67 research outputs found
Functionalization of corn stover with 3-aminopropyltrietoxysilane to uptake Reactive Red 141 from aqueous solutions
An alternative and low-cost adsorbent (CSâAPTES) was developed by the functionalization corn stover (CS) with 3-aminopropyltrietoxysilane (APTES) using a simple method. Several analytical techniques were used to prove the functionalization and then, CSâAPTES was employed to adsorb Reactive Red 141 (RR141) dye from aqueous solutions. The functionalization with APTES caused an increase of 15 times in the adsorption capacity. The adsorption of RR141 on CSâAPTES was favored at pH 3.0 using a dosage of 3.0 g Lâ1. The adsorption equilibrium was reached within 4 h, being the process thermodynamically favorable, endothermic, and controlled by chemisorption. The maximum adsorption capacity was 15.65 mg gâ1. CSâAPTES was efficient to treat a colored effluent containing various ions and molecules. The use of 10 g Lâ1 of CSâAPTES was sufficient to decolorize more than 98% of this effluent. It was concluded that CSâAPTES can be easily prepared from CS, generating an efficient and low-cost adsorbent which, in turn, is able to treat colored effluents
Adsorptive decontamination of wastewater containing methylene blue dye using golden trumpet tree bark (Handroanthus albus)
The golden trumpet tree bark (GTB), a wood-processing residue, was tested as adsorbent material for decontamination of wastewaters containing methylene blue dye (MB). The powdered material was preponderantly amorphous, containing an irregular surface with the presence of lignin and holocellulose. The adsorption was favorable at basic pH of 10 and adsorbent dosage of 0.5 g Lâ1. The kinetics has finished in only 30 min and fitted by the general order model (GO). The isotherm behaviors were successfully represented by the Langmuir model. The value found for the maximum adsorption capacity was 232.25 mg gâ1, being obtained at 328 K. The standard variation of Gibbs free energy (ÎG0) ranged from ââ10.77 to ââ8.09 kJ molâ1, indicating a spontaneous and favorable adsorption. A variation of standard enthalpy (ÎH0) of 18.58 kJ molâ1 revealed an endothermic adsorption. A sloped forward curve was found in the continuous operation, with breakthrough time (tb) of 325 min. The stoichiometry capacity of the column (qeq) and the length of mass transfer zone (Zm) were, respectively, 23.57 mg gâ1 and 11.28 cm. The GTB was efficient in the treatment of a simulated effluent, obtaining color removal of 96%. These results show that GTB can be applied as adsorbent for decontamination of wastewaters containing methylene blue
Adsorbents for glyphosate removal in contaminated waters: a review
Glyphosate is an herbicide used to control weeds and optimize agricultural production. However, since glyphosate is an emerging pollutant claimed to be potentially carcinogenic, glyphosate pollution of soils and water is a health issue. There is therefore a need for advanced techniques to remove glyphosate from the environment. Here, we review glyphosate properties and materials for glyphosate adsorption such as biochar and graphene, which display high glyphosate adsorption capacities
The NEOShield-2 EU project: The Italian contribution
The NEOShield-2 (2015-2017) project has been recently approved by the European Commission in the framework of the Horizon 2020 programme with the aim i) to study specific technologies and instruments to conduct close approach missions to NEOs or to undertake mitigation demonstration, and ii) to acquire in-depth information of physical properties of the population of small NEOs (50-300 m), in order to design mitigation missions and assess the consequences of an impact on Earth. The Italian scientific community is widely involved in this project
Photometric survey of 67 near-Earth objects
Context. The near-Earth object (NEO) population is a window into the original conditions of the protosolar nebula, and has the potential to provide a key pathway for the delivery of water and organics to the early Earth. In addition to delivering the crucial ingredients for life, NEOs can pose a serious hazard to humanity since they can impact the Earth. To properly quantify the impact risk, physical properties of the NEO population need to be studied. Unfortunately, NEOs have a great variation in terms of mitigation-relevant quantities (size, albedo, composition, etc.) and less than 15% of them have been characterized to date. Aims. There is an urgent need to undertake a comprehensive characterization of smaller NEOs (D < 300 m) given that there are many more of them than larger objects; their small sizes make them intrinsically fainter and therefore harder to study. One of the main aims of the NEOShield-2 project (2015-2017), financed by the European Community in the framework of the Horizon 2020 program, is therefore to retrieve physical properties of a wide number of NEOs in order to design impact mitigation missions and assess the consequences of an impact on Earth. Methods. We carried out visible photometry of NEOs, making use of the DOLORES instrument at the Telescopio Nazionale Galileo (TNG, La Palma, Spain) in order to derive visible color indexes and the taxonomic classification for each target in our sample. Results. We attributed for the first time the taxonomical complex of 67 objects obtained during the first year of the project. While the majority of our sample belong to the S-complex, carbonaceous C-complex NEOs deserve particular attention. These NEOs can be located in orbits that are challenging from a mitigation point of view, with high inclination and low minimum orbit intersection distance (MOID). In addition, the lack of carbonaceous material we see in the small NEO population might not be due to an observational bias alone
Deciphering OPA1 mutations pathogenicity by combined analysis of human, mouse and yeast cell models
OPA1 is the major gene responsible for Dominant Optic Atrophy (DOA) and the syndromic form DOA âplusâ. Over 370 OPA1 mutations have been identified so far, although their pathogenicity is not always clear. We have analyzed one novel and a set of known OPA1 mutations to investigate their impact on protein functions in primary skin fibroblasts and in two âad hocâ generated cell systems: the MGM1/OPA1 chimera yeast model and the Opa1â/â MEFs model expressing the mutated human OPA1 isoform 1. The yeast model allowed us to confirm the deleterious effects of these mutations and to gain information on their dominance/recessivity. The MEFs model enhanced the phenotypic alteration caused by mutations, nicely correlating with the clinical severity observed in patients, and suggested that the DOA âplusâ phenotype could be induced by the combinatorial effect of mitochondrial network fragmentation with variable degrees of mtDNA depletion. Overall, the two models proved to be valuable tools to functionally assess and define the deleterious mechanism and the pathogenicity of novel OPA1 mutations, and useful to testing new therapeutic interventions
Deciphering OPA1 mutations pathogenicity by combined analysis of human, mouse and yeast cell models
OPA1 is the major gene responsible for Dominant Optic Atrophy (DOA) and the syndromic form DOA âplusâ. Over 370 OPA1 mutations have been identified so far, although their pathogenicity is not always clear. We have analyzed one novel and a set of known OPA1 mutations to investigate their impact on protein functions in primary skin fibroblasts and in two âad hocâ generated cell systems: the MGM1/OPA1 chimera yeast model and the Opa1â/â MEFs model expressing the mutated human OPA1 isoform 1. The yeast model allowed us to confirm the deleterious effects of these mutations and to gain information on their dominance/recessivity. The MEFs model enhanced the phenotypic alteration caused by mutations, nicely correlating with the clinical severity observed in patients, and suggested that the DOA âplusâ phenotype could be induced by the combinatorial effect of mitochondrial network fragmentation with variable degrees of mtDNA depletion. Overall, the two models proved to be valuable tools to functionally assess and define the deleterious mechanism and the pathogenicity of novel OPA1 mutations, and useful to testing new therapeutic interventions
Interaction of p21CDKN1A with PCNA regulates the histone acetyltransferase activity of p300 in nucleotide excision repair
The cell-cycle inhibitor p21CDKN1A has been suggested to directly participate in DNA repair, thanks to the interaction with PCNA. Yet, its role has remained unclear. Among proteins interacting with both p21 and PCNA, the histone acetyltransferase (HAT) p300 has been shown to participate in DNA repair. Here we report evidence indicating that p21 protein localizes and interacts with both p300 and PCNA at UV-induced DNA damage sites. The interaction between p300 and PCNA is regulated in vivo by p21. Indeed, loss of p21, or its inability to bind PCNA, results in a prolonged binding to chromatin and an increased association of p300 with PCNA, in UV-irradiated cells. Concomitantly, HAT activity of p300 is reduced after DNA damage. In vitro experiments show that inhibition of p300 HAT activity induced by PCNA is relieved by p21, which disrupts the association between recombinant p300 and PCNA. These results indicate that p21 is required during DNA repair to regulate p300 HAT activity by disrupting its interaction with PCNA
Commentary: Case Report: Abdominal Lymph Node Metastases of Parathyroid Carcinoma: Diagnostic Workup, Molecular Diagnosis, and Clinical Management
In the issue of March 2021, Lenschow et al. reported the case of a 46-year-old woman with recurrent, programmed death-ligand-1 (PD-L1) negative, tumor mutational burden (TMB)-high parathyroid carcinoma (PC), who showed stable disease as her best response on imaging, and a three-fold drop in PTH after treatment with intravenous pembrolizumab. Given the remarkable results obtained by Lenschow et al. with the anti-PD-1 agent pembrolizumab in the above-mentioned case, we performed an extensive search for possible further relevant data sources, including a) full published articles in international online databases (PubMed, Web of Science, Scopus, and Embase); b) preliminary reports in selected international meeting abstract repositories (American Society of Clinical Oncology, ASCO; European Neuroendocrine Tumor Society, ENET; European Society for Medical Oncology, ESMO); c) registered clinical trials in the U.S. National Institutes of Health registry of clinical trials (http://clinicaltrials.gov) and in any primary register of the WHO International Clinical Trials Registry Platform (ICTRP)
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