244 research outputs found

    Tailoring the chemical structure of cellulose nanocrystals by amine functionalization

    Get PDF
    The surface functionalization of cellulose nanocrystals is presently considered a useful and straightforward tool for accessing very reliable biocompatible and biodegradable nanostructures with tailored physical and chemical properties. However, to date the fine characterization of the chemical appendages introduced onto cellulose nanocrystals remains a challenge, due to the low sensitivity displayed by the most common techniques towards surface functionalization. In this paper, we demonstrate the easy functionalization of cellulose nanocrystals with aliphatic and aromatic amines, demonstrating the tunability of their properties in dependence on the selected functionality. Then, we apply to colloidal suspensions of modified nanocrystals 1H NMR analysis to elucidate their surface structure. To the best of our knowledge, this is the first report where such investigation was performed on cellulose nanocrystals presenting both surface and reducing end modification. These results involve interesting implications for the fields of cultural heritage and of materials chemistry

    IDIOPATHIC PARTIAL EPILEPSY WITH AUDITORY FEATURES (IPEAF): A CLINICAL AND GENETIC STUDY OF 53 SPORADIC CASES

    Get PDF
    The purpose of our study was to describe the clinical characteristics of sporadic (S) cases of partial epilepsy with auditory features (PEAF) and pinpoint clinical, prognostic and genetic differences with respect to previously reported familial (F) cases of autosomal dominant partial epilepsy with auditory features (ADPEAF). We analysed 53 patients (24 females and 29 males) with PEAF diagnosed according to the following criteria: partial epilepsy with auditory symptoms, negative family history for epilepsy and absence of cerebral lesions on NMR study. All patients underwent a full clinical, neuroradiological and neurophysiological examination. Forty patients were screened for mutations in LGI1/epitempin, which is involved in ADPEAF. Age at onset ranged from 6 to 39 years (average 19 years). Secondarily generalized seizures were the most common type of seizures at onset (79%). Auditory auras occurred either in isolation (53%) or associated with visual, psychic or aphasic symptoms. Low seizure frequency at onset and good drug responsiveness were common, with 51% of patients seizure-free. Seizures tended to recur after drug withdrawal. Clinically, no major differences were found between S and F patients with respect to age at onset, seizure frequency and response to therapy. Analysis of LGI1/epitempin exons failed to disclose mutations. Our data support the existence of a peculiar form of non-lesional temporal lobe epilepsy closely related to ADPEAF but without a positive family history. This syndrome, here named IPEAF, has a benign course in the majority of patients and could be diagnosed by the presence of auditory aura. Although LGI1 mutations have been excluded, genetic factors may play an aetiopathogenetic role in at least some of these S cases

    Two novel precursors of the hiv-1 protease inhibitor darunavir target the UPR/proteasome system in human hepatocellular carcinoma cell line HepG2

    Get PDF
    Background: Several pre-clinical and clinical reports suggest that HIV-1 protease inhibitors, in addition to the antiretroviral properties, possess pleiotropic pharmacological effects including anti-cancer action. Therefore, we investigated the pro-apoptotic activity in tumor cells of two molecules, RDD-19 and RDD-142, which are hydroxyethylamine derivatives’ precursors of darunavir and several HIV-1 protease inhibitors. Methods: Three hepatoma cell lines and one non-pathological cell line were treated with RDD-19 and RDD-142, and cell viability was assessed. The expression levels of several markers for ER stress, autophagy, cellular ubiquitination, and Akt activation were quantified in HepG2 cells treated with RDD-19 and RDD-142 to evaluate apoptotic and non-apoptotic cell death. Results: RDD-19 and RDD-142 showed a greater dose-dependent cytotoxicity towards the hepatic tumor cell line HepG2 compared to the non-pathological hepatic cell line IHH. Both molecules caused two types of cell death, a caspase-dependent apoptosis, which was ascertained by a series of biochemical and morphological assays, and a caspase-independent death that was characterized by the induction of ER stress and autophagy. The strong increase of ubiquitinated proteins inside the cells suggested that the target of these molecules could be the proteasome and in silico molecular docking analysis that was used to support the plausibility of this hypothesis. Furthermore, cells treated with the two compounds displayed decreased levels of p-AKT, which interferes with cell survival and proliferation. Conclusions: These findings demonstrate that two compounds, RDD-19 and RDD-142, have pleiotropic effects and that they may represent promising anticancer candidates

    Validazione di Piani di Disaster Recovery mediante Simulatore

    Get PDF
    Contribution published online at: http://www.mimos.it/nuovo/contenuto_view.asp?check=10

    Associated factors of depressive symptoms in the elderly: EpiFloripa study

    Get PDF
    OBJECTIVE To estimate the prevalence and associated factors of depressive symptoms in the elderly. METHODS Cross-sectional population based epidemiological study (The EpiFloripa Elderly survey) was carried out in two stage clusters, census tracts and households, with1.656 elderly individuals in Florianópolis, SC. The prevalence of depressive symptoms (outcome) was obtained using Geriatric Depression Scale (GDS-15) and its associations with socio-demographic, health, behavioral and social variables were assessed. Crude and adjusted prevalence ratios (PR) with 95% confidence intervals were calculated using Poisson regression. RESULTS Depressive symptoms were observed in 23.9% of the elderly individuals (95%CI 21.84;26.01). In the final model, depressive symptoms were associated with: 5 to 8 years of schooling (PR = 1.50, 95%CI 1.08;2.08); one to four years of schooling (PR = 1.62, 95%CI 1.18;2.23) and no schooling (PR = 2.11, 95%CI 1.46;3.05); being in a worse financial condition than at the age of 50 (PR = 1.33, 95%CI 1.02;1.74); cognitive impairment (PR = 1.45, 95%CI 1.21;1.75); perceiving their health to be regular (PR = 1.95, 95%CI 1.47;2.60) or poor (PR = 2.64, 95%CI 1.82;3.83); functional dependence (PR =1.83, 95%CI 1.43;2.33) and chronic pain (PR = 1.35, 95%CI 1.10;1.67). Factors with protective effects were: being in the 70 to 79 year old age group (PR = 0.77, 95%CI 0.64;0.93); physical activity in leisure time (PR = 0.75, 95%CI 0.59;0.94); participation in social or religious groups (PR = 0.80, 95%CI 0.64;0.99) and having sexual relations (PR = 0.70, 95%CI 0.53;0.94). CONCLUSIONS : Adverse clinical situations, being socioeconomically disadvantaged and low social and sexual activity were associated with depressive symptoms in the elderly.OBJETIVO Analizar la prevalencia y factores asociados a síntomas depresivos en ancianos. MÉTODOS Estudio epidemiológico transversal y de base domiciliar (pesquisa EpiFloripa Anciano ) con 1.656 ancianos, realizado por conglomerados en dos fases, sectores censitarios y domicilios, en Florianópolis, SC, Brasil. La prevalencia de síntomas depresivos (resultado) fue obtenida por medio de la Geriatric Depression Scale (GDS-15), y evaluadas asociaciones según variables sociodemográficas, de salud, comportamiento y sociales. Se calcularon tasas de prevalencia brutas y ajustadas con intervalo de 95% de confianza por regresión de Poisson. RESULTADOS La prevalencia de síntomas depresivos fue de 23,9% (IC95% 21,84;26,01). Los factores de riesgo asociados en el modelo final fueron: escolaridad de cinco a ocho años (RP = 1,50; IC95% 1,08; 2,08), uno a cuatro años (RP = 1,62; IC95% 1,18; 2,23) y ningún año de estudio (RP = 2,11; IC95% 1,46;3,05); situación económica peor al compararse con la que tenía a los 50 años (RP = 1,33; IC95% 1,02;1,74); déficit cognitivo (RP = 1,45; IC95% 1,21;1,75); percepción de salud regular (RP = 1,95; IC95% 1,47;2,60) y mala (RP = 2,64; IC95% 1,82;3,83); dependencia funcional (RP = 1,83; IC95% 1,43; 2,33) y dolor crónico (RP = 1,35; IC95% 1,10;1,67). Grupo etario de 70 a 79 años (RP = 0,77; IC95% 0,64;0,93); actividad física de placer (RP = 0,75; IC95% 0,59;0,94); participación en grupos de convivencia o religiosos (RP = 0,80; IC95% 0,64;0,99) y tener relación sexual (RP = 0,70; IC95% 0,53;0,94) se mostraron como factores protectores de la aparición de los síntomas depresivos. CONCLUSIONES Situación clínica adversa, desventaja socioeconómica y poca actividad social y sexual se mostraron asociados a los síntomas depresivos en ancianos

    PEGylated Liposomes Loaded with Carbamate Inhibitor ANP0903 Trigger Apoptosis by Enhancing ER Stress in HepG2 Cancer Cells

    Get PDF
    Liver cancer is one of the most common causes of cancer death worldwide. In recent years, substantial progress has been made in the development of systemic therapies, but there is still the need for new drugs and technologies that can increase the survival and quality of life of patients. The present investigation reports the development of a liposomal formulation of a carbamate molecule, reported as ANP0903, previously tested as an inhibitor of HIV-1 protease and now evaluated for its ability to induce cytotoxicity in hepatocellular carcinoma cell lines. PEGylated liposomes were prepared and characterized. Small, oligolamellar vesicles were produced, as demonstrated by light scattering results and TEM images. The physical stability of the vesicles in biological fluids was demonstrated in vitro, alongside the stability during storage. An enhanced cellular uptake was verified in HepG2 cells treated with liposomal ANP0903, resulting in a greater cytotoxicity. Several biological assays were performed to elucidate the molecular mechanisms explaining the proapoptotic effect of ANP0903. Our results allow us to hypothesize that the cytotoxic action in tumor cells is probably due to the inhibition of the proteasome, resulting in an increase in the amount of ubiquitinated proteins within the cells, which in turn triggers activation of autophagy and apoptosis processes, resulting in cell death. The proposed liposomal formulation represents a promising approach to deliver a novel antitumor agent to cancer cells and enhance its activity

    VST: the telescope progress toward stars

    Get PDF
    The VST telescope is in an advanced stage of integration in Chile, after a period of work spent mainly on the active optics system, started in mid-2007. We present the results of the recent work on the primary and secondary mirror support systems and on the mirror cell auxiliary units
    corecore