bluuebunny/crossref_metadata_2025 huggingface dataset:
Surgical Phase Recognition for different hospitals
Authors: Wisotzky Eric L. , Renz-Kiefel Lasse , Beckmann Sophie , Lünse Sebastian , Mantke René , Hilsmann Anna , Eisert Peter
Published: September 2023

Surgical phase recognition is an important aspect of surgical workflow analysis, as it allows an automatic analysis of the performance and efficiency of surgical procedures. A big challenge for training a neural network for surgical phase recognition is the availability of training data and the large (visual) variability in procedures of different surgeons. Hence, a network must be able to generalize to new data. In this paper, we present an adaptation of a Temporal Convolutional Network for surgical phase recognition in order to ensure the generalization of the network to new scenes with different conditions on the example of cholecystectomy. We used publicly available datasets of 104 surgeries from four different centers for training. The results showed that the network was able to generalize to new scenes and we obtained recognition results with accuracy up to 82% on our own six captured surgeries, performed in a different hospital. This performance is similar for test data from the hospitals of the training data, suggesting that the network can well generalize to new surgical rooms and surgeons. The findings have important implications for the development of automated surgical decision support systems that can be applied in a variety of real-world surgical settings.
A fully automated normothermic machine perfusion system for kidney grafts supporting physiological motivated flow profiles
Authors: Wiartalla Marc , Berg Frederik , Kühn Jahn , Buglowski Mateusz , Bleilevens Christian , Kowalewski Stefan , Stollenwerk André
Published: September 2023

Research showed that the normothermic machine perfusion of kidneys can enable prolonged storage and improve conditions compared to traditional cold storage. For research in this area, there is a demand for a long-term in vitro perfusion setup. In this work, we present a fully automated normothermic machine perfusion (NMP) system as an experimental research platform. The perfusion system is intended as a tool for researching the effects of different perfusion strategies on the kidney. To enable the automation, the NMP system consists of a blood pressure control, a circulation volume level control and a pH-regulation component. The setup is realized as a medical cyber-physical system consisting of networked embedded microcontroller nodes.
Validation of Skin Perfusion Monitoring by Imaging PPG versus Laser Speckle Imaging
Authors: Fleischhauer Vincent , Adrians Jasmin , Zaunseder Sebastian
Published: September 2023

Assessment of skin perfusion can reveal signs of deterioration and help to prevent critical states. Commonly applied clinical tests to capture skin perfusion are subjective and often hard to quantify. Laser speckle contrast analysis (LASCA) is a technique that can capture skin perfusion at high spatial and temporal resolution. LASCA requires, however, a complex setting and is not suited for monitoring under clinical conditions. Imaging photoplethysmography (iPPG) might be an easy to use alternative. However, direct comparisons of LASCA and iPPG, and thus proves of iPPG’s capabilities to capture skin microperfusion, are rare. In this work, we compare the longitudinal development of the amplitude of green channel and near-infrared iPPG and LASCA after application of a hyperemic test. Our results show statistically significant increases in amplitude over time in all modalities. The maximum increase in median normalized amplitude is 1.281 for the green channel, 0.594 for near-infrared and 1.111 for LASCA. Median Spearman’s rank correlation coefficient of the amplitude for green channel and LASCA is r= 0.89 and r= 0.71 for near-infrared and LASCA.
Assessing the impact of a structural prior mask on EIT images with different thorax excursion models
Authors: Chen Rongqing , Battistel Alberto , Krueger-Ziolek Sabine , Chase James Geoffrey , Rupitsch Stefan J. , Moeller Knut
Published: September 2023

Electrical Impedance Tomography (EIT) has shown promising results as a low-cost imaging method for visualizing ventilation distribution within the lungs. However, clinical interpretation of EIT images is often hindered by blurred anatomical alignment and reconstruction artifacts. Integrating structural priors into the EIT reconstruction process has the potential to enhance the interpretability of the EIT images. Thus, a patient-specific structural prior mask is introduced in this contribution, which restricts the reconstruction of conductivity changes within the lung regions.We conducted numerical simulations on four finite element models representing four different thorax excursions to investigate the impact of the structural prior mask on EIT images. Simulations were performed under four different ventilation statuses. EIT images were reconstructed using the Gauss-Newton and discrete cosine transform-based EIT algorithms.We conducted a quantitative analysis using figures of merit to evaluate the images of the two reconstruction algorithms. The results show the structural prior mask preserves the morphological structures of the lungs and limits reconstruction artifacts.
Fallopian tube occlusion – anatomical ex vivo studies in advance of preclinical in vivo models for future microstent-based therapeutic concept evaluation
Authors: Stahnke Thomas , Dierke Ariane , Strübing Julia , Khaimov Valeria , Rosam Paula , Kruse Christine , Stiehm Michael , Wree Andreas , Muzzio Damián , Normann Nicole , Bock Andrea , Siewert Stefan , Schmitz Klaus-Peter , Zygmunt Marek
Published: September 2023

An unfulfilled pregnancy is often due to impaired patency of the female Fallopian tubes. To circumvent tubal obstruction, cost-intensive in vitro fertilisation (IVF) is currently indicated. The only therapeutic treatment concepts available are transvaginal tubal lavage/catheterization or laparoscopy with minimally invasive or complex surgical tubal reconstruction, which are associated with side effects. The development of new and cost-effective non- or minimally invasive therapeutic concepts that can restore the patency of the Fallopian tubes would be key in the treatment of female infertility and can fulfil the desire to have children. Therefore, in the present work, ex vivo anatomical studies are carried out on various laboratory mammals (pigs, rabbits, guinea pigs). Using these animal models, it was also evaluated whether a sensor-ureterorenoscope can be inserted through the whole female reproductive tract to the Fallopian tubes. This device will be used for endoscopically guided implantation of a novel tubal microstent prototype via its tailor-made delivery system into the isthmus region of the Fallopian tubes in upcoming studies. This work serves to identify an optimal species for a longitudinal animal study, in which the feasibility as well as the tissue reaction to the implant will be evaluated.
Unsupervised GAN epoch selection for biomedical data synthesis
Authors: Böhland Moritz , Bruch Roman , Löffler Katharina , Reischl Markus
Published: September 2023

Supervised Neural Networks are used for segmentation in many biological and biomedical applications. To omit the time-consuming and tiring process of manual labeling, unsupervised Generative Adversarial Networks (GANs) can be used to synthesize labeled data. However, the training of GANs requires extensive computation and is often unstable. Due to the lack of established stopping criteria, GANs are usually trained multiple times for a heuristically fixed number of epochs. Early stopping and epoch selection can lead to better synthetic datasets resulting in higher downstream segmentation quality on biological or medical data. This article examines whether the Frechet Inception Distance (FID), the Kernel Inception Distance (KID), or the WeightWatcher tool can be used for early stopping or epoch selection of unsupervised GANs. The experiments show that the last trained GAN epoch is not necessarily the best one to synthesize downstream segmentation data. On complex datasets, FID and KID correlate with the downstream segmentation quality, and both can be used for epoch selection.
Domain Transfer in Histopathology using Multi-ProtoNets with Interactive Prototype Adaptation
Authors: Kletzander Rosalie , Kuritcyn Petr , Bruns Volker , Eckstein Markus , Geppert Carol , Hartmann Arndt , Benz Michaela
Published: September 2023

Few-shot learning addresses the problem of classification when little data or few labels are available. This is especially relevant in histopathology, where labeling must be carried out by highly trained medical experts. Prototypical Networks promise transferability to new domains by using a pre-trained encoder and classifying by way of a prototypical representation of each class learned with few samples. We examine the applicability of this approach by attempting domain transfer from colon tissue (for training the encoder) to urothelial tissue. Furthermore, we address the problems arising from representing a class via a small amount of representatives (prototypes) by testing two different prototype calculation strategies. We compare the original “Prototype per Class” (PPC) approach to our “Prototype per Annotation” (PPA) method, which calculates one prototype for each example annotation made by the pathologist. We test the domain transfer capability of our approach on a dataset of 55 whole slide images (WSIs) containing six subtypes of urothelial carcinoma in two granularities: “Superclasses”, which combines the tumorous subtypes into a single “tumor” class on top of a aggregated “healthy” and additional “necrosis” class, and “subtypes”, which considers all eleven classes separately. We evaluate the classic PPC approach as well as our PPA approach on this data set. Our results show that the adaptation of the Prototypical Network from colon tissue to urothelial tissue was successful, yielding an F1 score of 0.91 for the “superclasses”. Furthermore, the PPA approach performs very comparably to the PPC strategy. This makes it a viable alternative that places more value on the intent of the pathologist during annotation.
Comparison of steady-state and transient flow measurements for the characterization of paravalvular leakage of transcatheter-aortic valve prostheses
Authors: Kaule Sebastian , Stiehm Michael , Siewert Stefan , Öner Alper , Schmitz Klaus-Peter , Borowksi Finja
Published: September 2023

Severe aortic valve stenosis has been successfully treated with minimally invasive transcatheter aortic valve replacement (TAVR) for more than 20 years. The therapy is applied to an increasing cohort of patients. Nevertheless, paravalvular leakage (PVL) remains one of the main complications after TAVR implantation reducing safety and efficacy of the implant. To improve TAVR performance, virtual patient cohorts can be used to generate a significant amount of data with biologically varying conditions comparable to clinically realworld data. For this purpose, in silico models need to be established which are used to evaluate the possible occurrence of PVL. When establishing in silico models, the question between simplification to reduce computational effort and still valid information from the model must always be clarified. Thus, we investigated the comparability between steadystate and transient PVL measurements as an input parameter for simulations in virtual cohorts. A clinically established TAVR was implanted into different annulus models and tested in a steady-state back-flow test bench and in a pulse duplicator system. As a result, leakage rates were compared and assumptions for the in silico models were derived. Although the trend of PVL is comparable in steady-state and transient conditions, absolute values differ making it difficult to extract generalized assumptions. Especially when PVL increased, e.g. in a larger implantation diameter or in an imperfect annulus, the variation also increased up to 50% of the measured value.
Evaluation of flushing parameters for clear view vascular endoscopy
Authors: Böckmann Julian , Klebingat Stefan , Schwab Roland , Behme Daniel , Boese Axel
Published: September 2023

Vascular diseases like aneurysms or atherosclerosis belong to the leading causes of death. For diagnosis and treatment, medical imaging is essential. Standard imaging methods are Ultrasound, X-ray-based Angiography, Computed tomography or Magnet Resonant Imaging. Additionally, Intravascular Ultrasound or Optical Coherence Tomography are available for intravascular imaging. One imaging technique for direct investigation of the inner vessel is vascular endoscopy, also called angioscopy. It is based on the insertion of an optical endoscope into the blood vessel for direct imaging. Dependent on the vessel diameter, these endoscopes have to be very small. Angioscopy can provide valuable information about the condition of the vessel wall and serve for procedure observation or implant assessment. But angioscopy requires the absence of blood for a clear field of view. In prior research, we have already developed methods for the placement of a tiny optical fiber inside a catheter combination. As an essential step toward a clinical study, we now want to evaluate the flushing parameters needed to achieve a clear field of view for the endoscope. The parameters are affected by the blood flow and vessel diameter. We designed a test setup that allows angioscopic examination and the simulation of realistic conditions, such as blood flow and different vessel diameters and that includes a test pattern for image quality assessment.
Training and education of young physicians and engineers in the field of endoscopy and laparoscopy – a review of Germany-wide joint cooperation and training possibilities
Authors: Wichmann Dörte , Duckwort-Mothes Benedikt , Hirt Bernhard , Wilhelm Dirk , Steger Jana , Zweimüller Martin , Küllmer Armin , Raithel Martin , Maiss Jürgen , Pott Peter , Wittenberg Thomas
Published: September 2023

Introduction: Application-related (hands-on) training and instruction is an essential component in the advanced education of physicians in residency. To teach and train required endoscopic examinations and interventions in a standardized manner, courses are offered by various societies. Within these courses the assistant endoscopists learn and train how to use the technical equipment and how to perform the examinations and related interventions. Similarly, for graduate biomedical engineering students with a job- or research-related interest in the field of endoand laparoscopy, an early involvement and practical introduction to the instrumentation and techniques - if possible already during their studies - can generate a fundamental understanding of the technical requirements as well needs of the physicians. Objective: As various such (hands-on) training-courses for flexible and rigid endoscopy specifically addressing young physicians, surgeons as well as engineers are offered by numerous institutes, this contribution tries do provide a structured overview on/over these possibilities. Material: Known cross-institutional courses in the field of endo- and laparoscopy currently offered in Germany in cooperation of physicians and engineers are listed and briefly described. Results: A total of n = 4 crossinstitutional courses for the introduction and training in flexible and rigid endoscopy have been identified. Discussion: The cross-institutional courses for physicians and technicians in the field of endo- and laparoscopy presented serve to provide a better understanding of the subject matter and the field of either discipline. Questions that arise in the field of endoscopy from physicians can be addressed at an early stage and, if necessary, worked on with little effort. Ideas for new instruments and even new interventions can arise and be pursued through an intensive exchange between technicians and physicians. Collaborations are established on a local basis which will foster national activities in this field and which allow to develop competencies relevant for the industrial sector of medical engineering.
Towards AI-driven minimally invasive needle interventions
Authors: Spiller Moritz , Esmaeili Nazila , Sühn Thomas , Boese Axel , Friebe Michael , Turial Salmai , Illanes Alfredo
Published: September 2023

The overall complication rate during laparoscopic access is estimated to be as high as 14 %. Surgeons have to rely heavily on their experience and haptic perception while inserting the Veress needle or a trocar into the peritoneal cavity. Surgical Audio Guidance (SURAG) is a promising alternative to current techniques. It acquires instrument-born vibroacoustic (VA) waves to track the insertion of the instrument and provide real-time feedback to surgeons. This article presents an initial evaluation of the SURAG technology through two sets of experiments to classify Veress needle events using different AI-models. The results demonstrate the feasibility of using AI for classifying Veress needle events and the potential of the SURAG technology to support surgeons during laparoscopic access and minimally invasive needle interventions in general.
PCB Coil Enables In Situ Calibration of Magnetoelectric Sensor Systems
Authors: Wolframm Henrik , Hoffmann Johannes , Burgardt Ralf , Elzenheimer Eric , Schmidt Gerhard , Höft Michael
Published: September 2023

Accurate calibration is key for any reliable sensor system. Magnetoelectric (ME) sensors, in particular, are influenced in their operating point by external parameters such as the Earth’s magnetic field or the ambient temperature. In this paper, we introduce a new planar coil design for the generation of a magnetic test field within the plane of the ME sensor. Furthermore, we implemented a method for measuring the sensor behaviour using a short-term magnetic noise signal. The combination of the printed circuit board (PCB) coil and the accelerated sensor characterization method allows the sensor system to be calibrated at the measurement site (in situ) without the need for laboratory equipment. We can show that the presented method for calibration achieves high-quality results in 10 seconds for a sensor affected by external interference fields.
Modified Allen Test Assessment via Imaging Photoplethysmography
Authors: Kossack Benjamin , Wisotzky Eric L. , Schraven Sebastian , Skopnik Lotte , Hilsmann Anna , Eisert Peter
Published: September 2023

The modified Allen test (MAT) is a widely used tool to examine the perfusion capacities of the arteries (ulnar or radial) of the hand. In clinical practice, MAT is utilized to ensure that in the event of occlusion, remaining vessels guarantee sufficient hand perfusion. This work shows that perfusion assessment via imaging photoplethysmography (iPPG) can be used to assess MAT. We captured the hands of seven subjects with a standard RGB camera while performing a MAT. Out of these captured video recordings, the iPPG signal was extracted via plane-orthogonal-to-skin transformation. Based on these extracted signals, we derive the heart rate, signal-to-noise ratio, DC parameter, and correlation with a reference iPPG signal to determine if an Allen test was pathological or inconspicuous. For all seven subjects, the results of our MAT assessment were identical to the medical expert’s assessment. This paper presents a procedure and initial thresholds for objectively evaluating and quantifying MAT.We show how globally and locally calculated parameters can be used to assess the perfusion of the investigated hand. This analysis makes it possible to quantify the exact point in time when the perfusion is again sufficient. If a reperfusion problem occurs, we are able to localize the spatial regions of occurrence. The presented hardware setup is affordable and can be easily installed and used in every doctor’s office.
Scalable mesh microelectrode arrays for neural spheroids and organoids
Authors: Stumpp Tom , Mierzejewski Michael , Pascual Domenic , Stumpf Angelika , Jones Peter D.
Published: September 2023

Introduction: Neural organoids promise to help understand the human brain and develop treatments for neurological diseases. Electrophysiological recordings are essential in neural models to evaluate the activity of neural circuits. Mesh microelectrode arrays (MEAs) have been demonstrated to be suitable for organoids and spheroids, and there is demand for easy-to-use devices that can be manufactured at scale. Methods: We present a new mesh MEA device with an easyto- use design. We produce mesh MEA chips on 100 mm carrier wafers and connect individual chips to PCBs by wirebonding. The devices are completed by assembly of a twopiece well and a glass cover slip. Results: Each device contains a suspended hammock-like mesh with 64 microelectrodes. The square grid’s pitch of 200 μm makes the mesh suitable for typical organoid sizes while spreading the electrodes across a 1.4 mm region. The well is designed for fluid handling by pipetting or pump systems. Impedance measurements indicate a high yield of functional microelectrodes, although further effort is needed to produce consistent low impedances. The devices are compatible with commercial amplifiers, while adaptation of the PCB to other formats will be straightforward. Conclusions: Using scalable production methods, we have developed a mesh MEA device design that offers improved ease-of-use. Next steps will include biological validation in collaboration with partners.
Using Hydrogel Beads as a Blood Model in Optical Coherence Tomography
Authors: Hentschel Gesine , Weiß Miriam , Hoffmann Simon , Nahm Werner , Glasmacher Birgit
Published: September 2023

Optical Coherence Tomography (OCT) is a standard imaging procedure in ophthalmology. OCT Angiography is a promising extension, allowing for fast and non-invasive imaging of the retinal vasculature analyzing multiple OCT scans at the same place. Local variance is examined and highlighted. Despite its introduction in the clinic, unanswered questions remain when it comes to signal generation. Multiphase fluids like intralipid, milk-water solutions and human blood cells were applied in phantom studies shedding light on some of the mechanisms. The use of hydrogel beads allows for the generation of alternative blood models for OCT and OCT Angiography. Beads were produced in Hannover, their size was measured and their long term stability was assessed. Then, beads were shipped to Karlsruhe, where OCT imaging resulted in first insights. The hydrogel acts as a diffusion barrier, which enables a clear distinction of bead and fluid when scattering particles were added. Further on, the scattering medium below the bead showed increased signal intensity. We conclude that the inside of the bead structure shows enhanced transmission compared to the plasma substitute with dissolved TiO2 surrounding it. Beads were found clumped and deformed after shipping, an issue to be addressed in further investigations. Nevertheless, hydrogel beads are promising as a blood model for OCT Angiography investigations, offering tunable optical parameters within the blood substitute solution.
Radial compliance of porcine Fallopian tubes ex vivo – perspectives for the development of a gynecological microstent
Authors: Siewert Stefan , Dierke Ariane , Stahnke Thomas , Großmann Swen , Brandt-Wunderlich Christoph , Supp Laura , Rosam Paula , Stiehm Michael , Bock Andrea , Zygmunt Marek , Schmitz Klaus-Peter
Published: September 2023

Fallopian tube occlusions represent one of the most common causes of female sterility. As an innovative treatment approach for affected persons, we previously presented the concept of a novel polymeric, self-expanding, and bioresorbable microstent. As a basis for microstent development, knowledge of the mechanical properties of the anatomical target structure represents a crucial requirement. The current work describes a methodological approach for the experimental determination of radial Fallopian tube compliance using optical coherence tomography. It could be shown that a quantitative assessment of the mechanical properties of porcine Fallopian tube samples - as a whole anatomical structure including the Tunica mucosa, the Tunica muscularis, and the Tunica serosa - is possible, using the described test setup. Future investigations on human samples will allow for valuable information regarding the structural-mechanical properties of the Fallopian tube. Therefore, the current work offers perspectives for the development of a novel gynecological microstent for the treatment of Fallopian tube occlusions.
A comparison of two CNN-based instrument detection approaches for automated surgical assistance systems
Authors: Bajraktari Flakë , Fleissner Kathrin , Pott Peter P.
Published: September 2023

The shortage of operating room technicians has led to a growing demand for automated systems in the OR to maintain the quality of care. Robotic scrub nurse (RSN) systems are increasingly being developed, which perform tasks such as handling instruments and documenting the surgery. While research has focused on detecting instruments in the hands of surgical staff or recognizing surgical phases, there is a lack of research on detecting instruments on the instrument tray. Therefore, this study proposes and evaluates two distinct methodologies for instrument detection on the OR table using the deep learning approaches YOLOv5 and Mask R-CNN. The performance of the two approaches has been evaluated on 18 YOLOv5 models and twelve Mask R-CNN models, mainly differing in model size. Two sets of instruments were used to assess generalizability of the models. The results show a mean average precision (mAP) score of 0.978 for YOLOv5 and 0.846 for Mask R-CNN on the test dataset comprising three classes. An mAP of 0.874 and 0.707 have been computed respectively for the test dataset including six classes. The study provides a comparison of the performance of two suitable approaches for instrument detection on the instrument tray in the OR to enhance the development of RSN systems.
Centriselect – A novel approach for centrifugal cell separation
Authors: Behrens Stephan , Hähne Philipp , Schmieder Peter , Schmieder Florian
Published: September 2023

The separation of bio-suspensions, such as blood, is of great interest for many biomedical applications, such as the extraction of leucocytes from whole blood, the laboratory analysis of specific cells or a mixed cell suspensions from bioreactors or the preparation of cellular products for cellbased therapy. In particular, mechanical separation processes have been established for the rapid separation of biosuspensions. The principle of mechanical separation is based on the specific density of the particles or the particle size. Thus, the corresponding processes are based on centrifugation and/or filtration. The standard process to prepare blood products from whole blood donations contains several steps. First the blood is separated into different phases by centrifugation and then further separated by filters containing specific filtration layers. The shortcomings of this process is the low yield due to bio-particles remaining in the filter and the high costs for equipment due to the use of multiple devices for centrifugation and filtration. Here we present the proof of principle of an adaptive, size-selective filter that addresses the above mentioned shortcomings. The filter is designed to combine the filtration and centrifugation process within one step. Therefore a novel filtration device was designed that can be used within a standard centrifugation tube. During centrifugation, the centrifugal force changes the filtration coefficient of the filter. This can be used to separate different sized of bio-particles at different centrifugation speeds. Moreover, the cells that were hold back in the filter can be removed afterwards by increasing the centrifugation speed. In this way, the filter is created to gradually release cells of a specific size yielding in a high purity of different cell fractions.
Core-Shell-Nanoparticles with Superparamagnetic Properties for Novel Applications as Biomaterials
Authors: Hagemann Valentin , Finck Laura , Herrmann Timo , Menzel Henning , Ehlert Nina
Published: September 2023

Due to the increasing average age of the population, the number of implants is also increasing and with it the number of explantations. Therefore, facilitated implant removal is of great interest. A nanocomposite consisting of superparamagnetic core-shell nanoparticles (CSNPs) and a synthetic polymer is supposed to be used as implant coating, aiming for a stimulus-inducible modification of the composite’s rheological properties by hyperthermia. Here, the first steps following this concept, the synthesis and modification of the CSNP are reported. In this work magnetite nanoparticles build the core and are surrounded by a periodic mesoporous organisilica (PMO) shell. For this reason, the CSNP are referred to as magnetic PMO (mPMO) particles in the following.
Acoustic Emission Analysis (AEA) in unilateral leg amputees as a future quality tool in orthopaedic technology to evaluate the adjusted prosthesis in relation to gonarthritis
Authors: Subke Joerg , Keller Adeline , Hermawan Hermawan , Schmeiler Michael , Schneider Benedict , Schwalbe Hans-Joachim
Published: September 2023

In orthopaedic technology unilateral leg amputees are provided with prosthesis which are attached through a shaft to the remaining part of the leg. The prosthesis legs are built according to manufacturer’s specifications and get adjusted to the individual needs through motion analysis. If the prosthesis is not adjusted correctly to the individual needs of the user, the chance for development of arthritis in the remaining knee joint is greatly increased. The goal of this paper is to develop a procedure based on AEA to detect signs of arthritis in the remaining knee joint early and the base of a procedure for a future assessment of the quality of the care. The measurement system consists of the AEA - measurement device, a force plate to measure ground reaction forces, two strain gauges which are attached to handles on a test rig and two video cameras which record the movement from frontal and sagittal view. The amputee performs a standard movement in the test rig which consists of three knee bends in ten seconds while wearing the prosthesis legs. The test rig is provided so the amputee can support themselves using arms and hands as prosthesis’ support during the extension phase of the knee bend. The posture and load of the knee joint during the movement is analyzed with the video and force data. The ground reaction forces show the load distribution between the remaining leg and the prosthesis and its support during the movement. The hand forces give clues how well the amputee can balance and which arm is favored under load. By combining kinematic data and AEA the state of the load transfer zones can be evaluated. Thus, it’s possible to examine the remaining knee joint for defects and evaluate the quality of the prosthesis adjustment.
The effect of fiber content and aspect ratio on anisotropic flow front and fiber orientation for injection-molded fiber composites
Authors: Tseng Huan-Chang
Published: September 2023

In state-of-the-art predictive engineering software for injection molded fiber composites, it is challenging to discuss the effect of fiber properties, including fiber content and aspect ratio, on the shell-core fiber orientation and anisotropic flow front. Recently, the flow-fiber coupled model of informed isotropic (IISO) viscosity was proposed for simulating the realistic flow-induced fiber orientation. At present, one attempts to improve the IISO viscosity in relation to fiber content and aspect ratio. Therefore, injection molding simulations of 30 wt% and 50 wt% short glass fiber-reinforced Polyamide66 (30 wt% SGF/PA66 and 50 wt% SGF/PA66) are performed in the IISO flow-fiber couple 3D-FVM (three-dimensional finite volume method) computation under the fixed aspect ratio of a

r
 = 20. As a result, the predicted fiber orientation distributions are in good agreement with related experimental data, while the core width is increased with fiber contents. In addition, the anisotropic ear flow occurs at the higher content. Based on shear viscosity of 30 wt% SGF/PA66, one can directly alter fiber content as 50 wt% SGF/PA66 in the IISO computation to anticipate the reliable trend of fiber orientation and flow behavior. When the a

r
 = 20 short fiber is lengthened as the a

r
 = 50 long fiber, the core obviously becomes the wider. It is significant to investigate the difference between the decoupled and coupled computation, as well as the influence of the flow-fiber coupled and fiber orientation model parameters.
Experimental studies on water absorption and mechanical properties of Hibiscus
sabdariffa (Roselle) and Urena
lobata (Caesar weed) plant Fiber–Reinforced hybrid epoxy composites: effect of weight fraction of nano-graphene fillers
Authors: Sasi Kumar Mani , Sathish Selvaraj , Makeshkumar Mani , Gokulkumar Sivanantham
Published: September 2023

This study aimed to develop novel hybrid composites with graphene (Gr) fillers incorporated in the epoxy (E) matrix with Caesar weed fiber (CF), and roselle fiber (RF) as reinforcements. Compression molding methods were used to fabricate hybrid composite materials with a variable-weight graphene filler in a constant fiber epoxy matrix. On the basis of the results, the mechanical characteristics of the composite with 6 wt% Gr exhibited the greatest flexural strength, tensile strength, and impact strength. This occurred because 6 wt% Gr particles are more uniformly dispersed in an epoxy matrix, resulting in better compatibility between reinforcementand matrix, thus increasing the mechanical properties. The composite with 8 wt% Gr filler reinforcement had the maximum hardness rating and the lowest percentage of water absorption. According to the results, adding graphene fillers to the CF/RF/E composite significantly improved the mechanical and water absorption performances. Scanning electron microscopy was used to examine the surfaces of the fabricated samples. The weight fraction of the graphene filler was optimized to enhance the mechanical properties of the composite for use in various engineering applications, such as automobile, defense, marine, sports, and musical instruments.
Can preoperative neopterin levels predict acute kidney injury in patients undergoing on-pump cardiac surgery?
Authors: Çiçek Ömer Faruk , Akyürek Fikret , Akbayrak Hakan , Orhan Atilla , Kaya Eyüp Cihan , Büyükateş Mustafa
Published: September 2023

Objectives

The aim of this study was to investigate the potential of preoperative neopterin levels as a predictive marker for postoperative acute kidney injury (AKI) in patients undergoing on-pump cardiac surgery, in addition to other potential risk factors.

Methods

This observational study included 91 patients who underwent elective cardiac surgery under cardiopulmonary bypass. Of these, 35 patients (38.46 %) experienced AKI following surgery, as outlined by the Kidney Disease Improving Global Outcomes (KDIGO) standards. The study participants were divided into two groups depending on whether they had developed AKI after the surgery or not. The study compared two groups and utilized logistic regression analysis to evaluate potential predictors. A receiver operating characteristic (ROC) analysis was conducted to determine the ability of preoperative neopterin levels to predict the occurrence of AKI.

Results

A comparison of the baseline demographic, clinical, laboratory, and echocardiographic characteristics was conducted between patients who suffered from AKI and those who did not. The multivariate analysis demonstrated that EuroSCORE II (OR, 4.525; 95 % CI, 1.29–15.87; p=0.019), X-clamp time (OR, 1.157; 95 % CI, 1.01–1.326; p=0.035), and neopterin levels (OR, 22.952; 95 % CI, 3.14–167.763; p=0.002) were independently predicted the post-cardiac surgery AKI. ROC analysis identified a cut-off value of 9.65 nmol/L, which had a sensitivity of 91.4 % and a specificity of 91.1 % (area under the curve, 0.98; 95 % CI, 0.958–1; p<0.001).

Conclusions

Our study emphasizes the potential of preoperative neopterin levels, EuroSCORE II, and X-clamp time as independent predictors of postoperative AKI, even in milder cases, in individuals undergoing on-pump cardiac surgery.
Millennials y Generación X frente a la realidad del big data y la protección de datos personales en internet
Authors: Martín Herrera Inmaculada , Guerrero Caballero Mercedes
Published: September 2023

Las gestiones telemáticas que se desarrollan en entornos colaborativos constituyen hoy en día procesos cotidianos in crescendo. Su ejecución implica la cesión de datos personales, que son almacenados por los organismos implicados, sin que, en la mayoría de los casos, los usuarios de estos servicios y plataformas puedan controlar el procesamiento y los usos que se hace de los mismos. En este contexto, la intención del presente estudio es indagar en las percepciones de la ciudadanía española mayor de edad en torno a la gestión de sus datos personales en el ciberespacio y su correlación con el big data. Igualmente, se pretende conocer cómo influyen en estas actitudes dos variables personales: el género y la edad, con objeto de determinar si existe una brecha entre hombres y mujeres, y entre los usuarios de dos generaciones poblacionales: los Millennials y la Generación X. Los datos fueron recabados mediante una escala Likert que consta de 20 ítems y que se administró a una muestra integrada por 344 personas. Por su parte, las pruebas para analizar esta información fueron un estudio descriptivo y un análisis de dependencia, que han permitido detectar discrepancias en los resultados en función de la edad. Los resultados concluyen que los usuarios demuestran un conocimiento exiguo sobre el concepto y el funcionamiento del big data; y manifiestan, por un lado, su interés por saber cómo se emplean sus datos y, por otro, su preocupación por verse implicados en problemas relacionados con su seguridad y con la comisión de ciberdelitos.
A Scoping Review of the Physiological Profiles of Motorsport Drivers: Implications for Athlete Training
Authors: Beaumont Patrick L. , van den Hoek Daniel , Holland Justin , Garrett Joel
Published: September 2023

Automotive racing is one of the most internationally recognized sports. Drivers within their respective disciplines are exposed to a variety of forces throughout the race, each of which is theorized to inflict a physiological adaptation within the driver. Therefore, the aim of this scoping review was to collate the evidence and provide a summary of the physiological profiles of these drivers and provide practitioners with recommendations to optimize these adaptations. Of the 1,304 articles screened, 24 met the inclusion criteria. Of the included studies, 13 reported on the anthropometric and physiological measures of 4-wheeled racing athletes from both open and closed-wheel disciplines. The remaining 11 studies reported on the physiological profiles of 2-wheeled racing athletes from both on-road and off-road riding disciplines. Open-wheel racers have greater cardiopulmonary fitness than close-wheel racers, as well as greater strength throughout movements of neck lateral flexion and isometric knee extension. Close-wheel racers were shown to be heavier with greater fat mass than the open-wheel racers but exhibited greater isometric shoulder flexion and plantarflexion strength. Female 2-wheeled racers were also shown to have a weaker handgrip strength than their male counterparts. Whereas male on-road riders demonstrated greater levels of handgrip strength than their off-road counterparts.
KOMBU ÇAYI ÜRETİMİNDE MUŞMULA (MESPILUS GERMANICA L.) KULLANIMININ ANTİOKSİDAN KAPASİTE VE BİYOERİŞİLEBİLİRLİK ÜZERİNE ETKİSİNİN ARAŞTIRILMASI
Authors: YILDIZ Elif , ÖZCAN SİNİR Gülşah , AYKAS Didem Peren , GÜRBÜZ Ozan
Published: September 2023

Kombu çayı, Kombu çayı kültüründe yer alan asetik asit bakterileri ve mayaların simbiyotik ilişkisi ile meydana gelen asetik asit ve alkol fermantasyonu ile karakterize olan ekşimsi-tatlımsı bir içecektir. Bu çalışmada sağlık açısından birçok faydası bulunan Kombu çayının biyoaktif potansiyelinin arttırılması hedeflenmiştir. Muşmula (Mespilus germanica L.) meyvesinin farklı oranlarda (%5, %10 ve %20) yeşil çaya katılmasını takiben gerçekleşen fermantasyon ile Kombu çayı hazırlanmıştır. Bu çaylar, antioksidan kapasite, toplam fenolik madde miktarı ve biyoerişilebilirlik açısından değerlendirilmiştir. Kombu çayı örneklerine ilave edilen muşmula oranının artması ile biyoaktif potansiyelin yükseldiği gözlemlenmiştir. %20 oranında muşmula ilavesi ile biyoerişilebilir fenolik fraksiyonların DPPH metoduna göre antioksidan kapasitesi 26.21±0.25 μmol TE/mL’den 38.54±0.08 μmol TE/mL’ye, toplam fenolik bileşen içeriği ise 42.83±1.02 mg GAE/100 mL’den 58.13±0.64 mg GAE/100 mL’ye yükselmiştir. Muşmula meyvesi ilavesi ile hazırlanan Kombu çayı hem yüksek biyoaktif içeriğe sahip bir içecek ortaya çıkartmış hem de yabani olarak yetişmekte olan muşmula meyvesinin endüstriyel kullanım alanını arttırma potansiyeli oluşturmuştur.
Mouse oocytes restore antral stage partial mechanical denudation in vitro
Authors: Herta Anamaria-Cristina , Akin Nazli , Segers Ingrid , Billooye Katy , Smitz Johan , Anckaert Ellen
Published: September 2023

In brief

Partially denuded mouse cumulus–oocyte complexes restore likely functional transzonal projections in culture, under meiotic inhibition, with no detectable impact on oocyte competence. This proof-of-concept study constitutes positive premises for improving the developmental competence of human capacitation (CAPA)–in vitro maturation (IVM) oocytes with inadequate somatic cell connections.

In vitro oocyte culture might be the sole option for fertility preservation in some patients. This relies on constant oocyte–somatic bidirectional communication, and its precocious disruption alters oocyte competence. In non-human chorionic gonadotropin-triggered human in vitro maturation (IVM), retrieval of cumulus–oocyte complexes (COCs) by needle aspiration from the targeted small follicles (2–8 mm) leads to the collection of some partially denuded (PD) COCs with poor developmental competence. Hypothetically, re-establishing connectivity in these COCs could rescue oocyte quality. To test this, we used a well-characterized mouse preantral follicle culture system. On day 8, at antral stage, in part of the follicles, the oocytes were mechanically denuded while in other follicles in vitro grown oocytes were replaced with age matched fully stripped in vivo grown ones. The denuded oocytes were cultured on top of the somatic compartment until day 12, when oocyte–somatic reconnection was assessed. Furthermore, to better mimic the current biphasic IVM setup, fully surrounded (FS) COCs were collected from 19- to 21- day-old unprimed mice. Following partial mechanical denudation, COCs were cultured under meiotic inhibition for 2–4 days, to test oocyte–cumulus cell (CC) reconnection. Meiotic and developmental competence endpoints were compared between reconnected and FS-cultured COCs. We concluded that (i) in vivo- and in vitro- grown antral oocytes reconnect with in vitro-grown somatic companions; (ii) PD–COCs restore the FS morphology in culture, under meiotic inhibition; and (iii) oocyte quality from reconnected and intact cultured COCs is comparable. These observations encourage translational work to rescue partially denuded oocytes in human IVM.
Communication in the Oil and Gas Industry
Authors: Pacheco Aline
Published: September 2023

This article aims to describe some features of communication in the oil and gas industry considering contributions from applied linguistics and Aviation English. Fostered by the need to have a picture of communication dynamics taking place in the proposed scenario, studies were conducted within the HF2 Project and were organized in three stages. Stage 1 revised accident reports to find out communication factors that could be associated with safety and help build a tentative version of a taxonomy based on the Taxonomy of Communication and Language factors in Aviation used for language analysis in aviation. Stage 2 comprehended interviews with workers from two different offshore operations so to assess metalinguistic information regarding a possible standardized language training and use during the performance of activities. Stage 3 encompassed in-loco data collection and analysis of linguistic information. Corpus Linguistics, Conversational Analysis, The Cooperative Principle, and the Taxonomy of Communication and Language factors in Aviation were some of the theoretical references that guided the analysis. The results presented are preliminary, yet significant, and show that procedural factors are outstanding when contemplating the possibility of miscommunication and, because of that, could be considered the core of a taxonomy. Additionally, metalinguistic data from the interviews show that there seems to be a standardized communicative behavior in the operations given the strict technical training to which the workers are submitted to. However, the misuse or non-use of certain lexical-morphological structures and strategies, and procedures could impact safety. In this line, the article also addresses some suggestions for optimized communication practices.
Rotavirus infection
Authors: Editorial Article
Published: September 2023

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Cora Diamond on Ethics (edited by Maria Balaska)
Authors: Just Amadeusz
Published: September 2023

Essay Review: Cora Diamond on Ethics (ed. Maria Balaska)
The impact of the ecological and climatic characteristics of the territory on the condition of the housing stock
Authors: Makarova Vera , Isaeva Irina
Published: September 2023

The relevance of the subject of the work lies in the analysis of external environmental factors affecting the state of residential development. This analysis is carried out on the example of the territory of Primorsky Krai, in dynamics from 2002 to 2020. In the paper, a primary analysis of environmental factors affecting residential development is carried out and the quantitative dynamics of these factors in the aspect of Primorsky Krai is studied. In the process of research, analysis of data on temperature changes in dynamics from 2002 to 2020. indicates an increase in the deviation from the average temperature in the cold season, which has an extremely negative effect on the state of residential development due to the risk of an increase in freezing and thawing cycles, which is standard when studying the quality of building materials, in particular cement and concrete. The industrial complex is the most developed part of the economy of Primorye. Yes, according to the Federal State Statistics Service, the largest sectors of industrial production are the food industry, electric power, engineering and metalworking, which account for more than 70 percent of the total industrial production. No direct relationship was found in terms of industrial production and emissions. Therefore, here it is better to expand the number of criteria in the analysis of this trend, in particular, to supplement with such indicators as the hazard classes of emitted substances, the composition of emissions, measures taken in the field of environmental protection and their economic component.
The purpose of this article is to analyze the environmental factors that affect the state of the housing stock, using the example of Primorsky Krai.