161 research outputs found

    Evaluation of air lime and clayish earth mortars for earthen wall renders

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    CIAV2013 – International Conference on Vernacular Architecture, 7º ATP, VerSus, 16-20 october 2013An experimental rammed earth wall was traditionally made with local earth and characterized in terms of superficial hardness, compactness, thermal conductivity and water absorption, in exterior environmental conditions. Two mortars were made with an air lime and a mixture of three washed graduated siliceous sands, with volumetric proportions of 1:2 and 1:3 (air lime:sand). A clayish earth was characterized and applied as partial substitutions of air lime on 1:2 mortars and as partial substitutions of the finest sand on 1:3 mortars. Mortars were formulated and characterized in terms of constitution and consistency and samples of mortars applied on ceramic brick were prepared. For each volumetric proportion, mortars without earth and the ones with earth that presented the best workability were applied as renders on panels on the experimental rammed earth wall; also prismatic samples were made. The mortar samples and the renders on the wall were characterized at 90 days of age. This paper presents and discusses some of the results obtained with the characterization of the rammed earth wall, the fresh mortars and its application on the bricks and on the wall. Differences between the mortars are highlighted while their compatibility with traditional rammed earth wall is verified

    Improving sustainable hydrogen production from green waste: [FeFe]-hydrogenases quantitative gene expression RT-qPCR analysis in presence of autochthonous consortia

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    BackgroundBio-hydrogen production via dark fermentation of low-value waste is a potent and simple mean of recovering energy, maximising the harvesting of reducing equivalents to produce the cleanest fuel amongst renewables. Following several position papers from companies and public bodies, the hydrogen economy is regaining interest, especially in combination with circular economy and the environmental benefits of short local supply chains, aiming at zero net emission of greenhouse gases (GHG). The biomasses attracting the largest interest are agricultural and urban green wastes (pruning of trees, collected leaves, grass clippings from public parks and boulevards), which are usually employed in compost production, with some concerns over the GHG emission during the process. Here, an alternative application of green wastes, low-value compost and intermediate products (partially composted but unsuitable for completing the process) is studied, pointing at the autochthonous microbial consortium as an already selected source of implementation for biomass degradation and hydrogen production. The biocatalysts investigated as mainly relevant for hydrogen production were the [FeFe]-hydrogenases expressed in Clostridia, given their very high turnover rates.ResultsBio-hydrogen accumulation was related to the modulation of gene expression of multiple [FeFe]-hydrogenases from two strains (Clostridium beijerinckii AM2 and Clostridium tyrobutyricum AM6) isolated from the same waste. Reverse Transcriptase quantitative PCR (RT-qPCR) was applied over a period of 288 h and the RT-qPCR results showed that C. beijerinckii AM2 prevailed over C. tyrobutyricum AM6 and a high expression modulation of the 6 different [FeFe]-hydrogenase genes of C. beijerinckii in the first 23 h was observed, sustaining cumulative hydrogen production of 0.6 to 1.2 ml H2/g VS (volatile solids). These results are promising in terms of hydrogen yields, given that no pre-treatment was applied, and suggested a complex cellular regulation, linking the performance of dark fermentation with key functional genes involved in bio-H2 production in presence of the autochthonous consortium, with different roles, time, and mode of expression of the involved hydrogenases.ConclusionsAn applicative outcome of the hydrogenases genes quantitative expression analysis can be foreseen in optimising (on the basis of the acquired functional data) hydrogen production from a nutrient-poor green waste and/or low added value compost, in a perspective of circular bioeconomy

    The Influence of the Type of Lime on the Hygric Behaviour and Bio-Receptivity of Hemp Lime Composites Used for Rendering Applications in Sustainable New Construction and Repair Works

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    The benefits of using sustainable building materials are linked not only to the adoption of manufacturing processes that entail reduced pollution, CO2 emissions and energy consumption, but also to the onset of improved performance in the building. In particular, hemp-lime composite shows low shrinkage and high thermal and acoustic insulating properties. However, this material also shows a great ability to absorb water, an aspect that can turn out to be negative for the long-term durability of the building. For this reason, the hygric properties of hemp-based composites need to be studied to ensure the correct use of this material in construction and repair works. The water absorption, drying and transpirability of hemp composites made with aerial (in the form of dry powder and putty) and hydraulic limes were investigated here and related to the microbial growth induced by the water movements within the material. Results show that hemp-natural hydraulic lime mixes exhibit the highest transpirability and drying rate, the lowest water absorption by immersion and capillary uptake and the least intense microbial attack and chromatic change. A microscopical study of the hemp shives also related their great ability to absorb water to the near-irreversible swelling of their structure under dry-wet conditions.The research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement n° 326983 (NaturALiMe), and the Spanish project MAT-2012-34473 of the Ministerio de Ciencia y Competitividad. Author MB, owner of the CANNABRIC company, had some role in the design and preparation of mortar samples and in the preparation of this manuscript, but did not have any additional role in data collection and analysis

    Basal-Like Phenotype in a Breast Carcinoma Case Series from Sudan: Prevalence and Clinical/Pathological Correlations

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    Basal-like breast cancer, an aggressive subtype associated with high grade, poor prognosis, and younger age, is reported frequently in Africa. We analyzed the expression of the basal cytokeratins (CKs) 5/6 and 17 in a case series from Central Sudan and investigated correlations among basal CK status, ER, PgR, and Her-2/neu, and individual/clinicopathological data. Of 113 primary breast cancers 26 (23%), 38 (34%), and 46 (41%) were, respectively, positive for CK5/6, CK17, and combined basal CKs (CK5/6 and/or CK17). Combined basal CK+ status was associated with higher grade (P < .03) and inversely correlated with ER (P < .002), PgR (P = .004) and combined ER and/or PgR (P < .0002). Two clusters based on all tested markers were generated by hierarchical cluster analysis and k-mean clustering: I: designated “hormone receptors positive/luminal-like” and II: designated “hormone receptors negative”, including both basal-like and Her-2/neu+ tumors. The most important factors for dataset variance were ER status, followed by PgR, CK17, and CK5/6 statuses. Overall basal CKs were expressed in a fraction of cases comparable to that reported for East and West African case series. Lack of associations with age and tumor size may represent a special feature of basal-like breast cancer in Sudan

    Poorly differentiated carcinoma arising from adenolymphoma of the parotid gland

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    BACKGROUND: There is only one previous case report of a poorly differentiated carcinoma arising from an adenolymphoma of the parotid gland (Warthin's tumour). The absence of clinical symptoms, and the aspecificity of the radiological pattern make the diagnosis very difficult. CASE PRESENTATION: We here report the case of a 73-year-old man with Warthin's tumour who was brought to our attention because of a swelling in the parotid region. CONCLUSIONS: In this case with an atypical clinical presentation, the intra-operative examination of a frozen section of the parotid mass allowed us to diagnose the malignant tumour correctly and consequently undertake its radical excision

    A pragmatic approach improves the clinical management of stage IV gastric cancer: Comparison between the Meta-Gastro results and the GIRCG's retrospective series

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    Introduction: The Italian Research Group for Gastric Cancer developed a prospective database about stage IV gastric cancer, to evaluate how a pragmatic attitude impacts the management of these patients. Materials and methods: We prospectively collected data about metastatic gastric cancer patients thanks to cooperation between radiologists, oncologists and surgeons and we analyzed survival and prognostic factors, comparing the results to those obtained in our retrospective study. Results: Three-hundred and eighty-three patients were enrolled from 2018 to September 2022. We observed a higher percentage of laparoscopic exploration with peritoneal lavage in the prospective cohort. In the registry only 3.6 % of patients was submitted to surgery without associated chemotherapy, while in the retrospective population 44.3 % of patients were operated on without any chemotherapy. At univariate and multivariate analyses, the different metastatic sites did not show any survival differences among each other (OS 20.0 vs 16.10 vs 16.7 months for lymphnodal, peritoneal and hepatic metastases, respectively), while the number of metastatic sites and the type of treatment showed a statistical significance (OS 16,7 vs 13,0 vs 4,5 months for 1, 2 and 3 different metastatic sites respectively, p &lt; 0.001; 24,2 vs 12,0 vs 2,5 months for surgery with/without chemotherapy, chemotherapy alone and best supportive treatment respectively, p &lt; 0.001). Conclusions: Our data highlight that the different metastatic sites did not show different survivals, but survival is worse in case of multiple localization. In patients where a curative resection can be achieved, acceptable survival rates are possible. A better diagnostic workup and a more accurate staging impact favorably upon survival

    Effects of mineral amendments on trace elements leaching from pre-treated marine sediment after simulated rainfall events

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    Bauxite extraction by-products (red mud) were used to evaluate their potential ability to stabilize trace elements from dredged and aerated/humidified marine sediment. The investigated by-products were: bauxaline®(BX) that is a press-filtered red mud; bauxsol™(BS) that is a press-filtered red mud previously washed with excess of seawater, and gypsum neutralized bauxaline® (GBX). These materials were separately mixed to dredged composted sediment sample considering 5% and 20% sediment: stabilizer ratios. For pilot experiments, rainfall events were regularly simulated for 3 months. Concentrations of As, Mo, Cd, Cr, Zn, Cu, and Ni were analyzed in collected leachates as well as toxicity. Results showed that Cd, Mo, Zn, and Cu were efficiently stabilized in the solid matrix when 20% of BX, BS, and GBX was applied. Consequently, toxicity of leachates was lower than for the untreated sediment, meaning that contaminants mobility was reduced. A 5% GBX was also efficient for Mo, Zn and Cu stabilization. In all scenarios, As stabilization was not improved. Compared to all other monitored elements, Mo mobility seemed to depend upon temperature-humidity conditions during pilot experiments suggesting the need of further investigations
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