Universidad de Zaragoza

Repositorio Universidad de Zaragoza
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    55969 research outputs found

    The effect of ultrafine WO3 nanoparticles on the organization of thylakoids enriched in photosystem II and energy transfer in photosystem II complexes

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    In this work, a new approach to construct self-assembled hybrid systems based on natural PSII-enriched thylakoid membranes (PSII BBY) is demonstrated. Superfine m-WO3 NPs (≈1–2 nm) are introduced into PSII BBY. Transmission electron microscopy (TEM) measurements showed that even the highest concentrations of NPs used did not degrade the PSII BBY membranes. Using atomic force microscopy (AFM), it is shown that the organization of PSII BBY depends strongly on the concentration of NPs applied. This proved that the superfine NPs can easily penetrate the thylakoid membrane and interact with its components. These changes are also related to the modified energy transfer between the external light-harvesting antennas and the PSII reaction center, shown by absorption and fluorescence experiments. The biohybrid system shows stability at pH 6.5, the native operating environment of PSII, so a high rate of O2 evolution is expected. In addition, the light-induced water-splitting process can be further stimulated by the direct interaction of superfine WO3 NPs with the donor and acceptor sides of PSII. The water-splitting activity and stability of this colloidal system are under investigation

    Nanoparticles Stokes radius assessment through permeability coefficient determination within a new stratified epithelium on-chip model

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    Tissue barrier permeability plays a crucial role in determining the selective transport of substances across epithelial tissues, including drugs, cosmetic substances, and chemicals. The ability of these substances to cross through tissue barriers affects their absorption into the bloodstream and ultimately their effectiveness. Therefore, the determination of their permeability on these type of tissue barriers represents a useful tool for pharmaceutical and cosmetic industries as well as for toxicological studies. In this regard, microfluidic devices and organ-on-chip technologies are becoming more important to generate reliable data. We have designed and performed an alternative new stratified epithelia-on-chip model that allows to correlate the Stokes radius and the diffusion of molecules and/or nanoformulations through the in vitro generated barrier and establish a system suitable for the analysis of diffusion through stratified epithelium. Thus, extrapolating from experimental data we can predict the Stokes radius for unknown fluorescent labelled particles within a molecular size range, such as gold nanoparticles

    Cytomegalovirus associated rectal ulcer as manifestation of primary HIV infection

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    We present the case of a 40-year-old male sent for fatigue, mild weight loss and rectal bleeding for 2 months, neither fever nor diarrhea. He referred unprotected intercourse. Blood test revealed mild elevation of transaminases. We requested serologies, with positive CMV IgG and CMV plasma levels of 47UI/ml (PCR), and a negative result of the rest of hepatotropic viruses. Abdominal ultrasound was normal and during colonoscopy we observed an ulcer in lower rectum, with negative biopsies for malignancy and a positive immunohistochemistry (IHC) for CMV. We amplified the serologic analysis and detected positive antibodies for the human immunodeficiency virus (HIV), with a viral load of 50500 copies/ml, negative p24 antigen and CD4+ cell count of 900 cells/mm3 (30%). Rest of serologies and triple-site testing were negative. We referred the patient to the infectious disease consultation and they started antiretroviral therapy (ART). We decided a watchful waiting approach for the rectal ulcer with close endoscopic follow-up, with early healing and complete resolution

    A systematic approach to the motivations for earnings management: a literature review

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    Earnings management literature attempts to understand why managers manipulate earnings. Our paper presents a review of growing body of literature on motivations for the earnings manipulation. In consequence, our objective is to provide an ample classification of the reasons. A selection of leading papers was reviewed systematically from 1985 to early 2019 resulting in 383 articles. The results of the paper are important for both theoretical and empirical researches on the earnings management. For one side, we offer a theoretical discussion on the incentives and factors; on the other side, the paper aims to highlight recent progresses in the field. Screening, classifying and systematic review of earnings management literature do not only generate a structured overview of the work performed in this area during more than thirty years, but it also provides insights for further research. Our findings confirm that earnings management topic remains a fertile ground for academic research. Second, although there are many possible motives for managing earnings, the spotlight has been mainly on those incentives that are related to the stock market. Third, in terms of the factors and characteristics of the environment, the impact of institutional factors (investor protection, ownership concentration, legal enforcement) is especially accentuated by the authors. Finally, our research confirms that there are still many other opportunities to research. Therefore, in the last section we identify potential line of investigations

    Emotional education as coping strategy for exhaustion and dysfunctional eating habits

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    Work shifts affect eating habits, social relationships in the workplace, and, more broadly, the physical and mental health of health professionals. The aim of this research was to differentiate BMI, eating behavior, and burnout between shift and non-shift nurses. The study involved 194 nurses (63% of whom work shifts and 37% of whom do not) who completed sociodemographic questionnaires, eating behavior questionnaires, and an exhaustion inventory (Maslach Burnout Inventory). The results showed that shift nurses were twice as likely to skip meals and obtained higher exhaustion scores. In conclusion, the need to establish prevention plans to promote adequate food intake and healthier eating behaviors among health professionals, while promoting specialized training in emotional education in order to prevent mental health problems, is emphasized

    Viscoelastic properties of porcine lenses using optical coherence elastography and inverse finite element analysis

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    The mechanical properties of the crystalline lens are crucial in determining the changes in lens shape that occur during the accommodation process and are also a major factor in the development of the two most prevalent age-related diseases of the lens, presbyopia and cataracts. However, a comprehensive understanding of these properties is currently lacking. Previous methods for characterizing the mechanical properties of the lens have been limited by the amount of data that could be collected during each test and the lack of complex material modeling. These limitations were mainly caused by the lack of imaging techniques that can provide data for the entire crystalline lens and the need for more complex models to describe the non-linear behavior of the lens. To address these issues, we characterized the mechanical properties of 13 porcine lenses during an ex vivo micro-controlled-displacement compression experiment using optical coherence elastography (OCE) and inverse finite element analysis (iFEA). OCE allowed us to quantify the internal strain distribution of the lens and differentiate between the different parts of the lens, while iFEA enabled us to implement an advanced material model to characterize the viscoelasticity of the lens nucleus and the relative stiffness gradient in the lens. Our findings revealed a pronounced and rapid viscoelastic behavior in the lens nucleus (g1 = 0.39 ± 0.13, τ1 = 5.01 ± 2.31 s) and identified the lens nucleus as the stiffest region, with a stiffness 4.42 ± 1.20 times greater than the anterior cortex and 3.47 ± 0.82 times greater than the posterior cortex. However, due to the complex nature of lens properties, it may be necessary to employ multiple tests simultaneously for a more comprehensive understanding of the crystalline lens

    Adaptive Dynamics of Settlement Models in the Urban Landscape of Termez (Uzbekistan) from c. 300 BCE to c. 1400 CE

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    The archaeological site of Ancient Termez is located in southern Uzbekistan. Despite the arid environment, the city benefited from its strategic position near two rivers, the Amu Darya and the Surkhan Darya. Its significance was mainly related to the expansion of trade routes connecting Eurasia. The city comprises several enclosures that attest long-term human-environment interactions. In order to identify the adaptive dynamics of the settlement models during an extended chronology covering the period from c. 300 BCE to c. 1220 CE (Greco-Bactrian/Yuezhi, Kushan, Kushano-Sasanian, and Islamic periods), a multidisciplinary study has been carried out, which includes: (1) archaeological excavations in several areas of the urban complex; (2) pedestrian surveying inside some enclosures and in the urban periphery; (3) an aerial survey based on high-resolution satellite imagery; (4) AMS dating of charcoal and bone samples; (5) archaeobotanical investigation through anthracological analysis; (6) zooarchaeological studies. The results point to variations in the development of the inhabited spaces, in which abandonment and occupation took place. The zooarchaeological and archaeobotanical data demonstrate the exploitation of natural resources in different environments (i.e., arid areas and irrigated land) and a certain evolution during the period considered

    Synthesis of Ir Catalysts Featuring Amide-functionalized NHC Ligands and Survey of their Activity on Formic Acid Dehydrogenation

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    2 a and 2 b, [Ir(CI)(COD)(NHC)] (COD=1,5-cyclooctadiene), have been prepared via transmetallation from NHC−Ag complexes. [Rh(CI)(COD)(NHC)] (4) was prepared analogously. [Ir({κ-C,N-(NHC-acetamide−1H)}(COD)] (3 c) has been synthesized via transmetallation from the deprotonated NHC−Ag complex. [IrCp*({κ-C,N-(NHC-acetamide−1H)}] (5) (Cp*=pentamethylcyclopentadienyl), has been obtained analogously. [Ir(CI)(CO)2(NHC)] (6) and [Ir({κ-C,N-(NHC-acetamide−1H)}(CO)2] (7) have been prepared by carbonylation of 2 b and 3 c, respectively. The catalytic activity of these complexes has been evaluated in the dehydrogenation of formic acid, under solventless conditions, in the presence of water as a cosolvent, and in a 5 : 2 HCOOH/Et3N mixture, with the best TOF values being obtained in the case of the latter. Stoichiometric experiments suggest COD hydrogenation as the preactivation step

    Spheresomes are the main extracellular vesicles in low-grade gliomas

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    Cancer progression and its impact on treatment response and prognosis is deeply regulated by tumour microenvironment (TME). Cancer cells are in constant communication and modulate TME through several mechanisms, including transfer of tumour-promoting cargos through extracellular vesicles (EVs) or oncogenic signal detection by primary cilia. Spheresomes are a specific EV that arise from rough endoplasmic reticulum–Golgi vesicles. They accumulate beneath cell membrane and are released to the extracellular medium through multivesicular spheres. This study describes spheresomes in low-grade gliomas using electron microscopy. We found that spheresomes are more frequent than exosomes in these tumours and can cross the blood–brain barrier. Moreover, the distinct biogenesis processes of these EVs result in unique cargo profiles, suggesting different functional roles. We also identified primary cilia in these tumours. These findings collectively contribute to our understanding of glioma progression and metastasis

    S12-3 School-based physical activity promotion in a cross-cultural context: interventions from France and Spain

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    Abstract citation ID: ckad133.060 S12-3 School-based physical activity promotion in a cross-cultural context: interventions from France and Spai


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