Structural damage identification has received considerable attention during the past decades. Although several reviews have been presented, some new developments have emerged in this area, ...particularly machine learning and artificial intelligence techniques. This article reviews the progress in the area of vibration-based damage identification methods over the past 10 years. These methods are classified in terms of different damage indices and analytical/numerical techniques used with discussions of their advantages and disadvantages. The challenges and future research for vibration-based damage identification are summarised. This review aims to help researchers and practitioners in implementing existing damage detection algorithms effectively and developing more reliable and practical methods for civil engineering structures in the future.
On 30 October 2020, a strong normal-faulting earthquake struck Samos Island in Greece and İzmir Province in Turkey, both in the eastern Aegean Sea. The earthquake generated a tsunami that hit the ...coasts of Samos Island, Greece and İzmir, Turkey. National teams performed two post-tsunami field surveys on 31 October to 1 November 2020, and 4–6 November 2020, along the Turkish coastline; while the former was a quick survey on the days following the tsunami, the latter involved more detailed measurement and investigation focusing on a ~ 110-km-long coastline extending from Alaçatı (Çeşme District of İzmir) to Gümüldür (Menderes District of İzmir). The survey teams measured runup and tsunami heights, flow depths, and inundation distances at more than 120 points at eight different localities. The largest tsunami runup among the surveyed locations was measured as 3.8 m in Akarca at a distance of 91 m from the shoreline. The maximum tsunami height of 2.3 m (with a flow depth of 1.4 m) was observed at Kaleiçi region in Sığacık, where the most severe tsunami damage was observed. There, the maximum runup height was measured as 1.9 m at the northeastern side of the bay. The survey team also investigated tsunami damage to coastal structures, noticing a gradual decrease in the impact from Gümüldür to further southeast. The findings of this field survey provide insights into the coastal impact of local tsunamis in the Aegean Sea.
Radiotherapy is a major modality used to combat a wide range of cancers. Classical radiobiology principles categorize ionizing radiation (IR) as a direct cytocidal therapeutic agent against cancer; ...however, there is an emerging appreciation for additional antitumor immune responses generated by this modality. A more nuanced understanding of the immunological pathways induced by radiation could inform optimal therapeutic combinations to harness radiation-induced antitumor immunity and improve treatment outcomes of cancers refractory to current radiotherapy regimens. Here, we summarize how radiation-induced DNA damage leads to the activation of a cytosolic DNA sensing pathway mediated by cyclic GMP-AMP (cGAMP) synthase (cGAS) and stimulator of interferon genes (STING). The activation of cGAS-STING initiates innate immune signaling that facilitates adaptive immune responses to destroy cancer. In this way, cGAS-STING signaling bridges the DNA damaging capacity of IR with the activation of CD8+ cytotoxic T cell-mediated destruction of cancer-highlighting a molecular pathway radiotherapy can exploit to induce antitumor immune responses. In the context of radiotherapy, we further report on factors that enhance or inhibit cGAS-STING signaling, deleterious effects associated with cGAS-STING activation, and promising therapeutic candidates being investigated in combination with IR to bolster immune activation through engaging STING-signaling. A clearer understanding of how IR activates cGAS-STING signaling will inform immune-based treatment strategies to maximize the antitumor efficacy of radiotherapy, improving therapeutic outcomes.
•Use of Shapely additive explanations for failure modes of RC columns and shear walls.•Importance factor for failure modes of RC columns and shear walls.•Identification of attribute contributions for ...failure mode predictions.•Explanation of the complex machine learning models.•Machine learning-based failure mode prediction models for RC columns and shear walls.
Machine learning approaches can establish the complex and non-linear relationship among input and response variables for the seismic damage assessment of structures. However, lack of explainability of complex machine learning models prevents their use in such assessment. This paper uses extensive experimental databases to suggest random forest machine learning models for failure mode predictions of reinforced concrete columns and shear walls, employs the recently developed SHapley Additive exPlanations approach to rank input variables for identification of failure modes, and explains why the machine learning model predicts a specific failure mode for a given sample or experiment. A random forest model established provides an accuracy of 84% and 86% for unknown data of columns and shear walls, respectively. The geometric variables and reinforcement indices are critical parameters that influence failure modes. The study also reveals that existing strategies of failure mode identification based solely on geometric features are not enough to properly identify failure modes.
Cell cycle control in cancer Matthews, Helen K; Bertoli, Cosetta; de Bruin, Robertus A M
Nature reviews. Molecular cell biology,
01/2022, Letnik:
23, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Cancer is a group of diseases in which cells divide continuously and excessively. Cell division is tightly regulated by multiple evolutionarily conserved cell cycle control mechanisms, to ensure the ...production of two genetically identical cells. Cell cycle checkpoints operate as DNA surveillance mechanisms that prevent the accumulation and propagation of genetic errors during cell division. Checkpoints can delay cell cycle progression or, in response to irreparable DNA damage, induce cell cycle exit or cell death. Cancer-associated mutations that perturb cell cycle control allow continuous cell division chiefly by compromising the ability of cells to exit the cell cycle. Continuous rounds of division, however, create increased reliance on other cell cycle control mechanisms to prevent catastrophic levels of damage and maintain cell viability. New detailed insights into cell cycle control mechanisms and their role in cancer reveal how these dependencies can be best exploited in cancer treatment.
To investigate the effects of prior cyclic loading damage in rocks on subsequent unloading failure characteristics under true-triaxial conditions, a series of complicated unloading tests ...incorporating the damage-controlled cyclic loading path and stress σ3 unloading path was conducted using a true-triaxial test system. The experimental results reveal that the prior cyclic loading damage has an impact on the strength and deformation characteristics, energy conversion and failure mode. As the number of prior cyclic loads increases, the unloading strength and Young's modulus increase firstly and then decrease, while the peak unloading strain, as well as the ratio (η) of crack damage stress to peak unloading stress, exhibits a descending trend. The energy storage capacity of rock samples is dramatically reduced as cycle number increases to 10 and enlarged slightly with a further increase in cycle number. Both shear fracture and tensile fracture appear in each rock sample under this unloading condition, as the prior cyclic loading number increases, the dominant failure mode of rock samples changes from tensile failure to mixed tensile-shear failure, then to shear failure, while the failure angle ranging from 65° to 80° deceases firstly and then turns to rise.
Complex DNA damage, defined as at least two vicinal lesions within 10-20 base pairs (bp), induced after exposure to ionizing radiation, is recognized as fatal damage to human tissue. Due to the ...difficulty of directly measuring the aggregation of DNA damage at the nano-meter scale, many cluster analyses of inelastic interactions based on Monte Carlo simulation for radiation track structure in liquid water have been conducted to evaluate DNA damage. Meanwhile, the experimental technique to detect complex DNA damage has evolved in recent decades, so both approaches with simulation and experiment get used for investigating complex DNA damage. During this study, we propose a simplified cluster analysis of ionization and electronic excitation events within 10 bp based on track structure for estimating complex DNA damage yields for electron and X-ray irradiations. We then compare the computational results with the experimental complex DNA damage coupled with base damage (BD) measured by enzymatic cleavage and atomic force microscopy (AFM). The computational results agree well with experimental fractions of complex damage yields, i.e., single and double strand breaks (SSBs, DSBs) and complex BD, when the yield ratio of BD/SSB is assumed to be 1.3. Considering the comparison of complex DSB yields, i.e., DSB + BD and DSB + 2BD, between simulation and experimental data, we find that the aggregation degree of the events along electron tracks reflects the complexity of induced DNA damage, showing 43.5% of DSB induced after 70 kVp X-ray irradiation can be classified as a complex form coupled with BD. The present simulation enables us to quantify the type of complex damage which cannot be measured through
experiments and helps us to interpret the experimental detection efficiency for complex BD measured by AFM. This simple model for estimating complex DNA damage yields contributes to the precise understanding of the DNA damage complexity induced after X-ray and electron irradiations.
•Closed form functions of static deflection change (DC) due to damage was developed.•The static DC follows certain patterns that clearly reveal the damage location.•Linear relationship between the ...relative DC and a damage severity derivative was developed.•A new damage quantification concept named damage-severity-consistency function was proposed.•The proposed method was comprehensively validated both numerically and experimentally.
This paper presents a new method that can locate and quantify damage in Euler-Bernoulli beams from changes in static deflection. Using the principle of Virtual Work, for the first time, the deflection change (DC) parameter is formulated as a function of both the damage location and damage severity. Through this, the study shows that the changes in static deflection follow certain patterns that clearly reveal the damage location. Therefore, by observing a plot of the measured DC, the damage locations can be identified conveniently. Once the damage is located, its severity is estimated directly from the measured relative deflection change through a new concept named damage severity consistency (DSC) function. A constant or nearly constant DSC function indicates a high precision of the damage detection results and reflects a good quality of the measurement data. Numerical and laboratory investigations demonstrate that the method accurately locates and quantifies the damage under various scenarios in statically determinate beams. The proposed damage detection method has a clear theoretical base, does not rely on an optimization algorithm, and can be extended to other beam-type structures including statically indeterminate beams.
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