3,376 research outputs found

    Una aproximación estadística al estudio de la carbonatación del hormigón

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    Carbonation is one of the factors that conditions reinforced concrete durability, while porosity is one of the parameters that determines the carbonation rate: as a rule, the greater the porosity, the higher the rate. While many papers have been published on the effect of CO2 penetration in the pore solutions of concretes prepared under different experimental conditions, the literature has yet to address the joint effect of the factors considered in concrete design, such as the water/cement (w/c) ratio, type of cement, type of aggregate and presence of admixtures. The present paper discusses the findings of a statistical study of the impact of the aforementioned factors on both system porosity and carbonation rate. The type of cement, individually and in its interaction with the rest of the factors, proved to be the major determinant in concrete carbonation.La carbonatación es uno de los factores que supedita la durabilidad del hormigón armado, siendo la porosidad uno de los parámetros que más condicionan la velocidad de carbonatación. Son muchos los trabajos que estudian el efecto de la penetración del CO2 en la solución de los poros de hormigones preparados bajo distintas condiciones experimentales, sin embargo, no se encuentran referencias que analicen de forma conjunta el efecto de ciertos factores como son la relación agua/cemento (a/c ratio), el tipo de cemento, el tipo de árido y la presencia de aditivos, normalmente consideradas a la hora de diseñar un hormigón. En este trabajo se discuten los resultados obtenidos tras realizar un estudio estadístico del efecto que tienen los factores previamente mencionados, tanto en la porosidad de estos sistemas como en su nivel de carbonatación. El cemento tanto de manera individual como en sus interacciones con el resto de los factores es el factor que mas afecta a la carbonatación del hormigón

    Temporal study of natural populations of Heterorhabditid and Steinernematid nematodes in horticultural crop soils

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    La dynamique des populations de nématodes entomopathogènes dans des sols horticoles a été étudiée par des prélèvements mensuels en huit sites de Catalogne (nord-est de l'Espagne) pendant 14 mois. Ces nématodes entomopathogènes ont été détectés dans six des huit sites et ont continué à l'être quels qu'aient été les traitements agricoles pratiqués sur ces sites. Pendant cette étude, les sites ont été labourés, détruisant ainsi l'habitat naturel des nématodes, puis laissés en jachère pendant plusieurs mois, sans que la présence des nématodes n'en paraisse affectée. Cependant, une influence saisonnière peut être observée, la présence des nématodes étant plus faible pendant les mois d'été où la température est élevée. Cette influence saisonnière apparaît également affecter la répartition verticale des nématodes qui migrent vers les couches plus profondes du sol, vraisemblablement pour éviter les effets néfastes de la température et du manque d'humidité. Les résultats de cette étude montrent que les populations naturelles de nématodes entomopathogènes sont capables de persister et de survivre dans le sol pendant de longues périodes en s'adaptant aux conditions fluctuantes et adverses de leur habitat naturel. (Résumé d'auteur

    Basic Principles of Hybrid Alkaline Cements

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    A line of research of particular interest being pursued at this time is the development of new cements known as blended or hybrid alkaline cements. These cements form when blends containing low proportions of cement and high proportions (60-70 %) of mineral additions (such as blast furnace slag, fly ash or  metakaolin) are alkali activated. The reaction products precipitating in these systems are very complex and actually comprise a mix of gels: C?(A)?S?H type gels (similar to the gels obtained during cement hydration, but with aluminium in their composition) and (C,N)?A?S?H gels (similar to the N?A?S?H gels obtained during the alkaline activation of aluminosilicates, but with calcium in their composition). The prevalence of one or the other gel depends on a number of factors, including the concentration of the initial species in the solution, type of activator used, pH values and reaction time. The paper reviews the fundamental chemistry governing these new systems and the activation mechanisms involved.  It also analyses the nature of the reaction products formed and their compatibility under different reaction conditions

    application in C-H activation catalysis

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    This work was supported by the Spanish Government, the Spanish National Research Council (CSIC). We also thank Dr Martinez from Novozymes. Publisher Copyright: © 2023 RSC.The effect of the temperature in the synthesis of Pd nanoparticles in the metal-enzyme biohybrids is evaluated. The effect on the formation, size, and morphology of nanoparticles was evaluated using C. antarctica B lipase as the protein scaffold. XRD analyses confirmed the formation of crystalline Pd(0) as the metal species in all cases. TEM analyses revealed spherical crystalline nanoparticles with average diameter size from 2 nm at 4 °C synthesis to 10 nm obtained at 50 °C synthesis. The thermal phenomenon was also critical in the final hybrid formation using more complex enzymes, where the relation of the protein structure and temperature and the influence of the latter has been demonstrated to be critical in the reducing efficiency of the enzyme in the final Pd nanoparticle formation, in the metal species, or even in the final size of the nanoparticles. Different Pd biohybrids were evaluated as catalysts in the C-H activation of protected l-tryptophan under mild conditions. Pd@CALB4 showed the best results, with >99% conversion for C-2 arylation in methanol at room temperature with a TOF value of 64 min−1, being 2 or 4 times higher than that of the other synthesized hybrids. This catalyst showed a very high stability and recyclability, maintaining >95% activity after three cycles of use.publishersversionpublishe

    Exploring Thermomyces lanuginosus Lipase (TLL)-PdNPs Nanohybrid as Suitable Catalyst for One-pot Synthesis of Bis(3-indolyl)phenylmethane

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    This work was supported by the Spanish Government, the Spanish National Research Council (CSIC). project PTDC/QUI‐QOR/0712/2020. We also thank Dr. Martinez from Novozymes. We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI) Publisher Copyright: © 2023 The Authors. ChemCatChem published by Wiley-VCH GmbH.Palladium nanohybrids were synthesized and applied to the one-pot synthesis of bis(3-indolyl)methanes by selective C−C bond reaction from benzyl alcohol and indole. A T. lanuginosus lipase-palladium nanoparticles hybrid (Pd@TLL) was synthesized, yielding PdNPs with an average diameter size of 5 nm. This heterogeneous catalyst was first tested in the selective oxidation of benzyl alcohol to benzaldehyde in different solvents. Then, the direct formation of bis(3-indolyl)methane, by in situ oxidation and C−C coupling, was successfully evaluated under different conditions, obtaining >99 % conversion at 80 °C in toluene, with a TOF value of 9 min−1 and 89 % in pure water, demonstrating the versatility of these biohybrids.publishersversionpublishe

    Inhibitor of cysteine protease and mortality of Diaphorina citri.

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    The Asian citrus psyllid, Diaphorina citri (Hemiptera: Psyllidae), is considered an important pest of citrus by its ability to transmit the HLB disease. Thus, the aim of this study was to evaluate the potential of protease inhibitors for the control of this insect. The tests were performed with Murraya paniculata plants. The following aqueous solutions were applied: (1) distilled water (control), (2) Triton X-100 (0.1 m L-1) and (3) cysteine proteinase inhibitor E-64 (0.05 mg mL-1) and Triton X -100 (0.1 mL L-1). Four treatments were performed: solutions (1), (2) and (3) were applied four days before the release of the insects on the plants and for the last treatment, solution (3) was applied immediately before the insects release. The solutions were applied to the stem of the plant, 20 mL per plant. Were used five plants per treatment. Ten adults of D. citri were released on each plant after four hours of starvation. Each plant was maintained in a cage and mortality was observed for five days. The data was analyzed by Tukey test (p>0.05). There was no significant difference in mortality of insects among the treatments. Enzymatic analysis showed that there is enzymatic activity of cysteine p roteases in the D. citri midgut, thus, the low mortality after ingestion of this compound may indicate the need to adapt the bioassay method

    Electronic health records and patient registries in medical oncology departments in Spain

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    We aimed to evaluate the current situation of electronic health records (EHRs) and patient registries in the oncology departments of hospitals in Spain. This was a cross-sectional study conducted from December 2018 to September 2019. The survey was designed ad hoc by the Outcomes Evaluation and Clinical Practice Section of the Spanish Society of Medical Oncology (SEOM) and was distributed to all head of medical oncology department members of SEOM. We invited 148 heads of oncology departments, and 81 (54.7%) questionnaires were completed, with representation from all 17 Spanish autonomous communities. Seventy-seven (95%) of the respondents had EHRs implemented at their hospitals; of them, over 80% considered EHRs to have a positive impact on work organization and clinical practice, and 73% considered that EHRs improve the quality of patient care. In contrast, 27 (35.1%) of these respondents felt that EHRs worsened the physician-patient relationship and conveyed an additional workload (n = 29; 37.6%). Several drawbacks in the implementation of EHRs were identified, including the limited inclusion of information on both outpatients and inpatients, information recorded in free text data fields, and the availability of specific informed consent. Forty-six (56.7%) respondents had patient registries where they recorded information from all patients seen in the department. Our study indicates that EHRs are almost universally implemented in the hospitals surveyed and are considered to have a positive impact on work organization and clinical practice. However, EHRs currently have several drawbacks that limit their use for investigational purposes. Not applicable The online version contains supplementary material available at 10.1007/s12094-021-02614-9

    EP05.02-003 Durvalumab after Chemoradiotherapy (CRT) in Unresectable Stage III NSCLC. Comparative Study of Two Cohorts in the Real-World Setting

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    [EN] Introduction: Durvalumab is the new standard of care for unresectable locally advanced NSCLC, with PD-L1 _1% and who did not have progression after CRT treatment in the European Union. Our study compares the effectiveness and the frequency of radiation pneumonitis in patients treated with concurrent CRT with or without durvalumab consolidation during the same period in real clinical practice. Methods: A single-center retrospective study. 71 treated patients with unresectable stage III NSCLC were included between March 2018 and December 2021, 37 with CRT followed by durvalumab and 34 with CRT alone. Real-world progression-free survival (rwPFS) and real-world overall survival (rwOS) were calculated since the date of the end CRT. Propensity score matching (PSM) 1:1 was used to account for differences in baseline characteristics. Results: Median age was 67 years (range 46-82). 25.4% of the patients were _75 years old. 78.9% were men and 53.5% former smokers. 54.9% had squamous histology and 28%, 51% and 21% stage IIIA, IIIB and IIIC disease, respectively. The most used scheme was carboplatinpaclitaxel (43.7%), receiving induction chemotherapy in up to 54.9% of patients. 73.2% received between 60-66 Gy doses of radiotherapy. Median time from end of CRT to onset durvalumab was 44 days (range 13-120) with a median of 14 infusions (range 6-27). Of the 34 patients without durvalumab treatment, the expression PD-L1 <1% (58.8%) was the most frequent cause for rejecting consolidation therapy. After PSM analysis, patients distributions were well balanced. With a median follow-up of 19.7 months (range 1.4-36.6); median rw-PFS was 9.3 months (95% CI, 5-13.5) without durvalumab and 17 months (95% CI, 11-22.9) with durvalumab (p¼0.013). Median rw-OS was 19.3 months (95% CI, 3.8-34.8) without durvalumab and 29.9 months (95% CI, 23.3-36.6) with durvalumab (p¼0.241) with a rw-OS% at 6, 18 and 24 months of 90%, 62% and 49% vs 100%, 86% and 74%, respectively. The rate of radiation pneumonitis was more frequent with durvalumab consolidation (56.8% against 44.1%), (p¼0.346), especially within 3 months after CRT. G3 pneumonitis was only observed in the consolidation therapy. Conclusions: Our results demonstrate the effectiveness of durvalumab consolidation after CRT in real-world patients with unresectable stage III NSCLC. Further sample and longer follow-up are required to obtain more accurate results. Active surveillance and appropriate management for radiation pneumonitis are needed, in especially in candidates for consolidation treatmentS
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