Síntesis y caracterización de membranas catalíticas de Cu-BTC y ZIF-8 soportadas en α-alúmina para la producción de hidrógeno

Esta tesis aborda las Redes Metal Orgánicas (MOFs), las cuales exhiben propiedades porosas, así como grandes áreas superficiales. Son eficientes en procesos de tamizado molecular, almacenamiento y catálisis heterogénea. Se sintetizaron membranas de dos diferentes MOFs, cobre y ácido benceno-1,3,5-tricarboxilico (BTC), y iones de zinc y 2-metilimidazol como ligando, este material es mejor conocido como ZIF-8. Las membranas homogéneas de CU-BTC y ZIF-8 fueron sintetizadas mediante el proceso de crecimiento secundario; y a través de la funcionalización de la superficie del soporte, para posteriormente caracterizarlas

Preclinical efficacy of [V 4 Q 5 ]dDAVP, a second generation vasopressin analog, on metastatic spread and tumor-associated angiogenesis in colorectal cancer

Purpose Control of metastatic spread of colorectal cancer (CRC) remains as a major therapeutic challenge. [V 4 Q 5 ]dDAVP is a vasopressin peptide analog with previously reported anticancer activity against carcinoma tumors. By acting as a selective agonist of arginine vasopressin type 2 membrane receptor (AVPR2) present in endothelial and tumor cells, [V 4 Q 5 ]dDAVP is able to impair tumor aggressiveness and distant spread. Our aim was to evaluate the potential therapeutic benefits of [V 4 Q 5 ]dDAVP on highly aggressive CRC disease using experimental models with translational relevance. Materials and Methods Murine CT-26 and human Colo-205 AVPR2-expressing CRC cell lines were used to test the preclinical efficacy of [V 4 Q 5 ]dDAVP, both in vitro and in vivo. Results In syngeneic mice surgically implanted with CT-26 cells in the spleen, sustained intravenous treatment with [V 4 Q 5 ]dDAVP (0.3 jg/kg) dramatically impaired metastatic progression to liver without overt signs of toxicity, and also reduced experimental lung colonization. The compound inhibited in vivo angiogenesis driven by Colo-205 cells in athymic mice, as well as in vitro endothelial cell migration and capillary tube formation. [V 4 Q 5 ]dDAVP exerted AVPR2-dependent cytostatic activity in vitro (IC50 1.08 |jM) and addition to 5-fluorouracil resulted in synergistic antiproliferative effects both in CT-26 and Colo-205 cells. Conclusion The present preclinical study establishes for the first time the efficacy of [V 4 Q 5 ]dDAVP on CRC. These encouraging results suggest that the novel second generation vasopressin analog could be used for the management of aggressive CRC as an adjuvant agent during surgery or to complement standard chemotherapy, limiting tumor angiogenesis and metastasis and thus protecting the patient from CRC recurrence.Fil: Garona, Juan. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Sobol, Natasha Tatiana. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pifano, Marina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Segatori, Valeria Inés. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gomez, Daniel Eduardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ripoll, Giselle Vanina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alonso, Daniel Fernando. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Monitoring the quality and perception of service in colombian public service companies with twitter and descriptive temporal analysis

The main goal of this research is to analyze the perception of service in public sector companies in the city of Bogota via Twitter and text mining to identify areas, problems, and topics aiming for quality service improvement. To achieve this objective, a structured method for data modeling is implemented based on the KDD methodology. Tweets from January to June 2022 related to the companies in the sector are processed, and a temporal analysis of the evolution of sentiment is performed based on the dictionaries Bing, AFINN, and NRC. Subsequently, the LDA algorithm (Latent Dirichlet Allocation algorithm) is used to visually identify the topics with the greatest negative impact reported by the users in each of the 6 months by adding the temporal dimension. The results revealed that, for Aqueduct (water supply service), the topic with the highest dissatisfaction is related to the “Water Tank Request” processes; for Enel (energy services) “Service Outages”; and for Vanti (gas services), “Case solution and request information”. Temporal patterns of tweets, sentiments, and topics are also highlighted for the three companies.Peer ReviewedPostprint (published version

Effects of the synthetic vasopressin analog desmopressin in a mouse model of colon cancer

Experimental and clinical data indicated that perioperative administration of the hemostatic peptide desmopressin (DDAVP) can inhibit progression of residual metastatic cells. The compound seems to act by inducing an agonist effect on specific V2 vasopressin membrane receptors present in both tumor cells and endothelial cells. Here we explored the antitumor effects of DDAVP in cultured colon carcinoma cells and in a syngeneic Balb/c mouse model. Both human Colo-205 and mouse CT-26 colon carcinoma cell lines expressed the V2 receptor, as revealed by immunofluorescence. DDAVP (at doses ranging from 100 ng/ml to 1 μg/ml) exerted a modest but significant antiproliferative effect on cultured CT26 and Colo-205 cells. In vivo, DDAVP (2 intravenous doses of 2 μg/kg) reduced accumulation of ascites and formation of intestinal tumor nodules in mice intraperitoneally inoculated with CT-26 cells. Perioperative administration of DDAVP significantly inhibited tumor progression in animals surgically implanted in the spleen with CT-26 cells, and caused some reduction in liver metastasis. Although DDAVP and 5- fluorouracil demonstrated additive cytostatic effects in vitro, no antitumor effects were observed in this study in mice receiving a single cycle of chemotherapy (25 mg/kg) in combination with the peptide. Our data suggest that DDAVP may be potentially used to minimize spread or survival of residual malignant cells during surgical procedures for colon and other gastrointestinal tumors.Fil: Ripoll, Giselle Vanina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garona, Juan. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hermo, Guillermo Adrian. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gomez, Daniel Eduardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alonso, Daniel Fernando. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Effects of the synthetic vasopressin analog desmopressin in a mouse model of colon cancer

Experimental and clinical data indicated that perioperative administration of the hemostatic peptide desmopressin (DDAVP) can inhibit progression of residual metastatic cells. The compound seems to act by inducing an agonist effect on specific V2 vasopressin membrane receptors present in both tumor cells and endothelial cells. Here we explored the antitumor effects of DDAVP in cultured colon carcinoma cells and in a syngeneic Balb/c mouse model. Both human Colo-205 and mouse CT-26 colon carcinoma cell lines expressed the V2 receptor, as revealed by immunofluorescence. DDAVP (at doses ranging from 100 ng/ml to 1 μg/ml) exerted a modest but significant antiproliferative effect on cultured CT26 and Colo-205 cells. In vivo, DDAVP (2 intravenous doses of 2 μg/kg) reduced accumulation of ascites and formation of intestinal tumor nodules in mice intraperitoneally inoculated with CT-26 cells. Perioperative administration of DDAVP significantly inhibited tumor progression in animals surgically implanted in the spleen with CT-26 cells, and caused some reduction in liver metastasis. Although DDAVP and 5- fluorouracil demonstrated additive cytostatic effects in vitro, no antitumor effects were observed in this study in mice receiving a single cycle of chemotherapy (25 mg/kg) in combination with the peptide. Our data suggest that DDAVP may be potentially used to minimize spread or survival of residual malignant cells during surgical procedures for colon and other gastrointestinal tumors.Fil: Ripoll, Giselle Vanina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Garona, Juan. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Hermo, Guillermo Adrian. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gomez, Daniel Eduardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alonso, Daniel Fernando. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Generating actionable predictions regarding MOOC learners' engagement in peer reviews

Peer review is one approach to facilitate formative feedback exchange in MOOCs; however, it is often undermined by low participation. To support effective implementation of peer reviews in MOOCs, this research work proposes several predictive models to accurately classify learners according to their expected engagement levels in an upcoming peer-review activity, which offers various pedagogical utilities (e.g. improving peer reviews and collaborative learning activities). Two approaches were used for training the models: in situ learning (in which an engagement indicator available at the time of the predictions is used as a proxy label to train a model within the same course) and transfer across courses (in which a model is trained using labels obtained from past course data). These techniques allowed producing predictions that are actionable by the instructor while the course still continues, which is not possible with post-hoc approaches requiring the use of true labels. According to the results, both transfer across courses and in situ learning approaches have produced predictions that were actionable yet as accurate as those obtained with cross validation, suggesting that they deserve further attention to create impact in MOOCs with real-world interventions. Potential pedagogical uses of the predictions were illustrated with several examples

The Role of the TGF-beta Coreceptor Endoglin in Cancer

Endoglin (CD105) is an auxiliary membrane receptor of transforming growth factor beta (TGF-beta) that interacts with type I and type II TGF-beta receptors and modulates TGF-beta signaling. Endoglin is overexpressed in the tumor-associated vascular endothelium, where it modulates angiogenesis. This feature makes endoglin a promising target for antiangiogenic cancer therapy. In addition, recent studies on human and experimental models of carcinogenesis point to an important tumor cell-autonomous role of endoglin by regulating proliferation, migration, invasion, and metastasis. These studies suggest that endoglin behaves as a suppressor of malignancy in experimental and human epithelial carcinogenesis, although it can also promote metastasis in other types of cancer. In this review, we evaluate the implication of endoglin in tumor development underlying studies developed in our laboratories in recent years

Insight into the effect of the vasopressin analog desmopressin on lung colonization by mammary carcinoma cells in BALB/c mice

Background/Aim: Desmopressin (dDAVP) is a synthetic peptide analog of vasopressin with antidiuretic and hemostatic properties. Recent experimental evidence suggested that dDAVP can inhibit metastasis formation by agonist action on V2 vasopressin receptors present in both tumor and endothelial cells. We have examined the kinetics of dDAVP effect during metastatic colonization and its potential association with hemostasis. Materials and Methods: The experimental metastasis assay was performed by injecting F3II mammary carcinoma cells into the lateral tail vein of syngeneic female BALB/c mice. Results: Clinically relevant doses of dDAVP (0.3 to 2 μg/kg intravenously (i.v.)) produced a dose-dependent inhibition in the formation of lung nodules when administered during the first 24 hours after F3II tumor cell injection. The hemostatic agent tranexamic acid (10 mg/kg, i.v.) had not effect on metastasis formation in the same experimental conditions, while the anticoagulant enoxaparin (1 mg/kg, subcutaneously (s.c.)) did not modify the antimetastatic action of dDAVP. In vitro, dDAVP had a strong inhibitory effect on F3II cell colony formation. Conclusion: dDAVP interferes with early metastatic disease, and direct association of this effect with hemostatic mechanisms is unlikely.Fil: Garona, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; ArgentinaFil: Pifano, Marina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scursoni, Alejandra Marcela. Municipalidad de Quilmes (buenos Aires). Hospital Zonal General de Agudos Doctor Isidoro Iriarte.; ArgentinaFil: Gomez, Daniel Eduardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Alonso, Daniel Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; ArgentinaFil: Ripoll, Giselle Vanina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología. Laboratorio de Oncología Molecular; Argentin