487 research outputs found

    Restablecimiento de una nueva normalidad biomecánica en las graves deformidades de la rodilla

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    En las graves alteraciones morfo-estructurales de la rodilla, con inestabilidad en varusvalgus, las prótesis vinculadas a bisagra simple, tendían a fallar. El presente trabajo se propone evidenciar que, en tales situaciones, la prótesis vinculada a rotación representa la solución más idónea para el restablecimiento de una nueva normalidad. 18 pacientes (13 mujeres y 5 hombres) con edad media de 68 años han sido sometidos a intervención para colocar prótesis de rodilla. Ha sido utilizado el implante Endo-Model® de Waldemar Link®, prótesis vinculada a rotación. El follow-up medio es de 19 meses con controles a 2, 3, 6 y 12 meses y después anuales. Los resultados han sido: óptimo para 17 pacientes y bueno para 1 paciente, en el cual se ha verificado la ruptura post-operatoria del tendón cuadricipital. Nuestra casuística muestra resultados comparables a los de otros autores. No hemos tenido movilizaciones asépticas o sépticas, ni complicaciones médicas intraoperatorias y post-operatorias. Consideramos que, en presencia de la correcta indicación clínica, la utilización de la prótesis vinculada a rotación es preferible a la de deslizamiento porque disminuye el riesgo de una movilización precoz del implante y del desgaste anormal de los componentes protésicos, restableciendo una nueva normalidad biomecánica.Peer Reviewe

    Facial emotion recognition in children and adolescents with specific learning disorder

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    (1) Background: Some recent studies suggest that children and adolescents with different neurodevelopmental disorders perform worse in emotions recognition through facial expressions (ER) compared with typically developing peers. This impairment is also described in children with Specific Learning Disorders (SLD), compromising their scholastic achievement, social functioning, and quality of life. The purpose of our study is to evaluate ER skills in children and adolescents with SLD compared to a control group without learning disorders, and correlate them with intelligence and executive functions. (2) Materials and Methods: Our work is a cross-sectional observational study. Sixty-three children and adolescents aged between 8 and 16 years, diagnosed with SLD, and 32 sex/age-matched controls without learning disorders were recruited. All participants were administered standardized neuropsychological tests, evaluating facial emotion recognition (NEPSY-II), executive functions (EpiTrack Junior), and intelligence profile (WISC-IV). (3) Results: Emotion recognition mean score was significantly lower in the SLD group than in the controls group on the Mann–Whitney U test for unpaired samples (p < 0.001). The SLD group performed significantly lower than the control group in their abilities to identify neutral expressions, happiness, sadness, anger, and fear compared to controls (p < 0.001). ER scores were positively correlated to the executive functions scores. There was no correlation with the Total Intelligence Quotient scores but there is a significant positive correlation with Working Memory Index and Processing Speed Index measured by WISC.IV. (4) Conclusions: Our study showed that children and adolescents with Specific Learning Disorders have facial emotion recognition impairment when compared with a group of peers without learning disorders. ER abilities were independent of their global intelligence but potentially related to executive functions

    39 hints to facilitate the use of semantics for data on agriculture and nutrition

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    In this paper, we report on the outputs and adoption of the Agrisemantics Working Group of the Research Data Alliance (RDA), consisting of a set of recommendations to facilitate the adoption of semantic technologies and methods for the purpose of data interoperability in the field of agriculture and nutrition. From 2016 to 2019, the group gathered researchers and practitioners at the crossing point between information technology and agricultural science, to study all aspects in the life cycle of semantic resources: Conceptualization, edition, sharing, standardization, services, alignment, long term support. First, the working group realized a landscape study, a study of the uses of semantics in agrifood, then collected use cases for the exploitation of semantics resources – a generic term to encompass vocabularies, terminologies, thesauri, ontologies. The resulting requirements were synthesized into 39 “hints” for users and developers of semantic resources, and providers of semantic resource services. We believe adopting these recommendations will engage agrifood sciences in a necessary transition to leverage data production, sharing and reuse and the adoption of the FAIR data principles. The paper includes examples of adoption of those requirements, and a discussion of their contribution to the field of data science

    Zn-induced interactions between SARS-CoV-2 orf7a and BST2/Tetherin

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    We present in this work a first X-ray Absorption Spectroscopy study of the interactions of Zn with human BST2/tetherin and SARS-CoV-2 orf7a proteins as well as with some of their complexes. The analysis of the XANES region of the measured spectra shows that Zn binds to BST2, as well as to orf7a, thus resulting in the formation of BST2-orf7a complexes. This structural information confirms the the conjecture, recently put forward by some of the present Authors, according to which the accessory orf7a (and possibly also orf8) viral protein are capable of interfering with the BST2 antiviral activity. Our explanation for this behavior is that, when BST2 gets in contact with Zn bound to the orf7a Cys(15) ligand, it has the ability of displacing the metal owing to the creation of a new disulfide bridge across the two proteins. The formation of this BST2-orf7a complex destabilizes BST2 dimerization, thus impairing the antiviral activity of the latter

    The role of Zn ions in the interaction between SARS-CoV-2 orf7a protein and BST2/tetherin

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    In this paper, we provide evidence that Zn2+ ions play a role in the SARS-CoV-2 virus strategy to escape the immune response mediated by the BST2-tetherin host protein. This conclusion is based on sequence analysis and molecular dynamics simulations as well as X-ray absorption experiments

    In cellulo serial crystallography of alcohol oxidase crystals inside yeast cells

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    The possibility of using femtosecond pulses from an X-ray free-electron laser to collect diffraction data from protein crystals formed in their native cellular organelle has been explored. X-ray diffraction of submicrometre-sized alcohol oxidase crystals formed in peroxisomes within cells of genetically modified variants of the methylotrophic yeast Hansenula polymorpha is reported and characterized. The observations are supported by synchrotron radiation-based powder diffraction data and electron microscopy. Based on these findings, the concept of in cellulo serial crystallography on protein targets imported into yeast peroxisomes without the need for protein purification as a requirement for subsequent crystallization is outlined

    Metal ion binding in wild-type and mutated frataxin: a stability study

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    This work studies the stability of wild-type frataxin and some of its variants found in cancer tissues upon Co2+ binding. Although the physiologically involved metal ion in the frataxin enzymatic activity is Fe2+, as it is customarily done, Co2+ is most often used in experiments because Fe2+ is extremely unstable owing to the fast oxidation reaction Fe2+ → Fe3+. Protein stability is monitored following the conformational changes induced by Co2+ binding as measured by circular dichroism, fluorescence spectroscopy, and melting temperature measurements. The stability ranking among the wild-type frataxin and its variants obtained in this way is confirmed by a detailed comparative analysis of the XAS spectra of the metal-protein complex at the Co K-edge. In particular, a fit to the EXAFS region of the spectrum allows positively identifying the frataxin acidic ridge as the most likely location of the metal-binding sites. Furthermore, we can explain the surprising feature emerging from a detailed analysis of the XANES region of the spectrum, showing that the longer 81-210 frataxin fragment has a smaller propensity for Co2+ binding than the shorter 90-210 one. This fact is explained by the peculiar role of the N-terminal disordered tail in modulating the protein ability to interact with the metal

    Anti-EGFR Therapy in Metastatic Small Bowel Adenocarcinoma: Myth or Reality?

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    Background: Due to the relative rarity of small bowel adenocarcinoma (SBA), prospective trials, helping to guide therapeutic decisions, are lacking and the optimal therapy for advanced SBA is unknown. The role of targeted agents, such as anti\u2013epidermal growth factor receptor (EGFR) and anti\u2013vascular endothelial growth factor (VEGF), is unknown. Patients and Methods: This is a retrospective multicenter observational study that included patients with metastatic SBA treated with anti-EGFR antibodies (cetuximab or panitumumab) \ub1 chemotherapy in the first (I) or second (II) line. Results: Thirteen patients with metastatic SBA, recruited from 5 Italian referral institutions, were included in the present retrospective analysis. All patients received anti-EGFR inhibitors as a single agent or in association with chemotherapy. More common G2 treatment\u2013related side effects were skin reaction (8 patients, 53.8%), hypomagnesemia (6 patients, 46.2%), and diarrhea (8 patients, 61.5%). Grade 3 diarrhea was observed in only 1 patient. Conjunctivitis was not reported in any patients. Grade 4 toxicity was not reported. In the overall population, median progression-free survival was 5.526 months (95% confidence interval [CI]: 3.684-12.467). Median overall survival was 15.86 months (95% CI: 14.43-24.30). Complete response was observed in 15% of patients, partial response in 39% of patients, stable disease in 23% of patients, and progression disease in 15% of patients. Conclusions: In this retrospective analysis, anti-EGFR inhibitors showed to be a suitable addendum to chemotherapy in the I and II line, with an excellent tolerance and safety profile both in I and II line

    The Implications of Sequential Investment in the Property Rights Theory of the Firm

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    In the property rights theory of the firm, control over assets (ownership) affords bargaining power in the case of re-negotiation, providing incentives for parties to make relationship specific investments. The models predict that property rights will be allocated so as to maximise surplus generated from investment. However, these models assume that investments are made simultaneously. In this thesis I extend the standard property-rights framework to allow for sequential investment; the model allows for two investment periods. If a party invests first (ex-ante), they sink their investment before any contracting is possible. The parties that invest second (ex-post) do so after some aspects of the project are tangible, so that they can contract on (at least some) of their investment costs. As well as being empirically relevant, sequencing has several important theoretical implications. First, if a party gets to invest second, then – ceteris paribus – it has a greater incentive to invest. Second, the investment of parties that invest first are affected by a more than one influence. Anticipating higher ex-post investment, they can have a greater incentive to increase their investments. However, higher ex-post investment leads to greater costs being borne by the ex-ante investors (via the cost sharing contracts); this reduces ex-ante incentives to invest. Overall either effect can dominate so that ex-ante investment can either increase or decrease as a result of sequential investment. Third, as noted, sequencing of investment provides the possibility to (partially) contract on ex-post investment and costs. This is an additional method of providing incentives to invest, beyond the allocation of property rights themselves. Consequently, ex-post investors can be protected (and be provided incentives to invest) via these contracts, whereas ex-ante investors –who can not contract on their investments at all – are more likely to require the protection of property rights (through the allocation of asset ownership). The addition of sequential investment alters some of the predictions of the standard models. For example, previously the literature found that if all assets are complements at the margin all agents should have access to all assets (Bel (2005)). However, when investment sequencing is possible, making a control structure more inclusive (increasing the number of agents who have access to assets) can reduce the incentives of the ex-ante investors, decreasing overall surplus; this is because increasing the property rights of ex-post investors increases the marginal costs borne by ex-ante investors, effectively reducing their claim on surplus, diminishing their incentives to invest. This result contradicts Bel (2005), and shows that even when all assets are complimentary at the margin allocating access rights can be detrimental to incentives. Furthermore, if assets are substitutes at the margin then transfer of assets from ex-ante investors to ex-post investors can increase ex-ante investment and surplus. This counter intuitive result can occur in the case when decreasing ex-post investment is necessary to provide an incentive to ex-ante investors to increase their investments.Discipline of Economic
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