Insertion Method Research Articles

Computed tomography in measuring electrode insertion angle and depth for cricopharyngeal muscle electromyography.

Electromyography of the cricopharyngeal muscle (CP-EMG) is one of many assessment tools for dysphagia. The key to performing EMG and BTX injections is to precisely locate the cricopharyngeal muscle with an electrode. One of the main difficulties of electrode insertion is the fact that the CP muscle is located deep within the neck. Since a neck computed tomography (CT) can clearly display the CP muscle, thyroid, and blood vessels in the neck, we speculate that a safe concentric needle electrode insertion path to the cricopharyngeal muscle can be simulated with the assistance of the patient's neck CT which clearly marks the angle and depth of concentric needle electrode insertion. The purpose of this study was to explore simulated electrode insertion angles and insertion depths for cricopharyngeal electromyography based on retrospective CT data and present a method of percutaneous localization of the cricopharyngeal muscle based on CT images of the neck. One hundred and forty-three neck CT scans performed between January 2019 and November 2020 were included in this study. With the assistance of the angle and straight-line tools found in the Advantage Workstation 4.4 (GE, HealthCare), simulated insertion angles and depths from the anterior border of the sternocleidomastoid muscle to the cricopharyngeal muscle were obtained. The 143 CT images originated from participants that included 63 males (44.1%) with an average age of 46.2±13.9 years old. The insertion angle, insertion depth, and neck thickness measured on the CT images were 53.2±10.7˚, 24.2±4.1 mm, and 130.1±17.7 mm, respectively. The insertion angle and depth were significantly greater in males than in females (P<0.05), and the insertion angle increased with the age of participants (P<0.05). A generalized linear model (GLM) showed that insertion angle was positively correlated with neck thickness (β=0.14; 95% CI: 0.03 to 0.25) and gender (β=5.08; 95% CI: 1.31 to 8.85), and negatively correlated with age (β=-5.88; 95% CI: -9.54 to -1.62). Insertion depth was only positively correlated with the neck thickness (β=0.11; 95% CI: 0.07 to 0.15). This study indicates that age, gender, and neck thickness are influencing factors for insertion angle, while neck thickness is the influencing factor for insertion depth. The simulated concentric needle electrode insertion method based on CT can assist clinical operation to ensure safety and effectiveness of cricopharyngeal electromyography.

Evaluation of thyromental distance versus tongue width versus weight-based method for size determination of laryngeal mask airway in adults

Background: Supraglottic airway devices (SGD) are indispensable for airway management. The successful placement of the laryngeal mask airway (LMA) supreme largely depends on the right size selection. Aims and Objectives: The study was undertaken to compare three LMA supreme insertion methods in short elective surgeries under general anesthesia. Materials and Methods: Atotal of 90 American Society of Anesthesiologists I and II patients (either gender, 18–55 years, Mallampati grade I and II) undergoing short surgeries were randomized into three equal groups (n=30 in each). Insertion of LMA was done after an adequate depth of anesthesia for jaw relaxation (Young’s criteria). The efficacy of controlled ventilation through LMA by each method, success rate, ease of insertion, insertion time, additional induction dose (propofol) required during insertion, hemodynamic stability (baseline vitals and 10 min after insertion), and adverse events after LMA removal were evaluated between groups. Results: Better ventilation (tidal volume at 10 cmH2O) was observed in the thyromental group (448±35) than in tongue width (440±46) and weight-based (409±33) groups. Minimum additional propofol requirement during insertion was in thyromental distance group. Thyromental distance group had the most easy LMA insertions (70%) with minimum insertion time (10±4) and minimum additional propofol requirement during insertion (P&lt;0.05) than other groups. Overall hemodynamic stability and incidence of adverse events were comparable. Conclusion: Thyromental distance may be an alternative attractive choice for size determination of LMA supreme in female adults with normal airway anatomy in comparison to tongue width and conventional body weight-based methods.

Copper Indium Sulfide Quantum Dots as Nanomanometers: Influence of Size and Composition

AbstractMechanical forces control the function of organisms and mediate the interaction between biological systems and their environments. Knowledge of these forces will increase the understanding of biological processes and can support the development of novel diagnostic and therapeutic procedures. Although techniques like atomic force microscopy and droplet insertion method allow measuring forces over a broad range of values, they are invasive and lack versatility. A promising way to overcome these hurdles is luminescent nanomanometry. Quantum dots (QDs) specifically have optical properties that depend on their size because of the quantum confinement, which makes them responsive to applied forces. Yet, a fine understanding of how fundamental parameters affect the response to applied stress is required before a QD family can be credibly proposed as luminescent nanomanometers. Here, a thorough study is conducted on how size and stoichiometry affect the nanomanometry performance of CuInS2 QDs. The studied QDs feature pressure‐dependent photoluminescence in the red/near‐infrared range, which can enable the measurement of mechanical forces in the range of physiological relevance in a remote and minimally invasive way. It is shown that tuning size and stoichiometry can simultaneously enhance the CuInS2 QDs’ brightness and response to applied pressure, thus providing guidelines for better luminescent nanomanometers.

Implementasi Penyisipan Pesan Teks Terenkripsi Menggunakan Kriptografi ElGamal pada Citra Digital Menggunakan Steganogarafi LSB

Message security is very important in maintaining the confidentiality of information, especially those containing important information whose contents should only be known by the entitled party. Therefore, security is needed for messages that are confidential so that messages cannot be intercepted by people who do not want them and the information content of the message becomes more secure. One way is to apply ElGamal and LSB cryptography methods to be able to provide security to text messages by inserting into digital images, the ElGamal algorithm focuses on the strength of the key in solving discrete logarithm problems. By utilizing large prime numbers and discrete logarithm problems which are quite difficult and also by applying the LSB method for text insertion, the security of the key is more guaranteed. The test results on five image objects with the .BMP extension on the application that was built were running well and correctly. The image that is inserted in the encryption process is the insertion of text in the image after it is decrypted and the image produced after the encryption and decryption process is no different from the original image and the same thing for the image size does not change

Reliability of intra-atrial ECG method of insertion of central venous line through right internal jugular vein when compared to formula and radiological landmark method: a prospective randomized study

BackgroundIdeal position of central venous catheter tip should be within 2 cm above and 1 cm below superior vena cava–right atrium (SVC-RA) junction. The objective of the study was to compare intra-atrial ECG method of Central venous catheterization of right internal jugular vein (IJV) with traditional methods. A prospective randomized trial enrolling 90 patients were alternatively allocated to three groups and comparison of intra-atrial electrocardiography, radiological landmark and Pere’s formula method for correct positioning of central venous catheter tip were done and tip position were confirmed with post-procedural TEE (transesophageal echocardiography).ResultsCatheter tip was present at the ideal position in 100% cases in intra-atrial ECG method compared to only 23.4% in formula method and 93.3% in landmark method (p value 0.001). In intra-atrial method group, the central venous catheter tip was placed perfectly in all patients, position of the catheter tip was not acceptable in 71.4% of the patients where formula method is used and not acceptable in 11.1% when landmark method is used (p value 0.001). However, we did not encounter any catheter related complications in any of these groups.ConclusionsIntra-atrial ECG method carries the advantage of ideal positioning of the central venous catheter tip by right IJV route in almost all cases when compared to conventional formula and landmark method to some extent. Also, immediate confirmation and real time verification of central venous catheter (CVC) tip is possible, thereby avoids the need for post-procedural chest X-ray and other methods of central venous placement confirmation like arterial blood gas analysis etc., Hence, intra-atrial ECG method is cost effective and safer for confirmation of CVC tip in all the situations.

Broadband inhomogeneous lens with conical radiation pattern

This manuscript presents a lens antenna with simultaneous broadside and conical beams. The lens is designed for the Ku band using the ray inserting method. The proposed conical radiation pattern is broadband due to good matching with the source and surroundings. The simulation is conducted using the CST microwave studio solver. Instead of complex antenna shapes used in other works, a simple circular patch ring and RF connector are used as the lens feed to generate broadside and omnidirectional conical patterns, respectively. To validate the performance of the designed lens and its two-port feed antenna, the lens structure is realized and fabricated using the 3D printing method. Polyethylene terephthalate glycol (PETG) plastic material is utilized for constructing the lens in this work. The electromagnetic characteristics of PETG in the Ku band are accurately measured. The results of simulations and experiments demonstrate the good performance of the designed lens over a wide frequency bandwidth. The advantage of this designed structure over other works is its high gain and broad bandwidth.

Integrated scheduling problems of open shop and vehicle routing using an ensemble of group teaching optimization and simulated annealing

Production and distribution are two parts of importance in supply chains. Yet, seldom attention is given to an integrated production and distribution in the case of open shop scheduling and vehicle routing problems. This article addresses an integrated scheduling problem of open shop and vehicle routing optimization, in which the jobs are processed in an open shop, and subsequently are delivered to customers at diverse places. First, a mixed integer programming model is developed to define the problem with minimizing maximum completion time. Second, an ensemble of group teaching optimization and simulated annealing methods is devised to optimally handle the considered problem. A heuristic rule is designed to generate a high-quality initial solution, while a simulated annealing method considering key machines is proposed to reinforce exploitation abilities. A nearest insertion method is used to make delivery decisions of vehicles. At last, the sensitivity analysis of user parameters in the developed approach is executed. Via solving a set of benchmark instances, we carry out extensive comparison experiments. The formulated model is verified by a mathematical programming optimizer CPLEX and the devised approach is compared with four meta-heuristics. The results and discussions confirm the strong competitiveness of the developed model and method for solving the concerned problems.

Synthesis and characterization of metabolite-nanoparticle conjugates for use in metabolite biosensor systems

Detecting specific metabolites and measuring their changing levels in various biofluids has played a key role in understanding health and diagnosing disease. While most metabolite measurements are performed via spectroscopic (colorimetric, UV, mass spectrometry-MS, nuclear magnetic resonance) methods, it is also possible to perform metabolite detection and quantification via metabolite-antibody interactions, such as those used in competitive enzyme-linked immunosorbent assays (ELISAs), and/or impedance measurements. While metabolite-specific antibodies are available, conjugated-metabolites needed for metabolite-antibody detection are rare. Here we describe a general method that allows for the efficient conjugation of different classes of metabolites (acids, amines, and aromatic compounds) to gold nanoparticles and liposomes. We also describe a method for the efficient insertion of metabolite-lipid complexes into liposomes. We extensively characterized these conjugates, confirming their identity and composition, using a wide variety of analytical (thermal gravimetric analysis), spectroscopic (dynamic light scattering, MS) and microscopic (transmission electron microscopy-TEM, cryo-EM, high resolution EM) techniques. We also demonstrated that these metabolite conjugates can successfully bind to their metabolite-specific antibodies. We used scanning electron microscopy, atomic force microscopy, and ELISA to confirm the successful binding of these NPs-conjugates (N1-acetylspermine (AcSpm), hippuric acid and creatinine) to metabolite-specific antibodies attached to silicon wafers and electrodes. We believe the methods developed here are quite general and could be used in the development of a number of different types of metabolite biosensors and portable metabolite assays.

Simulation of defect build-up in tungsten during low energy irradiation

Tungsten is the material chosen to be used in some of the most demanding parts of fusion test reactors and planned fusion power plants. The irradiation present will degrade the material over time, which lead to the need for component replacement. In order to understand the material degradation and to be able to predict the need for replacement, there is a need to understand how defects are produced in the material. Even though there will be high energy recoils in the material, there will be a substantial amount of recoils in the low energy regime. We study the effect of irradiation on the hundred eV scale and compare it to the commonly used Frenkel-pair insertion method. By conducting this investigation we can investigate if this insertion method is a possible speed up to full cascade simulations. These low energy simulations are also comparable with the energy given to recoils during electron irradiation. We found that the low energy cascades will produce damage as expected and that Frenkel-pair insertion will qualitatively give a similar result. However, we found, quantitatively in the form of clustering, that the results differ between methods, especially for the higher energies investigated.

Conformally Large-Area Single-Crystal Piezocomposites with High Performance for Acoustic Transducers.

Large-area and conformal piezoelectric elements are highly desired for acoustic transducers to possess a large power source level and wide detecting range. To date, single-crystal piezocomposites attract much attention on enhancing the power source level and bandwidth for next-generation acoustic transducers, owing to their higher piezoelectric and electromechanical coupling properties compared to traditional piezocomposites. Unfortunately, it is still challenging to achieve large-area and conformal single-crystal piezocomposites because of the fragile nature, large anisotropy, and the limited grown size of piezoelectric single crystals. Here, we successfully fabricate the conformally large-area single-crystal piezocomposite with an area of 160 × 50 mm2 and a bending angle of 162° by a modified 3D-printing-assisted inserting method. The single-crystal piezocomposite exhibits a high thickness electromechanical coupling factor kt of 85% and a large piezoelectric coefficient d33 of 1150 pC/N, surpassing those of the reported large-area piezocomposites. The influence of the volume fraction and curvature radius of single-crystal PCs and acoustic transducers was investigated. Furthermore, we designed an acoustic transducer based on the conformal single-crystal piezocomposite. Benefiting from the excellent piezoelectric and electromechanical properties of the single-crystal piezocomposite, the transducer indicates a high maximum transmitting voltage response of 171.8 dB. Especially, its bandwidth (-3 dB) achieves 60 kHz with a resonant frequency of 292 kHz, which is about 1.8 times superior to the conformal acoustic transducer based on the ceramic piezocomposite with a similar resonant frequency. This work may benefit the future design and fabrication of high-performance and complex-shape piezoelectric composites as key materials for next-generation transducers.

New technique for improving transient stability of standalone microgrid using superconductor fault current limiter

This study proposes a new insertion topology for Superconductor Fault Current Limiter (SFCL) to maintain and enhance the transient stability of a wind generation system in a standalone microgrid. The proposed topology is inserting the SFCL in series with the faulty phase only. The new insertion topology performance is compared with the traditional insertion method. The proposed insertion topology of the SFCL displays excellent performance compared to the traditional method. The overall performance of the Micro-Grid is improved. The performance of the wind generator is improved dramatically after employing the proposed controller. The proposed insertion topology suppresses the fluctuations of the wind generator speed (from ± 6% to less than ± 1%) as well as the post fault wind generator real power and imaginary power. For a single line to ground fault, the wind generator active power fluctuates between + 80 kW, and − 40 kW with traditional SFCL insertion topology. When using the proposed insertion topology, the wind generator active power fluctuates between + 27 kW, and + 12 kW. Also, the proposed SFCL insertion topology mitigates the fluctuations in voltage, real power and imaginary power not only at the generator bus but also at all other Micro-Grid buses (PV bus, and storage batteries bus). The voltage at all buses recover to steady state values fast (0.01 s) compared with the recovering time when using the traditional method (nearly 1 s). The proposed method is very simple and low cost because there is no additional hardware is required. This fact makes the proposed method highly attractive from the economical and implementation point of views.

The selection of the suitable long peripheral catheter in DIVA patients: The significance of ultrasonography.

There are several types of LPC (long peripheral catheters) that vary in length, size, insertion method, and cost. The aim of the study was to evaluate whether ultrasonography can be useful for the selection of the suitable LPC in DIVA (difficult intravenous access) patients. Based on the ultrasonographic examination, a long peripheral catheter was selected. A 6.4 cm LPC into a vein at a depth of up to 0.5 cm, a 8.5 cm LPC into a vein at a depth up to 1.5 cm, and a 9.8 cm catheter at a depth up to 2 cm using the cannula over needle method. A 12 cm catheter was inserted into the deeper veins using the direct Seldinger method. The catheter diameter was no more than 33% vein diameter. Dwell time and the number of complications of four vascular devices were recorded and compared. One thousand one hundred fifty-six patients, average age 76 years (19-102), 501 men and 655 women, were included in the study. Average dwelling time was 10 days (1-30), there were 136 complications (11.7%). A catheter 6.4 cm long was inserted in 346 (29.8%), 8.5 cm in 140 (12.1%), 9.8 cm in 320 (27, 5%), and 12 cm in 356 (30.6%) patients. There were no significant differences in dwelling time, rate, and type of complications among the four catheters used. Our results confirm that ultrasound examination can be useful for the selection of the suitable long peripheral catheter in DIVA patients.

A dynamic material distribution scheduling of automotive assembly line considering material-handling errors

PurposeIn a kitting supply system, the occurrence of material-handling errors is unavoidable and will cause serious production losses to an assembly line. To minimize production losses, this paper aims to present a dynamic scheduling problem of automotive assembly line considering material-handling mistakes by integrating abnormal disturbance into the material distribution problem of mixed-model assembly lines (MMALs).Design/methodology/approachA multi-phase dynamic scheduling (MPDS) algorithm is proposed based on the characteristics and properties of the dynamic scheduling problem. In the first phase, the static material distribution scheduling problem is decomposed into three optimization sub-problems, and the dynamic programming algorithm is used to jointly optimize the sub-problems to obtain the optimal initial scheduling plan. In the second phase, a two-stage rescheduling algorithm incorporating removing rules and adding rules was designed according to the status update mechanism of material demand and multi-load AGVs.FindingsThrough comparative experiments with the periodic distribution strategy (PD) and the direct insertion method (DI), the superiority of the proposed dynamic scheduling strategy and algorithm is verified.Originality/valueTo the best of the authors’ knowledge, this study is the first to consider the impact of material-handling errors on the material distribution scheduling problem when using a kitting strategy. By designing an MPDS algorithm, this paper aims to maximize the absorption of the disturbance caused by material-handling errors and reduce the production losses of the assembly line as well as the total cost of the material transportation.

Trigone point as an alternative location for ventricular shunt insertion

Link of Video Abstract: https://youtu.be/BtHvICeUONYBackground: Hydrocephalus is a condition in which cerebrospinal fluid (CSS) buildup in the ventricles is caused by excessive CSS production or disturbance of CSS circulation or absorption. Insertion of a shunt catheter into the lateral ventricle can be performed at the Kocher, Keen, Dandy, Frazier, Kaufmann, or Tubbs points. This study aims to evaluate the trigone point as an alternative location for ventricular shunt insertion Methods: This is a retrospective study. We performed a three-dimensional head CT scan reconstruction of hydrocephalus patients; then, we calculated the vertical and horizontal distances perpendicular to each other from the upper edge of the auricle that intersects the trigone point on the right and left sides of the patient. Data were analyzed using SPSS version 26.0 for Windows. Results: A total of 30 hydrocephalus patients at Kariadi Hospital Semarang from 2021 – 2022 were enrolled in this study. We got the averages of the vertical line is 25.05 mm and the horizontal is 33.00 mm for the right trigone point. In addition, the average vertical line is 25.78 mm and the horizontal line is 34.72 mm for the left trigone point. There was no significant difference between the vertical distance of the right and left trigone points (p=0.578) and the horizontal distance of the right and left trigone points (p=0.185). We found no significant difference between the location of the right and left trigone points. Conclusion: Trigone point can be an alternative location for ventricular shunt installation.

Did You Train on My Dataset? Towards Public Dataset Protection with CleanLabel Backdoor Watermarking

The huge supporting training data on the Internet has been a key factor in the success of deep learning models. However, this abundance of public-available data also raises concerns about the unauthorized exploitation of datasets for commercial purposes, which is forbidden by dataset licenses. In this paper, we propose a backdoor-based watermarking approach that serves as a general framework for safeguarding publicavailable data. By inserting a small number of watermarking samples into the dataset, our approach enables the learning model to implicitly learn a secret function set by defenders. This hidden function can then be used as a watermark to track down third-party models that use the dataset illegally. Unfortunately, existing backdoor insertion methods often entail adding arbitrary and mislabeled data to the training set, leading to a significant drop in performance and easy detection by anomaly detection algorithms. To overcome this challenge, we introduce a clean-label backdoor watermarking framework that uses imperceptible perturbations to replace mislabeled samples. As a result, the watermarking samples remain consistent with the original labels, making them difficult to detect. Our experiments on text, image, and audio datasets demonstrate that the proposed framework effectively safeguards datasets with minimal impact on original task performance. We also show that adding just 1% of watermarking samples can inject a traceable watermarking function and that our watermarking samples are stealthy and look benign upon visual inspection.

Safety of robotic-assisted screw placement for spine surgery: Experience from the initial 125 cases

BackgroundThe present study aimed to evaluate the safety of robot-assisted screw placement in 125 cases after introducing a spinal robotics system and to identify the situations where deviation was likely to occur. MethodsThe subjects were 125 consecutive patients who underwent robotic-assisted screw placement using a spinal robotics system (Mazor X Stealth Edition, Medtronic) from April 2021 to January 2023. The 1048 screws placed with robotic assistance were evaluated. We investigated intraoperative adverse events of the robotics system and complications occurring within 30 days after surgery. We evaluated screw accuracy and deviation and compared them for vertebral levels, screw insertion methods (open traditional pedicle screw [Open-PS], cortical bone trajectory screw [CBT], percutaneous pedicle screw [PPS], and S2 alar iliac screw [S2AIS]), diagnosis, and phases of surgical cases. ResultsThe deviation rate of robotic-assisted screw placement for spine surgery was 2.2%. Complications were reoperation due to implant-related neurological deficit in 0.8% and surgical site infection in 0.8%. There was significant difference in the deviation rate between vertebral levels. The deviation rate of the T1–T4 level was high at 10.0%. There was significant difference in the deviation rate between Open-PS, CBT, PPS, and S2AIS. The PPSs had a high deviation rate of 10.3%. The deviation rates were not significantly different between patients with and without deformity. The deviation rate did not change depending on the experience of surgical cases, and the deviation rate was favorable from the onset. ConclusionAlthough the robotic-assisted screw placement was safe, we should be extra vigilant when placing screws in the upper thoracic region (deviation rate 10.0%) and when using PPSs (deviation rate 10.3%).

Perioperative pain management in thoracic surgery: A survey of practices in Australia and New Zealand.

There are few data on current trends in pain management for thoracic surgery in Australia and New Zealand. Several new regional analgesia techniques have been introduced for these operations in the past few years. Our survey aimed to assess current practice and perceptions towards various modalities of pain management for thoracic surgery among anaesthetists in Australia and New Zealand. A 22-question electronic survey was developed and distributed in 2020 with the assistance of the Australian and New Zealand College of Anaesthetists Cardiac Thoracic Vascular and Perfusion Special Interest Group. The survey focused on four key domains-demographics, general pain management, operative technique, and postoperative approach. Of the 696 invitations, 165 complete responses were obtained, for a response rate of 24%. Most respondents reported a trend away from the historical standard of thoracic epidural analgesia, with a preference towards non-neuraxial regional analgesia techniques. If representative of anaesthetists in Australia and New Zealand more widely, this trend may result in less exposure of junior anaesthetists to the insertion and management of thoracic epidurals, potentially resulting in reduced familiarity and confidence in the technique. Furthermore, it demonstrates a notable reliance on surgically or intraoperatively placed paravertebral catheters as the primary analgesic modality, and suggests the need for future studies assessing the optimal method of catheter insertion and perioperative management. It also gives some insight into the current opinion and practice of the respondents with regard to formalised enhanced recovery after surgery pathways, acute pain services, opioid-free anaesthesia, and current medication selection.

#4062 PERITONEAL DIALYSIS CATHETER SURVIVAL: A TEN-YEAR SINGLE CENTER STUDY

Abstract Background and aims Timely insertion and adequate management of peritoneal dialysis catheter (PDC) related complications are crucial for the success of Peritoneal Dialysis (PD). The aim of the present study was to review the peritoneal dialysis catheter outcomes at our center and evaluate variables influencing catheter survival. Methods We conducted a retrospective study including 146 patients who had their first PD catheter implanted between 1st of August 2012 and 31st of July 2022 in our institution. The primary endpoint was PD catheter failure, defined as removal of the PD catheter due to catheter-related complications. Kaplan-Meier curves were used to estimate catheter survival. Cox regression model was used to identify factors that were independently associated with catheter survival. All demographic and clinical characteristics of the patients and PD complications were included as covariates. A p value of less than 0.05 was considered statistically significant. Results The study population included 85 men and 61 women, aged 55.1 $ \pm {\rm{\ }}$ 16.7 years. Mean follow-up was 26.5 +/- 22.7 months. Diabetes was the most common etiology of the stage 5 chronic kidney disease (n = 41, 28%), followed by chronic glomerulonephritis (n = 30, 20.5%). Ninety patients (61.2%) had one or more comorbidities and seventeen (11,6%) had previous abdominal surgery. In 98 patients (60.1%), the PDC was inserted using a mini-laparotomy approach, whereas the laparoscopic method was used in 54 patients (33.1%). Only 8 patients (4.9%) had their catheter placed percutaneously using the Seldinger technique. The total number of patients with one or more PD-related infectious complications during follow-up was 99 (67%): 51 patients (31%) had a single episode and 29 (17.8%) had multiple episodes of peritonitis; 34 patients (20.9%) had a single episode of PD catheter related exit site or tunnel infection, while 47 (28.8%) had more than 1 event. Sixty-six patients (45%) had PD-related mechanical complications, mostly due to outflow failure (19 patients with catheter migration, 11 with omental wrapping). The remaining non-infectious complications were hernia (n = 20, 13.7%), hemoperitoneum (n = 8, 5,5%), leakage (n = 4, 2.7%) and pleuroperitoneal shunt (n = 4, 2.7%). Fourteen patients required intervention due to mechanical complications, namely repositioning of the catheter with fluoroscopic technique in 8 patients and surgical repositioning in 6. Removal of the catheter was required in 49 patients (33.6%). The leading cause of catheter removal was infection (n = 29, 59%): peritonitis in 28 patients and refractory tunnel infection in 1. Mechanical complications were also a significant factor, accounting for 40.8% of the removals (n = 20). Overall PD catheter survival rates over 12, 24 and 36 months were 80.2%, 72.4% and 61.6%, respectively. PD catheter-related non-infectious complications was the only independent variable significantly associated with catheter survival (Hazard ratio 2.573; 95% CI 1.426–4.645). No significant association was observed between the PD catheter survival and other risk factors including age, diabetic status, comorbidities, previous abdominal surgeries, method of catheter insertion or infectious complications. Conclusions PDC non-infectious complications were the only independent factor significantly associated with catheter survival. Despite the significant number of infectious complications, including peritonitis, it was found that these complications did not result in a significant decrease in catheter survival. These findings highlight the crucial role of proper management of peritoneal dialysis catheter-related non-infectious complications for successful and long-term usage of PDC.

Optimization of Simultaneous Pickup and Delivery Vehicle Routing with Three-Dimensional Balanced Loading Constraints

In order to promote the cost reduction and efficiency improvement of the logistics distribution process and to guarantee the safety of goods transportation, this paper studies the portfolio optimization of goods loading and the problem of simultaneous pickup and delivery vehicle routing. A balanced loading constraint was introduced to restrict loading through two aspects of axle weight bearing and lateral center-of-gravity offset. With the shortest total route length as the objective, this paper constructs a simultaneous pickup and delivery vehicle routing model with three-dimensional (3D) balanced loading constraints (3BL-VRPSPD). Additionally, a hybrid tabu search (TS) algorithm embedded loading test was proposed to solve this problem. Firstly, a heuristic insertion method was applied to determine the initial routing scheme, and the node swapping and relocation operators were designed to construct the tabu neighborhood scheme for routing optimization. On this basis, the 3D balanced loading was incorporated into the routing iteration process. A balanced loading algorithm, combining multiple-indicator ordering and maximum space division strategies (MOMD), was formulated to develop a 3D-balanced loading plan for goods with a pickup and delivery vehicle routing scheme. Finally, standard instances verified the effectiveness of the method. The results show that the proposed method can effectively optimize 3BL-VRPSPD and outperform other algorithms.

Metasurface Cloaking Lens Designed by the Ray Insertion Method

This paper presents a metasurface cloak with the ability to make regions of any shape and size on the flat lens invisible in the microwave band. The gradient refractive index (GRIN) of the metasurface is designed by the ray insertion method (RIM), which enables the ray paths of electromagnetic surface waves to be tailored in a desired fashion. The lens is composed of periodic metallic square patches etched onto a grounded dielectric substrate to synthesize the required GRIN of the metasurface. The design technique is validated by simulations using a commercial software, which demonstrate the successful bending of impingent waves according to the prescribed paths and thus achieving the desired cloaking effect. A prototype of the GRIN metasurface cloak was manufactured and measured, yielding results that verify the theoretical predictions.