Partial Reduction Research Articles

Encoded information of mixed correlations: the views from one dimension higher

After reviewing the JT gravity, we discuss the four saddles in the mixed correlation measures of black holes Hawking radiation in the setup of geometric evaporation of [1]. By looking from 1d higher point of view and partial dimensional reduction, we examine the phase structures and the universalities for these four saddles. We also discuss the behavior of quantum error correction codes for each of these four phases, reaching to consistent results. Then, instead of dimension reduction between Einstein gravity and JT, we try to explore the connections between partition functions and saddles of 3d Chern-Simons and 2d BF theories, 2d Liouville and 2d Wess-Zumino-Witten models, and also the dimensionally reduced 1d Schwarzian and 1d particles on group. We specifically sketch on the connections between these theories in the setup of mixed correlations and island formulation.

An Enhancer Within Abcb11 Regulates G6pc2 in C57BL/6 Mouse Pancreatic Islets.

G6PC2 is predominantly expressed in pancreatic islet beta cells where it encodes a glucose-6-phosphatase catalytic subunit that modulates the sensitivity of insulin secretion to glucose by opposing the action of glucokinase, thereby regulating fasting blood glucose (FBG). Prior studies have shown that the G6pc2 promoter alone is unable to confer sustained islet-specific gene expression in mice, suggesting the existence of distal enhancers that regulate G6pc2 expression. Using information from both mice and humans, and knowledge that single nucleotide polymorphisms (SNPs) both within and near G6PC2 are associated with variations in FBG in humans, we identified several putative enhancers 3' of G6pc2. One region, herein referred to as enhancer I, resides in the 25th intron of Abcb11 and binds multiple islet-enriched transcription factors. CRISPR-mediated deletion of enhancer I in C57BL/6 mice had selective effects on the expression of genes near the G6pc2 locus: in isolated islets G6pc2 and Spc25 expression were reduced ~50%, and Gm13613 expression was abolished, whereas Cers6 and Nostrin expression were unaffected. This partial reduction in G6pc2 expression enhanced islet insulin secretion at basal glucose concentrations but did not affect FBG or glucose tolerance in vivo, consistent with the absence of a phenotype in G6pc2 heterozygous C57BL/6 mice.

Unexpected self-assembly of carbon dots during digital light processing 3D printing of vanillin Schiff-base resin

Bio-based and recyclable composite thermosets were obtained through digital light processing (DLP) 3D printing by dispersing cellulose-derived carbon dots (CDs) in a photocurable vanillin Schiff-base resin. The exposure of CDs to DLP induced a partial reduction of the oxygen functionalities and a self-assembly of CDs into micrometric fibers embedded in the thermoset matrix. A comparison with the vanillin Schiff-base thermoset, illustrated lower transition temperature from the glassy to the rubbery state and inferior shape memory properties for the CD containing thermoset. This is ascribed to a lower crosslinking density due to the replacement of the covalent interactions of the thermosets with supramolecular interactions generated inside the microfibers and between the microfibers and the surrounding matrix. This can also explain the inferior mechanical rigidity of the composites with respect to the single component thermosets. However, the supramolecular interactions endow the composites with better mechanical and chemical recyclability with an almost complete preservation of the original mechanical properties.

Abstract P3103: Heart Failure In Menopause: Treatment With Rock Inhibitor And Atorvastatin

In advanced age, women tend to develop heart failure with preserved ejection fraction (HFpEF) due to estrogen depletion. The signaling pathway of ROCK is involved in cardiac complications consequent to female aging. Thus, this work investigated the comparative effects of atorvastatin and ROCK inhibitor, fasudil on the treatment of HFpEF induced by oophorectomy (OVX) in spontaneously hypertensive rats (SHR). Protocols were approved by the Animal Care and Use Committee at Universidade Federal do Rio de Janeiro. Under anesthesia with ketamine (80 mg/kg, i.p.) and xylazine (15 mg/kg, i.p.), female SHR were submitted to OVX procedure and after 8 wks were randomly orally treated with either vehicle or atorvastatin (40 mg/kg) or fasudil (10 mg/kg) during 4 wks. At the end of treatment, hemodynamic parameters were evaluated using echocardiography and LV catheterization. Cardiac tissues were collected for histologic analysis. Cardiac hypertrophy was reversed by treatment with atorvastatin or fasudil. Increased systolic pressure of LV was observed in SHR-OVX group (149.2 ± 7.9 mmHg), which was partially reduced by fasudil (123.4 ± 7.4 mmHg) and normalized by atorvastatin (94.5 ± 3.9 mmHg). Reduction of the increased diastolic dysfunction observed by echocardiogram was confirmed, since the recovery of the increased LV end diastolic pressure of SHR-OVX (32.1 ± 1.8 mmHg) occurred after treatment with atorvastatin (22.4 ± 9.6 mmHg) and fasudil (11.9 ± 2.4 mmHg). Fibrosis was observed because of the increased collagen deposition in SHR-OVX (6.2 ± 0.1%), with partial reduction with fasudil (4.4 ± 0.3%) and normalization after treatment with atorvastatin (1.9 ± 0.7%). Cell proliferation was evaluated using the p38 marker, where the percentage of nuclei marked was determined in relation to the total, through immunohistochemical technique. An increase in nuclear p38 in the SHR-OVX group was observed (23.2 ± 3.2%), however, the treatment with atorvastatin (12.1 ± 1.7%) and fasudil (5.3 ± 1.3%) reduced the nuclear p38 detection. In conclusion, atorvastatin and fasudil promoted recovery of HFpEF induced by estrogen depletion in SHR. Inhibition of ROCK signalling by atorvastatin could be involved in the reduction of diastolic dysfunction observed in OVX-SHR group.

Abstract P3077: Withdrawal Of High Fat Diet And L-NAME Dampens T Cell Activation And Ameliorates Pathology In Experimental Heart Failure With Preserved Ejection Fraction (HFPEF) Through Modulation Of The T Cell IRE1a-XBP1 Axis

Introduction: Cardiometabolic HFpEF is characterized by T cell systemic inflammation and can be modeled preclinically with high fat diet (HFD) and L-NAME. Metabolic perturbations can alter T cell function through modulation of the unfolded protein response (UPR). How T cells are activated in HFpEF and whether T cell inflammation can be tuned by removing cardiometabolic stress remains unknown. Hypothesis: HFD and L-NAME induce reversible alterations in T cell UPR signaling that modulate T cell dependent cardiac inflammation and pathology in experimental HFpEF. Methods: Male C57/BL6J mice (wild-type, WT), OT-II antigen restricted mice, and CD4 Cre Xbp1 fl/fl mice were fed a high-fat diet (HFD) and L-NAME (H/L) for 5 weeks. WT mice were switched to standard diet (STD) for two additional weeks. WT mice receiving HFD or L-NAME only, or TAC surgery (a model of HF with reduced EF) were used as controls. Left ventricular (LV) end diastolic pressure volume relationship (EDPVR) was assessed using invasive hemodynamic analyses and LV EF by echocardiography. Cardiac and splenic T cells were characterized by flow cytometry and T cell UPR was evaluated by qPCR and Western blot. Results: 5 weeks of H/L was sufficient to induce cardiac T cell infiltration and splenic T cell activation. OTII mice fed H/L showed increased cardiac CD4 + T cell infiltration compared to STD controls, indicating T cell activation is not cardiac antigen restricted. Furthermore, splenic T cell characterization revealed H/L resulted in decreased phosphorylation of the UPR protein inositol-requiring enzyme 1α (IRE1α) and reduced expression of X box-binding protein 1 ( Xbp1s/u ) compared to T cells from mice exposed to HFD or L-NAME alone, STD, or WT TAC controls. CD4 Cre+ Xbp1 fl/fl mice (T cell Xbp1 -/- ) fed with H/L had increased cardiac T cell infiltration compared to Cre - controls. Lastly, Xbp1s expression in splenic CD4 + T cells was recovered after withdrawal of H/L and resulted in partial reduction of cardiac hypertrophy, decreased EDPVR, as well as less cardiac T cell infiltration compared to mice kept on H/L. Conclusions: Reversible downregulation of the T cell IRE1α-XBP1 axis is a unique T cell signature of HFpEF that contributes to T cell inflammation and adverse cardiac remodeling.

Improved approximate multiplier architecture for image processing and neural network applications

This paper proposes new approximate unsigned multiplier architecture which aims to reduce the power consumption and area with better accuracy. In our proposed design, the approximation is applied in partial product generation (PPG) and partial product reduction (PPR) stages. In PPG, we proposed two approximate sub-multipliers to reduce the number of partial product rows. For the 8-bit multiplier design, experimental results show an improvement of 38.78% and 50.53% in power and power-delay-product respectively, when the proposed design is compared against the exact design, and 26.11% and 33.17% respectively when compared to existing Ax8-1 design, without compromising on the accuracy. Finally, proposed designs are validated using image processing and neural network applications.

Isotope diffusion and re-equilibration of copper and evaporation of mercury during weathering of tetrahedrite in an oxidation zone

To understand the mobility of heavy metals during oxidative weathering of sulfides, we investigated weathering processes of tetrahedrite [(Cu,Fe,Zn,Hg)12(Sb,As)4S13] in an oxidation zone with abundant siderite (FeCO3) and baryte (BaSO4) at Rudňany (Slovakia). The focus of this work lied in the isotopic (δ65Cu, δ202Hg, δ34S) variations of the minerals during weathering and the interpretation of such changes. In the studied oxidation zone, Hg-rich tetrahedrite converts in situ to pockets of powdery cinnabar (HgS) and an X-ray amorphous mixture rich in Sb, Fe, and Cu that slowly re-crystallizes to Cu-rich tripuhyite (FeSbO4). Copper is mobile and precipitates as malachite [Cu2(OH)2(CO3)], azurite [Cu3(OH)2(CO3)2], or less abundant clinoclase [Cu3(AsO4)(OH)3]. The isotopic composition (δ65Cu) of tetrahedrite correlates well with the degree of weathering and varies between 0.0 ‰ and −4.0 ‰. This correlation is caused by isotopic changes during dissolution and subsequent rapid equilibration of δ65Cu values in the tetrahedrite relics. Simple diffusion models showed that equilibration of Cu isotopic values in the tetrahedrite relics proceeds rapidly, on the order of hundreds or thousands of years. Abundant secondary iron oxides draw light Cu isotopes from the aqueous solutions and shift the isotopic composition of malachite and azurite to higher δ65Cu values as the distance to the primary tetrahedrite increases. Clinoclase and tripuhyite have lower δ65Cu values and are spatially restricted near to the weathering tetrahedrite. The Hg and S isotopic composition of tetrahedrite is δ202Hg = −1.27 ‰, δ34S = −1.89 ‰, that of the powdery secondary cinnabar is δ202Hg = +0.07 ‰, δ34S = −5.50 ‰. The Hg isotopic difference can be explained by partial reduction of Hg(II) to Hg(0) by siderite and the following evaporation of Hg(0). The S isotopic changes indicate no involvement of biotic reactions in the oxidation zone, probably because of its hostility owing to high concentrations of toxic elements. This work shows that the Cu isotopic composition of the primary sulfides minerals changes during weathering through self-diffusion of Cu in those minerals. This finding is important for the use of Cu isotopes as tracers of geochemical cycling of metals in the environment. Another important finding is the Hg in the oxidation zones evaporates and contributes to the global cycling of this element through atmospheric emission.

Simple low power‐delay‐product parallel signed multiplier design using radix‐8 structure with efficient partial product reduction

AbstractThe continued quest for finding a low‐power and high‐performance hardware algorithm for signed number multiplication led to designing a simple and novel radix‐8 signed number multiplier with 3‐bit grouping and partial product reduction performed using magnitudes of the multiplicand and the multiplier. The pre‐computation stage constitutes magnitude calculation and non‐trivial computations required to generate partial products. A new partial product reduction strategy is deployed in the design to improve the speed with low cost. 8×8, 16×16, 32×32, and 64×64 designs are presented for the proposed architectures. Performance results include area, power, delay, and power‐delay‐product of synthesized and post‐layout designs using 32 nm CMOS technology with 1.05 V supply voltage.

A CLINICAL STUDY OF INTUSSUSCEPTION IN CHILDREN

A CLINICAL STUDY OF INTUSSUSCEPTION IN CHILDREN

Sufficient dimension reduction in the presence of controlling variable and missing multivariate response

In this paper, we focus on partial dimension reduction for conditional mean function in the presence of controlling variable when responses are multivariate and missing at random. A weighted-profile least squares estimate based on inverse probability weighted technique is proposed to estimate the central mean subspace. The profile least squares method does not need any distributional assumptions on the covariates, which is different from existing methods in sufficient dimension reduction. It turns out that under some mild conditions, the estimator of central mean subspace is asymptotically normal and root-n consistent. The proposed test statistic as well as its asymptotic distribution for parametric hypothesis tests are obtained. In addition, a BIC-type criterion is used to determine the structural dimension of the central mean subspace. Its consistency is also established. Both simulated and real data analysis results demonstrate promising performance of the proposed sufficient dimension reduction estimation method.

Geometry of cascade feedback linearizable control systems

Cascade feedback linearization provides geometric insights on explicit integrability of nonlinear control systems with symmetry. A central piece of the theory requires that the partial contact curve reduction of the contact sub-connection be static feedback linearizable. This work establishes new necessary conditions on the equations of Lie type - in the abelian case - that arise in a contact sub-connection with the desired static feedback linearizability property via families of codimension one partial contact curves. Furthermore, an explicit class of contact sub-connections admitting static feedback linearizable contact curve reductions is presented, hinting at a possible classification of all such contact sub-connections. Key tools in proving, and stating, the main results of this paper are truncated versions of the total derivative and Euler operators. Additionally, the Battilotti-Califano system with three inputs is used as a clarifying example of both cascade feedback linearization and the new necessary conditions.

Motion Simulation Analysis and Experimental Verification of Drill String Rotation Controller

Abstract Conventional directional drilling mainly relies on the sliding of screw motor and drill string to realize the change of wellbore trajectory, so the friction force is large. The use of friction reduction tools that generate axial force to change the friction state can only achieve partial friction reduction, and drill string is still in a sliding state during directional drilling. These problems are solved by using rotary steerable drilling system, which can achieve directional drilling when drill string rotates. But its use cost is high. Considering the principle of high efficiency and economy, a new friction reduction tool called drill string rotation controller is proposed, which is also used to reduce friction during directional drilling through drill string rotation. By adjusting the pump pressure, the meshing state of spline module of drill string rotation controller is changed to realize the conversion of drilling mode. In rotary drilling mode, upper drill string, drill string rotation controller, and bottom hole assembly rotate together. In directional drilling mode, upper drill string rotates and drill string rotation controller slides with bottom hole assembly. The function of the tool is verified by field experiment, and motion simulation of the tool is carried out. The results show that when the driving torque is set to 25,000 N · m, more reverse torque can be overcome in the directional drilling mode, and the drilling fluid pressure is set to 25 MPa, which can be converted to the rotary drilling mode faster.

Biomimetic dual-nanozymes with catalytic cascade reactions against diabetic wound infection

Diabetes-related chronic wounds characterized by hyperglycemia and weak alkaline milieu provide numerous advantages for bacteria growth and biofilm formation, setting a myriad of stumbling blocks for wound healing. Therefore, reshaping the spatially and temporally pathological wound microenvironment against bacterial infection is critical to rescue stalled healing progress in diabetes-related chronic wounds. Herein, we demonstrate on the room-temperature construction of a glucose oxidase (GOx)-mimicking and peroxidase (POD)-mimicking dual-nanozymes catalytic cascade system upon the partial reduction of Fe3+ to Fe2+ and the deposition of Au nanoparticles, simultaneously. The as-prepared dual-nanozymes catalytic cascade system possesses the capabilities of reshaping the pathological microenvironments of diabetic wound via glucose consumption and acidification, leading to amplified catalytic cascade activities for sterilization. On the one hand, the GOx-mimicking enzymatic activity of the catalytic cascade system can not only deplete glucose and acidize wound milieu to inhibit bacteria growth, but also utilize the weak alkaline milieu of diabetic wound to provide sufficient H2O2 and a favorable pH for subsequent OH generation. On the other hand, the POD-mimicking enzymatic activity of the catalytic cascade system can continuously produce OH for sterilization under the weak acidic milieu in the presence of abundant H2O2. Benefiting from the simply and mild preparation process and the excellent dual-nanozymes catalytic cascade activities under the deliberate evolved milieus of diabetes-related chronic wounds, our catalytic cascade system exhibits the promising healing effect and clinical translation potential against diabetic wound infection.

Catalytic behavior of Pt single-atoms supported on CeO2

In this study, we demonstrate that the CO oxidation activity of Pt/CeO2 single-atom catalysts (≤0.4 Pt/nm2) is significantly low despite the increase in reducibility, which is associated with the formation of oxygen vacancies that are critical for oxygen activation, with increasing Pt surface density. This result can be related to the negligible amount of CO adsorbed onto the Pt/CeO2 single-atom catalysts. As the Pt surface density increases to 0.8 Pt/nm2, the activity sharply increases; at this loading, Pt clusters are formed and the interactions with CO are enhanced. Notably, after the controlled reduction treatment using CO, the catalytic activity of 0.4 Pt/CeO2 increases to the level of 0.8 Pt/CeO2. The sudden increase in activity can be explained by the formation of a partially reduced Pt cluster and the enhanced CO interactions with the Pt atoms of the cluster. These results indicate that Pt cluster formation and its partial reduction are essential for low-temperature CO oxidation. Our study explains the cause of the significantly low CO oxidation activity of Pt/CeO2 single-atom catalysts and how controlled reduction treatment of these catalysts enhances their activity.

Charge Storage Mechanism in Electrospun Spinel-Structured High-Entropy (Mn0.2 Fe0.2 Co0.2 Ni0.2 Zn0.2 )3 O4 Oxide Nanofibers as Anode Material for Li-Ion Batteries.

High-entropy oxides (HEOs) have emerged as promising anode materials for next-generation lithium-ion batteries (LIBs). Among them, spinel HEOs with vacant lattice sites allowing for lithium insertion and diffusion seem particularly attractive. In this work, electrospun oxygen-deficient (Mn,Fe,Co,Ni,Zn) HEO nanofibers are produced under environmentally friendly calcination conditions and evaluated as anode active material in LIBs. A thorough investigation of the material properties and Li+ storage mechanism is carried out by several analytical techniques, including ex situ synchrotron X-ray absorption spectroscopy. The lithiation process is elucidated in terms of lithium insertion, cation migration, and metal-forming conversion reaction. The process is not fully reversible and the reduction of cations to the metallic form is not complete. In particular, iron, cobalt, and nickel, initially present mainly as Fe3+ , Co3+ /Co2+ , and Ni2+ , undergo reduction to Fe0 , Co0 , and Ni0 to different extent (Fe < Co < Ni). Manganese undergoes partial reduction to Mn3+ /Mn2+ and, upon re-oxidation, does not revert to the pristine oxidation state (+4). Zn2+ cations do not electrochemically participate in the conversion reaction, but migrating from tetrahedral to octahedral positions, they facilitate Li-ion transport within lattice channels opened by their migration. Partially reversible crystal phase transitions are observed.

Construction of Ni4Mo/MoO2 heterostructure on oxygen vacancy enriched NiMoO4 nanorods as an efficient bifunctional electrocatalyst for overall water splitting

Despite great efforts over the past decade, rational design of bifunctional electrocatalysts with low cost and high efficiency still remains a challenge to achieve industrial water splitting. Herein, we synthesized the nickel-molybdenum nanorod array catalyst supported on NF (NMO@NM/MO) by a two-step process of hydrothermal and reductive annealing. Partial reduction of the NiMoO4 induces the structural reconstruction and formation of the Ni4Mo/MoO2 heterostructure on oxygen vacancy enriched nanorod, which bring out sufficient active sites, large specific surface area and favorable interfacial charge transfer. Thanks to the unique core–shell structure with the heterostructured Ni4Mo/MoO2 surface and defect-rich NiMoO4 core, the obtained electrocatalyst shows greatly improved hydrogen evolution reaction (HER) activity with an ultralow overpotential of 63 mV at 100 mA cm−2 (vs. 314 mV for the NiMoO4). Density function theory calculations reveal that the construction of the Ni4Mo/MoO2 heterostructure effectively accelerates H2O dissociation kinetics, while the defective NiMoO4 facilitates H* adsorption/desorption. Moreover, the heterostructure catalyst also displays excellent oxygen evolution reaction (OER) performance with the low overpotential of 274 mV at 100 mA cm−2. When coupling HER and OER by using NMO@NM/MO as both the cathode and anode, the alkaline electrolyzer delivers a current density of 10 mA cm−2 at only 1.50 V as well as good robustness. The synergistic effect of the hetero-interface and the defect engineering endows the electrocatalyst with excellent bifunctional catalytic activity for HER and OER. This work may provide a route for rational design of heterostructure electrocatalysts with multiple active components.

Np(V) Retention at the Illite du Puy Surface.

In this study, Np(V) retention on Illite du Puy (IdP) was investigated since it is essential for understanding the migration behavior of Np in argillaceous environments. The presence of structural Fe(III) and Fe(II) in IdP was confirmed by Fe K-edge X-ray absorption near-edge structure (XANES) and 57Fe Mössbauer spectroscopy. In batch sorption experiments, a higher Np sorption affinity to IdP was found than to Wyoming smectite or iron-free synthetic montmorillonite. An increase of the relative Np(IV) ratio sorbed onto IdP with decreasing pH was observed by solvent extraction (up to (24 ± 2)% at pH 5, c0(Np) = 10-6 mol/L). Furthermore, up to (33 ± 5)% Np(IV) could be detected in IdP diffusion samples at pH 5. Respective Np M5-edge high-energy resolution (HR-) XANES spectra suggested the presence of Np(IV/V) mixtures and weakened axial bond covalency of the NpO2+ species sorbed onto IdP. Np L3-edge extended X-ray absorption fine structure (EXAFS) analysis showed that significant fractions of Np were coordinated to Fe─O entities at pH 9. This highlights the potential role of Fe(II/III) clay edge sites as a strong Np(V) surface complex partner and points to the partial reduction of sorbed Np(V) to Np(IV) via structural Fe(II).

Setting up In2O3-ZrO2/SAPO-34 Catalyst for Improving Olefin Production via Hydrogenation of CO2/CO Mixtures

The adequate configuration and the effect of the reduction was studied for the In2O3-ZrO2/SAPO-34 catalyst with the aim of improving its performance (activity and selectivity in the pseudo-steady state) for the hydrogenation of CO, CO2 and CO2/CO (COx) mixtures into olefins. The experiments were carried out in a packed bed reactor at 400 °C; 30 bar; a H2/COx ratio of 3; CO2/COx ratios of 0, 0.5 and 1; a space time (referred to as In2O3-ZrO2 catalyst mass) of 3.35 gInZr h molC−1; and a time on stream up to 24 h. The mixture of individual catalyst particles, with an SAPO-34 to In2O3-ZrO2 mass ratio of 1/2, led to a better performance than hybrid catalysts prepared via pelletizing and better than the arrangement of individual catalysts in a dual bed. The deactivation of the catalyst using coke deposition and the remnant activity in the pseudo-steady state of the catalyst were dependent on the CO2 content in the feed since the synergy of the capabilities of the SAPO-34 catalyst to form coke and of the In2O3-ZrO2 catalyst to hydrogenate its precursors were affected. The partial reduction of the In2O3-ZrO2/SAPO-34 catalyst (corresponding to a superficial In0/In2O3 ratio of 0.04) improved its performance over the untreated and fully reduced catalyst in the hydrogenation of CO to olefins, but barely affected CO2/CO mixtures’ hydrogenation.

A hybrid approach based energy management for building resilience against power outage by shared parking station for EVs

A major contribution of this work is to develop an efficient hybrid technique for building energy resilience against natural disasters, which cause power outages for commercial and residential buildings. The novelty of the proposed method is the combination of Chicken Search Optimization and the Spike Neural Network learning algorithm. The buildings are designed using shared electric vehicle parking station. Buildings are modeled with peer-to-peer functionality. Electric vehicle inside the parking station are available in a variety of forms, as the commercial building utilizes parking station at day time, also the residential building mostly utilizes at midnight. These variations help vehicles to be utilized for additional hours. A building is maintained through power management options to deal with these interruptions. The choices include peer-to-peer building operation, electric vehicle charging and discharging, partial charge capability, load reduction, and load adjustment. The proposed technique makes use of building components and does not require any additional components for building energy management. The main contribution of this paper is to diminish energy costs and increase energy resilience to natural disasters. Resiliency is described as the ability to restore harmful loads while experiencing minimum power loss after successive power outages. The performance of the proposed system is evaluated using the MATLAB platform and compared to existing systems.

Numerical dynamic characterisation of concrete bridge stays

AbstractFollowing the recent collapse of a cable‐stayed bridge in Genoa, Italy, an interest has arisen to understand if it would have been possible for unknown localised material deterioration and/or decrease in prestress levels to introduce noticeable changes in the dynamic behaviour of RC stays. As such, in this study we start by reviewing past research work, experimental and analytical, on the effects that prestress level may or may not have on the dynamic response of RC beam elements. We then review also available analytical formulations used to determine the natural frequency of vibration of prestressed beams, and, subsequently, complete the preliminary investigation on the effects of prestress levels, and local damage, through the analysis of finite element models of prestressed beams and stays. The comparison of analytical and numerical estimations with results obtained from an in‐situ dynamic characterisation campaign on a RC bridge stay is also undertaken. In the second part of the study, we explicitly consider the Morandi bridge case‐study, for which finite element models of the stays alone, as well as of the full bridge, are developed and analysed. The obtained results are then also compared with the observations made in pre‐collapse in situ dynamic characterisation endeavours. All results obtained and discussed lead to the conclusion that, most regrettably, dynamic characterisation endeavours do not have the capability of providing insight on possible localised material deterioration or partial reduction of the average state of compression in this type of structural elements.