Pancreatic Cancer: Updates in Pathogenesis and Therapies

Despite the progress in pancreatic cancer (PC) chemo/radiotherapies, immunotherapies, and novel targeted therapies and the improvement in its peri-operative management policies, it still has a dismal catastrophic prognosis due to delayed detection, early neural and vascular invasions, early micro-metastatic spread, tumour heterogeneities, drug resistance either intrinsic or acquired, unique desmoplastic stroma, and tumour microenvironment (TME). Understanding tumour pathogenesis at the detailed genetic/epigenetic/metabolic/molecular levels as well as studying the tumour risk factors and its known precancerous lesions aggressively is required for getting a more successful therapy for this challenging tumour. For a better outcome of this catastrophic tumour, it should be diagnosed early and treated through multidisciplinary teams of surgeons, gastroenterologists/interventional upper endoscopists, medical/radiation oncologists, diagnostic/intervention radiologists, and pathologists at high-volume centres. Moreover, surgical resection with a negative margin (R0) is the only cure for it. In this chapter; we discuss the recently updated knowledge of PC pathogenesis, risk factors, and precancerous lesions as well as its different management tools (i.e. surgery, chemo/radiotherapies, immunotherapies, novel targeted therapies, local ablative therapies, etc.)

Serviceability performance of buildings founded on rubber–soil mixtures for geotechnical seismic isolation

Base isolation is a low-damage seismic design strategy that can be used for constructing resilient structures. Geotechnical seismic isolation (GSI) is a new category of emerging base isolation techniques that has attracted global interest in the past decade. Research on GSI based on rubber-soil mixtures (RSM) has focused on structural performance under earthquake actions, whilst there are concerns over the serviceability limit states (SLS) requirements in relation to (i) human comfort under strong winds and (ii) ground settlement under gravity, which may induce cracking and durability issues in structures. This article presents the first study on the serviceability performance of buildings constructed with the GSI-RSM system. The finite element model of a coupled soil-foundation-structure system has been validated by data recorded from geotechnical centrifuge testing. The numerical estimates of ground settlement have also been compared with analytical predictions. It is concluded that the GSI-RSM system can satisfactorily fulfill the SLS requirements

On Construction of Tri-Concept Lattices

The main point is to define the structure of a Tri-Concept lattice to deal with data given by different sources and represent it by less complex structures without loosing knowledge. We suggest the algorithm TRI-NEST to form the nested diagrams corresponding to the Tri-Concept lattices. Adding the ICE-T algorithm enables us to generate all frequently closed concepts, which leads to simplifying the Tri-Concept lattices and using the Iceberg Concept lattices as a reduction method to the big data while preserving all information

Serviceability performance of buildings founded on rubber–soil mixtures for geotechnical seismic isolation

Base isolation is a low-damage seismic design strategy that can be used for constructing resilient structures. Geotechnical seismic isolation (GSI) is a new category of emerging base isolation techniques that has attracted global interest in the past decade. Research on GSI based on rubber-soil mixtures (RSM) has focused on structural performance under earthquake actions, whilst there are concerns over the serviceability limit states (SLS) requirements in relation to (i) human comfort under strong winds and (ii) ground settlement under gravity, which may induce cracking and durability issues in structures. This article presents the first study on the serviceability performance of buildings constructed with the GSI-RSM system. The finite element model of a coupled soil-foundation-structure system has been validated by data recorded from geotechnical centrifuge testing. The numerical estimates of ground settlement have also been compared with analytical predictions. It is concluded that the GSI-RSM system can satisfactorily fulfill the SLS requirements

Development and challenges in finite element modelling of post-installed anchors in concrete

Finite element analysis (FEA) has been used as a successful supplement to experimental testing in various studies for simulation of anchorage behaviour. Throughout the years, researchers have employed different modelling techniques in various FEA packages to capture the behaviour of post-installed anchors. However, the vast amount of knowledge accrued is yet to be reviewed. This article critically reviews all aspects of FEA from pre-processing to post-processing and provides a comprehensive review of published literature on FEA studies for predicting the behaviour of post-installed anchorage systems. Most current efforts focus on investigating failure mechanism of anchors in uncracked concrete under tensile loading. Findings show that developing finite element model for post-installed anchorage in concrete is very challenging due to complex geometrical configuration of anchors, difficulty in modelling concrete–anchor interface and lack of reliable information on selecting material properties and parameters. The analysis identified key gaps in research related to the effect of geometrical simplification, anchor subjected to dynamic loading and anchor performance in cracked concrete which needs attention in future research. This review article is a valuable resource in facilitating future research on assessing the performance of post-installed anchorage in concrete with FEA.</p

Geotechnical seismic isolation based on high-damping polyurethane:centrifuge modelling

Geotechnical seismic isolation (GSI) is a new category of low-damage resilient design methods that are in direct contact with geomaterials and of which the isolation mechanism primarily involves geotechnics. Various materials have been explored for placing around the foundation system in layer form to facilitate the beneficial effects of dynamic soil-foundation-structure interaction, as one of the GSI mechanisms. To reduce the thickness of the GSI foundation layer and to ensure uniformity of its material properties, the use of a thin and homogeneous layer of high-damping polyurethane (HDPU) was investigated in this study via centrifuge modelling. HDPU sheets were installed in three different configurations at the interface between the structural foundation and surrounding soils for realising GSI. It was found that using HDPU for GSI can provide excellent seismic isolation effects in all three configurations. The average rates of structural demand reduction amongst the eight earthquake events ranged from 35 to 80%. A clear correlation between the period-lengthening ratio and the demand reduction percentage can be observed amongst the three GSI configurations. One of the configurations with HDPU around the periphery of the foundation only is particularly suitable for retrofitting existing structures and does not require making changes to the structural systems or architectural features.</p

Experimental and numerical investigation of screw anchors in large crack width

In predicting the capacity of screw anchors under static tensile loading, the Concrete Capacity (CC) method is the state-of-the-art prediction model which covers concrete cone capacities in uncracked and cracked concrete up to 0.3 mm crack width. However, in seismic applications, anchors may be subjected to large crack widths of up to 0.8 mm. With large crack width, the behaviour of small-sized (typically 6 mm) screw anchors has not been studied. In this study, experimental investigations were conducted for a total of 29 anchors in uncracked and cracked concrete with large crack widths up to 0.8 mm. The experimental results showed that the load-carrying capacity of screw anchors significantly dropped resulting in a reduction factor of 0.13–0.47 for cracked concrete with 0.8 mm crack width (significantly lower than 0.7 assumed by the CC method for a crack width of up to 0.3 mm). This paper focused on developing modelling technique for predicting the performance of screw anchors in cracked concrete with a crack width of up to 0.8 mm since screw anchor in cracked concrete has not been studied using finite element analysis. Three-dimensional finite element models were developed for screw anchors in uncracked and cracked concrete and validated by the experimental results. Further, parametric analysis showed that dilation angle and shape factor are the two most influencing parameters among other of the concrete damage plasticity model.</p