Local Failure Research Articles

Comparative Analysis of the Switching Behavior of Synchronous and Asynchronous Online Learners in Higher Education

This study examines the phenomenon of learner behavior change in synchronous and asynchronous online learning environments. The article assesses the level, stage, reasons, and impact of change among online learners. To facilitate systematic analysis, a set of comparison parameters has been developed. These parameters include success and failure rates, mode and location of learning, level of interaction, group and individualized learning, courses with practical exercises, economic factors, self-regulated learning, indicators of change, technological tools, learner satisfaction, and the impact of a blended learning model. Overall, this article contributes to the understanding of online learners’ behavioral changes and provides valuable information to educators, administrators, and online education providers for designing effective online learning environments. The identified parameters can serve as a foundation for future research on how synchronous or asynchronous modes can either enhance or hinder the overall learning experience of online learners.

Elastic constant ratio for fatigue evaluation on rubber isolators

AbstractIn this study, a new concept of the elastic constant ratio was introduced to derive an S‐N base function, which has removed the requirement of the shear modulus to be measured in previous work, allowing much wider applications in fatigue prediction with significant reduction in the costs involved in conducting experiments and acceleration of the design process in industries. In this approach, the damage parameter was the effective tensile stress verified for both positive and negative R ratios (the ratio between the minimum stress and the maximum stress). Existing work only provided a general description of the criterion without detailed explicit equations, which does not provide sufficient clarity to the reader and could lead to variable fatigue life predictions. Here, detailed equations are introduced on the calculation procedure to allow accurate results to be obtained for fatigue assessment. The applicability of the approach was validated using two industrial components, that is, the Metacone spring and the bush spring. The maximum values of the damage parameter corresponded to the same failure locations observed in the experiments. The suggested S‐N base function, correlated with different materials and failure cycles, could be applied in a fatigue design stage and failure analysis for rubber isolators.Highlights For the first time, an elastic constant ratio is introduced on different rubbers. There is no additional test required for the material constants to save cost. The approach is experimentally validated on two industrial isolators. Monitoring stiffness in tests cannot determine the crack initiation accurately.

On the optimization of green multimodal transportation: a case study of the West German canal system

AbstractIn this study, we address a biobjective multimodal routing problem that consists of selecting transportation modes and their respective quantities, optimizing transshipment locations, and allocating port orders. In the objective functions, we minimize total transportation costs and use the EcoTransit methodology to minimize total greenhouse gas emissions. The optimization model selects the transportation mode and transshipment port where quantities are transshipped from one mode to another. We compare inland waterway transportation and trucks encountering infrastructure failures that require rerouting or modal shifting in a real-life case study on the supply of goods for the chemical industry in the West German canal system. We propose a population-based heuristic to solve large instances in a reasonable computation time. A sensitivity analysis of demand, of varying lock times, and of infrastructure failure scenarios was conducted. We show that compared with inland waterway transportation, multimodal transportation reduces costs by 23% because of longer lock times. Our analysis shows that the use of inland waterway transportation only during infrastructure failures imposes nearly 28% higher costs per day depending on the failure location compared to that of the case of no failures. We also show that the use of a multimodal transportation system helps to reduce this cost increase in lock failure scenarios.

On the question of determining the location of a short circuit on a power transmission line

An algorithm for eliminating aperiodic components from short circuit (SC) currents is proposed. The algorithm is implemented by computer technology and allows you to determine the location of a short circuit and phase loss in 0.5 - 0.6 milliseconds. During such a time interval, saturation of the magnetic circuits of current transformers (CTs) does not occur, and the processors receive undistorted information from the CTs. To implement the algorithm, four measurements of instantaneous current values, separated by equal time intervals (sampling intervals), are sufficient. Elimination of aperiodic components increases the accuracy of determining the location of the fault. The algorithm can be used to determine the location of phase failure, and in digital relay protection based on measuring currents and voltages.

Numerical simulation of microstructural failure of natural fibre–hydrogel composites

In this article, we conduct a numerical simulation to investigate the failure mechanism of natural fibre–hydrogel composites under tensile deformation and swelling. Firstly, a physical-based constitutive model is chosen to describe the deformation of the hydrogel matrix. Concurrently, a macroscopic phenomenological hyperelastic constitutive model, incorporated into the material database of Abaqus, is employed to describe the mechanical responses of natural fibres. Then, we implement the model for a numerical analysis. The material parameters of the model for the hydrogel matrix and fibres are determined by a trial-and-error method from the experimental curves of pure hydrogel and fibres; the numerically simulated stress–strain curve of the composites is compared with the experimental one to verify the effectiveness of the simulation. Subsequently, several numerical analyses are performed to discuss the failure mechanism of hydrogel composites caused by the microstructural features of fibres. The findings revealed that fibre protrusion, fibre orientation deviation, and interface strength significantly affect the local failure of the composites during tensile deformation and swelling; the composites’ strength and toughness mainly depend on the cooperation of various microstructural features. These results provide valuable insights into the design of fibre–hydrogel composites.

Radiation dose escalation and local control for intermediate-risk rhabdomyosarcoma on ARST1431: A report from the Children’s Oncology Group

10007 Background: The objective of this study was to evaluate local failure (LF) rates for patients with intermediate-risk rhabdomyosarcoma (IR-RMS) treated on the Children’s Oncology Group (COG) ARST1431 clinical trial. To improve local control, the radiation therapy (RT) dose was increased to 59.4 Gy for patients with tumors > 5cm at diagnosis and residual gross disease at the time of RT. Methods: The297 patients randomized on ARST1431 were included. LF was defined as progression or relapse at the primary tumor site. Gray’s test was used to compare the cumulative incidence of LF across variables. Results: There was a trend for lower 3-year LF in group III patients with fusion-positive disease (11.1%, 95% confidence interval (CI) 4.5%-21.1%) compared to patients with fusion-negative disease (21.8%, 95% CI 15.8%-28.4%), p = 0.09.There was no difference in the 3-year LF rate for patients who underwent proton RT (16.3%, 95% CI 9.6%-24.7%) compared to photon RT (16.2%, 95% CI 10.2%-23.6%;), p = 0.8. The 3-year LF rate for all patients with tumors > 5cm at diagnosis (24.9%, 95% CI 18.6%-31.7%) was significantly higher than that of patients with tumors ≤5cm at diagnosis (9.9%, 95% CI 5.2%-16.4%), p < 0.01. Of 81 patients with tumors > 5cm and residual gross disease after induction chemotherapy who went on to receive RT, 62 (76.5%) received the protocol-specified boost to 59.4 Gy. Patients who received the boost had a 3-year LF rate of 32.1% (95% CI 20.1%-44%), while patients who did not undergo an RT boost had a 3-year LF rate of 16.1% (95% CI 3.8%-36.2%), p = 0.3. For patients with group III, non-parameningeal disease, those who underwent delayed primary excision (DPE) had a significantly lower LF rate compared to those who did not undergo DPE (3-year rate of 5.6% (95% CI 1.4%-14.0%) vs. 22.0% (95% CI 14.5-30.7%), p < 0.01). Conclusions: On ARST1431, larger tumors ( > 5cm at diagnosis) were associated with increased risk of LF. Dose escalation to 59.4 Gy did not improve local control for patients with tumors > 5cm at diagnosis with residual gross disease at the time of RT. For a select group of non-parameningeal, group III patients who underwent DPE followed by RT, local control was improved. Clinical trial information: NCT02567435 .

Intra-treatment hypoxia directed major radiation de-escalation as definitive treatment for human papillomavirus-related oropharyngeal cancer.

6007 Background: We previously reported that surgery to the primary site with hypoxia-directed de-escalated radiation to the neck for human papillomavirus associated oropharyngeal carcinoma (HPV+ OPC) can lead to excellent oncologic outcomes. We now report the results of a successor multi-center phase II trial of hypoxia-directed de-escalated chemoradiotherapy without surgery for HPV+OPC. Methods: HPV+ OPC (T0-2/N1-N2c/AJCC 7th) patients were eligible for enrollment. Tumors without evidence of hypoxia on 18F-FMISO (fluoromisonidazole) PET received de-escalated chemoradiation to 30Gy while those with hypoxia received chemoradiation to 70Gy. The primary objective was achieving a 2-year locoregional control (LRC) of 95% (failure was locoregional recurrence where surgical salvage was unfeasible) with a 7% non-inferiority margin. We enrolled a total of 158 subjects upfront to account for a 5% loss due to death (of reasons other than cancer) or follow-up. Secondary objectives were local failure (LF), regional failure (RF), distant metastasis (DM), overall survival (OS), toxicities, and patient-reported MD Anderson Dysphagia Inventory (MDADI) scores. LF, RF, and DM were estimated using the Cumulative Incidence Function, and OS was estimated using the Kaplan-Meier method. Results were reported up to 1/31/2024. Results: From 4/28/20-4/17/23, 158 HPV+ OPC patients were enrolled where150 patients were eligible for analyses. Patient characteristics: Tonsil (43%); Base of Tongue (47%); unknown primary (10%); >/=10 pack years (22%); T0 (9%), T1 (44%), T2 (47%); N1 (14%), N2a (11%), N2b (59%), N2c (16%). 111 (74%) received 30Gy; 95% cisplatin. With 24 months (8-43) of median follow-up, the 2-year LF, RF, DM rates were 4.2%, 6.9%, 2.0%, respectively. The 2-year overall survival probability was 99%. Only 2 patients could not undergo salvage surgery [one 30Gy (second recurrence); one 70Gy (M1)], both received systemic therapy with durable response. Acute grade 3-4 toxicities were 32% (67% neutropenia). Mean MDADI scores: 92.93 (baseline); 68.24 (3 weeks), 91.45 (4 months) after chemoradiation. Conclusions: These early data indicate that major de-escalation to 30Gy based on hypoxia status achieved significant toxicity reduction without compromise in survival for HPV+ OPC treated with chemoradiation without surgery. Clinical trial information: NCT03323463 .

RMS13: A phase II trial using risk adapted focal proton beam radiation and/or surgery with the addition of maintenance chemotherapy in intermediate risk rhabdomyosarcoma.

10008 Background: European trials have demonstrated improved outcomes in SIOP high-risk/COG intermediate risk (IR) rhabdomyosarcoma (RMS) when 6 months of maintenance therapy (MTC) was added to ifosfamide, vincristine (VCR), dactinomycin (DAC) +/-doxorubicin chemotherapy. The effectiveness of MTC integrated with VCR, DAC and cyclophosphamide (CYC), standard North American chemotherapy, remains unclear. Methods: RMS13 is a phase II multicenter trial evaluating the safety and efficacy of risk adapted proton radiation therapy (RT) and the addition of MTC in patients with IR RMS (embryonal stage 1, Group III non-orbit, and stage 3 Group I, II were not eligible for MTC). Patients received 12 cycles of VCR (1.5mg/m2 weekly), DAC (0.045mg/kg q3weeks), and CYC (1200mg/m2 q3weeks) (VAC) followed by MTC with 4 cycles of oral CYC (50mg/m2 daily), bevacizumab (15mg/kg) q3wks, and sorafenib (90mg/m2 bid) (CBvSor). RT was prescribed based on local tumor status at the time of RT (Table 1). Five-year disease-free survival (DFS) using the Kaplan-Meier method and the cumulative incidence (CI) of primary site local failure (LF) was described. Results: 46 patients were enrolled (Table 1). One patient refused further therapy and was removed from the analysis. 5-year DFS for the entire cohort was 67.5% with a median follow up of 54 mo. The trial was halted since < 75% of enrolled patients received all prescribed CBvSor MTC. Of the 35 who were eligible for MTC, 24 initiated MTC and 18 completed protocol-directed MTC. Three pts received vinorelbine/CYC MTC after enrollment was stopped. Reasons for not completing CBvSor MTC included: progression prior (6), toxicity (5), refusal (3). The 5-year DFS for the 24 patients that started cycle 3 was 70.3%. When limited to patients classified as high-risk in RMS2005 trial, the 5-year DFS was 81.4%. No patients experienced LF after margin negative surgery. The CI of LF was: 0% following 36GyRBE RT for microscopic residual disease, 8% for patients with unresected tumors < 5cm receiving standard dose RT (50.4GyRBE), and 10% for patients with unresected tumors > = 5cm receiving dose escalated RT (59.4GyRBE). 5/6 patients with alveolar N1 disease recurred. Conclusions: Local control with risk adapted dose-escalated RT was excellent in IR patients. Those with nodal involvement fared poorly. While 4-cycles of MTC with CBvSor was not feasible, those who underwent at least 3 cycles experienced enhanced DFS outcomes, aligning with the positive results seen in other trials incorporating MTC. Clinical trial information: NCT01871766 . [Table: see text]

Analysis of the structural behavior of reinforced concrete components with acoustic emission analysis

The use of non-destructive testing methods can provide insights into processes within the interiors of structures. Acoustic emission testing is one of the non-destructive testing methods that allows the detection of material damage during its occurrence. When structures, such as concrete components, fail under load, elastic waves are generated, propagating within the component. These signals can be detected by acoustic emission sensors placed on the surface of the component, enabling the tracking of the material's condition and the location of failure. This paper summarizes recent applications of acoustic emission measurements on large-scale laboratory specimens made of reinforced concrete. The first example describes measurements during a tensile fatigue test on a large- scale reinforced concrete specimen to investigate the fatigue behaviour of an embedded concrete dowel. The second example involves measurements during a dynamic three-point bending test to examine the fatigue behaviour of a prestressed concrete railway sleeper. The third example describes a full-scale test conducted on a flat slab concrete test specimen with dimensions of 2.8 m × 2.8 m. The objective of these investigations is the development and optimization of new components to enhance punching shear resistance and provide an economical solution. To detect microcracking during loading acoustic emission measurement has been carried out using broadband sensors with a measurement frequency of up to 200 kHz which were especially developed for the detection of microcracks in concrete. For the three-dimensional location of the acoustic emission events, 16 of these acoustic emission sensors were attached to the surface of the specimens. Most of the events were in the centre of the sample in the punching area. These events form a circular structure with a diameter of approximately 1m. A visual inspection of the sample after the experiment shows that macroscopic cracks have formed in this area, which extend up to the surface of the sample.

MELODY: A prospective non-interventional multicenter cohort study to evaluate different imaging-guided methods for localization of malignant breast lesions (EUBREAST-4/iBRA-NET).

TPS623 Background: In the last decades, the proportion of breast cancer patients receiving breast-conserving surgery has increased, reaching 70-80% in developed countries. In case of non-palpable lesions, surgical excision requires some form of breast localization. While wire-guided localization has long been considered gold standard, it carries several limitations, including logistical difficulties, the potential for displacement and patient discomfort, and re-excision rates reaching 21%. Other techniques (radioactive seed or radio-occult lesion localization, intraoperative ultrasound, magnetic, radiofrequency, and radar localization) have been developed with the aim of overcoming these disadvantages. However, comparative data on the rates of successful lesion removal, negative margins, and re-operations are limited. In most studies, the patient perspective, addressing e.g. discomfort and pain, has not been evaluated. The aim of MELODY (Methods for Localization of Different Types of Breast Lesions) is to evaluate different imaging-guided localization methods with regard to oncological safety, patient-reported outcomes, and surgeon and radiologist satisfaction. Methods: The EUBREAST and the iBRA-NET have initiated the MELODY study to assess breast localization techniques and devices from several perspectives (NCT05559411, http://eubreast.org/melody ). MELODY is a prospective intergroup cohort study which enrolls female and male patients. planned for breast-conserving surgery with imaging-guided localization for invasive breast cancer or DCIS. Multiple or bilateral lesions and neoadjuvant chemotherapy are allowed. Primary outcomes are: 1) Intended target lesion and/or marker removal and 2) Negative resection margin rates. Secondary outcomes are, among others: rates of second surgery and secondary mastectomy, Resection Ratio (defined as actual resection volume divided by the calculated optimum specimen volume), duration of surgery, marker dislocation rates, rates of marker placement or localization failure, patient-reported outcomes, rates of “lost markers”, radiologist and surgeon satisfaction, and health economic evaluation of the different techniques. Target accrual: 7,416 patients. The study will be conducted in 30 countries. Clinical trial information: NCT05559411 .

Large feature cross-weld creep test performance in the novel creep strength enhanced ferritic steel Thor® 115 including consideration of the post-weld heat treatment temperature

No present manuscripts have assessed the cross-weld creep performance of Tenaris high oxidation resistance (Thor®) 115. Furthermore, few studies (if any) have compared the performance of martensitic creep strength enhanced ferritic (CSEF) steels in the as-welded or post-weld heat treatment (PWHT) temperature, and for feature test geometries. As CSEF steels are widely specified in modern thermal fleet applications, it is critically important to assess weldment performance and consider the influence of PWHT for new construction or repair applications. In this study, it is shown that the life and failure location in Thor® 115 is not a function of PWHT temperature and that failures in this steel are identical to those for the mainstay CSEF steel Grades 91 and 92.

Contact x-ray brachytherapy for the treatment of rectal cancer: A systematic review and meta-analysis.

e15628 Background: Rectal cancer is a highly prevalent disease, particularly among the elderly and frail populations. While surgical resection has traditionally been the primary management approach, it carries inherent risks, including operative mortality, morbidity, and poor long-term functional outcomes. These risks are particularly pronounced in older, co-morbid individuals. Evidence presented in the 2023 phase III OPERA randomised trial suggests that Contact X-ray Brachytherapy (CXB) is a viable organ-preserving alternative to radical surgery. We conducted a systematic review and meta-analysis to assess the clinical effectiveness of CXB in the treatment of rectal cancer. Methods: This systematic review was prospectively registered (CRD42021284969) and reported in accordance with PRISMA guidelines. PubMed, EMBASE, SCOPUS and Cochrane CENTRAL Libraries were interrogated using the search terms “Rectal cancer”, “Contact Brachytherapy”, and synonym terms. Literature search and data extraction were conducted by two reviewers, with recourse to a senior author for resolution of conflicts. Clinical complete response (cCR) was the primary outcome. Secondary outcomes include local regrowth, regional recurrence, salvage surgery rates, long-term disease control post-salvage surgery and survival outcomes. Proportional meta-analyses were conducted and presented as forest plots with summary proportions and 95% confidence intervals. The Higgins I2 statistic was used to assess for heterogeneity. The random effects model was employed in studies reporting substantial heterogeneity (I2> 50%). Results: The literature search identified 973 studies, of which 48 studies encompassing 5,447 patients were included in the meta-analysis. Pooled estimates of outcomes were as follows: cCR rate = 80% (95% CI 76-88%), local regrowth = 15% (95% CI 12-18%), regional failure rate = 3% (95% CI 2-4%), salvage surgery rate = 14% (95% CI 11-18%), long-term disease control post-salvage surgery rate = 88% (95% CI 78-96%) and organ preservation 82% (95% CI 75-88%). A subgroup analysis was conducted and stratified by concomitant therapy (CXB alone, CXB & EBRT, CXB & EBCRT). CXB, in conjunction with EBCRT, leads to a statistically significant reduction in both local regrowth and regional failure. The local regrowth rates were 16% (95% CI 11-21%), 17% (95% CI 11-23%), and 10% (95% CI 8-13%) respectively, with a p-value of 0.05. The regional failure rates were 4% (95% CI 2-8%), 4% (95% CI 2-5%), and 1% (95% CI 0-2%), p = 0.02. Conclusions: CXB, combined with EBCRT, in the appropriately selected patient can achieve long-term disease control whilst avoiding major surgery. Salvage surgery is a viable option for patients who experience disease regrowth, with excellent long-term disease control. CXB may be considered a safe alternative to surgery in the appropriately selected patient.

Adjuvant chemotherapy following concurrent chemoradiation (CRT) in patients with high-risk early-stage cervical carcinoma following radical hysterectomy: Results of NRG oncology/RTOG 0724/GOG-0724.

5504 Background: To assess the efficacy of adjuvant systemic chemotherapy following CRT for patients (pts) with high-risk early-stage cervical carcinoma. Methods: Pts with clinical stage IA2, IB, or IIA cervical carcinoma with at least one of the following high-risk features after radical hysterectomy: positive pelvic nodes, positive parametrium, and/or positive para-aortic nodes were stratified by intention to use brachy (yes v no), RT (Standard v IMRT); and RT dose (45 v 50.4 Gy) then randomized 1:1 to CRT or CRT and 4 cycles of adjuvant chemotherapy with paclitaxel and carboplatin (CRT + chemo). Primary endpoint was disease-free survival (DFS: death, local or regional failure, or distant mets). Reported secondary endpoints are OS (death due to any cause) and AEs (CTCAEv4). Sample size was 235 pts (50 DFS events, HR=0.47, corresponding to an increase in 4-year DFS from 80% to 90% for the CRT + chemo arm, 80% power, 1-sided log-rank α=0.05). Multivariable analysis (MVA) used Cox regression models. Results: From 9/16/2009 to 3/2/2022, this phase III international trial enrolled 236 pts, with 212 eligible/analyzed (109 CRT and 103 CRT + chemo). Median age was 46 yrs (min-max: 25-77) and median follow-up for all pts was 4.5 yrs (min-max: 0.02-12.8). Fifty-one percent of pts identified as white, 39% as Asian, and 6% Black. Most pts had squamous cell carcinoma (76%), with 18% adenocarcinoma and 5% adenosquamous. 56% of pts had open radical hysterectomy, 23% laparoscopic, and 22% robotic. Most pts had stage IB (87%) and 74% had positive pelvic nodes. Four (4%) pts on the CRT arm and 1 (1%) patient on CRT + chemo did not receive RT. The median (min-max) RT dose delivered was 50.4 Gy (7.2-60.4). Four pts (2 on each arm) did not receive concurrent cisplatin and 27 (26%) pts did not receive adjuvant carboplatin and paclitaxel on the CRT + chemo arm. Grade 3 and 4 events occurred in 36% and 7% of CRT pts; 44% and 21% in the CRT + chemo arm. There were 50 failures, 26 and 24 on the CRT and CRT + chemo arms, respectively, with 4-yr DFS estimates of 76% (90% CI: 69%, 83%) and 77% (90% CI: 70%, 84%) for the CRT and CRT + chemo arms, respectively (HR=1.05 [90% CI: 0.65, 1.68], p=0.56). Thirty-seven of 50 first failures were distant [74%], 20 (40%) and 17 (34%) in CRT and CRT + chemo arms, respectively. On MVA, factors that were statistically significant for worse DFS were receiving vaginal brachy (p<0.0001), RT dose ≥50 Gy (p=0.0021), and adenocarcinoma histology (p=0.03). Pts receiving brachy had close or positive margins. The estimated 4-yrs OS is 87% (90% CI: 82%, 93%) and 89% (90% CI: 84%, 94%) for the CRT and CRT +chemo arms, respectively (HR=0.91 [90% CI: 0.49 to 1.69]; 1-sided log-rank p=0.40). Conclusions: The addition of systemic chemotherapy following CRT didn't improve DFS or OS in cervical cancer patients with high-risk factors after radical hysterectomy. Clinical trial information: NRG Oncology/RTOG 0724/GOG-0724.

Interpectoral nodal dissection for invasive breast cancer: A retrospective single institution study from India.

e12585 Background: Interpectoral lymph nodes are one of the axillary lymphatic drainage sites in breast carcinoma. Usually dissection of Interpectoral nodes (IPN) avoided during axillary dissection as they are not the primary lymphatic drainage site. Our study aims to identify the rate of positivity of Interpectoral nodes in invasive breast cancer, predictors of IPN positivity in relation to tumour location, size, grade and hormone receptor status and to evaluate the need for IPN clearance during axillary dissection. Methods: A retrospective analysis of histopathology reports of 367 patients who underwent Axillary dissection in a single centre from Jan 2017-Dec 2022 for breast cancer was analysed. Inclusion criteria: Female Patients with operable Invasive Breast cancer with node positive axilla who underwent axillary dissection (upfront and post chemotherapy). Exclusion criteria: metastatic breast cancer, node-negative patients/sentinel lymph node biopsy, inadequate nodal dissection, and incomplete clinicopathological information. Data was analysed looking for presence of nodes in interpectoral tissue in Axillary dissection and to identify the positivity of interpectoral lymph nodes in specimens. Results: Interpectoral nodal dissection was done in n=216 of the 367 patients. The clinicopathological characters are described in Table. IPN were identified in 35% (n=77) of the 216 Axillary dissection specimens. IPN were positive in 7.8% (17 of 216) of patients who had interpectoral nodal dissection. 22% of the interpectoral lymph nodes removed were positive. As regards tumour size, Rotter's nodes were identified commonly in T3 and T4 tumours and positive in people with N2 and N3 disease. By multivariate analysis, T stage and N stage were the most important determinants of IPN yield and positivity. Site of tumour, neoadjuvant therapy, molecular subtype or Ki 67 were not found to be associated with either presence or positivity of interpectoral nodes. In 5 cases IPN positivity upstaged the nodal stage and in 1 patient it was the only positive node. Conclusions: As IPN is positive in most LABC, whenever axillary dissection is done in such cases Interpectoral nodes can be safely removed while dissecting level III nodes. Nodal recurrence is the most common site of recurrence post mastectomy and hence Interpectoral nodes need to be routinely removed in patients undergoing Axillary dissection for operable breast cancer to enable accurate staging and to prevent local or systemic failure. [Table: see text]

Capacity assessment of railway axle journal bearing addressing a localized rolling contact fatigue failure mechanism

Abstract A framework for assessing the capacity of railway axle journal bearings is presented after elaborating on the locale rolling contact fatigue (RCF) failure mechanism. Three phases are conducted, including the determination of bearing service loads, finite element analysis (FEA) on the localized RCF stresses of bearing components, and the life-related capacity assessment on the bearings and bearing components. Results prove that wheel-track (WT) contact forces inspected by an instrumented wheel set can be transferred into bearing service loads. Two-step FEA from the global wheel set to the local bearings is used to obtain localized RCF stresses at dangerous locations around the bearing contact regions. After determining the locations, a life-related capacity assessment is performed by evaluating equivalent RCF stresses and lives at the locations to determine the weakest bearing component. Typical practice is given in agreement with FEA. This method deals with the FEA of bearing structures, material cyclic stress-strain curves, and probabilistic RCF life curves. Therefore, this work greatly enhances the development of rail-bearing materials, innovative structures, and capacity assessment.

Brain vasculature accumulates tau and is spatially related to tau tangle pathology in Alzheimer’s disease

Insoluble pathogenic proteins accumulate along blood vessels in conditions of cerebral amyloid angiopathy (CAA), exerting a toxic effect on vascular cells and impacting cerebral homeostasis. In this work, we provide new evidence from three-dimensional human brain histology that tau protein, the main component of neurofibrillary tangles, can similarly accumulate along brain vascular segments. We quantitatively assessed n = 6 Alzheimer’s disease (AD), and n = 6 normal aging control brains and saw that tau-positive blood vessel segments were present in all AD cases. Tau-positive vessels are enriched for tau at levels higher than the surrounding tissue and appear to affect arterioles across cortical layers (I–V). Further, vessels isolated from these AD tissues were enriched for N-terminal tau and tau phosphorylated at T181 and T217. Importantly, tau-positive vessels are associated with local areas of increased tau neurofibrillary tangles. This suggests that accumulation of tau around blood vessels may reflect a local clearance failure. In sum, these data indicate that tau, like amyloid beta, accumulates along blood vessels and may exert a significant influence on vasculature in the setting of AD.

Three-dimensional calculation method on local slurry wall stability of diaphragm wall trench based on minimum potential energy principle

Because the soft weak soil layer rich in confined groundwater is prone to local instability and failure in the construction of diaphragm wall trenches, in order to check the local slurry wall stability in the construction of diaphragm wall trenches, a new three-dimensional (3D) calculation method on the local stability safety factor (LSF) of slurry walls is proposed based on the minimum potential energy principle. After the new method is applied to two engineering cases, the value of the LSF solved is 0.82 for engineering case 1, and the values of the LSF solved are 0.84 and 1.05 when the phreatic water levels are 2 and 4.5 m, respectively, for engineering case 2. These results are very close to the calculation results in the existing references, so the rationality of the new method is verified. Then the sensitivity of the LSFs obtained from the new method to various parameters has been analyzed and clarified on the basis of ten design examples. Finally, the new method is used to check the local slurry wall stability in the construction of diaphragm wall trenches for a practical project, and the obtained values of the LSF for three concerned weak soil layers are 1.37, 1.19, and 0.82, respectively. These results are in agreement with the actual situation in the construction site. This reveals that both the 3D model established and the 3D calculation method proposed in this paper are suitable for application in practical projects.

Electromigration and electrical sintering in printed silver from high current at room temperature

Improved understanding of the reliability and failure physics of metal nanoparticle conductive inks would facilitate their large-scale deployment across a range of flexible electronics applications. We conduct room-temperature electromigration experiments on printed silver nanoparticle conductive ink test devices. We observe significant variation in failure time, location, and structure during these tests and during post-failure analysis with optical and electron microscopy. We use in situ Atomic Force Microscopy measurements to track volume changes in the sample as a function of time. These measurements provide additional data and understanding of the failure process within printed silver nanoparticle conductive inks.

Stereotactic radiosurgery for prostate cancer spine metastases: local control and fracture risk using a simultaneous integrated boost approach.

Variation exists in approaches to delivery of spine stereotactic radiosurgery (SSRS). Here, the authors describe outcomes following single-fraction SSRS performed using a simultaneous integrated boost for the treatment of prostate cancer spine metastases. Health records of patients with prostate cancer spine metastases treated with single-fraction SSRS at the authors' institution were reviewed. Treatment was uniform, with 16 Gy to the clinical tumor volume and 18 Gy to the gross tumor volume. The primary endpoint was local recurrence, with secondary endpoints including vertebral fracture and overall survival. Univariate and multivariate competing risk regression models made using the Fine and Gray method were used to identify factors predictive of local recurrence, considering death to be a competing event for local recurrence. A total of 87 targets involving 108 vertebrae in 68 patients were included, with a median follow-up of 22.5 months per treated target. The 1-, 2-, and 4-year cumulative incidence rates of local failure for all targets were 4.6%, 8.4%, and 19%, respectively. The presence of epidural disease (subdistribution hazard ratio [sHR] 5.43, p = 0.04) and SSRS as reirradiation (sHR 16.5, p = 0.02) emerged as significant predictors of local failure in a multivariate model. Hormone sensitivity did not predict local control. Vertebral fracture incidence rates leading to symptoms or requiring intervention at 1, 2, and 4 years were 1.1%, 3.7%, and 8.4%, respectively. In an exploratory analysis of patterns of failure, 3 (25%) failures occurred in the epidural space and only 1 (8%) occurred clearly in the clinical tumor volume. There were several lesions for which the precise location of failure with regard to target volumes was unclear. High rates of local control were observed, particularly for radiotherapy-naïve lesions without epidural disease. Hormone sensitivity was not predictive of local control in this cohort and fracture risk was low. Further research is needed to better predict which patients are at high risk of recurrence and who might benefit from treatment escalation.

MRI-Linac radiation therapy outcomes in patients with prostate, breast and other advanced malignancies.

e13811 Background: MR-guided radiation therapy offers an innovative approach, providing superior soft tissue contrast that enables clinicians to deliver higher doses to the target site with fewer fractions. The objective of the study is to assess objective response rates and adverse effects related to a community-based single-institution experience with the ViewRay MRIdian. Methods: An IRB-approved registrational trial was conducted at the Providence Cancer Institute starting May 2020, with data cutoff of September 2023. All patients treated underwent MR screening, and the target site(s) were treated using hypofractionated radiation therapy in ≤5 fractions. The primary endpoint was to assess adverse effects attributed to radiation therapy. Secondary measures included local recurrence-free survival (LRFS), distant metastasis-free survival (DMFS), overall survival (OS), and change in prostate-specific antigen (PSA) for patients treated definitively for prostate cancer. The assessments were performed under the guidance of experienced radiation oncologists. Results: From May 2020 to September 2023, n=257 patients received treatment on the MRIdian with a median follow-up of 430 days [range 4-1221 days]. One and 2-year LRFS was 92% and 87%, and excluding prostate and breast cancer, 83% and 70%. Definitive prostatestereotactic body radiation therapy(SBRT) was delivered to 117 patients and significantly reduced PSA (mean difference -6.27, p<0.0001), with no local failures to date. One and 2-year DMFS was 75% and 67%, though if excluding definitive prostate SBRT and partial breast irradiation, these were 48% and 33%. The OS rate at 1 and 2 years was 86% and 76%. Excluding prostate and breast cancer, the 1 and 2-year OS was 74% and 55%. Grade 3+ adverse events possibly or definitely attributable to radiation therapy were noted in 5% (n=13/257) of patients, including 2 possible treatment-associated deaths (bowel perforation following liver SBRT, and respiratory failure following lung SBRT and trastuzumab-deruxtecan systemic therapy). Conclusions: Our institutional experience with the MRIdian demonstrated high levels of local control, while overall survival was driven by out-of-field failures. Serious adverse events were infrequent, but more common in abdominal targets highlighting the need for careful planning and tight organs at risk (OAR) constraints, particularly if systemic therapy is delivered soon after radiation.