Search Results (38)

The ability of computer simulations to model airflows in a tunnel can significantly contribute to the effectiveness of fire safety precautions. This study examines two ways of modelling the Polana tunnel (Slovakia) and its influence on the airflow created via longitudinal ventilation using a fire dynamics simulator. The first class of studied models is based on the assumption that the airflow in the tunnel is influenced to a large extent by the supporting structures and other installations under the tunnel ceiling. Due to the resolution of the computational grid, the constructions are modelled using a system of cuboids distributed along the tunnel at regular distances. The second class of models combines this approach with the previous one, in which tunnel drag is modelled by increased roughness of the tunnel walls. Unlike the previous model, the roughness values are not constant but reflect the curvature of the tunnel walls. The simulations results are compared against on-site measurements during a full-scale ventilation test conducted in 2017 by a grid of five anemometers, as well as with the results of the previous model. The results agree well with the experimental data with relative errors below 2% for bulk velocities and with mean absolute percentage deviations of 3, 6, and 10% for velocities measured using individual grid anemometers for three ventilation modes. The new models achieve several improvements in accuracy compared to the previous one. Full article

This work will review and discuss the use of computerised X-ray tomography (CXT) for analysing ancient, manufactured items, like stone building materials, glass and ceramics. It will consider particular techniques required, and/or of benefit, for CXT of heritage materials, such as special precautions during the experimentation to ensure there is no damage to the materials, special imaging methods such as elemental-specific imaging, and sample-specific image analysis requirements. This study shows how the knowledge of internal features, particularly pores, discerned from CXT can be used to reverse engineer the artefact fabrication process. CXT can be used to obtain information on both the raw materials (such as types and impurities) and fabrication techniques used. These abilities can then be used to establish technological evolution and the incidence of ancient behaviours like recycling and allow the linking of particular items to specific production sites. It will also be seen how CXT can aid the development of effective conservation techniques. This work will also consider how conclusions drawn from CXT data can be amended or augmented by the use of complementary non-destructive characterisation methods, such as gas overcondensation. Full article

Providing patients with accurate and organized information about colonoscopy, while reducing anxiety, is critical to the procedure’s success. This study evaluated the impact of an immersive 360° virtual reality (VR)-based educational intervention for first-time adult colonoscopy patients regarding anxiety, attitudes, knowledge, compliance with bowel preparation, and bowel cleanliness. A quasi-experimental design with a non-equivalent control group and non-synchronized pretest–post-test clinical trial was conducted with 40 patients in the experimental group and 40 in the control group. The 360° VR intervention included two sessions: precautions before colonoscopy and the colonoscopy process. The control group received education through individual verbal explanations with written materials. The findings indicated that the VR intervention significantly improved patients’ colonoscopy-related anxiety, attitudes, adherence to bowel preparation instructions, and bowel cleanliness. Utilizing 360° VR as an educational tool has the potential to enhance the effectiveness of educational programs by providing realistic information and engaging patients. These findings suggest that 360° VR has the capacity to enhance screening rates and clinical outcomes by reducing negative perceptions associated with colonoscopy. Furthermore, the application of this method can extend to diverse diagnostic testing-related nursing situations in clinical settings. Full article

Supervisory Control and Data Acquisition (SCADA) systems, which play a critical role in monitoring, managing, and controlling industrial processes, face flexibility, scalability, and management difficulties arising from traditional network structures. Software-defined networking (SDN) offers a new opportunity to overcome the challenges traditional SCADA networks face, based on the concept of separating the control and data plane. Although integrating the SDN architecture into SCADA systems offers many advantages, it cannot address security concerns against cyber-attacks such as a distributed denial of service (DDoS). The fact that SDN has centralized management and programmability features causes attackers to carry out attacks that specifically target the SDN controller and data plane. If DDoS attacks against the SDN-based SCADA network are not detected and precautions are not taken, they can cause chaos and have terrible consequences. By detecting a possible DDoS attack at an early stage, security measures that can reduce the impact of the attack can be taken immediately, and the likelihood of being a direct victim of the attack decreases. This study proposes a multi-stage learning model using a 1-dimensional convolutional neural network (1D-CNN) and decision tree-based classification to detect DDoS attacks in SDN-based SCADA systems effectively. A new dataset containing various attack scenarios on a specific experimental network topology was created to be used in the training and testing phases of this model. According to the experimental results of this study, the proposed model achieved a 97.8% accuracy rate in DDoS-attack detection. The proposed multi-stage learning model shows that high-performance results can be achieved in detecting DDoS attacks against SDN-based SCADA systems. Full article

Ozone-based chemiluminescence detection (CLD) has been widely applied for determining nitric oxide (^•NO) and its derived species in many different fields, such as environmental monitoring and biomedical research. In humans and animals, CLD has been applied to determine exhaled ^•NO and ^•NO metabolites in plasma and tissues. The main advantages of CLD are high sensitivity and selectivity for quantitative analysis in a wide dynamic range. Combining CLD with analytical separation techniques like chromatography allows for the analytes to be quantified with less disturbance from matrix components or impurities. Sampling techniques like microdialysis and flow injection analysis may be coupled to CLD with the possibility of real-time monitoring of ^•NO. However, details and precautions in experimental practice need to be addressed and clarified to avoid wrong estimations. Therefore, using CLD as a detection tool requires a deep understanding of the sample preparation procedure and chemical reactions used for liberating ^•NO from its derived species. In this review, we discuss the advantages and pitfalls of CLD for determining ^•NO species, list the different applications and combinations with other analytical techniques, and provide general practical notes for sample preparation. These guidelines are designed to assist researchers in comprehending CLD data and in selecting the most appropriate method for measuring ^•NO species. Full article

Throughout the world, emerging barriers in river systems block longitudinal connectivity for migrating fish, causing significant impacts by precluding them from carrying out vital life cycle activities. Fishways are still the main mitigation solution implemented, where barrier removal is not feasible. Within the multiple technical fish passage devices, the vertical slot fishway (VSF) is considered the most reliable. Early design guidelines, established for cyprinids, indicate that the volumetric dissipation power (P_v) in the pools should be P_v < 150 Wm⁻³, while most frequent slope values range from 10 to 12%. In this study, an experimental approach was conducted to question and debate the validity of these recommendations. For this, the Iberian barbel (Luciobarbus bocagei, Steindachner, 1864) passage performance was assessed in a full-scale fishway that exceeded P_v design guidelines, under different configurations. These varied in discharge (Q) and mean pool water depth (h_m): VSF1 (Q = 81 Ls⁻¹; h_m = 0.55 m); VSF2 (Q = 110 Ls⁻¹; h_m = 0.80 m); and the same design was equipped with a deep notch: DN1 (Q = 71 Ls⁻¹; h_m = 0.55 m); DN2 (Q = 99 Ls⁻¹; h_m = 0.80 m). The slope was set to 15.2% while the head drop per pool was Δh = 0.28 m, which generated a P_v that ranged from 222 in VSF1 to 187 Wm⁻³ in DN2. Passage behaviour was assessed using PIT telemetry and time-to-event analysis to evaluate the barbel upstream passage using standardized metrics: (i) motivation (ii) ascend success, and (iii) transit time. The hydrodynamic scenarios experienced by fish were characterized through a numerical model using computational fluid dynamics (CFD). The results, contrary to what was expected, showed a higher performance in VSF1 confirmed by the ascent analysis and transit time. Although no differences were found in fish motivation, the results indicate that larger fish displayed lower times to perform the first passage attempt. The CFD results show that, although maximum velocities and turbulence (turbulent kinetic energy (TKE) and Reynolds shear stress (RSS)) do not change significantly between configurations, their distribution in the pools is quite different. Regarding TKE, larger volumes with magnitudes higher than 0.05 m²s⁻² were notorious in both DN1 and DN2 configurations compared to VSF1, influencing passage efficiency which is in line with the ascent and transit time metrics results. Overall, the present research undeniably debates the literature design guidelines and reinforces the need to jointly assess species-specific fish passage criteria and fishway hydrodynamics, whereas precaution should be taken when using very general recommendations. Full article

Background: Adipokinetic hormones (AKHs) regulate important physiological processes in insects. AKHs are short peptides with blocked termini and Trp in position 8. Often, proline occupies position 6. Few post-translational modifications have been found, including hydroxyproline ([Hyp⁶]) and kynurenine. Our recent data suggest that the Hyp- and Kyn-containing AKHs occur more often than originally thought and we here investigate if they are natural or artifactual. Methods: From crude extracts of the corpora cardiaca (CC) of various insect species, AKHs were analyzed using liquid chromatography coupled to high-resolution mass spectrometry (LC-MS). Synthetic [Hyp⁶]-AKHs were tested in an in vivo metabolic assay. Freshly dissected Periplaneta americana and Blaberus atropos CCs (with precautions taken against oxidation) were analyzed. B. atropos CC were placed into a depolarizing saline and the released AKHs were measured. Results: Hyp was detected in several decapeptides from cockroaches. The modified form accompanied the AKH at concentrations below 7%. The [Hyp⁶]-AKHs of B. atropos were present in fresh CC preparations and were shown to be releasable from the CC ex vivo. Synthetic [Hyp⁶]-containing peptides tested positively in a hypertrehalosemic bioassay. Hydroxyprolination was also detected for Manto-CC from the termite Kalotermes flavicollis and for Tetsu-AKH of the grasshopper, Tetrix subulata. Oxidized Trp-containing forms of Nicve-AKH were found in species of the burying beetle genus Nicrophorus. Conclusions: Trp oxidation is known to occur easily during sample handling and is likely the reason for the present findings. For hydroxyprolination, however, the experimental evidence suggests endogenous processes. Full article

Background: Operating rooms (ORs) are healthcare areas that are high-risk regarding patient safety (PS). The prevention of PS errors such as wrong-site surgery, medication errors, and patient falls is important in the OR. Causes such as having insufficient information, not taking enough care and precautions, and inattention may lead to errors. Ensuring PS in an organization depends on the composition of a PS culture. Method: This study, as equivalent-control-group pretest–posttest research, aimed to develop and apply a simulation-based patient safety education program for operating room nurses and then to examine the influence of the program on patient safety management and compliance. Participants included a total of 45 operating room nurses: 22 in the experimental group and 23 in the control group. In the program, each member of the experimental and control groups underwent two 60 min sessions for a total of 120 min. Person-to-person individual lectures and simulation-based practice were provided to the experimental group, whereas booklets and person-to-person individual lectures were provided to the control group. Compliance with patient safety, the perception of patient safety culture, and satisfaction were measured using a structured Likert questionnaire. Intervention effects were analyzed using a t-test and ANCOVA. Results: As a result of the analysis, we found that the experimental group was significantly higher in terms of compliance with patient safety (p = 0.021), the perception of patient safety culture (p = 0.039), and education satisfaction (p < 0.001) than the control group. Conclusions: The results indicate that implementing a simulation-based patient safety education program can improve the patient safety competency of operating room nurses and, ultimately, prevent patient safety accidents in the operating room. Full article

(1) Background: According to the World Health Organization (WHO), 6.3 million intrauterine fetal deaths occur every year. The most common method of diagnosing perinatal death and taking early precautions for maternal and fetal health is a nonstress test (NST). Data on the fetal heart rate and uterus contractions from an NST device are interpreted based on a trace printer’s output, allowing for a diagnosis of fetal health to be made by an expert. (2) Methods: in this study, a predictive method based on ensemble learning is proposed for the classification of fetal health (normal, suspicious, pathology) using a cardiotocography dataset of fetal movements and fetal heart rate acceleration from NST tests. (3) Results: the proposed predictor achieved an accuracy level above 99.5% on the test dataset. (4) Conclusions: from the experimental results, it was observed that a fetal health diagnosis can be made during NST using machine learning. Full article

Erythrocyte deformability, crucial for oxygen delivery to tissues, plays an important role in the etiology of various diseases. As the factor maintaining the erythrocyte deformability, nitric oxide (NO) has been identified. Reduced NO bioavailability also plays a role in the pathogenesis of hypertension. Our aim was to determine whether aging and hypertension affect erythrocyte deformability and NO production by erythrocytes in experimental animals divided into six groups according to age (7, 20 and 52 weeks), labeled WKY-7, WKY-20 and WKY-52 for normotensive Wistar-Kyoto (WKY) rats, and SHR-7, SHR-20 and SHR-52 for spontaneously hypertensive rats (SHR). The filtration method for the determination of erythrocyte deformability and the fluorescent probe DAF-2 DA for NO production were applied. Deformability and NO production by erythrocytes increased at a younger age, while a decrease in both parameters was observed at an older age. Strain-related differences in deformability were observed at 7 and 52 weeks of age. SHR-7 had reduced deformability and SHR-52 had increased deformability compared with age-matched WKY. Changes in NO production under hypertensive conditions are an unlikely primary factor affecting erythrocyte deformability, whereas age-related changes in deformability are at least partially associated with changes in NO production. However, an interpretation of data obtained in erythrocyte parameters observed in SHRs of human hypertension requires precaution. Full article

Power and energy efficiency are among the most crucial requirements in high-performance and other computing platforms. In this work, extensive experimental methods and procedures were used to assess the power and energy efficiency of fundamental hardware building blocks inside a typical high-performance CPU, focusing on the dynamic branch predictor (DBP). The investigation relied on the Running Average Power Limit (RAPL) interface from Intel, a software tool for credibly reporting the power and energy based on instrumentation inside the CPU. We used well-known microbenchmarks under various run conditions to explore potential pitfalls and to develop precautions to raise the precision of the measurements obtained from RAPL for more reliable power estimation. The authors discuss the factors that affect the measurements and share the difficulties encountered and the lessons learned. Full article

As major projects such as nuclear power plants continuously increase, it is inevitable that loopholes will arise in safety precautions. Airplane anchoring structures, comprising steel joints and acting as a key component of such a major project, directly affect the safety of the project due to their resistance to the instant impact of an airplane. Existing impact testing machines have the limitations of being unable to balance impact velocity and impact force, as well as having inadequate control of impact velocity; they cannot meet the requirements of impact testing for steel mechanical connections in nuclear power plants. This paper discusses the hydraulic-based principle of the impact test system, adopts the hydraulic control mode, and uses the accumulator as the power source to develop an instant loading test system suitable for the entire series of steel joints and small-scale cable impact tests. The system is equipped with a 2000 kN static-pressure-supported high-speed servo linear actuator, a 2 × 22 kW oil pump motor group, a 2.2 kW high-pressure oil pump motor group, and a 9000 L/min nitrogen-charging accumulator group, which can test the impact of large-tonnage instant tensile loading. The maximum impact force of the system is 2000 kN, and the maximum impact rate is 1.5 m/s. Through the impact testing of mechanical connecting components using the developed impact test system, it was found that the strain rate of the specimen before failure was not less than 1 s⁻¹, meeting the requirements of the technical specifications for nuclear power plants. By adjusting the working pressure of the accumulator group, the impact rate could be controlled effectively, thus providing a strong experimental platform for research in the field of engineering for preventing emergencies. Full article

Epidural and intrathecal routes are the most effective drug administration methods for pain management in clinical and experimental medicine to achieve quick results, reduce required drug dosages, and overcome the adverse effects associated with the oral and parenteral routes. Beyond pain management with analgesics, the intrathecal route is more widely used for stem cell therapy, gene therapy, insulin delivery, protein therapy, and drug therapy with agonist, antagonist, or antibiotic drugs in experimental medicine. However, clear information regarding intrathecal and epidural drug delivery in rats and mice is lacking, despite differences from human medicine in terms of anatomical space and proximity to the route of entry. In this study, we discussed and compared the anatomical locations of the epidural and intrathecal spaces, cerebrospinal fluid volume, dorsal root ganglion, techniques and challenges of epidural and intrathecal injections, dosage and volume of drugs, needle and catheter sizes, and the purpose and applications of these two routes in different disease models in rats and mice. We also described intrathecal injection in relation to the dorsal root ganglion. The accumulated information about the epidural and intrathecal delivery routes could contribute to better safety, quality, and reliability in experimental research. Full article

This study aims to compare the shaping efficiency of the nickel–titanium instrument systems, One Reci and ProTaper Ultimate, using micro-CT (micro-computed tomography) in traditional and conservative endodontic access cavities. The experimental groups were formed according to the type of access cavity and Ni–Ti file system to be used. Sixty mandibular molar teeth were randomly divided into two main groups, the conservative access cavity (CAC) group and the traditional access cavity (TAC) group, and randomly divided into two subgroups according to the file system. The groups were compared with a two-way ANOVA analysis in terms of volume change, surface area, non-instrumented area transportation, and thickness of the dentin in the danger zone area after root canal preparation. The groups showed no statistically significant differences in terms of volume change, surface area, or the thickness of the dentin in the danger zone area after root canal preparation (p > 0.05). However, in the percentage of non-instrumented areas post-instrumentation between groups, the percentage of non-instrumented areas was statistically higher in specimens with CAC compared to TAC (p < 0.05). Canal transportation was higher in CAC at all distances from the apical region (p < 0.05). Within the limitations of this study, CAC can also be used with some precautions as an alternative to TAC. Full article

Fetal arrhythmias complicate 1% of pregnancies. Although most of them have a benign and intermittent course, sustained fetal tachyarrhythmias constitute an emerging situation, which is associated with high fetal morbidity and mortality. However, one of the major milestones in fetal therapy is the pharmacologic management of fetal arrhythmias by crossing the placental barrier. To date, there is no consensus on the first-line antiarrhythmic treatment for fetal tachyarrhythmias. The role of sotalol in therapeutic management, the use of flecainide versus digoxin as first line of treatment, the need for fetal intramuscular treatment administration, or the best treatment in case of fetal hydrops are situations whose application or management are controversial. The current paper is a scoping review of observational and experimental evidence, addressing the types of best management strategies for each type of tachyarrhythmia and the optimal pharmacological dose, considering precautions and safety elements. Finally, we will highlight new therapeutic perspectives and future diagnostic and therapeutic strategies. Full article