Insertion Technique Research Articles

Augmented Reality Navigation System Enhances the Accuracy of Spinal Surgery Pedicle Screw Placement: A Randomized, Multicenter, Parallel-Controlled Clinical Trial.

The pedicle screw insertion technique has evolved significantly, and despite the challenges of precise placement, advancements like AR-based surgical navigation systems now offer enhanced accuracy and safety in spinal surgery by integrating real-time, high-resolution imaging with virtual models to aid surgeons. This study aims to evaluate the differences in accuracy between novel AR-guided pedicle screw insertion and conventional surgery techniques. A randomized controlled trial was conducted from March 2019 to December 2023 to compare the efficacy of AR-guided pedicle screw fixation with conventional freehand surgery using CT guidance. The study included 150 patients, aged 18-75, with 75 patients in each group. The total number of pedicle screws planned for the clinical trial placement was 351 and 348 in the experimental and control groups. The safety and efficacy of the procedures were evaluated by assessing screw placement accuracy and complication rates. In the full analysis set (FAS) analysis, the difference in the excellent and good rates of screw placement (experimental group - control group) and 95% confidence interval was 6.3% [3.0%-9.8%], with a p value of 0.0003 for the superiority test. In the FAS sensitivity analysis, the success rate was 98.0% (344 out of 351) in the experimental group and 91.7% (319 out of 348) in the control group, with a difference and 95% confidence interval of 6.3% [2.9% and 9.8%, respectively]. In the per-protocol set (PPS) analysis, the difference in the excellent and good rates of screw placement between the experimental and control groups, and the 95% confidence interval was 6.4% [3.3%-9.5%], with a p value of 0.0001 for the superiority test. In the actual treatment set (ATS) analysis, the excellent and good rates of screw placement were 99.1% in the experimental group and 91.7% in the control group. The difference in the excellent and good rates of screw placement (experimental group - control group) and 95% confidence interval was 7.3% [4.1%-10.6%], with a p value of < 0.0001 for the superiority test. The AR surgical navigation system can improve the accuracy of pedicle screw implantation and provide precise guidance for surgeons during pedicle screw insertion.

3D-printed drill guide versus fluoroscopic-guided free-hand technique for pedicle screw insertion in the upper cervical spine: a systematic review and meta-analysis.

3D-printed (3DP) drill guides have demonstrated significant potential to accurately guide pedicle screw insertion in spinal surgery. However, their role in the upper cervical spine is not well established. This review aimed to compare the efficacy and safety of 3DP drill guides to the conventional fluoroscopic-guided free-hand technique for pedicle screw insertion in the upper cervical spine. A comprehensive literature search was conducted across five databases (Medline, Scopus, CENTRAL, Web of Science, and Embase). The meta-analysis compared the accuracy of pedicle screw placement, screw placement time, operative time, blood loss, fluoroscopy usage, and post-operative JOA and VAS scores between the two approaches. Seven studies were included in the review, encompassing 386 patients and 1,512 screws. The meta-analysis demonstrated that 3DP drill guides increased the rate of perfect screw insertion (OR: 4.34, P < 0.00001) and lowered the incidence of moderate (OR: 0.26, P < 0.00001) and poor (OR: 0.09, P < 0.00001) screw insertion compared to the free-hand technique. Additionally, operative time (MD: -36.07, P < 0.00001), blood loss (MD: -83.82, P < 0.00001), and fluoroscopy usage (MD: -3.47, P < 0.0001) was significantly reduced in the 3DP cohort. No significant difference was detected in screw placement time (MD: -2.65, P = 0.07), or post-operative JOA (MD: 0.17, P = 0.47), and VAS (MD: -0.09, P = 0.19) scores between the two cohorts. The review demonstrated that 3DP drill guides are a safe and effective tool to assist pedicle screw fixation in the upper cervical spine.

Synergistic role of rootstock and grafting in boosting growth, yield, and quality of cucumber cultivation

Cucumber (Cucumis sativus L.) is a widely grown and highly valued cucurbitaceous vegetable crop, commanding premium prices in the vegetable market. However, intensive cultivation and monocropping practices have led to significant challenges in cucumber production, particularly in greenhouses, due to root-knot nematode and soil-borne diseases. Grafting has emerged as an alternative approach to boost abiotic stress tolerance and mitigate root diseases caused by soil-borne pathogens, thereby improving crop productivity. A study was conducted during 2023-2024 on the farmer’s field to explore the interactive effects of various grafting techniques by grafting a hybrid cucumber scion onto various local rootstocks. The experiment evaluated the performance of the hybrid cucumber scion Emistar, grafted onto four rootstocks: fig-leaf gourd (Cucurbita ficifolia), pumpkin (Cucurbita pepo), ash gourd (Benincasa hispida), and bottle gourd (Lagenaria siceraria). Two grafting techniques-hole insertion and splice grafting, were tested using different scion-rootstock combinations. The study evaluated growth, yield, and fruit quality under controlled environmental conditions. The results indicated that the pumpkin rootstock outperformed the other rootstocks, particularly when grafted using the hole insertion techniques. This combination achieved the earliest flowering (26.33 days), longest plant growth (455.77 cm), and highest fruit yield (8.07 kg). In contrast, splice grafting on bottle gourd resulted in slower growth and lower yields. Additionally, hole insertion grafting on pumpkin produced superior fruit characteristics, including the longest fruits (16.43 cm), largest diameter (9.1cm), highest fruit weight (147.24 g), and the highest TSS content (2.85ºBrix). Correlation and principal component analysis (PCA) highlighted strong positive relationships between yield and growth traits, emphasizing the superiority of the pumpkin rootstock for cucumber grafting. The study showed vigorous rootstocks like pumpkin can significantly enhance cucumber growth and yield through improved nutrient uptake, hormone translocation, and optimized grafting techniques.

Freehand Placement of a Transiliac-Transsacral Screw for Fixation of Posterior Pelvic Ring Injuries.

There are many advantages to stabilize the posterior pelvic ring injuries with a transiliac-transsacral (TITS) screw percutaneously. To identify the correct entry point and insert a guidewire accurately for a TITS screw, we propose a method of specifying the optimal entry point, and introduce a technique of enabling freehand placement of a guidewire with fluoroscopic guidance. In this retrospective study, 116 patients who underwent pelvic CT scans and pelvic lateral radiographs at our institution from January 2020 to April 2022 were enrolled. The optimal entry point for a TITS screw was formulated in the strict mid-sagittal CT plane, and then transferred to the pelvic lateral radiograph relying on the sacral cortexes which were easily visible even in the poor fluoroscopy. The relative position of this point to other anatomical markers was checked to confirm its feasibility as an entry point. With the method to locate the entry point, 18 patients suffered the posterior pelvic ring injuries were treated with TITS screws through hammering a reverse Kirschner wire (K-wire) to insert a guidewire assisted by a canula, followed by the validation of the screw placement accuracy. The transferred point in radiograph was consistently beneath the sacral alar slope, and located posteroinferior to the iliac cortical density (ICD) and anterosuperior to the sacral nerve root tunnel in all 116 patients. In clinical practice, 18 TITS screws were successfully placed in 18 patients without cortex violation. The average operative time for each screw was 20.11 ± 6.29 min, with an average of 14.11 ± 6.81 fluoroscopic shots per screw. At the 3-month follow-up, fracture healing was confirmed in all patients. The average Majeed score was 89.61 ± 6.90 at the final follow-up. It's feasible to identify an entry point for a TITS screw based on the sacral cortexes, and hammering a reverse K-wire assisted by a percutaneous kyphoplasty (PKP) canula is a safe and practical technique for guidewire insertion.

Peritoneal Dialysis Catheter Placement on the Right Side of the Falciform Ligament to Prevent Obstruction by the Omentum.

We describe a simple and reproducible technique for neonatal peritoneal dialysis catheter insertion following cardiac surgery which prevents the catheter from becoming blocked by the omentum.

Atraumatic forceps-guided insertion of the cervical pessary: a new technique to prevent preterm birth in women with asymptomatic cervical shortening.

As previous studies on the use of a cervical pessary to prevent preterm birth (PTB) have produced conflicting results, we aimed to investigate the feasibility, acceptability and safety of a new technique for inserting a cervical pessary and compare it with the traditional technique in patients at high risk of PTB. Women at high risk of PTB treated with a cervical pessary between January 2018 and January 2021 were retrospectively evaluated. After applying exclusion criteria, a total of 68 eligible patients were identified and retrospectively analyzed. The primary outcome was spontaneous PTB before 34weeks' gestation (WG). Of 68 participants, 39 were treated with the traditional method (group 1) and 29 with the new insertion technique (group 2). The rate of spontaneous PTB before 34 WG was significantly lower in group 2 (p=0.020). Birthweight, APGAR scores and satisfaction with the method were significantly higher, while PTB before 37 WG was significantly lower in group 2 (p=0.043, 0.010, 0.009, 0.042 and 0.014, respectively). There were no significant differences in the rates of perinatal death (12.8 vs. 3.4 % in groups 1 and 2, respectively; p=0.229). The concomitant use of vaginal progesterone was required more frequently in group 1. According to the binary regression analysis, the new insertion technique resulted in a 5.42 and 3.97-fold protection against PTB before 34 and 37 WG. Our preliminary results show that our new technique of pessary insertion is more effective than the traditional method in preventing PTB due to cervical shortening.

The influence of electrode array design, scalar dislocation and insertion technique on postoperative vertigo in CI surgery - a prospective study.

This study aimed to examine the effect of electrode array design, insertion angle, scalar position, and insertion technique on the occurrence of postoperative subjective vertigo following cochlear implant (CI) surgery using questionnaires in conjunction with objective vestibular functional measurements. We prospectively evaluated subjective vertigo using the Dizziness Handicap Inventory (DHI). Additionally, we performed videonystagmography, video head-impulse tests, and vestibular-evoked myogenic potentials to assess the objective vestibular function preoperatively, at four weeks and 12 months after CI. These results were compared with those of postoperative imaging using digital volume tomography. Postoperative vertigo was observed in 2 out of 62 patients (3%). Cochleostomy (n = 8) did not lead to an increase in postoperative vertigo. Functional diagnostics revealed abnormalities in up to 23% of patients without subjective dizziness. In our patient cohort, neither electrode array dislocation nor increasing insertion depth was associated with an increase in postoperative vertigo. Both postoperative vertigo occurrence and electrode array dislocation rates have significantly decreased due to the optimized atraumatic electrode array design and improved surgical insertion techniques. Neither dislocation nor cochleostomy appeared to induce vertigo but the sample size was too small to draw definitive conclusions.

A Compound Data Poisoning Technique with Significant Adversarial Effects on Transformer-based Sentiment Classification Tasks

Transformer-based models have demonstrated much success in various natural language processing tasks. However, they are often vulnerable to adversarial attacks, such as data poisoning, which can intentionally fool the model into generating incorrect results. In this article, we present a novel, compound variant of a data poisoning attack on a transformer-based model that maximizes the poisoning effect while minimizing the scope of poisoning. We do so by combining the established data poisoning technique (label flipping) with a novel adversarial artifact selection and insertion technique aimed at minimizing detectability and the scope of the poisoning footprint. We find that by using a combination of these two techniques, we achieve a state-of-the-art attack success rate of approximately 90% while poisoning only 0.5% of the original training set, thus minimizing the scope and detectability of the poisoning action. These findings have the potential to advance the development of better data poisoning detection methods.

Trojan Insertion versus Layout Defenses for Modern ICs: Red-versus-Blue Teaming in a Competitive Community Effort

Hardware Trojans (HTs) are a longstanding threat to secure computation. Among different threat models, it is the fabrication-time insertion of additional malicious logic directly into the layout of integrated circuits (ICs) that constitutes the most versatile, yet challenging scenario, for both attackers and defenders.Here, we present a large-scale, first-of-its-kind community effort through red-versus-blue teaming that thoroughly explores this threat. Four independently competing blue teams of 23 IC designers in total had to analyze and fix vulnerabilities of representative IC layouts at the pre-silicon stage, whereas a red team of 3 experts in hardware security and IC design continuously pushed the boundaries of these defense efforts through different HTs and novel insertion techniques. Importantly, we find that, despite the blue teams’ commendable design efforts, even highly-optimized layouts retained at least some exploitable vulnerabilities.Our effort follows a real-world setting for a modern 7nm technology node and industrygrade tooling for IC design, all embedded into a fully-automated and extensible benchmarking framework. To ensure the relevance of this work, strict rules that adhere to real-world requirements for IC design and manufacturing were postulated by the organizers. For example, not a single violation for timing and design-rule checks were allowed for defense techniques. Besides, in an advancement over prior art, neither red nor blue teams were allowed to use any so-called fillers and spares for trivial attack or defense approaches.Finally, we release all methods and artifacts: the representative IC layouts and HTs, the devised attack and defense techniques, the evaluation metrics and setup, the technology setup and commercial-grade reference flow for IC design, the encompassing benchmarking framework, and all best results. This full release enables the community to continue exploring this important challenge for hardware security, in particular to focus on the urgent need for further advancements in defense strategies.

Percutaneous versus surgical catheter insertion for peritoneal dialysis: a systematic review and meta-analysis of randomized controlled trials.

Peritoneal dialysis (PD) is used as a kidney replacement therapy for patients with kidney failure. Institutional practices vary considerably, and the optimal technique for insertion of PD catheters is unknown. This study compared the efficacy and safety of surgical versus percutaneous approaches to PD catheter insertion for patients with end-stage kidney disease. Electronic databases (MEDLINE, Embase, CENTRAL) were systematically searched and analysed for relevant randomized controlled trials (RCTs). Eligible RCTs for inclusion were those that compared surgical versus percutaneous approaches to catheter insertion for patients undergoing PD dialysis. Outcomes of interest were patient- and catheter-related complications. In this study risk of bias was assessed using the Cochrane Risk of Bias Tool for RCTs. The certainty of the evidence was evaluated using the Grading of Recommendations Assessment and Evaluation (GRADE) approach. Four studies (397 participants) were included. With regards to surgical approaches, only one study evaluated laparoscopic insertion; all other studies reported on open surgical techniques. Percutaneous insertion techniques varied significantly between the studies. No difference in patient mortality was found (RR = 0.82, 95% CI = 0.43-1.57, I2 = 0%). Percutaneous techniques were associated with lower rates of early peritonitis (RR = 0.34, 95% CI = 0.12-0.91, I2 = 0%) and long-term catheter failure (RR = 0.69, 95% CI = 0.47-1.00, I2 = 0%) than surgical approaches. Percutaneous catheter insertion was also associated with reduced late peri-catheter leak rates (RR = 0.35, 95% CI = 0.12-0.98, I2 = 0%) and peri-procedural complications (RR = 0.25, 95% CI = 0.07-0.90, I2 = 0%). The overall risk of bias was moderate, and certainty of evidence was low or very low. Whilst percutaneous PD insertion techniques may have lower early and late complications compared to surgical technique, there was a lack of high-quality evidence comparing outcomes between contemporary percutaneous and surgical PD catheter insertion techniques. Future RCTs are required to compare the safety and efficacy of modern percutaneous with laparoscopic techniques.

Usage and Preferences of Orthodontic Mini-Implants Among Romanian Practitioners: A Survey Study.

Background/Objectives: Dental malocclusions are highly prevalent worldwide, negatively impacting patients' quality of life and leading to complex, often costly, orthodontic treatments. In Romania, the economic status of patients and the limited public funding for orthodontic care significantly influence treatment accessibility and choices. Advanced technologies, such as mini-implants (MIs), offer improved anchorage and treatment efficiency but are often underutilized due to financial constraints and variability in clinical training. In this context, there are limited data regarding the use and preferences of MI among orthodontists in Romania. This study aims to explore the characteristics, preferences, and challenges of Romanian orthodontists in their use of MI systems. Methods: A survey was conducted between June and September 2024, targeting orthodontists across Romania. The questionnaire, distributed via social media platforms, consisted of 24 items addressing professional experience, MI system preferences, insertion methods, and complications. Statistical analyses were conducted using IBM SPSS Statistics 25. Fisher's Exact Test and Pearson's Chi-Square Test were employed to evaluate relationships between categorical variables. When appropriate, logistic binomial univariable regression models were applied to predict key dependent variables (e.g., MI placement zones, MI experience, and MI complications) based on independent variables such as specific MI system usage and frequency of MI usage. A significance threshold of α = 0.05 was used for all tests. Results: Out of 105 participants, 85.7% reported using mini-implants (MIs) in their orthodontic practice, with the Dual Top and Benefit systems being the most frequently used (60% and 43.3%, respectively). The interradicular area was the most common placement site (60%), while the palatal and retromolar regions showed significant correlations with the Benefit system (p = 0.008). Practitioners with more than 10 years of experience reported a significantly higher frequency of MI use (p = 0.001), with frequent use being observed in 60.9% of these practitioners. Complications were common, with MI mobility reported by 92.2% and soft tissue damage by 57.8%. The midpalatal area was significantly associated with higher complication rates compared to other sites (p < 0.001). The success rates of MI usage ranged from 76% to 100% in 57.8% of respondents, with higher success rates being associated with infrazygomatic placements (p < 0.05). Conclusions: MI usage is prevalent among Romanian orthodontists, with experienced practitioners utilizing them more frequently. Despite high success rates, common complications highlight the need for improved insertion techniques and post-operative care. Further research and training are recommended to optimize MI application and reduce complication rates.

Qualitative study on the ability of neurological nurses to manage patients with indwelling gastrointestinal canal.

This study aims to assess the proficiency of nurses in the neurology department in managing patients with indwelling gastrointestinal canal. Many critically ill patients in neurology departments require the placement of nasoenteric tubes to provide enteral nutrition. However, in clinical practice, there exists considerable variability in nurses' competencies regarding the management of patients with nasoenteric tubes. A thorough understanding of the challenges nurses face throughout the entire process of nasoenteric tube care and the development of targeted improvement measures are crucial for delivering enhanced patient care and facilitating patient recovery. A qualitative interview study. From August to October 2023, 11 neurological nurses were recruited offline in three hospitals for semi-structured and in-depth interviews. The data analysis uses the KJ method to summarize and classify the themes from the semi-structured interview results, and then organize the themes into a coherent visual and logical path. The COREQ list is used. The researchers conducted semi-structured interviews with 11 neurology nurses from three hospitals using a purposive sampling method, of which 64% of the participants were female and 36% were male; the average age was 38.27 ± 7.85 years; 27% from the Department of Neurology, 73% from the Department of Neurosurgery; junior professional titles accounted for 18%, intermediate professional titles accounted for 64%, senior professional titles accounted for 18%; 27% of the subjects were head nurses and 73% were nurses. The study identified 5 themes: (1) Preparation and evaluation before intubation; (2) Enhancement of intubation success rates; (3) Prevention of complications; (4) Management of complications and emergencies; (5) The acquisition of relevant knowledge and experience. In clinical practice, the bedside blind insertion technique is random and has not yet formed a unified standard, and the specific operation details and techniques need to be further improved. Disparities exist in the nursing capabilities of neurology nurses due to variations in their knowledge and experience regarding gastrointestinal canal management.

A simple technique to improve docking time in robotic surgery

The docking process is a crucial step in robotic surgery, which determines the technical capability of moving the robotic arms during surgery and affects the performance of surgery. Robotic companies, therefore, provide setup guides recommending the trocar placement, arm carts, and operating table positioning for each procedure or body quadrant, to facilitate this process. This process takes time and although improves with experience, reported docking times range from 4 to 29 min. The final step of docking the robot is sometimes challenging and includes the insertion of the robotic instruments into the surgical field which involve patient safety. We implemented a simple new technique for safe insertion of robotic instruments and overcome the challenge of manipulating the camera arm for visualizing the trocars and advancing of the robotic instruments into the surgical field. This technique utilizes simple laparoscopic skills of laparoscopic instrument insertion. Docking times were recorded in ten consecutive patients undergoing robotic surgeries with the Hugo RAS™ and compared to our prospectively collected data registry prior to this technique. The new technique reduced the average docking time by 3.5 min and resulted in improvement of 45% in docking time. Integrating trivial laparoscopic skills into the docking process may simplify and reduce the docking time in robotic surgery.

Needle tip insertion technique for accurate and safe puncture in endoscopic ultrasound-guided tissue acquisition.

Needle tip insertion technique for accurate and safe puncture in endoscopic ultrasound-guided tissue acquisition.

Comparative efficacy and safety of mid-neck vs. supraclavicular vagus nerve stimulation in pediatric drug-resistant epilepsy.

A supraclavicular insertion approach for vagus nerve stimulation (VNS) may permit a wider range of VNS settings compared to traditional insertion techniques due to increased anatomic distance between VNS leads and the recurrent laryngeal nerve. Beyond potential technical advantages, this approach could offer greater cosmetic satisfaction for patients. However, the safety and efficacy of the supraclavicular approach is uncertain. We compared safety and efficacy of supraclavicular versus mid-neck insertion techniques for VNS in the treatment of pediatric drug-resistant epilepsy (DRE). Single-center retrospective analysis of children with epilepsy (< 21 years of age) who received VNS via supraclavicular or mid-neck insertion from May 2017 to December 2022. Continuous variables were compared using Wilcoxon rank-sum tests, while categorical variables were analyzed with Fisher's exact tests. The study included a total of 88 patients (Male/Female:38/50), with 18 having supraclavicular and 70 mid-neck VNS insertions. No significant differences between groups were found in demographics, clinical/seizure characteristics, VNS settings, side-effect profile related to VNS surgery or stimulation, or seizure outcomes at last follow up. The supraclavicular approach to VNS does not differ from the mid-neck method in terms of efficacy and overall safety profile. Future research with a larger cohort and longer-term follow-up is needed to explore the clinical significance of VNS settings in the context of different lead locations.

Refined Techniques in Tibial Nailing.

Intramedullary nail fixation of unstable tibial diaphyseal fractures is commonly used with excellent clinical results. Indications for nailing have rapidly expanded over recent years, allowing for more difficult fractures to be addressed with "extreme nailing." Despite its widespread use, evolution of newer nailing systems and varying techniques for insertion bring new difficulties with tibial fracture reduction, and malalignment occurs with relative frequency. This highlights the need for a methodical approach for efficient and predictable tibial nailing. An algorithmic approach is essential, beginning with identifying challenging patterns in proximal and distal fractures and addressing any intra-articular elements initially. A semiextended approach is helpful to neutralize deforming forces. Optimizing the starting point and confirming lateral termination of the guidewire mitigate fracture malreduction after nail placement. Fracture reduction is facilitated with clamps, fibular or tibial plating, blocking screws or wires, external fixation, universal distractor, or manual manipulation to optimize outcomes and avoid pitfalls in an effective tibial nailing.

Unsedated or On-Demand Minimally Sedated Water-Aided Outpatient Colonoscopy in Colorectal Cancer Screening and Surveillance: A Step Forward or Backward? Experience from Daily Practice in a Regional (Nonacademic) Hospital.

Background: By using optimal insertion techniques with water infusion and dynamic position changes, pain during colonoscopy is greatly reduced and the procedures can usually be performed without sedation. We investigated whether the excellent results with water-aided colonoscopy reported by experts are reproducible in daily practice in a regional hospital. Methods: During the year 2023, 500 consecutive outpatients 50-75 years old presenting for colorectal cancer screening and surveillance could choose between unsedated or on-demand minimally sedated colonoscopy, moderate sedation with midazolam, or deep sedation with propofol. A total of 57% opted for unsedated colonoscopy, and of those patients, 250 consecutive patients were included. The primary outcome was the feasibility of the procedure. Cecal intubation rate (CIR), pain scores, use of midazolam, and willingness to repeat future procedures in the same way were registered periprocedural. Additional outcomes were cecal intubation time (CIT), detection rate of lesions, polyp resection rate, rate of adequate bowel preparation, and volume of water aspirated during insertion. Results: 250 consecutive sedation-free or on-demand minimally sedated water-based colonoscopies were analyzed. The CIR was 98%. A total of 96.5% completed without sedation and 5% of the procedures were perceived as moderately painful, but none had severe pain. The willingness to repeat was 97%. The mean CIT was 8.2 min. Conclusions: Using water-aided insertion techniques, comfortable sedation-free, or on-demand minimally sedated colonoscopy in daily practice in a regional hospital is feasible in the vast majority of patients presenting for colorectal cancer screening and surveillance, and the willingness to repeat is very high.

Central venous catheter-related infections: a systematic review, meta-analysis, trial sequential analysis and meta-regression comparing ultrasound guidance and landmark technique for insertion

BackgroundDuring central venous catheterization (CVC), ultrasound (US) guidance has been shown to reduce mechanical complications and increase success rates compared to the anatomical landmark (AL) technique. However, the impact of US guidance on catheter-related infections remains controversial. This systematic review and meta-analysis aimed to compare the risk of catheter-related infection with US-guided CVC versus AL technique.MethodsA systematic search on MEDLINE, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science databases was conducted until July 31, 2024. Randomized controlled trials (RCTs) and non-randomized studies of intervention (NRSI) comparing US-guided versus AL-guided CVC placement were included. The primary outcome was a composite outcome including all types of catheter-related infection: catheter-related bloodstream infections (CRBSIs), central line-associated bloodstream infections (CLABSIs), catheter colonization, or any other type of reported infection. The secondary outcomes included individual infection types and mortality at day-28. Subgroup analyses based on study type and operator experience were also performed.ResultsPooling twelve studies (8 RCTs and 4 NRSI), with a total of 5,092 CVC procedures (2072 US-guided and 3020 AL-guided), US-guided CVC was associated with a significant reduction in catheter-related infections compared with the AL technique (risk ratio (RR) = 0.68, 95% confidence interval (CI) 0.53–0.88). In the RCT subgroup, the pooled RR was 0.65 (95% CI 0.49–0.87). This effect was more pronounced in procedures performed by experienced operators (RR = 0.60, 95% CI 0.41–0.89). In inexperienced operators, the infection risk reduction was not statistically significant. The pooled analysis of CRBSIs and CLABSIs also favored US guidance (RR = 0.65, 95% CI 0.48–0.87).ConclusionUS-guided CVC placement significantly reduces the risk of catheter-related infections compared to the AL technique, particularly when performed by experienced operators.Trial registration PROSPERO CRD42022350884. Registered 13 August 2022.

Pipe Insertion Technique for Slug Attenuation in a Downwardly Inclined Pipeline

Slug flow is more prevalent in downwardly inclined pipelines and it is important to develop effective and suitable mitigation strategies to reduce its occurrence and enhance stable flow. In this work, the application of pipeline insertion was proposed to reduce slugging in pipeline. A simulation based approach was adopted and a model with smaller pipe sizes of 3.958-inch, 1.995-inch and 6-inch diameter, inserted near the pipeline riser system. The developed model was run for 2 hours to monitor the harsh nature of the slug on the total liquid volume flow, the pressure at the pipeline riser outlet, surge liquid volume and accumulated liquid volume. The result shows a stable liquid production of approximately 3797.08bbl/day and 3798.44bbl/day for the 3.958-inch and 1.995-inch diameter pipe size, while the total liquid flow oscillated between 7366.45bbl/day and 1.917.37bbl/day, and repeated at 0.22 hours. There was a pressure buildup and later steady at 761.978 psia and 762.127 psia for the 3.958-inch and 1.995-inch diameter pipe at the riser base while the 6-inch diameter pipe was fluctuating. Smaller diameter pipe of 3.958-inch and 1.995-inch gave a stable fluid pressure of 725.196 psia at the riser top (outlet) .Therefore, smaller diameter pipe is the best to insert since there was no cyclic fluctuation of pressure at the riser top, which can lead to severe slugging.

Quantitative Equivalence and Performance Comparison of Particle and Field-Theoretic Simulations.

Particle and field-theoretic simulations are both commonly used methods to study the equilibrium properties of polymeric materials. Yet despite the formal equivalence of the two methods, no comprehensive comparisons of particle and field-theoretic simulations exist in the literature. In this work, we seek to fill this gap by performing a systematic and quantitative comparison of particle and field-theoretic simulations. In our comparison, we consider four representative polymeric systems: a homopolymer melt/solution, a diblock copolymer melt, a polyampholyte solution, and a polyelectrolyte gel. For each of these systems, we first demonstrate that particle and field-theoretic simulations are equivalent and yield exactly the same results for the pressure and the chemical potential. We next quantify the performance of each method across a range of different conditions including variations in chain length, system density, interaction strength, system size, and polymer volume fraction. The outcome of these calculations is a comprehensive look into the performance of each method and the systems and conditions when either particle or field-theoretic simulations are preferred. We find that field-theoretic simulations are equal to or faster than particle simulations for nearly all of the systems and conditions examined. In many situations, field-theoretic simulations are several orders of magnitude faster than particle simulations, especially if the polymer chains are long, the system density is high, and long-range Coulombic interactions are present. We also demonstrate that field-theoretic simulations are considerably faster at calculating the chemical potential and bypass the challenges associated with particle-based Widom insertion techniques. Taken together, our results provide quantitative evidence that field-theoretic simulations can reach and sample equilibrium considerably faster than particle simulations while simultaneously producing equivalent results.