17 research outputs found

    Differential Calculus on Manifolds with a Boundary. Applications

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    This paper contains a set of lecture notes on manifolds with boundary and corners, with particular attention to the space of quantum states. A geometrically inspired way of dealing with these kind of manifolds is presented,and explicit examples are given in order to clearly illustrate the main ideas.Comment: 42 pages, 6 figures, accepted for publication in International Journal of Geometric Methods in Modern Physic

    Associations between depressive symptoms and disease progression in older patients with chronic kidney disease: results of the EQUAL study

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    Background Depressive symptoms are associated with adverse clinical outcomes in patients with end-stage kidney disease; however, few small studies have examined this association in patients with earlier phases of chronic kidney disease (CKD). We studied associations between baseline depressive symptoms and clinical outcomes in older patients with advanced CKD and examined whether these associations differed depending on sex. Methods CKD patients (>= 65 years; estimated glomerular filtration rate <= 20 mL/min/1.73 m(2)) were included from a European multicentre prospective cohort between 2012 and 2019. Depressive symptoms were measured by the five-item Mental Health Inventory (cut-off <= 70; 0-100 scale). Cox proportional hazard analysis was used to study associations between depressive symptoms and time to dialysis initiation, all-cause mortality and these outcomes combined. A joint model was used to study the association between depressive symptoms and kidney function over time. Analyses were adjusted for potential baseline confounders. Results Overall kidney function decline in 1326 patients was -0.12 mL/min/1.73 m(2)/month. A total of 515 patients showed depressive symptoms. No significant association was found between depressive symptoms and kidney function over time (P = 0.08). Unlike women, men with depressive symptoms had an increased mortality rate compared with those without symptoms [adjusted hazard ratio 1.41 (95% confidence interval 1.03-1.93)]. Depressive symptoms were not significantly associated with a higher hazard of dialysis initiation, or with the combined outcome (i.e. dialysis initiation and all-cause mortality). Conclusions There was no significant association between depressive symptoms at baseline and decline in kidney function over time in older patients with advanced CKD. Depressive symptoms at baseline were associated with a higher mortality rate in men

    Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

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    Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

    Parameter identification of a second-gradient model for the description of pantographic structures in dynamic regime

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    Pantographic structures are examples of metamaterials with such a microstructure that higher-gradient terms' role is increased in the mechanical response. In this work, we aim for validating parameters of a reduced-order model for a pantographic structure. Experimental tests are carried out by applying forced oscillation to 3D-printed specimens for a range of frequencies. A second-gradient coarse-grained nonlinear model is utilized for obtaining a homogenized 2D description of the pantographic structure. By inverse analysis and through an automatized optimization algorithm, the parameters of the model are identified for the corresponding pantographic structure. By comparing the displacement plots, the performance of the model and the identified parameters are assessed for dynamic regime. Qualitative and quantitative analyses for different frequency ranges are performed. A good agreement is present far away from the eigenfrequencies. The discrepancies near the eigenfrequencies are a possible indication of the significance of higher-order inertia in the model

    Light-evoked hyperpolarization and silencing of neurons by conjugated polymers

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    The ability to control and modulate the action potential firing in neurons represents a powerful tool for neuroscience research and clinical applications. While neuronal excitation has been achieved with many tools, including electrical and optical stimulation, hyperpolarization and neuronal inhibition are typically obtained through patch-clamp or optogenetic manipulations. Here we report the use of conjugated polymer films interfaced with neurons for inducing a light-mediated inhibition of their electrical activity. We show that prolonged illumination of the interface triggers a sustained hyperpolarization of the neuronal membrane that significantly reduces both spontaneous and evoked action potential firing. We demonstrate that the polymeric interface can be activated by either visible or infrared light and is capable of modulating neuronal activity in brain slices and explanted retinas. These findings prove the ability of conjugated polymers to tune neuronal firing and suggest their potential application for the in-vivo modulation of neuronal activity

    Knowledge on the risk and practices on self-diagnosis and self-medication form common colds

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    This study utilized a descriptive correlational research design. Snowball sampling technique was used in the study. Barangay Timalan Balsahan have a total population of 646 and Barangay San Roque have a total population of 155. The overall population is 801 and the sample size obtained is 400. This study used a three-part self-made questionnaire that determines the knowledge on the risk and practices on self-diagnosis and self-medication for common colds. The data gathered were subjected to statistical treatments such as frequency distribution, percentage, mean, standard deviation, t-test, Pearson’s r, F-test or analysis of variance (ANOVA) and Duncan’s multiple range tests. Based on the findings of the study, the following conclusions were drawn: 1) Majority of the respondents were 29 years old and below, high school graduate, have a monthly family income of 10,000php, and belonged to the nuclear family type; 2) The respondents have an overall average knowledge on the risk of self-diagnosis and self-medication for common colds. Likewise, the majority of the respondents belonged to the average knowledge on the risk of self-diagnosis and self-medication; 3) The respondents have an overall moderate practice on self-diagnosis and self-medication for common colds. Likewise, majority of the respondents have a moderate level of practice on self-diagnosis and self-medication for common colds; 4) There were no significant differences in knowledge of the respondents on the risk of self-diagnosis and self –medication for common colds when groups according to age, educational attainment, monthly family income and type of family; 5) There was no significant difference in the practices of the respondents on the risk of self-diagnosis and self –medication for common colds when groups according to age. However, there were significant differences in the practices of the respondents with regards to self-diagnosis and self –medication for common colds when groups according to educational attainment, monthly family income, and type of family. Considering DMRT, respondents who graduated from college significantly have a better practice when compared to respondents who graduated elementary and high school. On the other hand, respondents belonged to the nuclear family, extended family and blended family significantly have a better practice when compared to respondents who belong a never married family; 6) There was no significant relationship between the knowledge of the respondent on the risk and practices on self-diagnosis and self-medication for common colds

    Polymer-Based Photocatalytic Hydrogen Generation

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    The study of the complex interfaces between organic semiconductors and liquids have recently gained increasing attention due to their interesting applications as biosensors in biological environments, in photovoltaics, and in bioinspired light-harvesting systems. Here, we report a detailed characterization of the interface between polymer films and electrolytic solutions, both by photocurrent spectroscopy and electrochemical measurements. In particular, we demonstrate that a photocatalytic semi-water splitting reaction, leading to hydrogen evolution, occurs at the polymer surface, directly contacted to an aqueous saline (NaCl) solution, as a consequence of visible-light generated photocurrent. We propose here a fully unexplored application of organic systems, i.e. the development of fuel cells: our results pave the way to the exploitation of organic polymers, seawater and solar energy as the sole raw materials for completely clean, sustainable, and economical hydrogen production
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