Investigating the Necessity of Standardized In-Situ Testing Procedures for One-Part Granite-based Geopolymers: Examining the Impact of Temperature and Confining Pressure through Experimental Study

Ordinary Portland cement (OPC) is widely used in primary cementing and plug and abandonment operations due to its well-known properties, global availability, and affordability. However, it has limitations and durability concerns in corrosive downhole environments. Additionally, OPC contributes significantly to global CO2 emissions (6-8 wt.%). Consequently, industries are exploring alternative cementitious materials that offer comparable or superior fluid-state and physical properties while being more economically viable and environmentally sustainable. Geopolymer cement (GPC) is an inorganic polymer with binding properties, forming a 3D network structure of silicate and aluminum. GPC exhibits stability at high temperatures, increased durability in corrosive environments, greater flexibility, and lower matrix permeability compared to OPC. Although these advantages make GPC an excellent alternative to OPC, its application in oilfields is still limited to laboratory-scale experiments due to the young age of the technology. This study is complementary to two other projects being conducted to reveal the potential necessity of standard procedures for testing in-situ rock mechanical properties of the GPC. Since the impact of pore pressure and loading rate is covered in the other two projects, this work presents the effect of temperature and confining pressure on the in-situ mechanical properties of the one-part granite-based geopolymer cement. A triaxial cell is used to analyze Young’s modulus, bulk modulus, Poisson’s ratio, and compressive strength of the material at three different temperatures and confining pressure. The GPC sample preparation procedure is optimized during the study after experiencing inconsistent and unreliable results during the first seven tests. The increase in test temperature resulted in a decrease in yield strength, peak stress, and Young’s modulus while causing an increase in the bulk modulus. The sensitivity of the material to temperature decreases with the increase of confining pressure. The increase in confining pressure also increased the yield strength and peak stress of the material

Solving multi-objective supplier selection and quota allocation problem under disruption using a scenario-based approach

Nowadays, experts believe there are abundant sources of risks in a supply chain. An important group of risks against a supply chain is the disruption risks group, which disturbs the flow of material in the chain and may lead to inefficiency in providing the final product in the supply chain. The aim of this article is to investigate the control of costs of disruption in a supply chain by considering the possibility of disruption. In fact, this research focuses on determining the best combination of suppliers and quota allocation with regards to disruption in suppliers. The proposed multi-objective mathematical model in this paper is a mixed-integer programming (MIP) model with objective functions to minimize transaction costs of suppliers, expected costs of purchasing goods, expected percentages of delayed products, expected returned products, and to maximize expected evaluation scores of the selected suppliers. Due to the uncertainty of demand and supplier disruption in the real world, their values are also considered uncertain; the proposed multi-objective model is studied by using a scenario-based stochastic programming (SP) method. In this method, all possible predictions for demand and disruption values are simultaneously included in the model; objective function results have more optimal value than a separate solution of the model for each predicted value

Esthetic and function rehabilitation of severely worn dentition with prosthetic-restorative approach and VDO increase. Case report

The aim of this study is to report a case of restorative treatment of severely worn dentition. In this case report, the erosive/abrasive worn dentition have been reconstructed with metal ceramic crown on the posterior teeth and with ceramic veneers on the anterior teeth 1.3 - 2.3 and 3.4 - 4.3. A prosthetic treatment was proposed to a male patient of 58 years old having a clinically significant tooth wear. After clinical exam, impressions of maxillary and mandible arches were taken with alginate to obtain preliminary casts for diagnostic waxing to all maxillary and mandibular teeth and fabrication of all provisional crowns in acrylic resin for posterior teeth, and from the diagnostic wax-up were fabricated a silicone guide masks for anterior teeth. An increase in VDO should be determined on the basis of a need to accomplish satisfactory and aesthetically pleasing restorations; it was proposed to increase the incisal lenght of the maxillary anterior incisors, together with alteration of the VDO 3 mm anteriorly. The posterior teeth 1.6 - 1.5 - 1.4 - 2.4 - 2.6 - 3.5 - 3.6 - 3.7 - 4.4 - 4.7, where the amount of tissue lost was greater, were recontructed with metal ceramic crowns. Two implants (Nobel replace 4.3x10) was placed. The implant were located in the area 4.5 - 4.6. The anterior teeth were restored with veneers. The prosthetic challenge with restoring severely worn dentitions is to preserve as much of the already diminished tooth structure as possible for retention while also providing enough interocclusal space for the restorative material

Development Cabinet Formalized

Alzheimer's disease (AD) is a kind of brain disease that arises due to the aggregation and fibrillation of amyloid β-peptides (Aβ). The peptide Aβ17-42 forms U-shape protofilaments of amyloid mature fibrils by cross-β strands, detected in brain cells of individuals with AD. Targeting the structure of Aβ17-42 and destabilizing its β-strands by natural compounds could be effective in the treatment of AD patients. Therefore, the interaction features of monomeric U-shape Aβ17-42 with natural flavonoids including myricetin, morin and flavone at different mole ratios were comprehensively studied to recognize the mechanism of Aβ monomer instability using molecular dynamics (MD) simulations. We found that all flavonoids have tendency to interact and destabilize Aβ peptide structure with mole ratio-dependent effects. The interaction free energies of myricetin (with 6 OHs) and morin (with 5 OHs) were more negative compared to flavone, although the total binding energies of all flavonoids are favorable and negative. Myricetin, morin and flavone penetrated into the core of the Aβ17-42 and formed self-clusters of Aβ17-42-flavonoid complexes. Analysis of Aβ17-42-flavonoids interactions identified that the hydrophobic interactions related to SASA-dependent energy are weak in all complexes. However, the intermolecular H-bonds are a main binding factor for shifting U-shape rod-like state of Aβ17-42 to globular-like disordered state. Myricetin and morin polyphenols form H-bonds with both peptide's carbonyl and amine groups whereas flavone makes H-bonds only with amine substitution. As a result, polyphenols are more efficient in destabilizing β-sheet structures of peptide. Accordingly, the natural polyphenolic flavonoids are useful in forming stable Aβ17-42-flavonoid clusters to inhibit Aβ17-42 aggregation and these compounds could be an effective candidate for therapeutically targeting U-shape protofilaments' monomer in amyloid mature fibrils

Epilithic diatoms (Bacillariophycae) from streams in Ramsar, Iran

Epilithic diatoms were identified from five small streams and one canal in Ramsar, northwest Iran. Atotal of 155 diatom taxa belonging to 37 genera were found and only two species remained unidentified (Fragilaria sp. and Nitzschia sp.). Achnanthes, Nitzschia, Navicula, Cocconeis, Melosira, Amphora, Craticula, Diatoma, Surirella, Cymbella, Diploneis and Entomoneis were among the most abundant genera. Eighty seven taxa were recorded for the first time in Iran. Thirty two of the genera belong to the Pennales and 5 to the Centrales. Species richness was rather high ranging from 66 to 95 taxa at the six sites studied. The epilithic diatom species found in Ramsar were dominated by cosmopolitan taxa found in meso- to fairly eutrophic waters with high conductivity and high nutrient concentrations. The abundances found at all six sites were compiled in order to estimate the overall abundance of each taxon in Ramsar. This study includes EM pictures of diatoms observed in Ramsar, Iran

Restoration of anterior teeth using an indirect composite technique. Case report

This article presents a case report of restoration of anterior teeth using an indirect technique with composite veneers in order to restore the dental anatomy and to provide aesthetic and function of anterior teeth. A treatment of upper anterior teeth with indirect microhybrid composite restoration was proposed to a 40-year-old woman with old discolored and fractured ceramic veneers. Upper six anterior teeth were prepared and, after impressions with VPS of maxillary arche, the composite veneers were placed. There are several advantages offered by indirect techniques compared to direct techniques. The increased practice of veneering technique with indirect composites is due to improvement in the properties of composite materials in the last years. The results are very favourable and the patient is satisfied. The restorations with composite veneers have proved durable and aesthetic, protect tooth structure and aesthetic and function is predictably re-established

EVALUATION OF THE IMPACT OF DIETARY INTERVENTIONS ON THE HUMAN INTESTINAL MICROBIAL ECOSYSTEM THROUGH IMPROVED BIOINFORMATICS AND STATISTICS

The aim of this PhD work was the characterization of the intestinal microbial ecosystem through bioinformatic and statistical analyses of the microbiomics data originated from three studies carried out on different human populations: healthy (non-diseased) adults, hyperlipidemic and normo-lipidemic children and adolescents, and subjects with diagnosed irritable bowel syndrome (IBS). Specifically, the three studies presented in this PhD theses were as follows: \u2022 Probiotic crossover intervention study: A randomized, double-blind, crossover, placebo-controlled intervention study was carried out to determine the impact of a Bifidobacterium bifidum strain on the IME of adult healthy volunteers. \u2022 Children\u2019s dyslipidemia single arm intervention study: In this trial, the IME of children and adolescents with primary hyperlipidemia (a risk factor for cardiovascular diseases) was compared with the IME of control (normo-lipidemic) group. In addition, the modulatory effect of the regular intake of hazelnuts on hyperlipidemic subjects\u2019s IME was examines in order to evaluate if the modulation of IME by hazelnuts ameliorates the lipid profile. \u2022 Irritable bowel syndrome (IBS) observational study: The aim of this trial was the characterization of the IME in human subjects affected by IBS. The characterization was performed through the analysis of the bacterial communities present in the faecal samples collected during a multicentre intervention trial (Cremon et al., 2017). Irritable bowel syndrome is the most common gastrointestinal disorder in western countries. IBS is conventionally classified in four different subtypes based on bowel clinical symptoms: constipation, diarrhoea, alternating constipation and diarrhoea, and unsubtyped IBS. Clinical and immunological data collected during the trial were used to investigate the potential correlations between the IME characteristic for a specific IBS subtypes and the physiological and clinical parameters of the host, including bowel symptoms, faecal levels of IgA and cytokines, and depression/anxiety scores. The analysis of the data collected during the three studies presented in this PhD thesis revealed significant correlations between the intestinal microbial ecosystem and specific physiological parameters, characteristic for the physiological conditions under study. Therefore, these findings suggest that the differential abundance of specific OTUs could be used as a biomarker for a specific host condition. Conclusion of the probiotic B. bifidum Bb crossover intervention trial The intervention trial based on the administration of B. bifidum strain Bb has shown that the probiotic treatment modified the relative abundances of bacterial taxa that have often been associated with healthy conditions. The treatment modulated the faecal levels of butyrate, a microbial metabolite exerting multiple effects on gut health. Therefore, the daily consumption of B. bifidum Bb cells may positively affect human health; however, as for most dietary interventions, the current state of knowledge does not allow us to better define the significance of any taxonomic or metabolite changes of the intestinal microbial ecosystem on the host health. Conclusion of children\u2019s dyslipidemia single arm intervention trial The results of this study support the hypothesis that young individuals with primary hyperlipidemia possess an dysbiotic intestinal microbial ecosystem, which could plausibly contribute to the abnormal lipid profile of these subjects. A limitation of this study is the small sample size, which may reduce the potential robustness of the obtained results. Moreover, further studies focusing on the mechanisms involved in such hypothesized association are warranted. Our study is the first human trial investigating the potential role of hazelnuts as IME modulator and, in specific, suggests that a dietary intervention with hazelnut could be an effective and practical strategy to positively modulate the IME of hyperlipidemic subjects. Conclusion of the IBS-subtypes observational study This descriptive study demonstrates that the altered distribution of bacteria within the Gram-positive order Clostridiales distinguishes the intestinal microbial ecosystem of IBS subtypes, plausibly contributing to the observed altered faecal levels of the SCFAs acetate, butyrate and propionate. Our study proposes intestinal Clostridiales and colonic SCFAs as IBS subtypes biomarkers that can also potentially represent therapeutic targets. In addition, this study supports the notion that distinct therapeutic approaches should be developed for the different IBS subtype