Análisis de estabilidad de geles acuosos de sepiolita bajo esfuerzos de corte

La sepiolita es un mineral fibroso que, por sus características absorbentes, posee la habilidad de formar suspensiones estables en forma de geles. Este silicato de magnesio presenta morfología fibrosa, cuya fórmula es Si12O30Mg8(OH)4(H2O)48H2O [1-2]. Su estructura consiste en bloques y canales que se extienden en la dirección de la fibra, en donde cada bloque está formado por dos capas tetraédricas de silicio y una capa octaédrica central de magnesio. Debido a la discontinuidad de las capas externas de silicio, un número significativo de grupos -OH está presente en la superficie de la sepiolita. Además presenta una elevada área superficial (340 m2/g). Por estas razones, tiene un amplio campo de aplicaciones, donde además, juegan un papel importante, las propiedades reológicas; desde aditivos en comida de animales, como portadores de insecticidas y herbicidas, agentes decolorantes, en el refinamiento de aceites, tratamiento de aguas residuales, eliminación de olores y en la industria del papel [3-5]

Clinical course impacts early kinetics,magnitude, and amplitude of SARS-CoV-2 neutralizing antibodies beyond 1 year after infection

To understand the determinants of long-term immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the concurrent impact of vaccination and emerging variants, we follow a prospective cohort of 332 patients with coronavirus disease 2019 (COVID-19) over more than a year after symptom onset. We evaluate plasma-neutralizing activity using HIV-based pseudoviruses expressing the spike of different SARS-CoV-2 variants and analyze them longitudinally using mixed-effects models. Long-term neutralizing activity is stable beyond 1 year after infection in mild/asymptomatic and hospitalized participants. However, longitudinal models suggest that hospitalized individuals generate both short- and long-lived memory B cells, while the responses of non-hospitalized individuals are dominated by long-lived B cells. In both groups, vaccination boosts responses to natural infection. Long-term (>300 days from infection) responses in unvaccinated participants show a reduced efficacy against beta, but not alpha nor delta, variants. Multivariate analysis identifies the severity of primary infection as an independent determinant of higher magnitude and lower relative cross-neutralization activity of long-term neutralizing responses.This work was partially funded by Grifols, the Departament de Salut of the Generalitat de Catalunya (grants SLD016 to J.B. and SLD015 to J.C.), the Spanish Health Institute Carlos III and the European Regional Development Fund (grant PI17/01518 and PI20/00093 to J.B. and PI18/01332 to J.C.), CERCA Programme/Generalitat de Catalunya 2017 SGR 252, and the crowdfunding initiatives #joemcorono, BonPreu/Esclat, and Correos. The funders had no role in study design, data collection and analysis, the decision to publish, or the preparation of the manuscript. E.P. was supported by a doctoral grant from the National Agency for Research and Development of Chile (ANID) (72180406). We are grateful to all participants and the technical staff of IrsiCaixa for sample processing. Francesc López-Seguí provided medical writing support during the preparation of the manuscript.Peer Reviewed"Article signat per 22 autors/es: Edwards Pradenas, Benjamin Trinité, Víctor Urrea, Silvia Marfil, Ferran Tarrés-Freixas, Raquel Ortiz, Carla Rovirosa, Jordi Rodon, Júlia Vergara-Alert, Joaquim Segalés, Victor Guallar, Alfonso Valencia, Nuria Izquierdo-Useros, Marc Noguera-Julian, Jorge Carrillo, Roger Paredes, Lourdes Mateu, Anna Chamorro, Ruth Toledo, Marta Massanella, Bonaventura Clotet, Julià Blanco"Postprint (published version

Alternative methodologies for sepiolite defibering

In this work, lyophilization and acid treatments were proposed as simple alternatives to defiber sepiolite samples, without affecting their length, in order to be applicable at industrial scale. Although it contains carbonates, themain remarkable feature of this clay mineral is its high crystalline development, reaching fiber lengths around 8 cm. Proposed alternatives were analyzed comparatively, evaluating mainly the defibering effect. The influence of lyophilization and acid treatments on sepiolite structure and purity was qualitatively studied based on mineral characterization, electronic and optical microscopy, X-ray diffraction and Fourier transform infrared spectroscopy. Results show that acid treatment allowed sepiolite purification by removing carbonates as well as the reduction of fiber length. Lyophilization demonstrated to be an effective defibering process that allowed obtaining individualized fiber from bundle disaggregation, without affecting sepiolite length and flexibility

Contribution of the HIV-1 Envelope Glycoprotein to AIDS Pathogenesis and Clinical Progression

In the absence of antiviral therapy, HIV-1 infection progresses to a wide spectrum of clinical manifestations that are the result of an entangled contribution of host, immune and viral factors. The contribution of these factors is not completely established. Several investigations have described the involvement of the immune system in the viral control. In addition, distinct HLA-B alleles, HLA-B27, -B57-58, were associated with infection control. The combination of these elements and antiviral host restriction factors results in different clinical outcomes. The role of the viral proteins in HIV-1 infection has been, however, less investigated. We will review contributions dedicated to the pathogenesis of HIV-1 infection focusing on studies identifying the function of the viral envelope glycoprotein (Env) in the clinical progression because of its essential role in the initial events of the virus life-cycle. Some analysis showed that inefficient viral Envs were dominant in non-progressor individuals. These poorly-functional viral proteins resulted in lower cellular activation, viral replication and minor viral loads. This limited viral antigenic production allows a better immune response and a lower immune exhaustion. Thus, the properties of HIV-1 Env are significant in the clinical outcome of the HIV-1 infection and AIDS pathogenesis.This work was funded by the Spanish AIDS network “Red Temática Cooperativa de Investigación en SIDA” RD12/0017/0002, RD12/0017/0028, RD12/0017/0034, RD16/0025/0011, RDCIII16/0002/0005 and RD16/0025/0041 as part of the Plan Nacional R + D+I and co-funded by the Spanish “Instituto de Salud Carlos III (ISCIII)-Subdirección General de Evaluación y el Fondo Europeo de Desarrollo Regional (FEDER)”. J.B. is a researcher from “Fundació Institut de Recerca en Ciències de la Salut Germans Trias i Pujol” supported by the Health Department of the Catalonian Government/Generalitat de Catalunya and ISCIII grant Nos. PI17/01318 and PI20/00093 (to J.B.). Work in C.C. Lab was supported by grants SAF (2010-17226) and (2016-77894-R) from MINECO (Spain), FIS (PI13/02269, ISCIII) and PI20/00093. A.-V.F.’s Lab is supported by the European Regional Development Fund (ERDF), PID2021-123031OB-I00 (“Ministerio de Ciencia e Innovación”, Spain), RTI2018-093747-B-100 (“Ministerio de Ciencia, Innovación y Universidades”, Spain), ProID2020010093 (“Agencia Canaria de Investigación, Innovación y Sociedad de la Información” and the European Social Fund), UNLL10-3E-783 (ERDF and “Fundación CajaCanarias”) and “SEGAI-ULL”. S.-P.Y. is funded by “Fundación Doctor Manuel Morales” (La Palma, Spain) and “Contrato Pre-doctoral Ministerio-ULL Formación de Doctores” (2019 Program) (“Ministerio de Ciencia, Innovación y Universidades”, Spain). R.-C.R. is funded by RD16/0025/0011 and ProID2020010093 (“Agencia Canaria de Investigación, Innovación y Sociedad de la Información” and European Social Fund). J.-G.L. is funded by the “Juan de la Cierva de Incorporación” Spanish Program (IJC2019-038902-I) (“Ayudas Juan de la Cierva de incorporación; Agencia Estatal de Investigación. Ministerio de Ciencia e Innovación”).S

The HR2 polymorphism N140I in the HIV-1 gp41 combined with the HR1 V38A mutation is associated with a less cytopathic phenotype

<p>Abstract</p> <p>Background</p> <p>Resistance to the fusion inhibitor enfuvirtide (ENF) is achieved by changes in the gp41 subunit of the HIV envelope glycoprotein (Env). Specific ENF-associated mutational pathways correlate with immunological recovery, even after virological failure, suggesting that the acquisition of ENF resistance alters gp41 pathogenicity. To test this hypothesis, we have characterized the expression, fusion capability, induction of CD4⁺T cell loss and single CD4⁺T cell death of 48 gp41 proteins derived from three patients displaying different amino acids (N, T or I) at position 140 that developed a V38A mutation after ENF-based treatment.</p> <p>Results</p> <p>In all cases, intra-patient comparison of Env isolated pre- or post-treatment showed comparable values of expression and fusogenic capacity. Furthermore, Env with either N or T at position 140 induced comparable losses of CD4⁺T-cells, irrespective of the residue present at position 38. Conversely, Env acquiring the V38A mutation in a 140I background induced a significantly reduced loss of CD4⁺T cells and lower single-cell death than did their baseline controls. No altered ability to induce single-cell death was observed in the other clones.</p> <p>Conclusions</p> <p>Overall, primary gp41 proteins with both V38A and N140I changes showed a reduced ability to induce single cell death and deplete CD4⁺T cells, despite maintaining fusion activity. The specificity of this phenotype highlights the relevance of the genetic context to the cytopathic capacity of Env and the role of ENF-resistance mutations in modulating viral pathogenicity <it>in vivo</it>, further supporting the hypothesis that gp41 is a critical mediator of HIV pathogenesis.</p

Gp120/CD4 blocking antibodies are frequently elicited in ART-naïve chronically HIV-1 infected individuals

Antibodies with the ability to block the interaction of HIV-1 envelope glycoprotein (Env) gp120 with CD4, including those overlapping the CD4 binding site (CD4bs antibodies), can protect from infection by HIV-1, and their elicitation may be an interesting goal for any vaccination strategy. To identify gp120/CD4 blocking antibodies in plasma samples from HIV-1 infected individuals we have developed a competitive flow cytometry-based functional assay. In a cohort of treatment-naïve chronically infected patients, we showed that gp120/CD4 blocking antibodies were frequently elicited (detected in 97% plasma samples) and correlated with binding to trimeric HIV-1 envelope glycoproteins. However, no correlation was observed between functional CD4 binding blockade data and titer of CD4bs antibodies determined by ELISA using resurfaced gp120 proteins. Consistently, plasma samples lacking CD4bs antibodies were able to block the interaction between gp120 and its receptor, indicating that antibodies recognizing other epitopes, such as PGT126 and PG16, can also play the same role. Antibodies blocking CD4 binding increased over time and correlated positively with the capacity of plasma samples to neutralize the laboratory-adapted NL4.3 and BaL virus isolates, suggesting their potential contribution to the neutralizing workforce of plasma in vivo. Determining whether this response can be boosted to achieve broadly neutralizing antibodies may provide valuable information for the design of new strategies aimed to improve the anti-HIV-1 humoral response and to develop a successful HIV-1 vaccine

Characterization of sheep production systems and their relation with gastrointestinal parasites in four municipalities of Campeche, Mexico

Objective: The increase in the number of sheep in herds is accompanied many times by bad practices, which lead to nutritional deficiencies, rises in parasitism and loss of homeostasis. Therefore, gastrointestinal parasites from sheep were characterized from four municipalities of the state of Campeche. Design/methodology/approach: The number of sheep studied was 243, evaluating the body weight, body condition, coloring of the eye mucosae, age, eggs per grams of feces, and family of parasites. The data were analyzed through an ANOVA and Tukey’s means test (P&lt;0.05), as well as Spearman’s correlation analysis using the statistical package Statistica 7. Results: Five parasite families were found (Trichostrongyloidae, Strongyloidae, Trichuridae, Eimeriidae and Anoplocephalidae). In the production systems of the municipality of Calakmul the five families of parasites were found, with a parasite load of 3,571 hpg. The family Trichostrongyloidae presented the highest frequency in the municipalities of Champotón and Calakmul with 52 and 75%, respectively. The animals with best body condition, FAMACHA© and lowest parasite load were observed in Hecelchakán. Limitations on study/implications: It is suggested to carry out a study of anthelmintic resistance, to establish a management of prevention and control of gastrointestinal parasites. Findings/conclusions: The frequency of gastrointestinal parasites is influenced by the management and the municipality of origin within the sheep production systems in the state of Campeche.Objective: The increase in the number of sheep in herds is accompanied many times by bad practices, whichlead to nutritional deficiencies, rises in parasitism and loss of homeostasis. Therefore, gastrointestinal parasitesfrom sheep were characterized from four municipalities of the state of Campeche.Design/methodology/approach: The number of sheep studied was 243, evaluating the body weight, bodycondition, coloring of the eye mucosae, age, eggs per grams of feces, and family of parasites. The data wereanalyzed through an ANOVA and Tukey’s means test (P&lt;0.05), as well as Spearman’s correlation analysisusing the statistical package Statistica 7.Results: Five parasite families were found (Trichostrongyloidae, Strongyloidae, Trichuridae, Eimeriidae andAnoplocephalidae). In the production systems of the municipality of Calakmul the five families of parasites werefound, with a parasite load of 3,571 hpg. The family Trichostrongyloidae presented the highest frequency inthe municipalities of Champotón and Calakmul with 52 and 75%, respectively. The animals with best bodycondition, FAMACHA© and lowest parasite load were observed in Hecelchakán.Limitations on study/implications: It is suggested to carry out a study of anthelmintic resistance, to establisha management of prevention and control of gastrointestinal parasites.Findings/conclusions: The frequency of gastrointestinal parasites is influenced by the management and themunicipality of origin within the sheep production systems in the state of Campeche

Síntesis de zeolita Na-P en solución alcalina a partir de una toba vítrea parcialmente zeolitizada

En este trabajo se realizaron ensayos de síntesis en condiciones alcalinas a partir de una toba vitrea parcialmente zeolitizada de la provincia de Mendoza (rica en mordenita), afin de incrementar su grado de zeolitización, m^orar su cristalinidady obtener un producto más homogéneo. Disponer de un material de estas características mediante procedimientos de síntesis simples permitirá en un futuro el diseño de compuestos de base polimérica, con propiedades mejoradas de absorción de agua y aromas. Los ensayos se llevaron a cabo con el material inicial molido (pasante tamiz #200) en soluciones 1, 0,5 y 0,1 N de NaOH a temperaturas de 40 °C y 95 °C, evaluando el desarrollo de la reacción cada 7 días durante 6 y 4 semanas respectivamente. El proceso jue monitoreado mediante difractometría de rayos X y microscopía electrónica de barrido acoplada con espectroscopia dispersiva de energías. A lo largo de las experiencias se observó un consumo progresivo de ¡a mordenita, disminución del contenido de material amorfo (vidrio volcánico) y desaparición de k fase tridimita. A seis semanas de ensayo en solución IN a 40 °C se obtuvo zeolita Na-P con escasa mordenita reUctica, mientras que a 4 semanas de ensayo en solución IN a 95 °C desapareció completamente k mordenita y se obtuvo zeolita Na-P y analcima. Mediante este procedimiento se incrementó k proporción de zeolita en k muestra y se mejoró k cristalinidad del material resultante, obteniéndose un producto de buena homogeneidad.In this Work, synthesis tests were carried out in alkaline conditions fivm a partially sseolitized vitreous tufffiom the province of Mendoza (rich in mordenite), in order to increase their degree of ¡seolitization, improve their crystaüinity and to obtain a more homogeneous product. Havingsuch a material by means of simple synthesis procedures wiU in the fiuture aUmv the design of polymer-based compounds with improved absorption properties of water and aromas. The tests were performed with the initial ground material (sieve # 200) in 1, 0.5 and 0.1 NNaOH Solutions at tempmtures of40 °C and95 °C, evaluating the devehpment ofthe reaction every 7days during 6 and 4 weeks respectively. Theprocess was monitored hy X-ray diffractometry and scanning electrón microscopy coupUd with energy dispersivo spectroscopy. Throughout the experiments a Progressive consumption ofthe mordenite, reduction ofthe amorphous material content (vokanic glass) and disappearance ofthe tridymite phase was observed. At 6 weeks of testing in IN solution at 40 °C Na-P zeolite was obtained with little relie mordenite, whereas at 4 weeks oftest in IN solution at 95 °C the mordenite disappeared completely and Na-P zeolite and analcime were obtained. By this procedure the proportion of zeolite in the sample was increased and the crystaüinity of the resulting material was improved, obtaining a product ofgood homogeneity

The role of CCR5/CXCR3 expressing CD8+ cells in liver damage and viral control during persistent hepatitis C virus infection

20 p.Background/Aims:CXCR3 and CCR5 play a major role in recruiting cytotoxic T cells (Tc) and secreting secondary type 1 cytokines (Tc1) in the liver. HCV could impair their expression as a survival mechanism. The role of these chemokine receptors on CD8+ cells in chronic hepatitis C is analysed. Methods:Serum, chemokines, peripheral blood and intrahepatic lymphocytes from chronic hepatitis C patients were studied. CXCR3 / CCR5 expressing CD8+ cells were quantified by flow-cytometry. Serum chemokines concentration (CXCL10/CCL3) was measured by ELISA. Basal data were correlated with liver inflammation. Longitudinal data were obtained during treatment and correlated with virologic response. Results:CCR5/CXCR3 expressing CD8+ cells were enriched in the liver and correlated with inflammation. Chronic HCV patients presented the same frequency of CCR5high/CXCR3high expressing CD8+ cells in peripheral blood as in healthy controls but higher serum concentration of CXCL10/CCL3. Treatment with PEG-interferon a-2b plus ribavirin increased CCR5high/CXCR3high expressing CD8+ cells frequency in peripheral blood and decreased CXCL10/CCL3 serum concentration. Increase in CXCR3high expressing CD8+ cells after 24 weeks of treatment was correlated with SVR. Conclusions:In chronic hepatitis C, anti-viral treatment induces an increase in CD8+ cells expressing chemokine receptors associated with Tc1 response and a reduction in their ligands. Achievement of viral control is associated with an increase in CXCR3high expressing CD8+ cells during treatmentSchering-Plough-SpainJunta de Comunidades de Castilla-La Manch