Tube Position Research Articles

Modelling and numerical simulation of heat transfer and hydrodynamic performance of multi-pass parallel flow condensers – A novel algebraic method to determine flow distribution

In multi-pass parallel flow condensers (MPFCs), refrigerant flow maldistribution poses a significant challenge, deteriorating heat transfer performance. A robust flow distribution prediction method is crucial for the accuracy and applicability of an MPFC model. This study originally develops a new algebraic method to determine refrigerant distribution in tube-passes for MPFCs. This algorithm can be directly integrated with the authors' previously developed 2-D distributed-parameter model for MPFCs with liquid-vapor separation (MPFCs-LS). The novel algorithm applies to conditions where: 1) the inlet tube of the first tube-pass is positioned arbitrarily along the vertical inlet header, and 2) the mediate headers have or lack liquid-vapor separation. The new condenser models are validated by comparing the predicted results with the experimental data of an MPFC and an MPFC-LS. The predicted heat transfer capacity and pressure drop show deviations within ±5% and ±35%, respectively. Results also reveal that the optimal position of the inlet tube is one tube pitch downward from the top of the inlet header under the given configuration and conditions. The best position of the inlet tube, compared with the worst case, improves the flow distribution by 67%, reduces the pressure drop by 68% and increases the heat transfer by 0.5%.

Accuracy of interpretation of nasogastric tube position on chest radiographs by diagnostic radiographers: A multi-case, multi-reader study.

Feeding via a misplaced nasogastric tube (NGT) is a common but preventable cause of patient harm. The aim of this study was to determine the accuracy of diagnostic radiographers' assessment of NGT position on chest radiographs (CXRs) and safe-to-feed decisions. A multi-case, multi-reader study was conducted using an online image interpretation platform. A test bank consisting of 15 CXRs with an NGT in-situ was created. Diagnostic radiographers without formal qualifications in CXR interpretation were recruited via two international conferences. Participants placed an electronic marker on each CXR to identify the location of the tip of the NGT and indicated whether or not they believed that the tube was safely positioned. 68 participants were recruited. Each participant reviewed 15 CXRs, providing 1020 unique image assessments. 76% (n=778/1020) image assessments were completely correct (both the position of the tip of the NGT was accurately located and an appropriate safe-to-use decision made). In 5% (n=56/1020) of cases the NGT was safely positioned and the location of the tip was correctly identified by the participant but the tube was erroneously determined to be unsafe for feeding. In a further 6% (n=59/1020) of cases the participant correctly located the tip of an NGT in an unsafe position but indicated that the tube was safe to use. Participants failed to correctly identify the tip of the NGT in the remaining 12% (n=127/1020) of cases. Consistent with previous studies involving other staff groups, diagnostic radiographers without formal qualification in CXR interpretation can assess NGT positioning on radiographs with moderate accuracy but require further training, including strategies for the identification of poorly-visualised tube tips, to achieve the 100% accuracy necessary for this safety-critical task. A bespoke training programme which includes teaching on image quality, tube tip identification and assessment of tube positioning using the National Patient Safety Agency (NPSA) four criteria, should be delivered prior to implementation of a radiographer-led NGT CXR evaluation service.

A biologically transparent illumination device is more useful in children for detecting the position of the nasogastric tube in the stomach.

The study aimed to evaluate the efficacy of the Biologically Transparent Illumination (BTI) device for confirming the correct placement of nasogastric (NG) tubes in children, as an alternative to X-ray, which exposes patients to radiation. In this prospective observational study, 106 pediatric patients (ages 0-16) undergoing NG-tube insertion after general anesthesia were evaluated. The BTI catheter was used to emit bio-permeable red light from the NG tube, which was then visually confirmed in the cervical, thoracic, and epigastric regions. X-ray confirmed NG-tube placement in all patients. The ethics committee approved the study. The average patient age was 3.8years, with a male-to-female ratio of 72:34. BTI was successfully detected in the epigastric area in 105 of 106 patients, with one 9-year-old patient having unclear BTI visibility. X-ray confirmed NG-tube placement in the stomach for all patients, resulting in a BTI sensitivity of 99%. The mean NG-tube insertion time was 38s, and the mean abdominal thickness was 9.8mm. The BTI device proved to be a safe and effective method for NG-tube placement in children, offering a radiation-free alternative with 100% successful placement when BTI was detected in the epigastric area.

Feculent Drainage from Percutaneous Endoscopic Gastrostomy Tube due to Gastrocolocutaneous Fistula Found in Emergency Department: A Case Report

Introduction Percutaneous endoscopic gastrostomy (PEG) placement is a common procedure for patients requiring non-oral feeding. One rare complication of PEG placement is the formation of a gastrocolocutaneous fistula that develops when bowel is caught between the stomach and abdominal wall during placement. This report explores an elderly patient's gastrocolocutaneous fistula development months post-PEG placement who presented with malodorous leakage from the gastrostomy tube to the Emergency Department (ED). Case Report A 73-year-old male on hospice presented to the ED with malodorous leakage from his PEG tube. He had received the PEG tube four months prior to this presentation and had it replaced once at an outside hospital due to blockages. In the ED, his PEG tube was found to have a deflated balloon stopper. The PEG tube was replaced, but the feculent discharge persisted. Imaging showed the tube's position in the transverse colon. The patient underwent non-surgical management, with PEG tube removal and nutritional support via nasogastric tube. He was discharged with improvement of PEG site. Conclusion Gastrocolocutaneous fistula should be considered in patients experiencing unexpected PEG tube drainage or feeding-related complications such as diarrhea. Careful replacement techniques after dislodgement or blockage are important. Radiologic confirmation should be considered after replacement of tubes with feculent drainage. The rarity of gastrocolocutaneous fistula cases in literature explains the lack of standardized management approaches. Clinical signs such as feculent leakage through PEG tube site should prompt recognition and diagnosis by the ED clinician.

Optimizing Ship Draft Observation with Wave Energy Attenuation and PaddlePaddle-OCR in an Anti-Fluctuation Device

With the development and application of artificial intelligence (AI) in the shipping industry, using AI to replace traditional draft survey methods in bulk carriers can significantly reduce manpower, lower the risks associated with visual observations, improve measurement accuracy, and minimize the impact of human subjective factors. Ultimately, the integration of software and hardware technologies will replace human visual observations with automated draft measurement calculations. A similar anti-fluctuation device described in this article has been used in ship draft observation based on AI-assisted proving, which can ease the fluctuation of the wave inside the pipe. Observers can directly read the water surface inside the pipe and compare it to the ship’s draft mark to obtain the final draft, effectively improving draft observation accuracy. However, some surveyors refuse to accept the readings obtained from this device, citing a lack of theoretical basis or the absence of accreditation from relevant technical authorities, leading to the rejection of results. To address these issues, this paper integrates wave energy attenuation theory with PaddlePaddle-OCR recognition to further validate the anti-fluctuation device for accurate ship draft observation. The experimental results are as follows: first, the pipe effectively suppresses the amplitude of external water surface fluctuations by 75%, explaining the fundamental theory that wave heights within the anti-fluctuation device are consistent with external swell heights. When taking a draft measurement, the system dynamically adjusts the position of the main tube in response to the ship’s movements, maintaining the stability of the measurement section and significantly reducing the difficulty of observations. Due to the reduction in fluctuation amplitude, there is a noticeable improvement in observation accuracy.

Accuracy and costs of bedside methods for confirming nasoenteral feeding tube position: a diagnostic accuracy study.

To analyze the accuracy and costs of bedside methods for confirming the position of a nasoenteral feeding tube newly inserted blindly by nurses. Diagnostic accuracy study of three clinical methods (ultrasound, epigastric auscultation, and pH measurement) compared to radiography. The direct costs of each method used to confirm the positioning of the nasoenteral tube were also measured. Seventy-six adult patients underwent a total of 87 nasoenteral tube insertion procedures in hospital units located within the Northeast region of the State of São Paulo, Brazil. The clinical methods were conducted on all study participants in the specified sequence: ultrasound (as index test), followed by epigastric auscultation and pH measurement (also index tests). The outcomes regarding the confirmation of the accurate positioning of the nasoenteral tube are as follows: ultrasonography demonstrated sensitivity and specific of 79.0% and 66.7%, respectively. Epigastric auscultation exhibited a sensitivity of 81.3% and specificity of 83.3%. The pH measurement method displayed sensitivity and specificity of 89.3% and 100% respectively. Additionally, in terms of estimated direct costs, the pH measurement method incurred a higher cost (USD $8.31) compared to the other methods, with a difference of USD $6.68. Based on these results, X-ray examination remains the primary method for confirming the placement of nasoenteral tubes recently inserted blindly at the bedside. However, when considering the costs of the evaluated methods, it is advisable to consider the variations in expenses between non-radiological methods and X-ray examinations.

Patient radiation risk reduction by controlling the tube start angle in single and dual source spiral CT scans: A simulation study.

Organ doses in spiral CT scans depend on the tube startangle. To determine the effective dose in single source CT (SSCT) and dual source CT (DSCT) scans as a function of tube start angle and spiral pitch value to identify the dose reduction potential by selecting the optimal startangle. Using Monte Carlo simulations, dose values for different tube positions with an angular increment of and a longitudinal increment of were simulated over a range of with collimations of , , and . The simulations were performed for the thorax region of six adult patients based on clinical CT data. From the resulting dose distributions, organ doses and effective dose were determined as a function of tube angle and longitudinal position. Using these per-view dose data, the individual organ doses, as well as the total effective dose, were determined for spiral scans with and without tube current modulation (TCM) with pitch values ranging from 0.5 to 1.5 for SSCT and up to 3.0 for DSCT. The dose of the best and worst tube start angle in terms of dose was determined and compared to the mean dose over all tube startangles. With increasing pitch and collimation, the dose variations from the effective dose averaged over all start angles increase. While for a collimation of , the variations from the mean dose value stay below for SSCT, we find that for a spiral scan with a pitch of 3.0 for DSCT with TCM and collimation of , the dose for the best starting angle is on average lower than the mean value and lower than the maximumvalue. Variation of the tube start angle in spiral scans exhibits substantial differences in radiation dose especially for high pitch values and for high collimations. Therefore, we suggest to control the tube start angle to minimize patientrisk.

Obstructed Branching Networks: A Constructal Approach in Fluid Flow Investigation

Tree flow networks are common in both natural and manufactured systems. The organization of the flow hierarchy passes through the dimensional evolution of the form that is linked to the function. Thus, the objective of comparing bifurcated tube networks obtained by the constructal design method, where part of the structure is obstructed, aims to understand the effects on fluid flow and the prediction of evolutionary deviations in its function. This study compares designs of 3D tree networks with various homothety reduction factors for sizes, having tubes obstructed in some locals of the network. In this computational fluid dynamics study, the geometric constraint applied to these networks is the equal total volume of tubes at each branch level. The evaluation is based on the flow resistance of the networks. This study shows, among other things, that the performance of tree designs is highly dependent on geometric characteristics and the branching level where the obstructions are applied. The effect of the number and position of tubes obstructed in the network, as well as the alignment of the tubes across the network branching levels, on the asymmetry of fluid flow through the network is also studied. It is recommended that the results presented be considered when designing networks for engineering systems.

Performance prediction of tube-in-shell thermal storage devices with different inner tube positions using the HHO-BP neural network

This paper presents a numerical simulation study and a machine learning based prediction of the melting process in the Tube-in-shell thermal storage device. The two-dimensional Tube-in-shell thermal storage devices models are built to represent the position of the inner tube by two parameters, the eccentricity distance e and the eccentricity angle θ. The melting process of phase change material (PCM) under different conditions is simulated using computational fluid dynamics (CFD) to determine the effects of the inner tube position, inner tube radius and heating temperature on the variation of liquid phase fraction. Then, on this basis, a neural network of HHO-BP is constructed and trained by simulation data to predict the change of liquid phase fraction when the PCM melts under other conditions. The results show that the change of position in the vertical direction of the inner tube has a great influence on the melting. However, the change in the position of the inner tube in the horizontal direction has little effect on the melting rate, and the melting time is almost the same. In addition, the inner tube radius and the heating temperature both contribute significantly to the melting rate. The melting time of the model with an inner tube radius of 20 mm is 51.08 % faster than that of the model with an inner tube radius of 10 mm. The liquid phase fraction distributions of the models with heating temperatures of 60 °C and 70 °C are 0.697 and 0.935 when the melting of the models with heating temperature of 80 °C is completed. The prediction data of the HHO-BP neural network can respond to the simulation results more accurately, and all kinds of evaluation indexes are within the acceptable range. The machine learning model developed in this paper can reduce the simulation computation cost and shorten the optimization design cycle.

Diagnostic accuracy of airway ultrasound in confirming the endotracheal tube depth in critically ill children

BackgroundChest X-ray, the established standard of confirming endotracheal tube (ETT) position, has important drawbacks including radiation exposure. Point-of-care airway ultrasound, which has been insufficiently studied in children, can overcome these problems. Materials and methodsThis was a prospective cross-sectional study done on children aged 2 months to 17 years undergoing intubation with cuffed ETT in the PICU. The ETT cuff was filled with saline and three ultrasonographic techniques were used– 1) Suprasternal (SS) method 2) Cricoid (CC) metho and 3) Tracheal ring (TR) method. Position of the ETT as determined by ultrasound and X-ray were compared. The main outcomes were sensitivity, specificity, and area under curve (AUC) for ultrasound-based methods vs. X-ray. For the TR method, concordance between the X-ray and ultrasound categories were taken. ResultsTotal 62 patients were enrolled. The sensitivity and specificity of SS method were 71% (95% CI: 57–83%) and 100% (40–100%). The CC distance method had an AUC of 0.94 (95% CI: 0.86, 1.0). In the TR method, 98% of correct position on X-ray were correctly classified by USG. The agreement between X-ray and ultrasound categories with the cuff between the first and third tracheal rings, was very good [kappa (95% CI): 0.87 (0.70, 1.00), p ≤0.001)]. ConclusionBedside ultrasound is a good method to confirm ETT depth in children. The tracheal ring method had the best diagnostic accuracy and is easy to perform. The new method using cricoid cuff distance needs further validation in different ICU settings.

Safety and feasibility of percutaneous abdominal lavage cytology screening (PACS) prior to surgical resection for pancreatic cancer.

This study aimed to evaluate the feasibility, safety, diagnostic yield, and technical aspects of percutaneous abdominal lavage cytology screening (PACS) in patients with resectable pancreatic cancer. This single-center, retrospective study included patients with resectable pancreatic cancer who underwent PACS before pancreatectomy between May 2022 and October 2023. The technical success rate, position of the drainage tube, volume of fluid administered, volume of fluid retrieved, fluid retrieval rate, and adverse events were evaluated. The cytological results of PACS were compared with those of surgical peritoneal lavage performed during pancreatectomy. Forty-four patients were enrolled in this study. The technical success rate for PACS was 100%. Drainage tube placement was outside the pouch of Douglas in all patients in the right-sided abdominal approach group (n = 10), whereas the placement was in the pouch of Douglas in all patients in the suprapubic approach group (n = 34). The mean volume of fluid administered, mean volume of fluid retrieved, and fluid retrieval rate were 185.0 ± 22.9ml vs. 97.1 ± 32.0ml (p < 0.001), 36.8 ± 25.6ml vs. 50.5 ± 21.6ml (p = 0.059), and 19.0 ± 12.4% vs. 54.9 ± 21.9% (p < 0.001) in the right abdominal approach and suprapubic approach groups, respectively. No adverse events were reported. The cytological results were benign in 42 patients; no discrepancy was observed in the results of surgical peritoneal lavage (n = 36). PACS is a feasible and safe procedure that can be performed before pancreatectomy in patients with resectable pancreatic cancer. the suprapubic approach may be ideal and PACS could be a screening method to detect carcinomatous peritonitis.

Estimation of doses absorbed by the thyroid and salivary glands, eyes, and brains of pediatric dental patients

In addition to the quality of the image, radiological protection of the patient must be considered to ensure an adequate diagnosis in dental radiology, especially in regard to those parts of the patient's body that are close to the radiation beam, such as the thyroid, salivary glands, and brain. In this work, the doses absorbed by the thyroid, salivary glands, eyes and brain of pediatric dental patients undergoing radiographic examinations are estimated using MCNP 6.2 coupled with virtual anthropomorphic phantoms, based on information from dental scenarios with a periapical X-ray unit. The absorbed doses were estimated for five- and 10-year-old male and female children. In the occlusal position, a higher absorbed dose to the thyroid was found for a five-year-old patient, whereas in the molar tube position, the brain was found to receive a higher absorbed dose for five- and 10-year-old patients. The results obtained here, expressed in terms of the absorbed dose, indicate that the beam direction and the use of different image acquisition techniques strongly influence the entrance dose values for the organs of interest in this study.

Lightweight bobbin yarn detection model for auto-coner with yarn bank

The automated replacement of empty tubes in the yarn bank is a critical step in the process of automatic winding machines with yarn banks, as the real-time detection of depleted yarn on spools and accurate positioning of empty tubes directly impact the production efficiency of winding machines. Addressing the shortcomings of traditional methods, such as poor adaptability and low sensitivity in optical and visual tube detection, and aiming to reduce the computational and detection time costs introduced by neural networks, this paper proposes a lightweight yarn spool detection model based on YOLOv8. The model utilizes Darknet-53 as the backbone network, and due to the dense spatial distribution of yarn spool targets, it incorporates large selective kernel units to enhance the recognition and positioning of dense targets. To address the issue of excessive focus on local features by convolutional neural networks, a bi-level routing attention mechanism is introduced to capture long-distance dependencies dynamically. Furthermore, to balance accuracy and detection speed, a FasterNeck is constructed as the neck network, replacing the original convolutional blocks with Ghost convolutions and integrating with FasterNet. This design minimizes the sacrifice of detection accuracy while achieving a significant improvement in inference speed. Lastly, the model employs weighted IoU with a dynamic focusing mechanism as the bounding box loss function. Experimental results on a custom yarn spool dataset demonstrate a notable improvement over the baseline model, with a high-confidence mAP of 94.2% and a compact weight size of only 4.9 MB. The detection speed reaches 223FPS, meeting the requirements for industrial deployment and real-time detection.

Deep Learning-Based Localization and Detection of Malpositioned Nasogastric Tubes on Portable Supine Chest X-Rays in Intensive Care and Emergency Medicine: A Multi-center Retrospective Study.

Malposition of a nasogastric tube (NGT) can lead to severe complications. We aimed to develop a computer-aided detection (CAD) system to localize NGTs and detect NGT malposition on portable chest X-rays (CXRs). A total of 7378 portable CXRs were retrospectively retrieved from two hospitals between 2015 and 2020. All CXRs were annotated with pixel-level labels for NGT localization and image-level labels for NGT presence and malposition. In the CAD system, DeepLabv3 + with backbone ResNeSt50 and DenseNet121 served as the model architecture for segmentation and classification models, respectively. The CAD system was tested on images from chronologically different datasets (National Taiwan University Hospital (National Taiwan University Hospital)-20), geographically different datasets (National Taiwan University Hospital-Yunlin Branch (YB)), and the public CLiP dataset. For the segmentation model, the Dice coefficients indicated accurate delineation of the NGT course (National Taiwan University Hospital-20: 0.665, 95% confidence interval (CI) 0.630-0.696; National Taiwan University Hospital-Yunlin Branch: 0.646, 95% CI 0.614-0.678). The distance between the predicted and ground-truth NGT tips suggested accurate tip localization (National Taiwan University Hospital-20: 1.64 cm, 95% CI 0.99-2.41; National Taiwan University Hospital-Yunlin Branch: 2.83 cm, 95% CI 1.94-3.76). For the classification model, NGT presence was detected with high accuracy (area under the receiver operating characteristic curve (AUC): National Taiwan University Hospital-20: 0.998, 95% CI 0.995-1.000; National Taiwan University Hospital-Yunlin Branch: 0.998, 95% CI 0.995-1.000; CLiP dataset: 0.991, 95% CI 0.990-0.992). The CAD system also detected NGT malposition with high accuracy (AUC: National Taiwan University Hospital-20: 0.964, 95% CI 0.917-1.000; National Taiwan University Hospital-Yunlin Branch: 0.991, 95% CI 0.970-1.000) and detected abnormal nasoenteric tube positions with favorable performance (AUC: 0.839, 95% CI 0.807-0.869). The CAD system accurately localized NGTs and detected NGT malposition, demonstrating excellent potential for external generalizability.

Comparison between ultrasonography and capnography for ascertaining placement of endotracheal tube in patients undergoing general anesthesia – A prospective observational study

Background: Confirmation of the position of the endotracheal tube (ETT) is an essential step for verification of intubation. Failure to diagnose esophageal intubation may lead to fatal consequences. Capnography is the gold standard for confirmation of ETT position, but it is practically impossible to be performed in all situations. Ultrasonography (USG) or “visual stethoscope” can be used as an effective alternative for all intubators in all situations. Aims and Objectives: The study was conducted to evaluate the ultrasonography (USG) technique with respect to its efficacy to detect the proper endotracheal position of ETT compared to end-tidal capnography among patients undergoing general anesthesia; to compare the time taken by the USG technique with that of capnography for detection of proper placement of ETT; to assess the feasibility of USG to detect accidental esophageal intubation. Materials and Methods: This prospective comparative cross-sectional observational study was conducted on 68 patients. Both capnography and upper airway USG were performed immediately after intubation to confirm the ETT placement. Sensitivity, specificity, and positive and negative predictive values of upper airway USG were determined against capnography as the reference method. The time required to determine ETT placement by the two methods was found out and compared. Agreement between the methods was assessed with kappa statistics. Results: USG detected all three cases of esophageal intubation but could not detect two patients with correct tracheal intubation. Upper airway USG had a sensitivity of 96.92% (95% confidence interval [CI]: 93.54–100%), specificity of 100%, positive predictive value of 100%, and negative predictive value of 60% (95% CI: 50.4–69.6%). The Kappa value was found to be 0.735, indicating a good agreement between upper airway USG and capnography for confirmation of ETT placement. Time taken for confirmation of ETT by capnography was 21.68±2.63 s versus 11.44±1.38 s for upper airway USG (P&lt;0.001). USG demonstrated bilateral lung sliding in 60 (88.2%) patients, unilateral lung sliding in 3 (4.4%) patients, and lung sliding was absent in 5 (7.4%) patients. Conclusion: Real-time upper airway USG is an alternative method of confirmation of ETT that is not only sensitive and accurate but is faster than the current gold standard method, capnography.

Accuracy of pH strip testing and pH liquid testing versus standard pH meter of gastric contents in critically ill patients: a diagnostic accuracy study

ObjectiveThe utilisation of pH level measurements from gastric contents may indicate the preferred tip position of a nasogastric tube or monitor the efficacy of stress ulcer prophylaxis in critically ill...

Induced voltage in piezoelectric tube driven segments and their use in nanopositioning, an assessment

AbstractA piezoelectric tube actuator has a number of segments or electrodes. The induced voltage and the piezoelectric voltage, two easy‐to‐measure electrical signals in piezoelectric tubes, have been used in position estimation of these actuators since 2006 and 1982. However, since introduction, the induced voltage has never been compared with the piezoelectric voltage for piezoelectric tubes’ position estimation. In addition, only linear models have been used to present the relationship between the induced voltage and the position of piezoelectric tubes. In other words, in the literature, it has been practically assumed that (1) the relationship between the induced voltage and the position is linear, and (2) the induced voltage can estimate the position more accurately compared to the piezoelectric voltage. This article assesses and nullifies both these assumptions. In this research, with the use of the experimental data, both aforementioned voltage signals were mapped into the position through linear and nonlinear models. It was shown that the position can be estimated less accurately with the induced voltage compared to the piezoelectric voltage, and the relationship of the position with the induced voltage presents higher and non‐negligible nonlinearity compared to the one with the piezoelectric voltage.

Effect of aripiprazole on neural tube development in early chick embryos

IntroductionAripiprazole (ARI) is a recently developed antipsychotic medication that belongs to the second generation of antipsychotics. The literature has contradictory information regarding ARI, which has been classified as pregnant use category C by the FDA. Methods125 pathogen-free fertilized eggs were incubated for 28 h and divided into five groups of 25 eggs each (including the control group), and 18 eggs with intact integrity were selected from each group. After the experimental groups were divided, ARI was administered subblastodermally with a Hamilton micro-injector at 4 different doses (1 mg/kg, 5 mg/kg, 10 mg/kg, 20 mg/kg). At the 48th hour of incubation, all eggs were hatched and embryos were removed from the embryonic membranes. And then morphologic (position of the neural tube (open or closed), crown-rump length, number of somites, embryological development status), histopathologic (apoptosis (caspase 3), cell proliferation (PCNA), in situ recognition of DNA breaks (tunnel)), genetic (BRE gene expression) analyzes were performed. ResultsAccording to the results of the morphological analysis, when the frequency of neural tube patency was evaluated among the experimental groups, a statistically significant difference was determined between the control group and all groups (p < 0.001). In addition, the mean crown-rump length and somite number of the embryos decreased in a dose-dependent manner compared to the control group. It was determined that mRNA levels of the BRE gene decreased in embryos exposed to ARI compared to the control group (p < 0.001). ConclusionMorphologically, histopathologically, and genetically, aripiprazole exposure delayed neurogenesis and development in early chick embryos. These findings suggest its use in pregnant women may be teratogenic. We note that these results are preliminary for pregnant women, but they should be expanded and studied with additional and other samples.

Study of Buffeting Excitation Acting on Coil Tube Bundles in Cross Flow

Abstract The amplitudes induced by random excitation forces on the tubes bring continuous friction between the tube and supports, which results in gradual failure of the tubes due to fretting wear. Therefore, it is very important to determine the envelope lines of the random excitation force spectrum for the coil tube. To the authors' knowledge, there are no published studies on the normalized force spectrum of coil tubes. In this paper, a simplified three-layer experimental model was established. The robustness of the numerical method was demonstrated by comparing the experimental and simulated results, including the vibration response and the fluid excitation force spectrum. Then, a semi-empirical equation for predicting the dominant frequency of turbulent buffeting was constructed by employing the threshold envelope method. Through the observation of time-history and root-mean-square (RMS) data, it was found that the pitch diameter ratio between adjacent tube layers, a, had the greatest influence on the force coefficients. The smaller a is, the larger the force coefficients are. The pitch diameter ratio in the same layer, b, and helix angle, α, had little effect on the force coefficients. With the increase of α, the flow instability in the shell-side flow enhanced and the fluctuation of force coefficients became larger. Finally, the mechanisms of the tube position, Reynolds number (Re), and bundle structure on the normalized force spectrum were studied. The normalized envelope force spectrum for coil tubes was proposed as the guidelines to predict and evaluate the random excitation force acting on the tubes.

Experimental and simulation study on seismic performance of the new beam-column transfer joint as the embedded part of the basement roof

A new beam-column transfer joint is proposed, which consists of an upper column with a concrete-filled steel tube column (CFST), a lower column with a variable-diameter steel-concrete column (SRC), and a reinforced concrete beam. The new transfer joint is mainly set on the roof of the basement of a high-rise building structure. Compared with traditional transfer joints, it reduces the amount of steel used, increases the use space of the basement, and improves the seismic performance of the structure. New transfer joint and traditional joint were tested under cyclic loading to investigate response of the proposed joint. The main performance indicators studied are hysteretic response, energy dissipation, ductility, and stiffness degradation. Research results show that the energy consumption and carrying capacity of the new transfer joint are higher than those of the traditional joint. The correctness of the finite element analysis was verified through the test results, and a parametric analysis was carried out on this basis. It was found that the diameter reduction position of the steel tube and the length of the corbels of the lower column have little impact on the seismic performance of the new transfer joint. The thickness of the steel tube has a greater impact on the seismic performance of the new transfer joints. The peak bearing capacity is increased by about 17 %. Finally, according to the formula given by the specification, the embedding effect of the new transfer joint and the traditional joints are compared. The effect of the new transfer joints is better than that of the traditional one, which can provide a reference for future basement design of high-rise building structures.