1,519 research outputs found

    Problems Affecting Labor

    Get PDF
    Much experimental work has been devoted in comparing the folding behavior of proteins sharing the same fold but different sequence. The recent design of proteins displaying very high sequence identities but different 3D structure allows the unique opportunity to address the protein-folding problem from a complementary perspective. Here we explored by ℙ-value analysis the pathways of folding of three different heteromorphic pairs, displaying increasingly high-sequence identity (namely, 30%, 77%, and 88%), but different structures called G A (a 3-α helix fold) and G B (an α/β fold). The analysis, based on 132 site-directed mutants, is fully consistent with the idea that protein topology is committed very early along the pathway of folding. Furthermore, data reveals that when folding approaches a perfect two-state scenario, as in the case of the G A domains, the structural features of the transition state appear very robust to changes in sequence composition. On the other hand, when folding is more complex and multistate, as for the G Bs, there are alternative nuclei or accessible pathways that can be alternatively stabilized by altering the primary structure. The implications of our results in the light of previous work on the folding of different members belonging to the same protein family are discussed

    A new genus of microphthalmic Rhytirrhinini from Andean leaf litter (Coleoptera: Curculionidae)

    Get PDF
    Fil: Anderson, Robert S.. Research Division. Canadian Museum of Nature. Ottawa; CanadaFil: Morrone, Juan José. Laboratorio de Sistemática y Biología Evolutiva (LASBE). Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

    Indiana University’s Affordable E-text Model and Strategies to Increase Impact Beyond Savings – The Evolution of Affordable Content Efforts in the Higher Education Environment: Programs, Case Studies, and Examples

    Get PDF
    Hyperinflation in overall college costs and in textbook prices in the last decade is no secret, as demonstrated by extensive coverage in several major news reports. High textbook prices are deterring students from buying required textbooks or taking courses that have high-priced textbooks. The cost of textbooks, in other words, gets in the way of learning, and derails students from degrees they want to pursue in college. Many universities and even state systems (Acker, 2011) are trying to lower the cost of textbooks for students. Indiana University (IU) started a pilot e-text program in 2009 to make publisher/commercial content more affordable. The program is based on an inclusive access model, addressed in more detail in the previous two chapters of this book. After a successful pilot phase, the IU eTexts Program moved into full production. As of March, 2018, it has served close to 200,000 students in over 9,000 course sections, and saved them more than $13 million in textbook costs. In this chapter, we explain the Indiana University eText model, the research efforts behind the program, support for faculty and students, and the factors behind the program’s success

    Differential effects on membrane permeability and viability of human keratinocyte cells undergoing very low intensity megasonic fields

    Get PDF
    Among different therapeutic applications of Ultrasound (US), transient membrane sonoporation (SP) - a temporary, non-lethal porosity, mechanically induced in cell membranes through US exposure - represents a compelling opportunity towards an efficient and safe drug delivery. Nevertheless, progresses in this field have been limited by an insufficient understanding of the potential cytotoxic effects of US related to the failure of the cellular repair and to the possible activation of inflammatory pathway. In this framework we studied the in vitro effects of very low-intensity US on a human keratinocyte cell line, which represents an ideal model system of skin protective barrier cells which are the first to be involved during medical US treatments. Bioeffects linked to US application at 1 MHz varying the exposure parameters were investigated by fluorescence microscopy and fluorescence activated cell sorting. Our results indicate that keratinocytes undergoing low US doses can uptake drug model molecules with size and efficiency which depend on exposure parameters. According to sub-cavitation SP models, we have identified the range of doses triggering transient membrane SP, actually with negligible biological damage. By increasing US doses we observed a reduced cells viability and an inflammatory gene overexpression enlightening novel healthy relevant strategies

    Ultrasound delivery of Surface Enhanced InfraRed Absorption active gold-nanoprobes into fibroblast cells: a biological study via Synchrotron-based InfraRed microanalysis at single cell level

    Get PDF
    Ultrasound (US) induced transient membrane permeabilisation has emerged as a hugely promising tool for the delivery of exogenous vectors through the cytoplasmic membrane, paving the way to the design of novel anticancer strategies by targeting functional nanomaterials to specific biological sites. An essential step towards this end is the detailed recognition of suitably marked nanoparticles in sonoporated cells and the investigation of the potential related biological effects. By taking advantage of Synchrotron Radiation fourier transform infrared micro-spectroscopy (SR-microftiR) in providing highly sensitive analysis at the single cell level, we studied the internalisation of a nanoprobe within fibroblasts (NIH-3T3) promoted by low-intensity US. To this aim we employed 20 nm gold nanoparticles conjugated with the IR marker 4-aminothiophenol. The significant Surface Enhanced Infrared Absorption provided by the nanoprobes, with an absorbance increase up to two orders of magnitude, allowed us to efficiently recognise their inclusion within cells. Notably, the selective and stable SR- microftiR detection from single cells that have internalised the nanoprobe exhibited clear changes in both shape and intensity of the spectral profile, highlighting the occurrence of biological effects. Flow cytometry, immunofluorescence and murine cytokinesis-block micronucleus assays confirmed the presence of slight but significant cytotoxic and genotoxic events associated with the US-nanoprobe combined treatments. our results can provide novel hints towards US and nanomedicine combined strategies for cell spectral imaging as well as drug delivery-based therapies

    Introduction Special Issue on Physical Spaces

    Get PDF

    Homeless persons and migrants in precarious housing conditions and COVID-19 pandemic: peculiarities and prevention strategies

    Get PDF
    Homeless persons and migrants in precarious housing conditions are vulnerable populations that have been peculiarly impacted by the Coronavirus Disease 19 (COVID-19) pandemic. These populations are more at risk of contracting COVID-19 as they often find it difficult to adhere to public health directives and, if exposed, may be more susceptible to illness or death due to the higher prevalence of underlying physical and mental comorbidities compared to the general population. In addition, vulnerable populations may have limited access to essential diagnostics and treatments, thus leading to untreated COVID-19 cases and their development into more severe forms. Health, social and government agencies should collaborate to develop services that support these communities, in accordance with the World Health Organization principles. Migrant and homeless centers have a central role, as they provide a significant contribution to prevent infection spread and favor access to early medical treatment to those affected, thus preventing more severe forms of infection

    investigation of integrated organic rankine cycles and wind turbines for micro scale applications

    Get PDF
    Abstract The aim of this work is the investigation of the performance of an innovative biomass/wind energy integrated system for Combined Heat and Power (CHP) generation in small-scale applications. The system is based on an Organic Rankine Cycle (ORC) fed with biomass and a wind turbine (WT). The ORC and WT sub-systems operate in parallel to produce the required electrical energy and an auxiliary boiler provides thermal energy if the CHP output is low. A preliminary investigation is performed to define the proper size of the wind turbine. Afterwards, the analysis is focused on the integrated system. In particular, the application to the Italian residential sector is analysed. Results illustrate that hybridisation improves the global conversion efficiency, by reducing the biomass consumption and overcoming the intermittency of the wind source. When the wind source is significant, the ORC system can be switched off or operated at partial load

    Analysis of multi-source energy system for small-scale domestic applications. Integration of biodiesel, solar and wind energy

    Get PDF
    The paper aims at analysing the energy performance of an innovative multi-source energy system for residential small-scale combined heat and power (CHP) applications. The integrated system is based on an Organic Rankine Cycle (ORC) fuelled by biodiesel, a wind turbine, and a photovoltaic unit. The application refers to the Italian residential sector. The ORC system operates in order to satisfy the thermal demand of domestic users while wind and solar based sub-systems work in parallel to increase the electric self-consumption rate. An auxiliary boiler provides thermal energy when the CHP thermal output is low. Furthermore, when the solar and/or wind sources are significant, the ORC can be switched-off or operated at partial load.A preliminary investigation is performed to define the proper size of the ORC unit. Afterwards, the analysis is focused on a multi-variable optimisation of the integrated system. In particular, the nominal power of the wind turbine and photovoltaic units have been found in order to guarantee a proper trade-off between electric self-consumed and surplus energy. Keywords: Biodiesel, Combined heat and power, Multi-source generation, Organic Rankine cycle, Solar, Win

    The Epigenetics of the Endocannabinoid System

    Get PDF
    The endocannabinoid system (ES) is a cell-signalling system widely distributed in biological tissues that includes endogenous ligands, receptors, and biosynthetic and hydrolysing machineries. The impairment of the ES has been associated to several pathological conditions like behavioural, neurological, or metabolic disorders and infertility, suggesting that the modulation of this system may be critical for the maintenance of health status and disease treatment. Lifestyle and environmental factors can exert long-term effects on gene expression without any change in the nucleotide sequence of DNA, affecting health maintenance and influencing both disease load and resistance. This potentially reversible "epigenetic" modulation of gene expression occurs through the chemical modification of DNA and histone protein tails or the specific production of regulatory non-coding RNA (ncRNA). Recent findings demonstrate the epigenetic modulation of the ES in biological tissues; in the same way, endocannabinoids, phytocannabinoids, and cannabinoid receptor agonists and antagonists induce widespread or gene-specific epigenetic changes with the possibility of trans-generational epigenetic inheritance in the offspring explained by the transmission of deregulated epigenetic marks in the gametes. Therefore, this review provides an update on the epigenetics of the ES, with particular attention on the emerging role in reproduction and fertility
    • …
    corecore