Stages Of Failure Research Articles

An Experimental Study of the Acoustic Signal Characteristics of Locked-Segment Damage Evolution in a Landslide Model.

Three-section landslides are renowned for their immense size, concealed development process, and devastating impact. This study conducted physical model tests to simulate one special geological structure called a three-section-within landslide. The failure process and precursory characteristics of the tested samples were meticulously analyzed using video imagery, micro-seismic (MS) signals, and acoustic emission (AE) signals, with a focus on event activity, intensity, and frequency. A novel classification method based on AE waveform characteristics was proposed, categorizing AE signals into burst signals and continuous signals. The findings reveal distinct differences in the evolution of these signals. Burst signals appeared exclusively during the crack propagation and failure stages. During these stages, the cumulative AE hits of burst signals increased gradually, with amplitude rising and then declining. High-amplitude burst signals were predominantly distributed in the middle- and high-frequency bands. In contrast, cumulative AE hits of continuous signals escalated rapidly, with amplitude monotonously increasing, and high-amplitude continuous signals were primarily distributed in the low-frequency band. The emergence of burst signals and high-frequency AE signals indicated the generation of microcracks, serving as early-warning indicators. Notably, the early-warning points of AE signals were detected earlier than those of video imagery and MS signals. Furthermore, the early-warning point of burst signals occurred earlier than those of continuous signals, and the early-warning point of the classification method preceded that of overall AE signals.

The progressive failure features of shield tunnel lining with large section

Investigating the failure process of segmental lining is of great significance to the design and maintenance of shield tunnel. Indoor scaled model tests are carried out to study the inner force, structural displacement, acoustic emission signals and damage pattern of lining. Meanwhile, a new numerical approach is put forward based on particle element method to study the influence of geo-stress field and the position of void or key block to the failure features of lining. The results showed that the failure of lining is progressive and can be divided into four stages, that is, the initial elastic stage, meso-damage stage, macroscopic failure stage and overall instability stage. For the key block is located at the crown, there are two concentrated intervals for the generation of micro-cracks. For the key block is located on the spandrel, micro-cracks are uniformly produced throughout the loading process after the initial elastic stage. For the key block is located on the haunch, micro-cracks distributed in a large concentrated range. The influence of the position of void on the damage of lining can be divided into three kinds, namely, no effect; affecting the emerging order of cracks while not final fracture pattern; affecting the emerging order of cracks and the final fracture pattern.

A comprehensive analysis method of the performance degradation of planetary roller screws under the time-varying load and errors

Time-varying loads, manufacturing errors, and assembly errors are the main factors leading to the performance degradation of the planetary roller screw mechanism. This paper proposes a comprehensive analysis method for the performance degradation of the planetary roller screw mechanism caused by time-varying loads and manufacturing and assembly errors. Firstly, a simulation analysis model of the planetary roller screw mechanism was established and its effectiveness was verified. A quantitative analysis was conducted on the influence of manufacturing and assembly errors on the load distribution, revealing the load-bearing mechanism under the influence of errors. Secondly, loading experiments were conducted on the planetary roller screw mechanism, and the degradation of its load-bearing performance was divided into the normal degradation stage, the accelerated degradation stage, and the failure stage. The experimental results prove that the initial transmission accuracy has a significant impact on the degradation of the load-bearing performance, determining the occurrence of the node where the accelerated degradation stage appears in the load-bearing performance. Thirdly, the wear status of the threads and gears was examined, and the results showed that material peeling was the main factor causing the degradation of load-bearing performance.

Bearing capacity and failure behavior of segments with a mid-span opening of a shield subway tunnel

This paper investigates the load-bearing properties and failure mechanisms of shield segments with a circular mid-span opening in shield subway tunnels. Two full-scale specimens with opening diameters of 100 and 200 mm were manufactured and tested, revealing that with an increasing opening diameter, the failure mode transferred from uniform tensile fracture of inner arc concrete to the peeling and crushing of the outer arc concrete. Moreover, the loading process can be divided into four stages, i.e. elastic, plastic expansion, failure, and ultimate stages, and each stage shares a critical load. Subsequently, numerical models were established using the elastoplastic damage constitutive of concrete, and its reliability is verified by the experimental results. Afterward, parametric analysis was performed considering the plain concrete loss and reinforced concrete loss. The analysis results show that the plain concrete loss significantly weakens the cracking load of the segment, while reinforced concrete loss has the greatest impact on the failure load. Finally, a comparative analysis is conducted between the bearing characteristics of the local failure segment, standard shield segment, and the segment joint. Overall, the research results can provide a theoretical basis for the field reinforcement and the safety assessment of local failed shield tunnels.

Study on the influence of temperature on the damage evolution of hot dry rock in the development of geothermal resources

In order to more accurately understand the rock mechanics properties of hot dry rock (HDR) reservoirs under high-temperature conditions and further guide the drilling and construction of HDR wells, conducting research on rock damage evolution under high-temperature conditions plays a guiding role in the efficient development of geothermal resources. To reveal the evolution law of fracture damage of HDR under temperature influence, taking marble as an example, the thermo-mechanical damage and failure mechanism under the conditions of 30 °C, 60 °C, 90 °C, 120 °C and 150 °C were studied using a rock high-temperature rheometer and an acoustic emission (AE) testing system. The numerical simulation results were compared with the indoor experimental results by combining the particulate flow program Particle Flow Code 3D (PFC3D) to verify the effectiveness of the simulation analysis model of thermo-coupled particulate flow at the micro scale. The results show that under high temperature, the marble three-axis compression failure passes through the compaction and elastic deformation stage, plastic deformation stage, ductile failure stage and instability failure stage, and the peak strength and elastic modulus of the marble decrease with the increase of temperature, and the acoustic emission b-value of the sample can judge the damage evolution process of the marble. At the micro scale, high temperature accelerates the force chain transmission between particles, the contact force between marble particles gradually decreases during the heating process, and the number of particle bonding failures increases steadily; the bearing capacity and elastic modulus attenuation of the rock are the result of microcrack evolution, and the force chain void zone and particle displacement field inside the sample are consistent with its macroscopic failure form. The development of microcracks in marble under different test loading conditions is different, and with the increase of test temperature, the total number of cracks inside the sample increases, but the proportion of shear cracks decreases, the activity of particle displacement increases, and the “plastic extension” characteristic of marble becomes more significant. The thermal damage evolution of marble was quantitatively analyzed based on the elastic modulus method and the peak stress method, and the damage evolution law of marble under different temperatures was obtained.

Dapagliflozin Use in Children with Advanced Heart Failure Undergoing Heart Transplantation: A Matched Case-Control Study.

Dapagliflozin has been associated with euglycemic ketoacidosis in adults with diabetes contributing to poor outcomes when continued prior to surgery. It is unknown if preoperative use of dapagliflozin may lead to adverse events (AE) in nondiabetic children with advanced heart failure (HF) undergoing heart transplantation (HTx). We performed a single-center, matched case-control analysis of nondiabetic primary pediatric HTx recipients < 21years-old who underwent HTx and followed through postoperative day (POD) 3. Cases who received dapagliflozin leading up to HTx (n = 22) were matched by age and cardiac diagnosis to two historical controls who did not receive dapagliflozin (n = 44). Median age at HTx was 13.8years (range 0.36-20.7) and 48% were female. Cardiac diagnoses included cardiomyopathy (45%), Fontan failure (41%), and single ventricle status post stage I palliation (14%). Cases received median dapagliflozin dose of 0.17mg/kg once daily; therapy was stopped one day prior to HTx. There were no significant differences in blood glucose nadirs, arterial blood gas indices including nadirs of pH, bicarbonate, or peaks of arterial blood lactic acid POD0-3. Vasopressor, inotrope, and insulin infusion usage were not different. No patients were treated for severe hypoglycemia, euglycemic ketoacidosis, or urinary tract infections. There were no deaths. Length of stay in ICU and time from HTx to hospital discharge did not differ between cohorts. Use of dapagliflozin in children with advanced HF until HTx is not associated with AE in the immediate postoperative period nor increased length of hospitalization post-HTx. Potential cardiovascular benefits of dapagliflozin in patients awaiting HTx should be prioritized.

Experimental and Meshless Numerical Simulations on the Crack Propagation of Semi-Circular Bending Specimens Containing X-Shaped Fissures Under Three-Point Bending.

Cracks in rock and concrete have a great adverse effect on the stability of engineering structures; however, there are few studies on X-shaped fissures which widely exist in rock and concrete structures. Based on this background, three-point bending fracture tests of SCB specimens containing X-shaped fissures are carried out. The momentum equations in the SPH method are improved, and the crack propagations of SCB specimens under three-point bending are simulated. The results show that cracks grow simply along the vertical direction in the sample with no X-shaped fissures, and the existence of an X-shaped fissure changes the crack growth path and final failure modes of the SCB samples. The crack propagation simulation results are consistent with the experimental results, which verifies the rationality of the improved SPH method. The load-displacement curves mainly present three typical stages: the initial compaction stage, linear elastic deformation stage, and failure stage. The peak load decreases first then increases with an increase in eccentricity. With an increase in X-shaped fissure length and decrease in X-shaped fissure angle, the peak load decreases. The damage counts remain at 0 at the initial loading stage, corresponding to the initial compaction stage and the linear elastic deformation stage, and increase sharply at the later loading stage, corresponding to the failure stage, which is consistent with the experimental results. The influence mechanisms of X-shaped fissures on the crack propagation paths are discussed; the existence of different X-shaped fissure morphologies aggravate the tensile stress concentration at specific positions, leading to different crack propagation modes in the experiments. The research results can provide a certain reference for understanding the failure mechanisms of engineering structures containing X-shaped fissures and promote the applications of the SPH method into the simulations of cross-fissure crack propagations.

Strengthening of reinforced concrete slabs using carbon fiber reinforced polymers rods and concrete jacket with a mechanical anchorage system

This study presented the development of a new method for strengthening of Reinforced Concrete (RC) slabs using Carbon Fiber Reinforced Polymer rods (CFRP) and an Ultra-High Performance Fiber Reinforcement Concrete (UHPFRC) external jacket with a Mechanical Anchorage System (MAS). The mechanical anchorage system includes two components: high-carbon steel plates and the Mechanical Expansion Anchorage Bolt System (MEABS), and it’s employed to prevent any premature de-bonding between the existing concrete surface and the externally strengthening layers (CFRP rods and UHPFRC jacket). The efficiency of the proposed strengthening method was evaluated through conducting an experimental test on a few fortified slabs by applying cyclic loads using a dynamic actuator. For this purpose, three distinct concrete slabs were tested to assess various design parameters, including a control slab, a strengthened slab with the UHPFRC jacket only, and a strengthened slab with CFRP bars at the bottom of the slab with an external UHPFRC jacket. The results of experimental tests reveal that the proposed strengthening system significantly enhanced the load capacity of the slab and prevented premature debonding failures between the old concrete of the slab and the new UHPFRC layer until the stage of slab failure. Accordingly, the new proposed strengthening system played a crucial role in enhancing the tension zone of the slabs and delaying the occurrence of diagonal crack loads. On the other hand, embedding CFRP bars within the UHPFRC jacket in the strengthened slab led to a notable enhancement of 82 % in the ultimate load capacity of the slab. The FE and analytical models were developed to predict the behavior of the specimens. The models' outcomes were in good agreement with the experimental data. Consequently, the new proposed strengthening system emerges as a reliable technique for enhancing the performance of reinforced concrete slabs, eliminating the risk of debonding between old and new parts.

Recovery from severe cardio-respiratory failure: the trajectory of muscle mass, strength, function and health related quality of life

Abstract Background The impact of intensive care unit acquired weakness (ICUAW) is associated with reduced muscle mass, strength, function and health related quality of life (HRQoL). Patients suffering from severe cardio-respiratory failure are known to lose considerable muscle mass and strength in the first 7 days of admission to the intensive care unit (ICU). Furthermore, patients surviving critical illness have a considerable less HRQoL and physical function with long term outcomes such as inability to return to work being reported. However, more information regarding muscle loss and recovery is required when patients leave hospital. Currently there are no treatments for ICUAW as once the process is established management is supportive, such as physical therapy. Purpose We Sought to investigate the effects of severe cardio-respiratory failure, in patients receiving extra corporeal membrane oxygenation (ECMO), on ICUAW (including muscle mass, strength, function and HRQoL). Researching a real life model of ICUAW allows the observation of the loss of muscle mass and strength in the first stages of critical illness and severe cardio-respiratory failure. Methods Adults receiving ECMO for severe cardiorespiratory failure were included. Muscle mass was measured using ultrasound of the rectus femoris cross sectional area (RFcsa). Muscle strength was measured using hand held dynamometry for both hand held grip strength and isometric leg extension. HRQoL was measured using the EQ-5D-5L. Function was measured using the short physical performance battery (SPPB). Measurements were taken on day 0, day 7, ICU discharge, hospital discharge and at out-patient follow up. Results 17 patients were recruited with 10 patients completing follow up. Patients lost 24% muscle mass in the first 7 days of ICU admission and ECMO initiation, with muscle loss continuing up until ICU discharge. Contrary to the hypothesis only 50% of the patients were seen to recover muscle mass at follow up. Strength and function all considerably improved between ICU discharge and out patient follow up. The EQ5D crosswalk index supported this suggesting considerable functional improvement. Conclusion Patients in severe cardio-respiratory failure lose considerable muscle mass in the first 7 days of admission, with only 50% of these patients recovering the initial muscle loss at follow up. However, strength, function and HRQoL all improve following ICU discharge suggesting an element of functional recovery. Strength and function have shown to improve regardless of the status of the muscle mass. Therefore, given the advantages of the real-life model and novel findings, this could serve as a platform to assess muscle loss and recovery over a longer time frame continuing to build the understanding of the patients recovery trajectory from critical illness.Rectus Femoris Muscle MassHand-Held Grip Strength

Association between self-reported and objectively assessed physical functioning in the general population

Knowledge about a patient’s physical fitness can aid in medical decision-making, but objective assessment can be challenging and time-consuming. We aimed to investigate the concordance of self-reported health status and physical functioning with the 6 minute walking distance (6MWD) as objective measure of physical performance. The prospective characteristics and course of heart failure stages A/B and determinants of progression (STAAB) cohort study iteratively follows a representative sample of residents of the city of Würzburg, Germany, aged 30–79 years, without a history of heart failure (HF). The 6MWD was measured in 2752 individuals (aged 58 ± 11 years, 51% women) from a population-based cohort under strictly standardized conditions. Self-reported health status and physical functioning were assessed from items of the short form 36 (SF-36). After the respective classification of self-reported health status and physical functioning into ‘good’, ‘moderate’, and ‘poor’, we determined the association of these categories with 6MWD by applying a generalized linear model adjusted for age and sex. Prevalence of self-reported good/moderate/poor general health and physical functioning was 41/52/7% and 45/48/7%, respectively. Mean 6MWD in the respective categories was 574 ± 70/534 ± 76/510 ± 87 m, and 574 ± 72/534 ± 73/490 ± 82 m, with significant sex-specific differences between all categories (all p < 0.001) as well as significant differences between the respective groups except for the categories ‘moderate’ and ‘poor’ health status in men. This cross-sectional analysis revealed a strong association between self-reported health status and physical functioning with the objective assessment of 6MWD, suggesting that physicians can rely on their patients’ respective answers. Nevertheless, sex-specific perception and attribution of general health and physical functioning deserve further in-depth investigation. Decision-making based on self-reported health requires prospective evaluation in population-based cohorts as well as adult inpatients.

Sixteen-Frame Gated Myocardial Perfusion SPECT as a Surrogate for Equilibrium Radionuclide Angiography in Measurement of Systolic and Diastolic Indices: A Cross-Sectional Study

Abstract Introduction Equilibrium radionuclide angiography (ERNA) has long been assumed as the preferred method to assess cardiac volumes as well as left ventricular systolic and diastolic indices. ERNA was used to diagnose subtle changes in cardiac function during chemotherapy or early stages of heart failure. Gated myocardial perfusion SPECT (GMPS) was introduced as a more feasible and versatile alternative to ERNA, but the precision of GMPS to assess systolic and diastolic indices has not yet been fully reviewed. Method We studied the left ventricular systolic and diastolic functional indices measured by a 16-frame GMPS and compared the results with those of ERNA in 25 patients. All the images were analyzed visually, semi-quantitatively, and quantitatively using quantitative gated SPECT (QGS), quantitative blood pool SPECT (QBS), and planar gated blood pool (PGBP) software. The left ventricular functional indices calculated using QGS compared with those obtained using QBS and PGBP Result Our study found a significant correlation between the left ventricular ejection fraction (LVEF) calculated using the PGBP, QGS, and QBS methods. There was a significant correlation between the LV peak ejection rate (LVPER) calculated by the PGBP and QGS analyses, and there was no significant difference in the LVPER calculated with the QGS and QBS methods. This study also revealed a significant correlation between the LV peak filling rate (LVPFR) calculated by QBS and QGS, with no significant difference between them. We also found a significant correlation between LV end systolic volume (LVESV) calculated using QGS and QBS and between LV end diastolic volume (LVEDV) calculated using QGS and QBS software. This study also revealed a significant correlation between the LV mean filling rate over the first third of diastole (LVMFR/3) calculated using the QGS and QBS software. Conclusion Considering the significant correlation between LVEF, LVPER, LVPFR, LVESV, LVMFR/3, and LVEDV calculated using the QGS and QBS methods in our study, the 16-frame GMPS could be regarded as an acceptable substitute for ERNA in the investigation of systolic and diastolic indices.

Synovial Lubrication Factors‐Recruiting Biomimetic Polyphenolized Hyaluronic Acid for Promoting Cartilage Repair

AbstractOsteoarthritis is a common degenerative disease characterized by continuous detachment of lubrication factors from damaged cartilage matrix. This study proposes a paradigm that combines natural polyanionic polysaccharides (hyaluronic acid, HA) with dopamine (DA) to design a synovial lubrication factors‐recruiting biomimetic polyphenolized lubrication system. The biomimetic lubricants can use DA's polarity and hydrophilic groups as specific binding sites of type II collagen's polarity and hydrophilic groups to stably bind cartilage surface, and further utilize molecular specific interaction to recruit detached, joint endogenous or chondrocytes expressed synovial lubrication factors, continuously forming supramolecular lubrication complex onto cartilage matrix to induce joint lubrication. Simultaneously, the biolubricants can also utilize catechol groups to eliminate anionic free radicals and resist reactive oxygen species invasion in the early stages of joint lubrication failure. The prepared biolubricants exhibit low coefficient of friction (µ &lt; 0.08), which is attributed to fluid and hydration lubrication provided by HA and DA side chains through fluid dynamic effect and interfacial hydration adsorption. Cell and animal experiments also demonstrate polyphenolic biolubricants have good biocompatibility and promote cartilage regeneration. Therefore, the developed synovial lubricants‐recruiting biomimetic polyphenolized biolubricants have potential for treating osteoarthritis, and also provide a theoretical basis for other biological tissues with lubrication problems.

Penerapan Slow Deep Breathing Untuk Menurunkan Keletihan pada Pasien Chronic Kidney Disease: Studi Kasus

Fatigue is the most common physical symptom felt by chronic kidney failure patients. Manifestations of fatigue are the body's inability to carry out routine activities, lethargy, and feeling tired all the time. Non-pharmacological therapy that can reduce fatigue is slow deep breathing relaxation therapy. To determine the intervention for providing slow deep breathing relaxation therapy in chronic kidney failure patients with fatigue. This research design is a case study using nursing care. Mr. I is 64 years old suffering from chronic kidney failure stage v who experiences problems with nursing fatigue. The intervention provided is by providing pharmacological and non-pharmacological therapy, slow deep breathing relaxation therapy. This study used the Functional Assessment of Chronic Illness Therapy-Fatigue Scale instrument. Fatigue complaints decreased with an increase in fatigue score. Before being given therapy, the slow deep breathing reaction was at a score of 22.6 became 40.33 after being given therapy for 3 days. Slow deep breathing can be given as an alternative non-pharmacological therapy which has the effect of reducing fatigue. It is hoped that nursing students or nurses in inpatient rooms can provide this therapy as a non-pharmacological intervention for chronic kidney failure patients with fatigue.

Acute Renal Failure in the Pediatric Intensive Care Unit: Incidence and Its Effects on Clinical Outcomes

Background: Renal dysfunction is a prevalent complication among patients admitted to intensive care units (ICUs), significantly impacting patient outcomes. Objectives: This study focuses on assessing the incidence of acute renal failure (ARF) in pediatric patients hospitalized in ICUs, exploring its occurrence and associated effects on patient outcomes. Methods: A prospective observational study was conducted to examine the incidence of ARF in pediatric patients admitted to a tertiary pediatric hospital's intensive care unit (PICU) in Iran from September 2019 to August 2020. Patients who developed ARF during their ICU stay were included in the study. Clinical and laboratory data were systematically collected upon admission and on a daily basis thereafter. This data collection aimed to elucidate differences in etiology, disease severity, and clinical practices, and to ascertain their impact on patient outcomes. Results: Out of 1145 pediatric ICU admissions, 4.3% experienced acute renal failure during their hospitalization. Of the 49 affected patients, information was available for 46 individuals, constituting the final analysis cohort. The staging of renal failure was categorized as follows: Stage I (45.7%), Stage II (19.6%), and Stage III (34.8%). Acute tubular necrosis emerged as the predominant cause of acute kidney injury (60.8%). The mortality rate among these patients was notably high at 39.1%, compared to the general PICU mortality rate of 7.1% during the study period. Non-survivors exhibited a higher prevalence of antibiotic use, particularly aminoglycosides and antifungal drugs. Additionally, resuscitation procedures were more frequently documented among non-survivors. Conclusions: Approximately 4.3% of pediatric ICU patients develop acute renal failure, with half of the cases manifesting within the initial 24 hours of hospitalization. Acute tubular necrosis stands out as the primary cause of acute kidney injury. A substantial proportion of patients (39.1%) succumb to the condition, particularly those subjected to resuscitation efforts or prescribed multiple antibiotics and antifungal drugs during hospitalization.

Analysis of Factors Influencing Work Accidents Among Workers at Exploitation Facilities and Offshore Oil and Gas Production at PT X from 2018 – 2023

Background: The workplace risks faced at PT X oil and gas company, located offshore Natuna, are relatively high evidenced by fluctuations in accidents from 2018 – 2022. In 2018, recordable injury attributable to accidents was recorded, then in 2019-2020, there were no accidents, and the prevalence increased in 2021-2022. The company analyzed the main causes responsible for work accidents during this period and carried out intervention measures in Occupational Health and Safety (OHS) program to reverse the trend in 2023. By implementing OHS program, the number of accidents in recordable injury category fell from 4 (2021- 2022) to 1 (2023). This shows that the program has been successful in managing work accidents. Considering that the investigation and analysis identified unsafe acts as the direct causes, Human Factor Analysis and Classification System (HFACS) method was used to analyze other factors associated with accidents. Objective: This study aimed to investigate OHS program actions at PT X in responding to increased work accidents in 2021-2022, and compare with recommendations for improvements from HFACS method. Method: A qualitative design was used with secondary data, comprising 10 work accidents records and investigation reports for recordable injury cases from 2018 – 2022 available in PT X information system. Subsequently, the secondary data were then classified according to four failure stages in HFACS, namely unsafe acts, the precondition of unsafe acts, unsafe supervision, and organizational influence. This classification produced recommendations for improvement, which were then compared with the prevention intervention program for accidents at PT X. Results: The results showed that OHS program intervention to reduce the number of accidents in 2023 was in accordance with the recommendations of HFACS analysis. Conclusion: The application of HFACS in analyzing accidents records and investigation reports produced relatively comprehensive recommendations by focusing on the component stages. Several additional recommendations from the analysis of latent conditions will further improve OHS performance at PT X.

Exploring Beishan Granite Damage Patterns: Statistical Analysis of Single and Multiple Loading via Acoustic Emission Techniques.

Using acoustic emission (AE) methods, a research is carried out to examine the failure features of Beishan granite for both loads i.e. continuous and single. The findings demonstrated that the AE signal level increased following dilatancy during single loading but reduced as the tension in the axial direction neared the highest level of tension.AE signals were mostly created during the elastic stage of loading, when loading numerous times, but they were also generated during the failure and residual stages of unloading. In the AE waveforms, three frequency bands were seen in the majority, this was less than 200 kHz in prevailing frequency and less than 80 dB in amplitude. As the loading tension rise, the AE signals' amplitude grew. The AE a- and b-values for the specimens that experienced repeated loads showed that microcracks developed rapidly at the time of the damage stage and helped to generate macrocracks during the residual stage.

1147 Long Term Outcomes Following Combined Liver-Kidney Transplantation

Abstract Aim Combined liver kidney transplant (CLKTx) is the mainstay of treatment for concurrent liver failure and end stage renal failure. The use of CLKTx has increased markedly since the introduction of the MELD (Model for End Stage Liver Disease) score for liver allocation. In this study we examined the long-terms outcomes of 25 years of CLKTx in our centre. Method From a database of all transplants from 1997 – 2022, 158 recipients of CLKTx were identified. Primary outcomes of interest were mortality and graft failure. Data was analysed in R studio and GraphPad prism. Results Overall patient survival was 89% at 1 year, 87% at 2 years, 81% at 5 years, 72% at 10 years and 50% at 20 years. The 20-year patient survival with a pre-transplant (preTx) MELD of &amp;lt;20 was 52%, with a preTx MELD of &amp;gt;20 associated with significantly lower 20-year patient survival of 26% (P&amp;lt;0.05). Death censored (dc) liver graft survival was 99% at 1 year, 98% at 2 years, 97% at 5 years and ten years, and 88% at 25 years. A donor age of &amp;lt;40 showed 20-year liver graft survival (dc) of (100%), which was significantly greater than the donor age &amp;gt;40 group (72%, P&amp;lt;0.05). Death censored kidney graft survival was 96% at 1 year, 95% at 2 and 5 years, 92% at ten years and 84% at twenty years post Tx. Conclusions We report favourable long-term outcomes following 25 years of CLKTx. Predictors for better long-term patient and graft survival include pre transplant MELD score and donor age.

Nonlinear Lamb wave phased array for revealing micro-damage based on the second harmonic reconstruction

It is challenging but meaningful to detect and image the micro-damage in the early stages of engineering structure failure. The nonlinear ultrasonic technique has gained considerable attention for micro-damage detection, meanwhile, the Lamb wave phased array technique has become a practical tool for macro-damage imaging. The combination of these two techniques can pave a promising way for micro-damage imaging in plate-like structures. However, the research on nonlinear Lamb wave phased array imaging is complicated and not reported. The weak nature and hard extraction of the nonlinear features, such as the second harmonic generation, limits the application of the nonlinear Lamb wave phased array. A framework of nonlinear Lamb wave phased array for micro-damage imaging in the plate-like structure is developed. To maximize the second harmonic response of the recorded Lamb waves, two kinds of lead zirconate titanate (PZT) wafers are selected to compose the nonlinear phased array. Furthermore, focusing on the nonlinear feature extraction, the sparse representation approach is introduced for reconstructing the time-domain second harmonic generated by the micro-damage, from which a wealth of waveform information corresponding to the micro-damage can be extracted. The total focusing method (TFM) is used for micro-damage imaging based on the reconstructed second harmonic. Numerical simulation and experimental validation demonstrate the capability of the proposed framework to image the local contact acoustic nonlinearity represented by the barely visible closed fatigue crack with the nonlinear Lamb wave phased array.

Model test study of bridge pile horizontal bearing behavior under landslide deformation

Pile is a common foundation on the slope, which poses a serious threat to the construction and operation if the slope deformation and causes landslide. In this study, a model device of pile foundation on landslide was independently developed by relative displacement loading between pile and soil to explore the influence of landslide deformation on pile and analysis the soil failure rule and the deformation characteristics of pile in different stages of landslide deformation, a few model tests were completed including the relative displacement between soil and pile from 1 to 17 cm, and the pile diameter and the modulus of slide bed were also considered. The results indicated that: the evolution process of landslide deformation with pile foundation on could be divided into four stages including soil compaction, cracks growth, yield stage, and failure stage; ratios of the maximum soil pressure and bending moment growth from the soil compaction stage to the cracks growth stage to the total growth in these four stages are both exceeding 60%; the soil pressure increases with the increase of pile diameter and sliding bed modulus. Therefore, it is best to effectively monitor and control the landslide in the initial soil compression stage that in soil compaction stage and methods such as increasing pile foundations or reinforcing the sliding bed can be used for protection.

CircRNA Interference Pathway: A New Target for Intervention in Different Stages of Heart Failure.

Cardio-cerebrovascular disease has seen a rapid rise in recent years, with Heart Failure (HF) - a terminal stage of various cardiovascular diseases - also on the rise. HF has a complex pathogenesis involving multiple factors, such as inflammation, fibrosis, and oxidative stress. Due to its unique reverse shear mechanism, HF exhibits distinct expression patterns across different diseases. CircRNA has been linked to conditions like cancer, diabetes, and osteoarthritis. This article briefly introduces the mechanisms of circRNA biogenesis and its associated biological functions, focusing on CircSLC8A1-1, CircRNA_000203, and others at the early stage of HF, CircRNA PAN3, CircRNA (ACR), and others during the progression of HF, and CircHIPK3, CircNfix, and others at the end stage of HF. These circRNAs play a participatory role in the exact mechanism. As a research method, circRNA can be utilized to study the pathogenesis of heart failure and serve as a target for drug discovery and development. Therefore, circRNA's ability to mark the disease at different stages has significant guiding implications for HF monitoring, treatment, and prognosis.