bluuebunny/crossref_metadata_2025 huggingface dataset:
A Statistical Shape Model Pipeline to Enable the Creation of Synthetic 3D Liver Data
Authors: Krnjaca Denis , Krames Lorena , Schaufelberger Matthias , Nahm Werner
Published: September 2023

The application of machine learning approaches in medical technology is gaining more and more attention. Due to the high restrictions for collecting intraoperative patient data, synthetic data is increasingly used to support the training of artificial neural networks. We present a pipeline to create a statistical shape model (SSM) using 28 segmented clinical liver CT scans. Our pipeline consists of four steps: data preprocessing, rigid alignment, template morphing, and statistical modeling. We compared two different template morphing approaches: Laplace-Beltrami-regularized projection (LBRP) and nonrigid iterative closest points translational (N-ICP-T) and evaluated both morphing approaches and their corresponding shape model performance using six metrics. LBRP achieved a smaller mean vertex-to-nearest-neighbor distances (2.486±0.897 mm) than N-ICP-T (5.559±2.413 mm). Generalization and specificity errors for LBRP were consistently lower than those of N-ICP-T. The first principal components of the SSM showed realistic anatomical variations. The performance of the SSM was comparable to a state-of-the-art model.
Reflection of the Medical Device Regulation
Authors: Sojka Karolina , Sohrabi Keywan , Gross Volker , Scholtes Michael
Published: September 2023

The MDR states the objectives of the law in the preface. There you will find, among other things, a consideration of small and medium-sized enterprises as well as high health protection and an innovative effect. Therefore, the question arises to what extent these goals have been achieved so far or can be achieved in the foreseeable future. To this end, a systematic literature review was conducted to present the perspectives of various stakeholders in the healthcare sector. Critical situations certainly arise for certain manufacturers, Notified Bodies and certain patient groups. The adopted extension of the transitional periods could be helpful but will not solve all problems.
A comparative evaluation of spatial pooling methods for surgical tool detection
Authors: Abdulbaki Alshirbaji Tamer , Aldeen Jalal Nour , Docherty Paul D. , Neumuth Thomas , Moeller Knut
Published: September 2023

Surgical tool detection is an important aspect for recognising surgical activities and understanding surgical workflow. Laparoscopic videos represent an information source that can be used for recognising surgical tools. However, manual labelling of tool incidence and location in such data is extremely time intensive. Therefore, weaklysupervised approaches have been developed to perform tool localisation. In this study, three types of spatial pooling methods were implemented to evaluate the influence of each method on the performance of weakly-supervised model. The best achieved performance was a mean average precision (mAP) of 94% for tool classification and a f1-score of 70% for tool localisation. Experimental results showed the importance of selecting an appropriate pooling function to enhance model performance.
Contactless camera-based AHI score estimation in SAS patients
Authors: Alic Belmin , Zauber Tim , Wiede Christian , Viga Reinhard , Seidl Karsten
Published: September 2023

Sleep apnea syndrome (SAS) is a common sleeprelated breathing disorder characterized by recurring cessations of airflow during sleep. The gold standard for diagnosing SAS is polysomnography (PSG) which requires the patient to spend one or several nights in a sleep clinic. A PSG involves a significant amount of contact-based sensors, which leads to discomfort and deviations in sleep behavior. In this work, a contactless, multispectral camera-based approach for the autonomous detection of events of nocturnal airflow reduction is presented. The detected events are further employed in estimators of sleep diagnostic metrics, such as the apnea-hypopnea index (AHI) and the SAS stage. The AHI estimation resulted in a Pearson correlation coefficient of r = 0.9993. The SAS stage estimator correctly predicted the SAS stage for all three recruited patients.
Conveyor-based robot allows fast and safe instrument handling in the operating room
Authors: Yamashita Keisuke , Wex Cora , Croner Roland , Boese Axel
Published: September 2023

According to [1]-[3], the healthcare systems are suffering from severe personnel shortages with a lack of medical care workers, operating room nurses, and surgical technicians. This deficiency will become worse in the upcoming decades. Automatization of highly standardized procedures could be a promising approach to address this issue. We designed a new concept for the automated handover and return of surgical instruments to the surgeon in an operating theater scenario to relieve operating room personnel from their workload. In this setup, the surgical instruments are delivered pre-sorted in an upright position by the sterilization unit in an instrument basket or drum. A single-use, doublelayered, brushy conveyor belt system mounted on a robot arm acts as the connector between pick-position (instrument basket) and individually pre-definable hand-over-position. The system is placed next to the table inside the operation room (OR). Based on voice commands, the conveyor intake moves over to the selected instrument and delivers it to the surgeon in a fast and short motion. After use, the surgeon can feed the instrument into the intake at the handover position and place it back in the instrument basket. The robot arm allows precise maneuvering of the intake and output position. The concept was realized as a minimal-viable product and will be evaluated for further improvement.
Development of a camera-marker system (CMS) for locking nails during intramedullary osteosynthesis in large animals – First results
Authors: Walther Sebastian , Reuter Thomas , Grundmann Andreas , Preuß Friederike , Barnewitz Dirk
Published: September 2023

In large animals, fractures of the upper long tubular bones such as forearm and humerus as well as lower and upper leg, continue to represent a major surgical challenge. An implant and a corresponding surgical procedure for intramedullary osteosynthesis in fractures of long bones were developed at fzmb GmbH. Fixation of the implanted nail to the distal drill holes has proven to be difficult and requires a high level of X-ray monitoring. Therefore, a camera-marker system (CMS) was developed without the need for X-ray monitoring during drilling. The test was performed on 10 equine femora. The results showed that 8 of 10 implants could be securely fixed and no complications occurred in the experimental procedure. For the first two implants, the distal drill holes could not be hit in the first attempt. This is due to the circumstance, that the handling of the CMS needs to be practiced to hit the distal drill holes accurately and appropriately, resulting in a hit rate of 80 %. However, the described method has great potential and does not require X-ray exposure.
Investigation of knee joint stability in surgically repaired canine cruciate ligament ruptures by cyclic passive joint motions
Authors: Reuter Thomas , Grundmann Andreas , Siebert Jens , Preuß Friederike , Barnewitz Dirk
Published: September 2023

The cranial cruciate ligament (CCL) rupture is a prevalent injury in dogs. A consequence of a cruciate ligament rupture is instability in the affected knee joint. A veterinary, mostly surgical treatment of the cruciate ligament rupture is usually unavoidable. The suitability of an arthroscopic surgical method with ligament replacement material was investigated. The stability of the knee joint was determined several times during 1,200 passive robotic motion cycles with movement radius between 90° flexion and 140° extension. The stability condition was measured by triggering the drawer test. After 300 motion cycles, the drawer test could be triggered (positive drawer test). In the following movement cycles up to 1,200 cycles, the drawer test could also be triggered. However, no significant differences occurred between these triggered drawer tests. The ligament replacement material showed no damage and no loosening after the tests. The first results showed that the developed arthroscopic surgical method could be a promising approach for the surgical treatment of cruciate ligament ruptures in canines.
Auditory Neurons on the Silk Road – spider silk for bridging the nerve-electrode-gap
Authors: Schwieger Jana , Scheper Verena , Lenarz Thomas , Vogt Peter M. , Strauß Sarah
Published: September 2023

The cochlear implant (CI) restores hearing to patients with severe to profound sensorineural hearing loss by stimulating the spiral ganglion neurons (SGN). Due to the inner ear anatomy, a fluid-filled gap remains between the SGN and the electrode array. This gap impedes focused stimulation and thus optimized performance with the CI. Regenerating neurites may bridge this fluid-filled gap for a direct nerveelectrode- link but require a supportive matrix. Spider silk might be a suitable candidate for this support. Therefore, silk fibers were tested for biocompatibility with inner ear neuronal tissue, suitability as neurite outgrowth matrix and applicability to the CI-electrode array. Dragline silk from female Trichonephila spiders was woven around a frame and autoclaved. Spiral ganglia of young rats were prepared, cut and placed in a drop of medium on the parallel silk fibers for pre-cultivation to support adherence before remaining medium was added. After 5d of cultivation, cells were fixed and immunocytologically stained. For CIapplication, silk was wrapped around a silicone dummy and a one-sided spacer. Opposite the spacer, alginate-hydrogel was applied for silk-fixation and -shielding. After gelation, silk loops were cut in the middle to form protruding threads. Cells showed a high degree of migration and neurite regeneration along the silk fibers and in some cases the outgrown neurites directly contacted the silk. It was possible to fix the silk to the dummy as protruding fibers. The tested spider silk is compatible with the inner ear tissue in culture, supports cell growth and seems to be an attractive material for neurite contacting. Application to the CI as protruding fibers is possible, making it a promising candidate for structural support to bridge the nerve-electrode-gap.
Speech Intelligibility: Lateral Lisp Detection for Real-Time Monitoring
Authors: Munnich Patrick , Dederichs Stefanie , Klein Paula , Bruno Figura Carl
Published: September 2023

Correcting lisps in speech can prove to be of great difficulty to many, as they may be unaware of whether they are lisping. To help those affected, we have developed a simple algorithm for the real-time identification of the sigmatismus lateralis in ”S” sounds within speech via analysis in the frequency domain. The algorithm identifies peaks within the lisp’s frequency band after calibration. A frequency band of 3000-4000 Hz has been identified to be generally accurate for lisp and 2500-3000 Hz for the correct pronunciation for a single male test subject. The algorithm splits given speech recordings into smaller segments and compares the number of lisps and non-lisps detected in these segments to categorize. From tests, it was concluded that a segment length of 0.5 s produces the best results. The algorithm does not detect every lisp section, however it does not raise false positives. Our implementation in Julia with multi-threaded per-file analysis is able to analyze 20 files of lengths between 5 s and 10 s within 0.21 s on a Qualcomm Snapdragon 860 smartphone chipset, meaning analysis is far faster than real-time. The proposed algorithm is a simple prototype algorithm capable of realtime analysis of audio in the frequency domain to identify whether lateral lisps are the dominant sibilant pronunciation in a given window. The method was only tested for a single test subject. However, a calibration algorithm capable of adjusting parameters to new individuals is proposed. The algorithm itself should be easily expandable to identify other speech impediments.
U-Net-based SUV calculation in FDG-PET imaging of mice brain for enhanced analysis
Authors: Pashazadeh Ali , Jafarian Forough , Tanha Kaveh , Hoeschen Christoph
Published: September 2023

Positron emission tomography (PET) is a widely used imaging modality in nuclear medicine for a variety of applications. Amongst the methods used for the quantifying and interpretation of PET images, the standardized uptake value (SUV) is a widely-adopted semi-quantitative tool that supplements visual understanding with quantitative information. SUV is used in both clinical and preclinical practices to report the status of various normal organs and tumors under investigation using PET imaging. While the determination of SUVs is typically done manually, which can be tedious, artificial intelligence (AI) can be utilized to enhance the efficiency of the process. In this study, a U-Net-based approach was employed for semi-automated determination of SUV in FDG-PET scans of mice brains. First, a U-Net model was trained using 50 FDG-PET images of six mice to perform the automatic segmentation task. The trained model then delineated the brain of a mouse which was then processed by a short in-house code to extract data and calculate the SUV. The process was also replicated in a manual way for comparison purposes. The comparison of the results from the U-Net-based segmentation method and the conventional manual method at nine different time points revealed that there were errors of less than 4.5% in eight out of the nine-time points. Although our U-Net model’s performance needs improvement, adapting a well-trained AIbased approach for SUV determination, particularly in preclinical studies, can help reduce the workload of organ delineation and minimize associated errors, facilitating SUV determination.
Mask R-CNN Outperforms U-Net in Instance Segmentation for Overlapping Cells
Authors: Rettenberger Luca , Rieken Münke Friedrich , Bruch Roman , Reischl Markus
Published: September 2023

U-Net is the go-to approach for biomedical segmentation applications. However, it is not designed to segment overlapping objects, a challenge Mask R-CNN has shown to have great potential in. Yet, Mask R-CNN receives little attention in biomedicine. Hence, we evaluate both approaches on a publicly available biomedical dataset. We find that Mask RCNN outperforms U-Net in segmenting overlapping cells and achieves comparable performance if they do not intersect. Our study provides valuable decision support to practitioners in selecting an appropriate method when solving instance segmentation tasks using deep learning, as well as important insights into enhancing the accuracy of such approaches in biomedical image analysis.
Validation of ergonomic running handgrip elements to improve arm posture of running novices
Authors: Sesselmann Stefan , Turcanu Michael , Fleischmann Christopher , Leher Irina , Schleip Robert , Buhl Sebastian , Schuh Alexander
Published: September 2023

Running is one of the most popular sports worldwide motivating many non-athletic people to start new physical activities. But especially novice runners are at risk to develop injuries as they tend to run with prejudicial posture. Hence, there has been considerable research to identify factors improving running performance. One of these factors is the correct movement of arms as a swinging pendulum during running. Based on this knowledge ergonomically shaped handgrip elements were designed to improve the posture of the shoulder-arm complex during running. The main objective of this study was the validation of the actual effectiveness on shoulder-arm posture of these handgrips. In this sense 25 adult, healthy persons without running experience were examined by motion capture analysis during running on a treadmill with and without the use of the handgrips. The focus of movement analysis was on changes of hand supination, shoulder abduction and shoulder rotation. Flexion of elbows and shoulders were not expected to change and thus, were investigated as an internal control. Significant changes were found in sense of a reduction of forearm pronation, shoulder abduction, and internal rotation of the shoulder, resulting in improved posture during running. At the same time, no significant changes were found in elbow flexion and shoulder flexion. Future studies are needed to investigate the effects of the detected improvement of arm posture on other important running parameters, such as trunk stability, movement of lower limbs, running economy, and risk of injury. These studies should also compare effects in competitive athletes, recreational runners, and novice runners.
Single-photon avalanche diode (SPAD) array detector for high-throughput fluorescence lifetime flow cytometry
Authors: Rottmann Jonas , Schierbaum Nicolas , Netaev Alexander , Ligges Manuel , Seidl Karsten
Published: September 2023

Time-domain measurement of the fluorescence lifetime in flow cytometry offers a complementary method to traditional flow cytometry, especially for the analysis of cells and biomolecules. Short measurement times due to high throughputs (cells/s) make a suited detector mandatory for a sufficient detection of the fluorescence signal and therefore the application of this method. We summarize the requirements for a suited detector for time resolved flow cytometry (TRFC) and present a new developed SPAD array detector with 100 pixels and 340 ns time between measurement windows, allowing a high-throughput of up to 60,000 cells/s. The functionality of the detector is shown with the measurement of a 22.2 ns laser pulse, making it applicable for an improved TRFC.
Novel airflow ring for the reduction of germ load in a surgical field
Authors: Scherrieble Andreas , Haab Elena , Held-Föhn Evi , Linti Carsten , Baumgartner Tobias , Wandres Claus G. , Doser Michael , Gresser Götz T.
Published: September 2023

Hospital-acquired infections occur through microbial contamination of the surgical wound and can lead to severe complications. A significant transmission path is the aerogenic transmission, where pathogens stick to floating particles like skin scales or to air moisture. A novel porous airflow ring which is placed around the surgical field aims to overcome this by applying sterile air directly at the operation wound. The ring is provided with an air tight coating at the outer side and allows for fixation on the skin by an adhesive coating at the lower side. To evaluate its performance the airflow ring was placed in an atmosphere with nebulized suspension of Staphylococcus arlettae of a concentration of 5.0 x 10^5 CFU/ml resp. 5.0 x 10^6 CFU/ml within a box. The formation of bacterial colonies (CFU) on contact plates placed within the airflow ring was subsequently determined by visual counting after incubating at 37 °C for one day. CFU counts of the ventilated and the unventilated situation were compared. With the smaller inoculum, the introduction of bacteria into the inner site of the ring was completely prevented, whereas the contact plate of the unventilated ring resulted in 77 to 427 colonies in different trials. With the higher inoculum, the bacteria ingress was very strongly reduced by 99.7% respectively 99.9%. In conclusion the airflow ring shows a strong shielding effect for germs adhered to fog-sized water droplets. To clearly demonstrate the effect, the number of bacteria was greatly increased compared to reality in this setup. It was shown that it can withstand even conditions significantly worse than those encountered in an operating theatre. In order to demonstrate the effect in vivo, clinical trials have to be conducted to confirm the laboratory results.
Fabrication of flexible intracranial aneurysm models using stereolithography 3D printing
Authors: Stahl Janneck , Kassem Leheng , Behme Daniel , Klebingat Stefan , Saalfeld Sylvia , Berg Philipp
Published: September 2023

The use of 3D printing technology for medical applications is becoming increasingly popular. Recent stereolithography (SLA)-based printing methods allow the generation of complex structures with a high surface quality. This is particularly useful for applications in the neurovascular field, where sophisticated structures are involved. In this study patient-specific intracranial aneurysm models are extracted based on medical image data und printed as thin-walled vascular phantom models. For this purpose, two commercially available 3D printers are used to print flexible vascular models with three different silicone-like elastic resins (Ultracur3D FL 300, Prusament Flex80 and Formlabs Elastic 50A) of various Shore hardness. Three aneurysm models of different size and complexity are chosen. To evaluate the geometric accuracy of the flexible models, angiographic measurements are performed for an exemplary case and morphological parameters are extracted from the generated 3D models. The printed results demonstrate a successful generation of hollow aneurysm phantoms. There are dependencies regarding the print quality from the model to platform positioning for two materials. The quantitative geometric accuracy analysis shows notable differences between the materials. The extracted morphological parameter values for all materials show a mean decrease compared to the original reference model of aneurysm volume (4.5 %) and maximum diameter (1.0 %) as well as an increase of ostium area (6.0 %) and maximum height (4.9 %). However, Formlabs Elastic 50A in particular exhibits just slight reductions with respect to the reference model, with a mean decrease for all parameters of 5.7 % as well as no dependence on printing position and resulting artifacts. The study investigates the feasibility of using SLA-based 3D printing to generate realistic flexible aneurysm phantoms. In this context, the Formlabs Elastic 50A could be identified as potentially applicable for phantom creation in terms of reproducible quality and geometric validity.
Deep.Neural.Signal.Pre-Processor - Towards Development of AI-enhanced End-to-End BCIs
Authors: Buron Leo , Erbslöh Andreas , Ur-Rehman Zia , Klaes Christian , Seidl Karsten , Schiele Gregor
Published: September 2023

This paper presents a software-based Python framework for developing future AI-enhanced end-to-end Brain-Computer-Interfaces (BCI). This framework contains modules from the emulated analogue front-end and from neural signal pre-processing for invasive neural applications. These modules can be assembled into several pipeline versions for evaluation and benchmarking. The aim of this framework is to accelerate the development of BCIs due to system-wide optimizations in order to set the requirements for hardware development without prior knowledge on the basis of accuracy (recall and precision) and latency. In the next step, the pipeline can be optimised for on-chip and embedded execution.
Development of a test setup for hydrodynamic characterization of hydrocephalus shunts
Authors: Stiehm Michael , Siewert Stefan , Borowski Finja , Großmann Swen , Schmitz Klaus-Peter , Freiman Thomas M. , Strauß Andreas
Published: September 2023

Implantation of a shunt system is the most common neurosurgical procedure for the treatment of hydrocephalus. Hydrodynamic parameters of hydrocephalus shunt systems are valuable variables to address patients' needs. In this report, we present a test setup to evaluate hydrodynamic parameters of hydrocephalus shunt systems. The test setup was validated using a stainless steel capillary and compared with the analytical solution according to Bernoulli's equation. It was demonstrated that the experimental setup is able to model the pressure in a physiologically relevant range. The measured and averaged flow resistance was 2.96 mmHg/(ml min-1). According to the analytical solution of Bernoulli's equation, the flow resistance is 2.86 mmHg/(ml min-1). Therefore, the measured flow resistance is 3.5% higher than the analytical solution. Moreover, the nonlinear characteristic of the pressure drop at the inlet and outlet of the capillary plays a minor role compared to the friction of the tube flow. As a result, the increase in flow rate with increasing pressure load can be well approximated by a linear function for the low flow rates measured here. The experimental setup presented will be used in the future to characterize commercially available shunt systems under various hydrodynamic conditions.
Discrepancy Between LGE-MRI and Electro-Anatomical Mapping for Regional Detection of Pathological Atrial Substrate
Authors: Goetz Christian , Martínez Díaz Patricia , Sánchez Jorge , Jadidi Amir , Eichenlaub Martin , Dössel Olaf , Loewe Axel
Published: September 2023

Atrial fibrillation (AF) is the most common sustained arrhythmia posing a significant burden to patients and leading to an increased risk of stroke and heart failure. Additional ablation of areas of arrhythmogenic substrate in the atrial body detected by either late gadolinium enhancement magnetic resonance imaging (LGE-MRI) or electroanatomical mapping (EAM) may increase the success rate of restoring and maintaining sinus rhythm compared to the standard treatment procedure of pulmonary vein isolation (PVI). To evaluate if LGE-MRI and EAM identify equivalent substrate as potential ablation targets, we divided the left atrium (LA) into six clinically important regions in ten patients. Then, we computed the correlation between both modalities by analyzing the regional extents of identified pathological tissue. In this regional analysis, we observed no correlation between late gadolinium enhancement (LGE) and low voltage areas (LVA), neither in any region nor with regard to the entire atrial surface (-0.3<r<0.3). Instead, the regional extents identified as pathological tissue varied significantly between both modalities. An increased extent of LVA compared to LGE was observed in the septal wall of the LA (asept.,LVA= 19.63% and asept.,LGE= 3.94%, with = median of the extent of pathological tissue in the corresponding region). In contrast, in the inferior and lateral wall, the extent of LGE was higher than the extent of LVA for most geometries (ainf.,LGE= 27.22% and alat.,LGE= 32.70% compared to ainf.,LVA= 9.21% and alat.,LVA= 6.69%). Since both modalities provided discrepant results regarding the detection of arrhythmogenic substrate using clinically established thresholds, further investigations regarding their constraints need to be performed in order to use these modalities for patient stratification and treatment planning.
Accuracy Evaluation of 3D Pose Estimation with MediaPipe Pose for Physical Exercises
Authors: Dill Sebastian , Rösch Andreas , Rohr Maurice , Güney Gökhan , De Witte Luisa , Schwartz Elias , Hoog Antink Christoph
Published: September 2023

With the recent increase in interest in machine learning and computer vision, camera-based pose estimation has emerged as a promising new technology. One of the most popular libraries for camera-based pose estimation is MediaPipe Pose due to its computational efficiency, ease of use, and the fact that it is open-source. However, little work has been performed to establish how accurate the library is and whether it is suitable for usage in, for example, physical therapy. This paper aims to provide an initial assessment of this. We find that the pose estimation is highly dependent on the camera’s viewing angle as well as the performed exercise. While high accuracy can be achieved under optimal conditions, the accuracy quickly decreases when the conditions are less favourable.
Transmission of Vital Data into the German Electronic Health Record
Authors: Keil Alexander , Brück Rainer , Hahn Kai
Published: September 2023

Patient’s vital data will have an important role in future medicine. Best way to store this data is the patient’s electronic health record (EHR) in a structured form. In Germany, several laws, regulations and standards must be considered to store vital data in the health record, like SGB V, DIGAV and Medical Information Objects. In the near future, it will be possible to upload self-recorded vital data to the German EHR special smartphone apps. It will also be possible to automatically evaluate this data using machine learning.
Deep Semantic Segmentation of Cell Painted Nuclei Images using UNet++
Authors: Palliyil Sreekumar Sreelekshmi , Palanisamy Rohini , Swaminathan Ramakrishnan
Published: September 2023

Fluorescence microscopy based cell painting technique profiles the morphological characteristics of specific cell organelles with high resolution. However, photo toxicity, photo bleaching and advanced instrumentation limits its utility for comprehensively annotating the cell structure. Generating cell painted organelles from simple and least invasive transmitted light microscopy provides a surrogate for clinical applications. In this study, the employability of semantic segmentation model for delineating the nuclei from composite image using UNet++ is investigated. For this, a public dataset consisting of 3456 composite images are considered from Broad Bioimage Benchmark collection. The binary masks of endoplasmic reticulum (ER), nuclei and cytoplasm are generated for pixel wise labelling. The composite images and their labelled dataset are fed to the UNet++ model for segmenting the cell painted nuclei. The performance of the deep semantic network is analysed for 50 epochs and the segmentation results are validated with mean intersection-over-union (IoU). The UNet++model provides an accuracy of 95.8% with a minimum loss of 0.1. Mean IoU of 0.91 is achieved for the prediction of nuclei from the composite images. The obtained results suggest that this study could be employed for predicting the subcellular components from transmitted light microscopy without the use of fluorescent labelling.
Reduction of Uncertainty in Bolus Transit Time Measurement in Quantitative Fluorescence Angiography
Authors: Gao Yang , Weiß Miriam , Nahm Werner
Published: September 2023

During cerebral revascularization surgeries, blood flow values help surgeons to monitor the quality of the procedure, e.g., to avoid cerebral hyperperfusion syndrome due to excessively enhanced perfusion. The state-of-the-art technique is the ultrasonic flow probe that has to be placed around the blood vessel. This causes contact between probe and vessel, which, in the worst case, leads to rupture. The recently developed intraoperative indocyanine green (ICG) Quantitative Fluorescence Angiography (QFA) is an alternative technique that overcomes this risk. However, it has been shown by the developer that the calculated flow has deviations. After determining the bolus transit time as the most sensitive parameter in flow calculation, we propose a new two-step uncertainty reduction method for flow calculation. The first step is to generate more data in each measurement that results in functions of the parameters. Noise can then be reduced in a second step. Two methods for this step are compared. The first method fits the model for each parameter function separately and calculates flow from models, while the second one fits multiple parameter functions together. The latter method is proven to perform best by in silico tests. Besides, this method reduces the deviation of flow comparing to original QFA as expected. Our approach can be generally used in all QFA applications using two-point theory. Further development is possible if number of dimensions of the achieved parameter data are broadened that results in even more data for processing in the second step.
Resolution-based comparative analysis of 4D-phase-contrast magnetic resonance images and hemodynamic simulations of the aortic arch
Authors: Korte J. , Groschopp P. , Berg P.
Published: September 2023

Introduction: In this study, phase-contrast magnetic resonance imaging (PC-MRI) 4D flow data for patients with bicuspid aortic valve (BAV) were analyzed based on the spatial resolution of the images. BAV is a congenital heart defect characterized by the presence of two cusps in the aortic valve, leading to various complications. PC-MRI is a noninvasive imaging technique used to assess the hemodynamics in patients. However, interpretation of PC-MRI data can be challenging due to complex hemodynamics, which makes numerical simulations necessary to complement the results. Methods:Within this study PC-MRI 4D flow data in the aortic arch (AA) were compared with hemodynamic numerical simulations based on the MRI resolution for six patient-specific AAs with BAV. First, the segmentations were reconstructed and divided into three groups based on the resolution. Second, the numerical simulations were performed and resulting hemodynamics compared to PC-MRI results at three time points in the cardiac cycle using velocity and wall shear stress. Results: Results from group 1 (highest resolution) show an overestimation of wall shear stress (WSS) values during peaksystole in the three arteries and along the AA and descending aorta (DAo). Nevertheless, velocity mean values show an overall good agreement. Group 2 shows higher velocity magnitudes in the simulation than in PC-MRI. Within group 3, velocity values differ from the measurements. Conclusion: The study shows that with a low resolution, flow patterns can already be evaluated based on PC-MRI, but to get an insight into the flow quantitatively a higher resolution is necessary.
Quantitative ECG based emotion state recognition using Detrended Fluctuation Analysis
Authors: Anandan Meena , Veluswamy Pandiyarasan , Palanisamy Rohini
Published: September 2023

Wearable emotion recogniton system is essential in identifying mental health disorders by early detection and continuous monitoring of human emotions to provide proper treatment care. Electrocardiogram (ECG) signals can be used for emotion recognition for its noninvasiveness and easy usability. In this study, Detrended Fluctuation Analysis (DFA) and Extreme Gradient Boost (XG Boost) classifier is used to classify the scary and boring emotion from the ECG signals. For this, ECG signal corresponding to these emotions are obtained from public database. The preprocessing is performed by adding the video IDs to the signal and annotating it. This preprocessed signal is subjected to DFA to understand the power-law correlations and similarity property. Further, from the power law correlations, features namely Hurst exponent and DFA intercept are extracted. These features are subjected to XG Boost classifier to differentiate the two emotions. Results shows that the log-log plot of power law correlation is linear in nature which indicates that ECG signals of both the emotions have long range correlations and self-similarity property. The extracted scaling exponent indicates variations between scary and boring with a mean and standard deviation of 0.81±0.13 and 0.68±0.07 respectively. Similarly, DFA intercept provides mean and standard deviation for scary and boring 0.15±0.06 and 0.17±0.07 respectively, showing less variability in the ECG signal. XG Boost classifier gives accuracy of 80.5% for classifying scary and boring emotion. Thus, the proposed approach can be used for wearable emotion recognition system to differentiate scary and boring emotion.
Investigation of the antiadhesive properties of biomimetic titanium nanostructures in fluidic flow
Authors: Kremer Lea , Falk Fabian , Hüschelrath Litsy , Doll Patrick
Published: September 2023

Within this work, the bacterial adhesion on biomimetic titanium nanostructures is investigated in fluidic flow. The motile, gram-negative bacteria strain Escherichia coli was used for the experiments and was incubated on nanostructured titanium, polished titanium and on the wings of the dragonfly Neuorbasis kaupi. After incubation period different flow velocities have been applied and the reduction of adhered bacteria was determined via fluorescence microscopy. Results show that nanostructured titanium surfaces have the ability to reduce the bacterial contamination as it is for the dragon fly wings used in this study. This behavior can also be predicted by analyzing the bearing area of the nanotopography which describes the actual part of the topography which is in contact to the bacteria.
Evaluating thermal properties and activation energy of phthalonitrile using sulfur-containing curing agents
Authors: Lee Joon Hyuk , Jeon Eunkyung , Song Jung-kun , Son Yujin , Choi Jaeho
Published: September 2023

This work used the Kissinger equation to compute the activation energy of phthalonitrile to observe thermal properties. We initiated our investigation by synthesizing phthalonitrile samples, incorporating sulfur-containing curing agents ranging from 2 to 10%. Energy-dispersive X-ray spectroscopy confirmed the success of the curing process. Subsequently, we used thermogravimetric analysis (TGA) to acquire the necessary dataset for input into the Kissinger equation. The TGA results pointed to a direct relationship between the concentration of the curing agent and the thermal stability of the samples. Specifically, a sample treated with a 2% sulfur-containing curing agent demonstrated a moderate thermal stability (Td5%: 527.11°C). However, samples treated with higher concentrations of the curing agent, namely, 5 and 10%, exhibited increased Td5% values of 532.75 and 540.01°C, respectively. The increased thermal degradation-onset temperatures suggest a boost in the cross-linking density and mechanical properties, a result of the increased curing agent concentration. Further substantiating these findings, the Kissinger equation yielded high activation energies of 43.6222, 46.1365, and 67.9515 kcal·mol−1 for the 2, 5, and 10% curing agent dosages, respectively, with R² values ranging from 0.9650 to 0.9701.
The crystal structure of ethyl 4-hydroxy-2-(4-methoxyphenyl)-5-oxo-1-(2-oxo-2H-chromen-6-yl)-2,5-dihydro-1H-pyrrole-3-carboxylate, C23H19NO7
Authors: Chakraborty Bimal Bhushan , Paul Saurav , Anwar Siddique , Choudhury Sudip
Published: September 2023

C23H19NO7, monoclinic, P21/n (no. 14), a = 17.9964(9) Å, b = 5.9211 Å, c = 18.8608(10) Å, β = 98.201(3)°, V = 1989.23(18) Å3, Z = 4, R

gt
(F) = 0.0496, wR

ref
(F
2) = 0.1561, T = 296 K.
Design and optimization of a TiO2/RGO-supported epoxy multilayer microwave absorber by the modified local best particle swarm optimization algorithm
Authors: Karami Mohammad Reza , Jaleh Babak , Eslamipanah Mahtab , Nasri Atefeh , Rhee Kyong Yop
Published: September 2023

Microwave absorbers have many applications in medical, industrial, and military devices. Polymeric composites including carbon-based filler can be used as lightweight absorbers with high electromagnetic (EM) wave absorption performance. Hence, multilayer microwave absorbers were designed using titanium dioxide (TiO2)/reduced graphene oxide (RGO)/epoxy nanocomposites with different weight percentages manufactured using refluxing and annealing methods. The characterization of nanocomposite indicated thin layers of TiO2/RGO as divided sheets in epoxy. The EM properties of the nanocomposites were examined using the Nicolson-Ross-Weir (NRW) detection method. The S-parameters were measured using PNA-N5222A Microwave Network Analyzer. The multilayer absorber software was designed based on the modified local best particle swarm optimization algorithm by MATLAB software, in which the material and thickness of layers were optimized with two cost functions in X-band frequencies. The first cost function seeks to reach the best absorption bandwidth, and the second cost function seeks to reach the maximum average return loss (RL) of the frequency range of 8.2–12.4 GHz. A maximum bandwidth with an RL of less than −12.81 dB was obtained with a thickness of 2.4 mm. A maximum average RL of −22.1 dB was obtained with a thickness of 2.6 mm. The maximum absorption peak was observed with a thickness of 2.5 mm with −62.82 dB at a frequency of 10.86 GHz.
IMPLEMENTACIÓN DEL LABORATORIO H5P PARA EJERCITAR LA CREACIÓN DE CONTENIDO DIGITAL EN EL PROFESORADO UNIVERSITARIO
Authors: Diaz Rodas Samuel
Published: September 2023

Introducción: la competencia en creación de contenido digital ha caído en un nivel entre básico e intermedio que aparenta imposibilidad de pasar a un nivel avanzado. El propósito del presente estudio fue implementar un laboratorio H5P para el fortalecimiento de dicha competencia en el profesorado universitario UNAH. Metodología: mediante un enfoque cuantitativo de tipo descriptivo, se identificó el nivel de autopercepción que tiene el profesorado en torno a dos dimensiones: creación de contenido digital y reelaboración y creación de objetos virtuales de aprendizaje (OVA). Asimismo, el laboratorio H5P se construyó mediante un Modelo ADDIE y la fase de diseño con Modelo de Cascada. Resultados: se obtuvieron de una muestra de 25 docentes en la cual se observa para ambas dimensiones un nivel de desarrollo básico A1. No obstante, competencias específicas como los procesadores de texto y el uso de presentaciones poseen un nivel intermedio. Discusión: por otro lado, se determinó que el Modelo ADDIE es eficaz para el proceso de estructuración y organización de contenidos. Asimismo, el diseño bajo un Modelo de Cascada resultó ser eficiente para proyectos pequeños por su simplicidad y facilidad para identificar fortalezas y debilidades en los pasos secuenciales del Laboratorio H5P. Concluciones: al considerar la herramienta H5P para la creación de OVA en el marco de fortalecer la competencia en creación de contenido digital, se puede establecer un proceso de formación específico (teórico-práctico) que ayude a alcanzar los mejores niveles competenciales en el profesorado universitario.
DETERMINATION OF PESTICIDE RESIDUES IN POMEGRANATES GROWN IN ANTALYA AND HEALTH RISK ASSESSMENT
Authors: BALKAN Tarık , YILMAZ Özlem
Published: September 2023

Pesticide residues were screened in samples collected from pomegranate orchards in Antalya, Türkiye, and the health risks of such residues for consumers were assessed in this study. Analytical method verification was conducted to determine 260 pesticide residues by liquid chromatography-tandem mass spectrometry (LC–MS/MS). A total of 54 pomegranate samples were analyzed using this method. Ten of pomegranate samples contained pesticide residues above European Union Maximum Residue Limits (EU-MRLs). Both buprofezin and tebuconazole were detected in two of these samples, acetamiprid in three, tebuconazole in two, deltamethrin in two, and chlorpyrifos in one. In the risk assessment, deltamethrin has the potential for chronic toxicity for consumers, and chlorpyrifos shows both acute and chronic toxicity risks.
Post-ovulatory aging affects mitochondria, spindle and protein metabolism in mouse oocytes
Authors: Zhang Chuanxin , Dong Xueqi , Yuan Xinyi , Song Jinzhu , Wang Jiawei , Yin Xiaoyu , Hou Zhenzhen , Li Cheng , Ma Shuiying , Chen Zi-Jiang , Wu Keliang
Published: September 2023

In brief

Post-ovulatory aging (POA) results in a decline in oocyte quality and embryonic developmental capacity although the underlying mechanisms remain elusive. This study provides comprehensive mRNA expression profiles of fresh and aging oocytes in mice for the first time.

POA impairs the quality of mammalian oocytes with harmful effects on the developmental potential of the embryo. This is a major problem for humans since it is associated with low rate of natural fertility, with high rate of spontaneous abortion and low efficiency of in vitro fertilization. However, the molecular mechanisms underlying this process remain unclear and new methods are demanded to control POA. In this study, we performed single-cell RNA-sequencing (scRNA-seq) analysis on fresh and aging MII mouse oocytes and compared their global RNA transcription patterns. Nine hundred and twenty-one differentially expressed genes (DEGs) were identified. Five hundred and sixty-nine genes were downregulated, while 356 were upregulated in the group of aging oocytes. Gene ontology (GO) enrichment analysis demonstrated that a series of DEGs were significantly enriched involving mitochondrial functions, spindle functions and protein metabolism. The results of qPCR and a series of functional tests further confirmed that the disorder of mitochondrial functions, spindle functions and impairment of protein metabolism were actually involved in the progression of POA. In this study, panoramic mRNA expression profiles of fresh and aging oocytes were depicted and fully validated. Our data will provide a useful resource for further research on the regulation of gene expression of POA and suggest potential strategies to delay and reverse POA.
Algal biomass extract as mediator for copper oxide nanoparticle synthesis: Applications in control of fungal, bacterial growth, and photocatalytic degradations of dyes
Authors: Alsalamah Sulaiman A. , Alghonaim Mohammed Ibrahim , Mohammad Abeer M. , Abdel Ghany Tarek M.
Published: September 2023

Recently, algae have attracted the attention of investigators as a renewable source of compounds that can contribute to nanoparticle creation. The use algae biomass to facilitate preparation of copper oxide nanoparticles (CuONPs), as well as their application, were the aims of the present study. High performance liquid chromatography analysis of algal biomass indicated the presence of daidzein (2550 µg/mL), followed by ellagic acid (596 µg/mL). Algal biomass extract was successful as a bio-reducing agent for CuONPs fabrication at different temperatures up to 50 °C. Transmission electron microscopy characterized the created CuONPs with average size 5 to 17 nm. The colony radius of M. anisopliae, T. harzianum, C. lunata, F. oxysporium, A. flavus, and A. terreus was 1.84 ± 0.08, 1.97 ± 0.03, 1.00 ± 0.08, 2.04 ± 0.03, 2.32 ± 0.06, and 2.42 ± 0.05 cm, respectively at 200 mg of CuONPs. CuONPs exhibited inhibition zones of 26, 23, 25, and 22 mm when tested against B. subtilis, E.coli, K. pneumoniae, and S. aureus, respectively. Methyl orange and methyl green dyes were degraded by CuONPs with percentages ranging from 9.5 to 63.7% and from 22.3 to 75.7% at 15 to 90 min, respectively. Therefore, the created CuONPs can be regarded as excellent candidates for controlling fungal/bacterial development and dyes degradation.
Converting and its effects on barrier properties of coated packaging materials: A Review
Authors: Lev Roman , Tanninen Panu , Lyytikäinen Johanna , Leminen Ville
Published: September 2023

Considerable research is ongoing, examining opportunities for substituting plastic packaging with more sustainable alternatives, and some encouraging results have been achieved. Coated paper and paperboard demonstrate promising performance; however, several serious drawbacks still need to be overcome. Recent research in this area is reviewed in the current work, including mechanical and machinery aspects of paperboard converting, as well as barrier properties of coated materials before and after processing. The main objective of the study was to establish how coated paperboard behaves during converting operations and investigate what changes in its properties occur, considering not only the convertibility of the material as a whole but also effects on substrates and coatings. The results of the literature review show that creasing, folding, and the presence of forming stresses severely damage barrier and pigment coatings even if the paperboard-based product is reported as having good oxygen and water vapour barrier or oil resistance after production. Thus far, most materials cannot fully match the performance of plastic packaging materials due to a noticeable reduction in barrier properties after converting. The work presents factors linking the convertibility of coated materials and their subsequent barrier properties as valuable knowledge to support future development of sustainable materials.