Protocol for manufacturing the GFRP sample using VARI applied to a modified complex Arcan fixture.

Manufacturing techniques play an essential role in obtaining optimum mechanical properties of composites. Vacuum-assisted resin infusion (VARI) is a composite fabrication approach for optimal fiber volume fraction. Here, we present a protocol for manufacturing glass fiber-reinforced polymer (GFRP) samples by applying VARI to a modified complex Arcan fixture. We describe steps for material preparation, molding preparation, setting vacuum system, resin mixing, and degassing. We then detail procedures for vacuum infusion process and cutting composites for shear testing samples. For complete details on the use and execution of this protocol, please refer to Alandro et al.1.

Load-displacement experimental data from shear loading of hybrid GFRP-graphite filler using a complex Arcan fixture.

This paper presents a dataset of load-displacement obtained from shear loading tests on pure GFRP laminates and hybrid GFRP-graphite filler laminates. The specimens were cut according to the ASTM D 7078 standard, and the width and thickness of the notch area were measured at least three times. Shear loading was applied at a rate of 2 mm/min, and data were recorded from unloading until specimen failure. The data provides information on the maximum load and unique behavior of GFRP laminates. Based on the obtained load, the shear stress (MPa) unit can be calculated. This data can serve as a basis for researchers and engineers working with GFRP laminates and hybrid GFRP-graphite filler laminates.

Linear versus Quadratic Detrending in Analyzing Simultaneous Changes in DC-EEG and Transcutaneous pCO2.

Physiological direct current (DC) potential shifts in electroencephalography (EEG) can be masked by artifacts such as slow electrode drifts. To reduce the influence of these artifacts, linear detrending has been proposed as a pre-processing step. We considered quadratic detrending, which has hardly been addressed for ultralow frequency components in EEG. We compared the performance of linear and quadratic detrending in simultaneously acquired DC-EEG and transcutaneous partial pressure of carbon dioxide during two activation methods: hyperventilation (HV) and apnea (AP). Quadratic detrending performed significantly better than linear detrending in HV, while for AP, our analysis was inconclusive with no statistical significance. We conclude that quadratic detrending should be considered for DC-EEG preprocessing.

Genotype variation of ACE and ACE2 genes affects the severity of COVID-19 patients.

OBJECTIVE: Genetic polymorphisms in ACE and ACE2 genes are involved in the RAS regulation of blood pressure and their activity may confer susceptibility to hypertension. In addition, they may play a role in SARS-CoV-2 pathogenesis and the severity of COVID-19. This study aims to determine the effect of genetic variations in the ACE (rs4331) and ACE2 (rs2074192) genes with hypertension comorbidity on the severity of COVID-19 in the Indonesian population. RESULT: 186 patients were enrolled and assigned into the COVID-19 group (n = 95) and non-COVID-19 group (n = 91) in this cross-sectional study. GG genotype frequency was dominant in ACE gene, but there were no significant differences between the groups (p = 0.163). The two groups had a significant difference (p = 0.000) for the CC genotype frequency (0,37 vs. 0.01) in the ACE2 gene. The proportion of women with COVID-19 is higher (51%), but men with hypertension had more severe symptoms (44%). Men with hypertension comorbidity, GG (ACE), and TT (ACE2) genotypes tended to have moderate-to-severe symptoms (25%). Similarly, women with hypertension as well as GG and CT genotypes tended to have moderate-to-severe symptoms (21%). We conclude that hypertension and mutations in the ACE (rs4331) and ACE2 (rs2074192) genes affect the severity of COVID-19.

Multi-Center Evaluation of Gel-Based and Dry Multipin EEG Caps.

Dry electrodes for electroencephalography (EEG) allow new fields of application, including telemedicine, mobile EEG, emergency EEG, and long-term repetitive measurements for research, neurofeedback, or brain-computer interfaces. Different dry electrode technologies have been proposed and validated in comparison to conventional gel-based electrodes. Most previous studies have been performed at a single center and by single operators. We conducted a multi-center and multi-operator study validating multipin dry electrodes to study the reproducibility and generalizability of their performance in different environments and for different operators. Moreover, we aimed to study the interrelation of operator experience, preparation time, and wearing comfort on the EEG signal quality. EEG acquisitions using dry and gel-based EEG caps were carried out in 6 different countries with 115 volunteers, recording electrode-skin impedances, resting state EEG and evoked activity. The dry cap showed average channel reliability of 81% but higher average impedances than the gel-based cap. However, the dry EEG caps required 62% less preparation time. No statistical differences were observed between the gel-based and dry EEG signal characteristics in all signal metrics. We conclude that the performance of the dry multipin electrodes is highly reproducible, whereas the primary influences on channel reliability and signal quality are operator skill and experience.

Regulated Monosyllabic Talk Test vs. Counting Talk Test During Incremental Cardiorespiratory Exercise: Determining the Implications of the Utterance Rate on Exercise Intensity Estimation.

Purpose: When utilizing breathing for speech, the rate and volume of inhalation, as well as the rate of exhalation during the utterance, seem to be largely governed by the speech-controlling system and its requirements with respect to phrasing, loudness, and articulation. However, since the Talk Test represents a non-standardized form of assessment of exercise intensity estimation, this study aimed to compare the utterance rate and the estimated exercise intensity using a newly introduced time-controlled monosyllabic Talk Test (tMTT) versus a self-paced Counting Talk Test (CTT) across incremental exercise stages and examined their associations with the exercise physiological measures. Methods: Twenty-four participants, 10 males and 14 females (25 ± 4.0 yr; 160 ± 10 cm; 62 ± 14.5 kg) performed two sessions of submaximal cardiorespiratory exercise at incremental heart rate reserve (HRR) stages ranging from 40 to 85% of HRR: one session was performed with a currently available CTT that was affixed to a wall in front of the participants, and the other session was conducted with a tMTT with a 1-s inter-stimulus interval that was displayed from a tablet. In each session, the participants performed six stages of exercise at 40, 50, 60, 70, 80, and 85% HRR on a treadmill and were also asked to rate their perceived exertion based on Borg's 6 to 20 Rating of Perceived Exertion (RPE) at each exercise stage. Results: The newly designed tMTT significantly delineated all the six stages of incremental exercise (p ≤ 0.017), while CTT could only delineate exercise stages at 60, 80, and 85% HRR. However, in estimations of exercise intensity, the tMTT demonstrated only moderate associations with HRR and Borg's RPE, similarly to the CTT. Conclusion: If the purpose of exercise monitoring is to detect the intensity of light, moderate, and vigorous exercise intensity, the tMTT could be more universally applicable. However, due to its larger variability of speech rate across exercise intensities, the time-regulated approach may alter the speech breathing characteristics of the exercising individuals in other ways that should be investigated in future research.

A high-density 256-channel cap for dry electroencephalography.

High-density electroencephalography (HD-EEG) is currently limited to laboratory environments since state-of-the-art electrode caps require skilled staff and extensive preparation. We propose and evaluate a 256-channel cap with dry multipin electrodes for HD-EEG. We describe the designs of the dry electrodes made from polyurethane and coated with Ag/AgCl. We compare in a study with 30 volunteers the novel dry HD-EEG cap to a conventional gel-based cap for electrode-skin impedances, resting state EEG, and visual evoked potentials (VEP). We perform wearing tests with eight electrodes mimicking cap applications on real human and artificial skin. Average impedances below 900 kΩ for 252 out of 256 dry electrodes enables recording with state-of-the-art EEG amplifiers. For the dry EEG cap, we obtained a channel reliability of 84% and a reduction of the preparation time of 69%. After exclusion of an average of 16% (dry) and 3% (gel-based) bad channels, resting state EEG, alpha activity, and pattern reversal VEP can be recorded with less than 5% significant differences in all compared signal characteristics metrics. Volunteers reported wearing comfort of 3.6 ± 1.5 and 4.0 ± 1.8 for the dry and 2.5 ± 1.0 and 3.0 ± 1.1 for the gel-based cap prior and after the EEG recordings, respectively (scale 1-10). Wearing tests indicated that up to 3,200 applications are possible for the dry electrodes. The 256-channel HD-EEG dry electrode cap overcomes the principal limitations of HD-EEG regarding preparation complexity and allows rapid application by not medically trained persons, enabling new use cases for HD-EEG.

Digitization and Analysis of Capnography Using Image Processing Technique.

The study of carbon dioxide expiration is called capnometry. The graphical representation of capnometry is called capnography. There is a growing interest in the usage of capnography as the usage has expanded toward the study of metabolism, circulation, lung perfusion and diffusion, quality of spontaneous respiration, and patency of airways outside of its typical usage in the anesthetic and emergency medicine field. The parameters of the capnograph could be classified as carbon dioxide (CO2) concentration and time points and coordinates, slopes angle, volumetric studies, and functional transformation of wave data. Up to date, there is no gold standard device for the calculation of the capnographic parameters. Capnography digitization using the image processing technique could serve as an option. From the algorithm we developed, eight identical breath waves were tested by four investigators. The values of the parameters chosen showed no significant difference between investigators. Although there were no significant differences between any of the parameters tested, there were a few related parameters that were not calculable. Further testing after refinement of the algorithm could be done. As more capnographic parameters are being derived and rediscovered by clinicians and researchers alike for both lung and non-lung-related diseases, there is a dire need for data analysis and interpretation. Although the proposed algorithm still needs minor refinements and further large-scale testing, we proposed that the digitization of the capnograph via image processing technique could serve as an intellectual option as it is fast, convenient, easy to use, and efficient.

Automatic segmentation of skin cells in multiphoton data using multi-stage merging.

We propose a novel automatic segmentation algorithm that separates the components of human skin cells from the rest of the tissue in fluorescence data of three-dimensional scans using non-invasive multiphoton tomography. The algorithm encompasses a multi-stage merging on preprocessed superpixel images to ensure independence from a single empirical global threshold. This leads to a high robustness of the segmentation considering the depth-dependent data characteristics, which include variable contrasts and cell sizes. The subsequent classification of cell cytoplasm and nuclei are based on a cell model described by a set of four features. Two novel features, a relationship between outer cell and inner nucleus (OCIN) and a stability index, were derived. The OCIN feature describes the topology of the model, while the stability index indicates segment quality in the multi-stage merging process. These two new features, combined with the local gradient magnitude and compactness, are used for the model-based fuzzy evaluation of the cell segments. We exemplify our approach on an image stack with 200 × 200 × 100  µm3, including the skin layers of the stratum spinosum and the stratum basale of a healthy volunteer. Our image processing pipeline contributes to the fully automated classification of human skin cells in multiphoton data and provides a basis for the detection of skin cancer using non-invasive optical biopsy.

A literature review on beneficial role of vitamins and trace elements: Evidence from published clinical studies.

COVID-19 is a kind of SARS-CoV-2 viral infectious pneumonia. This research aims to perform a bibliometric analysis of the published studies of vitamins and trace elements in the Scopus database with a special focus on COVID-19 disease. To achieve the goal of the study, network and density visualizations were used to introduce an overall picture of the published literature. Following the bibliometric analysis, we discuss the potential benefits of vitamins and trace elements on immune system function and COVID-19, supporting the discussion with evidence from published clinical studies. The previous studies show that D and A vitamins demonstrated a higher potential benefit, while Selenium, Copper, and Zinc were found to have favorable effects on immune modulation in viral respiratory infections among trace elements. The principles of nutrition from the findings of this research could be useful in preventing and treating COVID-19.

Pareto optimization for electrodes placement: compromises between electrophysiological and practical aspects.

Wearable electronics and sensors are increasingly popular for personal health monitoring, including smart shirts containing electrocardiography (ECG) electrodes. Optimal electrode performance requires careful selection of the electrode position. On top of the electrophysiological aspects, practical aspects must be considered due to the dynamic recording environment. We propose a new method to obtain optimal electrode placement by considering multiple dimensions. The electrophysiological aspects were represented by P-, R-, and T-peak of ECG waveform, while the shirt-skin gap, shirt movement, and regional sweat rate represented the practical aspects. This study employed a secondary data set and simulations for the electrophysiological and practical aspects, respectively. Typically, there is no ideal solution that maximizes satisfaction degrees of multiple electrophysiological and practical aspects simultaneously; a compromise is the most appropriate approach. Instead of combining both aspects-which are independent of each other-into a single-objective optimization, we used multi-objective optimization to obtain a Pareto set, which contains predominant solutions. These solutions may facilitate the decision-makers to decide the preferred electrode locations based on application-specific criteria. Our proposed approach may aid manufacturers in making decisions regarding the placement of electrodes within smart shirts.

Enriched Mechanical Strength and Bone Mineralisation of Electrospun Biomimetic Scaffold Laden with Ylang Ylang Oil and Zinc Nitrate for Bone Tissue Engineering.

Scaffolds supplemented with naturally derived materials seem to be a good choice in bone tissue engineering. This study aims to develop polyurethane (PU) nanofibers added with ylang ylang (YY) and zinc nitrate (ZnNO3) using the electrospinning method. Field emission scanning electron microscopy (FESEM) images showed that the diameter of the PU nanofibers (869 ± 122 nm) was reduced with the addition of YY and ZnNO3 (PU/YY-467 ± 132 nm and PU/YY/ZnNO3-290 ± 163 nm). Fourier transform infrared (FTIR), a thermal gravimetric analysis (TGA) and an X-ray diffraction (XRD) analysis confirmed the interactions between PU with YY and ZnNO3. In addition, a thermal gravimetric analysis (TGA) study revealed the improved thermal stability for PU/YY and a slight reduction in the thermal stability for PU/YY/ZnNO3. A tensile test indicated that the addition of YY and ZnNO3 (PU/YY-12.32 MPa and PU/YY/ZnNO3-14.90 MPa) improved the mechanical properties of the pristine PU (6.83 MPa). The electrospun PU/YY (524 nm) and PU/YY/ZnNO3 (284 nm) showed a reduced surface roughness when compared with the pristine PU (776 nm) as depicted in the atomic force microscopy (AFM) analysis. The addition of YY and ZnNO3 improved the anticoagulant and biocompatibility nature of the pristine PU. Furthermore, the bone mineralization study depicted the improved calcium deposition in the fabricated composites (PU/YY-7.919% and PU/YY/ZnNO3-10.150%) compared to the pristine PU (5.323%). Hence, the developed composites with desirable physico-chemical properties, biocompatibility and calcium deposition can serve as plausible candidates for bone tissue engineering.

Blood compatibility assessments of electrospun polyurethane nanocomposites blended with megni oil for tissue engineering applications.

Tissue engineering holds as a prominent technique to repair or replace the damaged human parts to recreate its native function. In this research, a novel scaffold based on polyurethane (PU) comprising megni oil was electrospun for tissue engineering applications. The obtained polyurethane blended with megni oil nanofibers were characterized by scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), contact angle measurement and atomic force microscopy (AFM). Furthermore, the blood compatibility of the fabricated nanocomposites evaluated through activated prothrombin time (APTT), partial thromboplastin time (PT) and hemolysis assay to determine the anticoagulant nature. The morphological results showed that the fabricated nanocomposites showed reduced fiber size (789 ± 143.106 nm) than the pristine control (890 ± 116.91 nm). The interaction between PU and megni oil was identified by the hydrogen bond formation evident in the FTIR. The incorporation of megni oil in the PU decreased the wettability behavior (113.3° ± 1.528) and improved the surface roughness (646 nm). Preliminary evaluation of blood compatibility assessments was carried out using APTT, PT and hemolysis assay revealed the enhanced antithrombogenicity nature of the fabricated nanocomposites than the PU. Hence, we conclude that the fabricated new nanocomposite membrane with desirable characteristics which might find potential application in the tissue engineering applications.

Predicting Down syndrome and neural tube defects using basic risk factors.

Congenital anomalies are not only one of the main killers for infants but also one of the major causes of deaths under 5. Among congenital anomalies, Down syndrome or trisomy 21 (T-21) and neural tube defects (NTDs) are considered the most common. Expectant mothers in developing countries may not have access to or may not afford the advanced prenatal screening tests. To solve this issue, this paper explores the practicality of using only the basic risk factors for developing prediction models as a tool for initial risk assessment. The prediction models are based on logistic regression. The results show that the prediction models do not have a high balanced classification rate. However, these models can still be used as an effective tool for initial risk assessment for T-21 and NTDs by eliminating at least 50% of the cases with no or low risk. Graphical Abstract Prenatal Risk Assessment of Trisomy-21 and Neural Tube Defects.

Effects of incremental cardiorespiratory exercise on the speech rate and the estimated exercise intensity using the counting talk test.

[Purpose] This study examined how incremental cardiorespiratory exercise may affect the speech rate and Counting Talk Test (CTT)-estimated exercise intensity. [Participants and Methods] Twenty-four healthy adults performed the CTT while exercising on a treadmill at 6 stages of incremental exercise ranging from 40% to 85% of heart rate reserve (HRR). Each participant started walking on the treadmill at 3 to 4 km/h and 0% elevation to warm up. The increments of treadmill grades were adjusted until targeted heart rates corresponding to the percentages of HRR were reached. Then, the participants were asked to rate their perceived exertion while the treadmill grades were maintained for 2-minutes bouts of each exercise stage. At the last minute of the exercise stage, the CTT was performed within a single breath. [Results] The speech rates in the CTT appeared to vary significantly during exercise. Moreover, the CTT-estimated exercise intensity showed significant reductions at several exercise stages. [Conclusion] The CTT estimates exercise intensity semi-quantitatively throughout incremental exercise. However, moderate and vigorous intensities could not be significantly delineated by the current CTT method. This could be due to the variability in speech rates that were indicated as the exercise progressed.

Towards Robot-Assisted Echocardiographic Monitoring in Catheterization Laboratories : Usability-Centered Manipulator for Transesophageal Echocardiography.

This paper proposes a robotic Transesophageal Echocardiography (TOE) system concept for Catheterization Laboratories. Cardiovascular disease causes one third of all global mortality. TOE is utilized to assess cardiovascular structures and monitor cardiac function during diagnostic procedures and catheter-based structural interventions. However, the operation of TOE underlies various conditions that may cause a negative impact on performance, the health of the cardiac sonographer and patient safety. These factors have been conflated and evince the potential of robot-assisted TOE. Hence, a careful integration of clinical experience and Systems Engineering methods was used to develop a concept and physical model for TOE manipulation. The motion of different actuators of the fabricated motorized system has been tested. It is concluded that the developed medical system, counteracting conflated disadvantages, represents a progressive approach for cardiac healthcare.

Fabrication and characterization of chitosan nanoparticles and collagen-loaded polyurethane nanocomposite membrane coated with heparin for atrial septal defect (ASD) closure.

Atrial septal defect (ASD) constitutes 30-40% of all congenital heart diseases in adults. The most common complications in the treatment of ASD are embolization of the device and thrombosis formation. In this research, an occluding patch was developed for ASD treatment using a well-known textile technology called electrospinning. For the first time, a cardiovascular occluding patch was fabricated using medical grade polyurethane (PU) loaded with bioactive agents namely chitosan nanoparticles (Cn) and collagen (Co) which is then coated with heparin (Hp). Fourier transform infrared spectrum showed characteristic vibrations of several active constituents and changes in the absorbance due to the inclusion of active ingredients in the patch. The contact angle analysis demonstrated no significant decrease in contact angle compared to the control and the composite patches. The structure of the electrospun nanocomposite (PUCnCoHp) was examined through scanning electron microscopy. A decrease in nanofiber diameter between control PU and PUCnCoHp nanocomposite was observed. Water uptake was found to be decreased for the PUCnCoHp nanocomposite against the control. The hemocompatibility properties of the PUCnCoHp ASD occluding patch was inferred through in vitro hemocompatibility tests like activated partial thromboplastin time (APTT), prothrombin time (PT) and hemolysis assay. It was found that the PT and APTT time was significantly prolonged for the fabricated PUCnCoHp ASD occluding patch compared to the control. Likewise, the hemolysis percentage was also decreased for the PUCnCoHp ASD patch against the control. In conclusion, the developed PUCnCoHp patch demonstrates potential properties to be used for ASD occlusion.

New Vertical Handover Method to Optimize Utilization of Wireless Local Area Network in High-Speed Environment.

In heterogeneous wireless networks, wireless local area network (WLAN) is highly preferred by mobile terminals (MTs) owing to its high transmission bandwidth and low access cost. However, in high-speed environment, handover from a cellular network to a WLAN cell will lead to a high number of handover failures and unnecessary handovers due to the WLAN coverage limitation and will become worse at high speed. A new vertical handover method is proposed to minimize the probability of handover failure and unnecessary handover while maximizing the usage of WLAN in high-speed environment. The simulation results show that the proposed method kept the probability of handover failure and unnecessary handover below 0.5% and 1%, respectively. Compared with previous studies, the proposed method reduced the number of handover failures and unnecessary handovers up to 80.0% and 97.7%, respectively, while the MT is highly mobile. Using the proposed prediction method, the MT can benefit high bandwidth and low network access cost from the WLAN with minimum interruption regardless of speed.

Antioxidant Activity and ROS-Dependent Apoptotic Effect of Scurrula ferruginea (Jack) Danser Methanol Extract in Human Breast Cancer Cell MDA-MB-231.

Scurrula ferruginea (Jack) Danser is one of the mistletoe species belonging to Loranthaceae family, which grows on the branches of many deciduous trees in tropical countries. This study evaluated the antioxidant activities of S. ferruginea extracts. The cytotoxic activity of the selected extracts, which showed potent antioxidant activities, and high phenolic and flavonoid contents, were investigated in human breast cancer cell line (MDA-MB-231) and non-cancer human skin fibroblast cells (HSF-1184). The activities and characteristics varied depending on the different parts of S. ferruginea, solvent polarity, and concentrations of extracts. The stem methanol extract showed the highest amount of both phenolic (273.51 ± 4.84 mg gallic acid/g extract) and flavonoid contents (163.41 ± 4.62 mg catechin/g extract) and strong DPPH• radical scavenging (IC50 = 27.81 µg/mL) and metal chelation activity (IC50 = 80.20 µg/mL). The stem aqueous extract showed the highest ABTS•+ scavenging ability. The stem methanol and aqueous extracts exhibited dose-dependent cytotoxic activity against MDA-MB-231 cells with IC50 of 19.27 and 50.35 µg/mL, respectively. Furthermore, the extracts inhibited the migration and colony formation of MDA-MB-231 cells in a concentration-dependent manner. Morphological observations revealed hallmark properties of apoptosis in treated cells. The methanol extract induced an increase in ROS generation and mitochondrial depolarization in MDA-MB-231 cells, suggesting its potent apoptotic activity. The present study demonstrated that the S. ferruginea methanol extract mediated MDA-MB-231 cell growth inhibition via induction of apoptosis which was confirmed by Western blot analysis. It may be a potential anticancer agent; however, its in vivo anticancer activity needs to be investigated.