Interacción entre cementos de diferente composición y aditivos superplastificantes

The slump behavior of ordinary Portland-, pozzolanic (red brick powder)-, sulfate resistant-, and limestone cement pastes caused by ≤ 1% additions of polycondensates and polycarboxylates superplasticizers are monitored for up to 90 minutes. With the plolycondensates, Portland- and pozzolanic cements gain fluidity at higher dosages than sulfate resistant and limestone cements. Limestone cement shows the best slump retention. The aluminate and sulfate phases play a major role in the fluidity. With the polycarboxylates, all cements gain fluidity with dosages of ≤ 0.3%. A polycarboxylate with no resonance of methyl methylene proton in the main chain identified in the NMR spectra creates good slump retention. This is explained by a low mobility of the structure and the predominance of the steric effect. The polycarboxylate shows also strong ether bands relative to the ester groups in the IR spectra and a low polydispersity observed in the elution of few low molecular weight species in the HPLC chromatogram.Se ha estudiado el efecto fluidificante (hasta 90 minutos) ejercido por la incorporación de entre 0-1% de aditivos policondensados y policarboxilatos en pastas de cemento Portland, puzolánico, resistente a sulfatos y con adición de caliza. Con la incorporación de los aditivos policondensados, se produjo un incremento de la fluidez de los cementos Portland y puzolánico a mayores dosificaciones que las necesarias en los cementos resistente a sulfatos y con adición de caliza. Éste último presentó la mejor retención de la fluidez. Las fases aluminatos y sulfatos juegan un importante papel en la fluidez inducida. Todos los cementos incrementaron su fluidez con la incorporación de aditivos policarboxilatos a dosificaciones menores del 0,3%. El policarboxilato que no presenta en los espectros de RMN, resonancia asignada al protón de los grupos metil metileno, presenta buena retención de la fluidez. Esto es debido a la baja flexibilidad de la estructura y predominancia del efecto estérico. Este aditivo presenta también, mayor relación de grupos eter frente a grupos ester en los espectros IR, asi como una baja polidispersidad observada en la elución de especies de bajo peso molecular a través de HPLC

Interaction Analysis between Existing Loaded Piles and Braced Excavation Design Parameters

Three-dimensional numerical analyses are conducted using the finite element software PLAXIS 3D to gain insight into the interaction behavior between deep excavation and adjacent piled foundations in fully saturated sand. Effects of excavation width and depth, the distance between strut level and the excavation surface with each excavation stage, strut stiffness, diaphragm wall stiffness, and diaphragm wall depth are examined during the adjacent excavation. In practice, incorrect values of the braced excavation design parameters may result in an uneconomical or even unsafe design. The analyses revealed that increasing the excavation width or depth has a significant influence on the adjacent pile group behavior. Additionally, it is also observed that reducing the distance between the strut level and the excavation surface with each excavation stage, increasing the struts stiffness, increasing diaphragm wall thickness or depth, and reducing the horizontal or vertical span of struts can assist to reduce settlement and tilting of the pile group induced by the adjacent excavation

Comparison between the Outcomes of Using Biodegradable-Polymer Drug-Eluting Stents and Those of Using Durable-Polymer Drug-Eluting Stents in Acute Coronary Syndrome Patients Undergoing Percutaneous Coronary Intervention

BACKGROUND: Many randomised control studies showed that percutaneous coronary interventions using biodegradable-polymer drug-eluting stents (DES) offer a safe and effective alternative to durable-polymer DES. However, not many studies have discussed its use in the setting of acute coronary syndromes. AIM: We aim to compare the biodegradable-polymer DES with durable-polymer DES when it comes to reducing the incidence of non-ST elevation acute coronary syndrome (NSTEACS) associated with adverse events. METHODS: We enrolled 205 patients presenting with NSTEACS and a TIMI risk score ≥ 3 in this study and divided them into two groups, group A and group B. Biodegradable-polymer DESs were exclusively used in group A, while durable-polymer DESs were used in group B. Major adverse events were reported in both groups during the hospital stay and patients were followed-up for 1 year. RESULTS: In our patients, we intervened on 390 diseased segments in a total of 360 vessels. After intervention, TIMI 0 was achieved in 0.97%, TIMI 1 in 1.46%, TIMI 2 in 2.45%, and TIMI 3 in 95.12% of the treated segments (P-value= 0.677). We implanted 121 biodegradable-polymer DESs and 146 durable-polymer DESs. Clinical success was achieved in 95.12% of our cases. We had 55 patients who needed repeated coronary angiography within 1 year (15 patients treated with biodegradable-polymer DES and 24 patients treated with durable-polymer DES). Eighteen patients experienced angina pains (8 patients treated with biodegradable-polymer DES and 10 patients treated with durable-polymer DES). Only 5 patients needed TLR (2 patients treated with biodegradable-polymer DES and 3 patients treated with durable -polymer DES) (P-value = 0.591), three of them had a myocardial infarction with documented angiographic evidence of significant in-stent restenosis (1 patient treated with biodegradable-polymer DES and 2 patients treated with durable-polymer DESs). CONCLUSION: Biodegradable-polymer DES represents a comparable alternative to durable-polymer DES in the setting of acute coronary syndromes

In Vitro Inhibition of Histamine Release Behavior of Cetirizine Intercalated into Zn/Al- and Mg/Al-Layered Double Hydroxides

The intercalation of cetirizine into two types of layered double hydroxides, Zn/Al and Mg/Al, has been investigated by the ion exchange method to form CTZAN and CTMAN nanocomposites, respectively. The basal spacing of the nanocomposites were expanded to 31.9 Å for CTZAN and 31.2 Å for CTMAN, suggesting that cetirizine anion was intercalated into Layered double hydroxides (LDHs) and arranged in a tilted bilayer fashion. A Fourier transform infrared spectroscopy (FTIR) study supported the formation of both the nanocomposites, and the intercalated cetirizine is thermally more stable than its counterpart in free state. The loading of cetirizine in the nanocomposite was estimated to be about 57.2% for CTZAN and 60.7% CTMAN. The cetirizine release from the nanocomposites show sustained release manner and the release rate of cetirizine from CTZAN and CTMAN nanocomposites at pH 7.4 is remarkably lower than that at pH 4.8, presumably due to the different release mechanism. The inhibition of histamine release from RBL2H3 cells by the free cetirizine is higher than the intercalated cetirizine both in CTZAN and CTMAN nanocomposites. The viability in human Chang liver cells at 1000 μg/mL for CTZAN and CTMAN nanocomposites are 74.5 and 91.9%, respectively

Recent developments in chemical reactivity of N,N-dimethylenamino ketones as synthons for various heterocycles

The current review presents recent progress in the utility of N,N-dimethyl enaminones as building blocks for a diverse range of acyclic, carbocyclic, five- and six-membered heterocyclic a broad range of heterocyclic and fused heterocyclic derivatives. Most importantly, these N,N-dimethyl analogues have proven to be of biological interest and provide an access to new class of biologically active heterocyclic compounds for biomedical applications. All of these topics are drawn from the recent literature till 2016

Oxidative Stress in Cancer

Contingent upon concentration, reactive oxygen species (ROS) influence cancer evolution in apparently contradictory ways, either initiating/stimulating tumorigenesis and supporting transformation/proliferation of cancer cells or causing cell death. To accommodate high ROS levels, tumor cells modify sulfur-based metabolism, NADPH generation, and the activity of antioxidant transcription factors. During initiation, genetic changes enable cell survival under high ROS levels by activating antioxidant transcription factors or increasing NADPH via the pentose phosphate pathway (PPP). During progression and metastasis, tumor cells adapt to oxidative stress by increasing NADPH in various ways, including activation of AMPK, the PPP, and reductive glutamine and folate metabolism

Flow Ramping from Hydropower Operation Evaluation of Trends and Mitigation of Peak Supply and Environmental Impacts in Norway

Increased flexibility is vital in hydropower systems to meet future market demands, and work is undertaken to improve hydropower machinery to handle larger ramping rates and more frequent starts and stops. This increased flexibility simultaneously can cause rapid changes in the flow rate known to be as flow ramping. The impacts of flow ramping on downstream rivers due to hydropower operation are documented in several studies and expected to increase in the future that it would require mitigation measures to provide an environmentally friendly production regime. This work aims for two main tasks. First, to put a grasp on the current level and characteristics of the flow ramping in Norway by analyzing the hourly turbine discharge data for various hydropower plants using various hydrological indicators and tools used to quantify this impact and assessing the efficiency of the provided environmental legislation and restrictions to eliminate this impact. Second, to evaluate this flow ramping impact and mitigation measures in future production scenarios with the implementation of the HydroFlex production scenario using hydraulic modeling on the river Nidelva in Norway. Results show that the occurred flow ramping varies in terms of level and characteristics depending on the type and operational pattern of the power plant itself. Additionally, the provided measures and environmental legislation to restrict this ramping showed some efficiency in reducing the magnitude of this ramping, yet; they did not cover all potentially ecologically power plants. On the contrary, the intensity of flow ramping is expected to increase severely due to the implementation of the HydroFlex production scenario, and the provided traditional measures are not feasible solutions for mitigating this increased impact in the investigated river Nidelva. It can be concluded that it is crucial to further assess the efficiency of innovative technologies to coop with this increasing ramping ratio. Lastly, using hydraulic modeling can be a very efficient tool for mapping out the impact of flow ramping, and its recommended to use for further assessment of such impact from different production scenarios

Wanas

Wanas Folk Music Festival is an already existing festival curated by El Mastaba Centre For Egyptian Folk Music, an organization that has devoted the past 30 years in establishing local bands that represent different regions in Egypt, from Nubia to Port Said. With the festival lacking proper outreach to its audience, this branding project aims at promoting Egyptian folk music by using Wanas as a platform to showcase the diversity of Egyptian culture and its music. The concept revolves around creating an identity for Egyptian folk music that changes how the genre is perceived by Egyptians. The challenge was in creating an identity that spoke both to the rich culture of folk music and the younger generations that have distanced themselves from it. Folk music is about free spirit, passion, and authenticity, a combination that has been used in bringing the brand to life

Caractérisation du phénotype hépatosplénique d'un nouveau modèle de rats acéruloplasminémiques pour une meilleure compréhension des mécanismes physiopathologiques de l'acéruloplasminémie héréditaire

Hereditary aceruloplasminemia is a rare genetic disease, resulting in a lack of functional ceruloplasmin in plasma. This pathology leads to iron overload, especially in hepatocytes. However, liver and spleen macrophages are not iron overloaded, despite the reported important role of ceruloplasmin in iron egress from macrophages. Our hypothesis was that ceruloplasmin is not essential for iron egress from macrophages, and that some mechanisms, not in direct link with the ceruloplasmin reported role, are the cause of the hepatosplenic phenotype observed in the disease. We performed a synthesis of aceruloplasminemia clinical cases reported in the literature, confirming by this way the presence of an hépatosplenic phenotype that suggest an imperfect undersanding of ceruloplasmin role. We then performed and characterized a new rat model of aceruloplasminemia, reproducing the human hepatosplenic phenotype. The data obtained in this model suggested that ceruloplasmin is not essential for macrophage iron egress. Otherwise, some other results highlighted abnormalities regarding to non-iron metals metabolism, in link with aceruloplasminemia.L’acéruloplasminémie héréditaire est une pathologie génétique rare, résultant en une absence de céruloplasmine fonctionnelle dans le plasma. La pathologie entraîne des surcharges en fer, notamment au niveau hépatocytaire. Cependant, les macrophages hépatiques et spléniques des patients ne semblent pas impactés par la surcharge en fer, alors même que la céruloplasmine est décrite comme nécessaire à la sortie du fer macrophagique. Notre hypothèse était que la céruloplasmine n’est pas indispensable à la sortie du fer macrophagique, et que des mécanismes sans lien direct avec le rôle rapporté de la céruloplasmine sont à l’origine du phénotype hépatosplénique rencontré dans la pathologie. Nous avons réalisé une synthèse des cas cliniques d’acéruloplasminémie rapportés dans la littérature, confirmant la présence d’un phénotype hépatosplénique suggérant que le rôle de la céruloplasmine est incomplètement compris. Nous avons par la suite développé et caractérisé un modèle original de rats acéruloplasminémiques, reproduisant le phénotype hépatosplénique humain. Les données récoltées dans ce modèle suggéraient que la céruloplasmine n’est pas nécessaire à la sortie du fer macrophagique. D’autres résultats ont par ailleurs mis en évidence des anomalies du métabolisme des métaux non-ferreux, en lien avec la pathologie