324 research outputs found
An empirical failure model to predict biofouling growth on fired bricks due to microalgae
The purpose of this study was to provide an empirical failure model predicting the microalgae growth on fired bricks surfaces. It was developed through a numerical fitting of experimental data present in literature. It considered the substrate properties related to biofouling (i.e. porosity and roughness) of different bricks under several environmental conditions (i.e. relative humidity and temperature). Results shows that the model is able to simulate the microalgae biofouling by explicitly taking into account such influencing factor. Finally, this empirical failure model is validated on a different dataset from literature and applied to time varying temperature
Pedestrian Single and Multi-Risk Assessment to SLODs in Urban Built Environment: A Mesoscale Approach
Pedestrians are increasingly exposed to slow-onset disasters (SLODs), such as air pollution and increasing temperatures in urban built environments (BEs). Pedestrians also face risks that arise from the combination of the BE features, the effects of SLODs on the microclimate, their own characteristics (e.g., health and ability), and the way they move and behave in indoor and outdoor BE areas. Thus, the effectiveness of sustainable risk-mitigation solutions for the health of the exposed pedestrians should be defined by considering the overlapping of such factors in critical operational scenarios in which such emergency conditions can appear. This work provides an innovative method to define a BE-oriented pedestrian risk index through a dynamic meso-scale approach that considers the daily variation of risk conditions. The method is ensured by a quick-to-apply approach, which also takes advantage of open-source repositories and tools to collect and manage input data, without the need for time-consuming in situ surveys. The resulting risk conditions are represented through meso-scale maps, which highlight the risk differences between BEs by focusing on their open spaces as fundamental parts of the urban road network. The method is applied to a significant case study (in Milan, Italy). The results demonstrate the ability of the approach to identify key input scenarios for risk assessment and mapping. The proposed methodology can: (1) provide insights for simulation activities in critical BE conditions, thanks to the identification of critical daily conditions for each of the factors and for single and multiple risks and (2) support the development of design and regeneration strategies in SLOD-prone urban BEs, as well as the identification of priority areas in the urban BE
Mechanistic insights into the release of doxorubicin from graphene oxide in cancer cells
Liposomal doxorubicin (L-DOX) is a popular drug formulation for the treatment of several cancer types (e.g., recurrent ovarian cancer, metastatic breast cancer, multiple myeloma, etc.), but poor nuclear internalization has hampered its clinical applicability so far. Therefore, novel drug-delivery nanosystems are actively researched in cancer chemotherapy. Here we demonstrate that DOX-loaded graphene oxide (GO), GO-DOX, exhibits much higher anticancer efficacy as compared to its L-DOX counterpart if administered to cellular models of breast cancer. Then, by a combination of live-cell confocal imaging and fluorescence lifetime imaging microscopy (FLIM), we suggest that GO-DOX may realize its superior performances by inducing massive intracellular DOX release (and its subsequent nuclear accumulation) upon binding to the cell plasma membrane. Reported results lay the foundation for future exploitation of these new adducts as high-performance nanochemotherapeutic agents
Managing Natural Disasters in Historic Areas: a Novel Holistic Seismic Risk Assessment Method Applied to a Relevant Case Study
The resilience of historic areas is highly threatened by natural sudden onset events such as earthquakes. Major weak points of an urban environment, widely debated in the past literature, concern mainly masonry buildings. However, also the complex urban paths system could be prone to lose its functionality in the aftermath of a seismic event. Urban paths alterations due to earthquake effects can be attributed to extrinsic (i.e.: ruins formation from buildings) and intrinsic (e.g.: ground instability due to landslide or underground cavities) vulnerability; these factors jointly combined with exposure condition of hosted population in urban areas and with the local seismic hazard represent a possible impediment to evacuation process and at the same time, an obstacle to rescuers’ teams occupied in offering a first aid response. Therefore, the work aim is to apply a tool for preliminary evaluation of risk, strictly related to urban paths system considering all abovementioned aspects from a holistic point of view. This goal is achieved by a simplified methodology applicable to a wide-scale on a whole historic centre that takes advantages from a series of easy-to-detect parameters influencing the risk with limited availability of resources. Parameters grouped by topics (i.e.: path use and exposure; geometric features; physical-structural features; extrinsic vulnerability; seismic hazard) are assigned to scores and weights according to a multi-criteria decision-making process generating a numerical index. A typical Italian urban centre made by historical masonry constructions is assumed as a case study to implement the existing method. The detected risk indexes are then graphically provided through risk maps, a chromatic scale indicates which areas are more prone to possible unavailability of paths rather than others. Evacuation planners and emergency managers could embody this tool in their studies to prevent the high number of losses by guiding evacuees toward assembly points through the risk lower paths and to direct risk-reduction interventions punctually where critical condition emerges with different priority levels. Paths accessibility evaluation through a risk characterization could also result useful as a tool for rescuers’ activities optimization and for inhabitant disaster preparedness in terms of being familiar with safest and alternatives paths in emergency conditions
From A to Z: Using Alphabet Books as an instructional Tool with Older Readers
Alphabet books provide a literature source for teachers to use in the classroom that focuses on a common sequence of textual organization which upper elementary and middle school students have known since they were young children. These students most likely had in their repertoire of beginning to read activities, alphabet books using common symbols to match the letters such as A is for apple, B is for bear, C is for cat. The objects were selected to match the true sound of the letter with a single or small number of illustrations to demonstrate the concept. The alphabet book addresses the 26 letters in picture book format with typically 24 to 48 pages, illustrations on double pages, and brief text (Kormanski and Stevens, 1993)
A multi-parameter field monitoring system to investigate the dynamics of large earth slides–earth flows in the Northern Apennines, Italy
Large earth slides and rocks lides evolving into earth flows are quite widespread in the Northern Italian Apennines. Despite being simply referred to as landslides, many of them are, in fact, large complexes of landslides. They evolved through multiple and/or successive movements, undergoing partial and/or total reactivations. The reactivation of pre-existing landslide bodies is the prevalent mechanism for the known landslide events, as the historical records and the technical reports indicate. Landslide reactivation is, indeed, a relevant topic from the perspective of risk assessment and mitigation. A multi-parameter monitoring system was installed on a large complex of landslides that underwent partial or total reactivations after heavy rainfall events, causing damages to buildings and infrastructures. Two clusters of automatic piezometers—each coupled with an inclinometer—and a time-lapse resistivity deployment were the core of the monitoring system. A weather station, collecting data from subsurface thermometers, and a water content probe completed the system. After the construction of a new geological model of the slope, this study aimed at understanding the possible mechanisms leading to the reactivation of the landslide. This goal was achieved by gaining insights into the process of rainfall infiltration into the landslide deposits, by determining the groundwater flow and evaluating the landslide displacements. The monitoring system captured the processes that took place in the landslide bodies and the bedrock in response to a rainfall event in early February 2017, which followed a dry period of eight months. The recorded data provided indications on the variation of the hydraulic head in the groundwater within the landslide and the bedrock, particularly at the sliding surfaces. The electrical conductivity of the groundwater and the resistivity of the terrain varied across the failure surfaces. In particular, a sudden increase in the electrical conductivity was related to the locations of the main sliding surfaces. The joint analysis of time-lapse resistivity, hydraulic heads, and groundwater electrical conductivity helped identify the locations of weaker levels within the landslide masses, which were confirmed by data from inclinometers. This study improved the knowledge of the hydrogeological behaviour of a complex of landslides in heterogeneous low-permeability media. Moreover, the obtained results contributed to the understanding of the role played by different portions of the landslide complex in the evolution of the movement
Multiplexed detection of pancreatic cancer by combining a nanoparticle-enabled blood test and plasma levels of Acute-Phase Proteins
The development of new tools for the early detection of pancreatic ductal adenocarcinoma (PDAC) represents an area of intense research. Recently, the concept has emerged that multiplexed detection of different signatures from a single biospecimen (e.g., saliva, blood, etc.) may exhibit better diagnostic capability than single biomarkers. In this work, we develop a multiplexed strategy for detecting PDAC by combining characterization of the nanoparticle (NP)-protein corona, i.e., the protein layer that surrounds NPs upon exposure to biological fluids and circulating levels of plasma proteins belonging to the acute phase protein (APPs) family. As a first step, we developed a nanoparticle-enabled blood (NEB) test that employed 600 nm graphene oxide (GO) nanosheets and human plasma (HP) (5% vol/vol) to produce 75 personalized protein coronas (25 from healthy subjects and 50 from PDAC patients). Isolation and characterization of protein corona patterns by 1-dimensional (1D) SDS-PAGE identified significant differences in the abundance of low-molecular-weight corona proteins (20–30 kDa) between healthy subjects and PDAC patients. Coupling the outcomes of the NEB test with the circulating levels of alpha 2 globulins, we detected PDAC with a global capacity of 83.3%. Notably, a version of the multiplexed detection strategy run on sex-disaggregated data provided substantially better classification accuracy for men (93.1% vs. 77.8%). Nanoliquid chromatography tandem mass spectrometry (nano-LC MS/MS) experiments allowed to correlate PDAC with an altered enrichment of Apolipoprotein A-I, Apolipoprotein D, Complement factor D, Alpha-1-antichymotrypsin and Alpha-1-antitrypsin in the personalized protein corona. Moreover, other significant changes in the protein corona of PDAC patients were found. Overall, the developed multiplexed strategy is a valid tool for PDAC detection and paves the way for the identification of new potential PDAC biomarkers
Visible light photoactivity of Polypropylene coated Nano-TiO2 for dyes degradation in water
The use of Polypropylene as support material for nano-TiO2 photocatalyst in the photodegradation of Alizarin Red S in water solutions under the action of visible light was investigated. The optimization of TiO2 pastes preparation using two commercial TiO2, Aeroxide P-25 and Anatase, was performed and a green low-cost dip-coating procedure was developed. Scanning electron microscopy, Atomic Force Microscopy and X-Ray Diffraction analysis were used in order to obtain morphological and structural information of as-prepared TiO2 on support material. Equilibrium and kinetics aspects in the adsorption and successive photodegradation of Alizarin Red S, as reference dye, are described using polypropylene-TiO2 films in the Visible/TiO2/water reactor showing efficient dyes degradation
Multi-analytical investigation into painting materials and techniques: the wall paintings of Abuna Yemata Guh church
ANGPTL8/Betatrophin R59W variant is associated with higher glucose level in non-diabetic Arabs living in Kuwaits
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