476 research outputs found
Development of a Software for Design and Design Comparison of Prestressed I-Beam for Highway and Railway Bridges Based on International Standards
New computer software is being developed within Bridgewiz R&D Co. for the aim
of rapidly comparing design solutions for a prestressed I-beam (highway or railway
bridge) according to different international specifications. The software will perform
a series of beam designs based on user inputs and then make a comparison in terms
of dimensions, material quantities, and total costs (using either user-defined or autoacquired
unit prices). The design and comparison results will be presented to the user
in the form of a PDF report (as well as an on-screen window) which includes tables and
charts for easy visualization. The initial specifications that are planned to be included
in the software are AASHTO-LRFD, EUROCODE, and Turkish Highway Bridge
Specifications for highway bridges and AREMA, EUROCODE, and Turkish Railway
Bridge Specifications for railway bridges. Fresh engineers will be able to use the
program for verifying their designs and experienced engineers can utilize the program
for staying up-to-date with requirements of contemporary specifications. The parameters
that will be designed by the software are the optimum number of girders, their geometry,
girder lateral spacing, number of prestressing tendons and jacking forces (taking the
losses into account), prestressing tendon distribution, deck reinforcement area, and deck
section stresses. The development is supported by KOSGEB - a Turkish government
organization for supporting micro and small companies on research and development
projects
A rare clinic presentation of abdominal pain: rupture of splenic artery aneurysm: a case report
Comparison of adjacent segment degeneration in patients using cervical cage and disc prosthesis in anterior cervical surgery
Aim: To examine the prevalence of adjacent segment degeneration associated with the use of cages and disc prostheses in patients who underwent cervical disc surgery via an anterior cervical approach.
Methods: We retrospectively reviewed the medical records of 60 patients who underwent cervical disc surgery via an anterior cervical approach at our clinic between 2018 and 2023. The patients were divided into two groups based on the type of implant used: those with a cervical cage (Group 1) and those with a cervical disc prosthesis (Group 2). Patients' demographic and clinical details, including age, gender, smoking habits, follow-up durations, and any additional comorbid diseases, were recorded. Radiological evaluations focused on degeneration rates in the segments adjacent to where either the cage or disc prosthesis was implanted.
Results: In the study comparing two groups, participants' average ages were 48.9 in Group 1 and 48.1 in Group 2 (p=0.720). Group 1 had a higher proportion of smokers (p=0.052) and more discopathy (p=0.196). In terms of disc degenerations, variations existed but were not statistically significant (p=0.259). Utilizing the Pfirrmann grading, Group 1 had more Grade III degeneration (p=0.088) and a significantly higher presence of ossification or osteophytes (p=0.038). Both groups showed high rates of adjacent segment degeneration, yet Group 1 had notably more proximal degeneration (p=0.012). Stenosis and facet hypertrophy differences were not significant (p=0.417, p=0.071). Follow-up duration averaged around 38 months for both groups (p=0.929).
Conclusions: No substantial difference in the overall incidence of adjacent segment degeneration between the two procedures. Nevertheless, further large-scale and long-term studies are essential to draw comprehensive conclusions regarding the optimal surgical intervention for cervical disc ailments
Learning soft millirobot multimodal locomotion with sim‐to‐real transfer
With wireless multimodal locomotion capabilities, magnetic soft millirobots have emerged as potential minimally invasive medical robotic platforms. Due to their diverse shape programming capability, they can generate various locomotion modes, and their locomotion can be adapted to different environments by controlling the external magnetic field signal. Existing adaptation methods, however, are based on hand‐tuned signals. Here, a learning‐based adaptive magnetic soft millirobot multimodal locomotion framework empowered by sim‐to‐real transfer is presented. Developing a data‐driven magnetic soft millirobot simulation environment, the periodic magnetic actuation signal is learned for a given soft millirobot in simulation. Then, the learned locomotion strategy is deployed to the real world using Bayesian optimization and Gaussian processes. Finally, automated domain recognition and locomotion adaptation for unknown environments using a Kullback‐Leibler divergence‐based probabilistic method are illustrated. This method can enable soft millirobot locomotion to quickly and continuously adapt to environmental changes and explore the actuation space for unanticipated solutions with minimum experimental cost.Max Planck SocietyHORIZON EUROPE European Research CouncilThe Ministry of National Education of the Republic of Turkiy
Characterization of cisplatin loaded hydrophilic glycol chitosan modified eumelanin nanoparticles for potential controlled-release application
Explainable 2D Vision Models for 3D Medical Data
Training Artificial Intelligence (AI) models on three-dimensional image data
presents unique challenges compared to the two-dimensional case: Firstly, the
computational resources are significantly higher, and secondly, the
availability of large pretraining datasets is often limited, impeding training
success. In this study, we propose a simple approach of adapting 2D networks
with an intermediate feature representation for processing 3D volumes. Our
method involves sequentially applying these networks to slices of a 3D volume
from all orientations. Subsequently, a feature reduction module combines the
extracted slice features into a single representation, which is then used for
classification. We evaluate our approach on medical classification benchmarks
and a real-world clinical dataset, demonstrating comparable results to existing
methods. Furthermore, by employing attention pooling as a feature reduction
module we obtain weighted importance values for each slice during the forward
pass. We show that slices deemed important by our approach allow the inspection
of the basis of a model's prediction
Effect of hypoxia-inducible factor-1 alpha expression on survival in patients with metastatic cervical squamous cell carcinoma treated with first-line chemotherapy and bevacizumab
This study addresses the gap in understanding the prognostic relevance of hypoxia-inducible factor-1 alpha (HIF-1 alpha) expression in metastatic cervical squamous cell carcinoma (SCC) patients undergoing anti-vascular endothelial growth factor-based therapy. A retrospective multicenter study (n = 34) explored HIF-1 alpha expression via immunohistochemistry in patients treated with platinum chemotherapy and bevacizumab. Median progression-free survival (PFS) was significantly lower in the HIF-1 alpha low score group compared to the high score group (4.9 vs 12.9 months, P = 0.014). Similarly, the median overall survival (OS) was significantly reduced in the HIF-1 alpha low score group (8.3 vs 20.4 months, P = 0.006). This study, the first of its kind, highlights the prognostic significance of HIF-1 alpha expression in metastatic cervical SCC patients treated with bevacizumab-based therapy
Examining the association between exposome score for schizophrenia and functioning in schizophrenia, siblings, and healthy controls: Results from the EUGEI study.
Background. A cumulative environmental exposure score for schizophrenia (exposome score for schizophrenia [ES-SCZ]) may provide potential utility for risk stratification and outcome prediction. Here, we investigated whether ES-SCZ was associated with functioning in patients with schizophrenia spectrum disorder, unaffected siblings, and healthy controls. Methods. This cross-sectional sample consisted of 1,261 patients, 1,282 unaffected siblings, and 1,525 healthy controls. The Global Assessment of Functioning (GAF) scale was used to assess functioning. ES-SCZ was calculated based on our previously validated method. The association between ES-SCZ and the GAF dimensions (symptom and disability) was analyzed by applying regression models in each group (patients, siblings, and controls). Additional models included polygenic risk score for schizophrenia (PRS-SCZ) as a covariate. Results. ES-SCZ was associated with the GAF dimensions in patients (symptom: B = 1.53, p-value = 0.001; disability: B = 1.44, p-value = 0.001), siblings (symptom: B = 3.07, p-value < 0.001; disability: B = 2.52, p-value < 0.001), and healthy controls (symptom: B = 1.50, p-value < 0.001; disability: B = 1.31, p-value < 0.001). The results remained the same after adjusting for PRS-SCZ. The degree of associations of ES-SCZ with both symptom and disability dimensions were higher in unaffected siblings than in patients and controls. By analyzing an independent dataset (the Genetic Risk and Outcome of Psychosis study), we replicated the results observed in the patient group. Conclusions. Our findings suggest that ES-SCZ shows promise for enhancing risk prediction and stratification in research practice. From a clinical perspective, ES-SCZ may aid in efforts of clinical characterization, operationalizing transdiagnostic clinical staging models, and personalizing clinical management
Replicated evidence that endophenotypic expression of schizophrenia polygenic risk is greater in healthy siblings of patients compared to controls, suggesting gene-environment interaction. The EUGEI study
Background
First-degree relatives of patients with psychotic disorder have higher levels of polygenic risk (PRS) for schizophrenia and higher levels of intermediate phenotypes.
Methods
We conducted, using two different samples for discovery (n = 336 controls and 649 siblings of patients with psychotic disorder) and replication (n = 1208 controls and 1106 siblings), an analysis of association between PRS on the one hand and psychopathological and cognitive intermediate phenotypes of schizophrenia on the other in a sample at average genetic risk (healthy controls) and a sample at higher than average risk (healthy siblings of patients). Two subthreshold psychosis phenotypes, as well as a standardised measure of cognitive ability, based on a short version of the WAIS-III short form, were used. In addition, a measure of jumping to conclusion bias (replication sample only) was tested for association with PRS.
Results
In both discovery and replication sample, evidence for an association between PRS and subthreshold psychosis phenotypes was observed in the relatives of patients, whereas in the controls no association was observed. Jumping to conclusion bias was similarly only associated with PRS in the sibling group. Cognitive ability was weakly negatively and non-significantly associated with PRS in both the sibling and the control group.
Conclusions
The degree of endophenotypic expression of schizophrenia polygenic risk depends on having a sibling with psychotic disorder, suggestive of underlying gene–environment interaction. Cognitive biases may better index genetic risk of disorder than traditional measures of neurocognition, which instead may reflect the population distribution of cognitive ability impacting the prognosis of psychotic disorder
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