeast (M -> Y) transition, PbDRK1 mRNA expression increased 14-fold after 24 h incubation at 37A degrees C, consistent with similar observations in other virulent fungi. These results demonstrate that the PbDRK1 gene is differentially expressed during the dimorphic M -> Y transition. Finally, when P. brasiliensis mycelium cells were exposed to a histidine kinase inhibitor and incubated at 37A degrees C, there was a delay in the dimorphic M -> Y transition, suggesting that histidine kinases could be targets of interest for PCM therapy.CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico/Brazil)FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo/Brazil)Univ Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Unidade Jose Alencar, St Sao Nicolau 210,4 Floor, BR-04023900 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Ciencias Farmaceut, R Sao Nicolau 210, BR-09913030 Diadema, SP, BrazilUniv Fed Sao Paulo, Dept Microbiol Imunol & Parasitol, Unidade Jose Alencar, St Sao Nicolau 210,4 Floor, BR-04023900 Sao Paulo, BrazilUniv Fed Sao Paulo, Dept Ciencias Farmaceut, R Sao Nicolau 210, BR-09913030 Diadema, SP, BrazilCNPq: 478023/2013-8FAPESP: 2014/13961-1FAPESP: 2015/09727-6Web of Scienc

    Embodying compassion: A virtual reality paradigm for overcoming excessive self-criticism

    Get PDF
    Virtual reality has been successfully used to study and treat psychological disorders such as phobias and posttraumatic stress disorder but has rarely been applied to clinically-relevant emotions other than fear and anxiety. Self-criticism is a ubiquitous feature of psychopathology and can be treated by increasing levels of self-compassion. We exploited the known effects of identification with a virtual body to arrange for healthy female volunteers high in self-criticism to experience self-compassion from an embodied first-person perspective within immersive virtual reality. Whereas observation and practice of compassionate responses reduced self-criticism, the additional experience of embodiment also increased self-compassion and feelings of being safe. The results suggest potential new uses for immersive virtual reality in a range of clinical conditions.N/

    Wnt/ÎČ-Catenin Signaling Induces the Aging of Mesenchymal Stem Cells through the DNA Damage Response and the p53/p21 Pathway

    Get PDF
    Recent studies have demonstrated the importance of cellular extrinsic factors in the aging of adult stem cells. However, the effects of an aged cell–extrinsic environment on mesenchymal stem cell (MSC) aging and the factors involved remain unclear. In the current study, we examine the effects of old rat serum (ORS) on the aging of MSCs, and explore the effects and mechanisms of Wnt/ÎČ-catenin signaling on MSC aging induced by ORS treatment. Senescence-associated changes in the cells are examined with SA-ÎČ-galactosidase staining and ROS staining. The proliferation ability is detected by MTT assay. The surviving and apoptotic cells are determined using AO/EB staining. The results suggest that ORS promotes MSC senescence and reduces the proliferation and survival of cells. The immunofluorescence staining shows that the expression of ÎČ-catenin increases in MSCs of old rats. To identify the effects of Wnt/ÎČ-catenin signaling on MSC aging induced with ORS, the expression of ÎČ-catenin, GSK-3ÎČ, and c-myc are detected. The results show that the Wnt/ÎČ-catenin signaling in the cells is activated after ORS treatment. Then we examine the aging, proliferation, and survival of MSCs after modulating Wnt/ÎČ-catenin signaling. The results indicate that the senescence and dysfunction of MSCs in the medium containing ORS is reversed by the Wnt/ÎČ-catenin signaling inhibitor DKK1 or by ÎČ-catenin siRNA. Moreover, the expression of Îł-H2A.X, a molecular marker of DNA damage response, p16INK4a, p53, and p21 is increased in senescent MSCs induced with ORS, and is also reversed by DKK1 or by ÎČ-catenin siRNA. In summary, our study indicates the Wnt/ÎČ-catenin signaling may play a critical role in MSC aging induced by the serum of aged animals and suggests that the DNA damage response and p53/p21 pathway may be the main mediators of MSC aging induced by excessive activation of Wnt/ÎČ-catenin signaling

    Anti-Streptococcal activity of Brazilian Amazon Rain Forest plant extracts presents potential for preventive strategies against dental caries

    Get PDF
    Caries is a global public health problem, whose control requires the introduction of low-cost treatments, such as strong prevention strategies, minimally invasive techniques and chemical prevention agents. Nature plays an important role as a source of new antibacterial substances that can be used in the prevention of caries, and Brazil is the richest country in terms of biodiversity. OBJECTIVE: In this study, the disk diffusion method (DDM) was used to screen over 2,000 Brazilian Amazon plant extracts against Streptococcus mutans. MATERIAL AND METHODS: Seventeen active plant extracts were identified and fractionated. Extracts and their fractions, obtained by liquid-liquid partition, were tested in the DDM assay and in the microdilution broth assay (MBA) to determine their minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs). The extracts were also subjected to antioxidant analysis by thin layer chromatography. RESULTS: EB271, obtained from Casearia spruceana, showed significant activity against the bacterium in the DDM assay (20.67±0.52 mm), as did EB1129, obtained from Psychotria sp. (Rubiaceae) (15.04±2.29 mm). EB1493, obtained from Ipomoea alba, was the only extract to show strong activity against Streptococcus mutans (0.08 mg/mL<MIC<0.16 mg/mL; MBC=0.16 mg/mL) in the MBA. CONCLUSIONS: The active extracts, discovered in the Amazon rain forest, show potential as sources of new antibacterial agents for use as chemical coadjuvants in prevention strategies to treat caries

    Mitochondrial physiology

    Get PDF
    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology

    Get PDF
    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery
    • 

    corecore