Insertion Length Research Articles

Impact of cochlear detailed morphology on insertion results and intracochlear trauma of a slim pre-curved electrode array: a micro-CT study.

This study aimed to evaluate the impact of detailed cochlear dimensions, assessed using micro-CT (µCT) imaging, on insertion outcomes and associated trauma with a new slim, precurved electrode array. Eleven temporal bone specimens underwent implantation of a 22-electrode slim precurved array via the round window. High-resolution µCT scans post-implantation enabled visualization of cochlear structures and electrode positioning. Combination with subsequent scans taken after electrodes removal, we analyzed angular insertion depth (AID), insertion length, number of electrodes inserted, cochlear dimensions (specifically cochlear duct length (CDL), basal turn diameter, scala tympani dimension), and intracochlear trauma of fine structures. Statistical analyses were performed to correlate cochlear detailed dimensions and morphology with insertion outcomes and trauma. The mean AID was 351.82°, and the mean insertion length was 21.07mm. CDL showed positive correlations with AID and insertion length. Basal turn diameter (value B) positively correlated with AID and insertion length, unlike value A. Middle-basal turn (M/B) relationships (angle and height) significantly influenced insertion depth. The cochleae with smaller M/B heights and specific angles were more susceptible to insertion trauma. Larger basal turn diameters correlated with increased trauma and electrode translocation into the scala vestibuli. This study highlights the importance of precise cochlear measurements in predicting and optimizing cochlear implant outcomes. Specific cochlear dimensions and anatomical shapes were identified as critical factors affecting insertion depth, trauma risk, and electrode positioning. Utilizing micro-CT provided detailed insights into cochlear anatomy and insertion outcomes, offering valuable data for advancing cochlear implant technology and surgical practices.

Quantifying Distal Deltoid Disruption With Linear versus Curvilinear Plating of Proximal Humerus Fractures: A Cadaveric Study

BACKGROUND: Plate fixation of proximal humeral fractures is usually associated with some degree of distal deltoid dissection. The purpose of this study was to quantify deltoid release with standard linear versus curvilinear plates used in the repair of proximal humeral fractures. METHODS: Seven nonpaired, fresh-frozen, clavicle-to-fingertip cadaveric shoulders met the inclusion criteria for this study. Four different proximal humerus implants were tested. One of these plates was curvilinear (89 mm), and the other 3 plates were linear (85, 98, 109 mm in length). Plates were compared based on the amount of deltoid insertion released for proper plate positioning. An analysis of variance with post hoc Tukey tests was conducted to compare mean deltoid disruption across the 3 shortest plate types from each manufacturer. A linear regression analysis was conducted to analyze the effect of plate length on mean deltoid release. RESULTS: The mean deltoid insertion length was 39.6 ± 8.6 mm (n = 7). The curvilinear plate (89 mm) required the least amount of average deltoid release at 4.1 ± 4.5 mm, or 12.1% of the deltoid insertion. Independent analysis of variance, including the 3 shortest plates from each manufacturer, found a significant effect of which plate was used on the amount of deltoid disruption that resulted (F(2, 18) = 18.0, P < 0.001, ω = 0.6). A linear regression including all 4 plates demonstrated a statistically significant direct relationship between the plate length and the mean deltoid released (y = 0.6x − 43.8, r2 = 4). CONCLUSION: This study demonstrates that proximal humerus plate length has a direct relationship with the amount of deltoid released during plating. Although deltoid disruption is length dependent, plate shape (curvilinear vs. linear) could also be contributory. When comparing a curvilinear and a linear plate of similar lengths, the curvilinear plate resulted in less mean deltoid release.

EP274 - A clinical audit on nasogastric tube placement documentation and adherence with NICE guidelines in general surgical patients across a district general hospital

Abstract Aims NICE provide clear guidelines on confirming correct nasogastric (NG) tube siting using pH testing of aspirates or with X-rays where indeterminate samples are drawn. We aimed to audit documentation following nasogastric tube insertion to ascertain adherence to NICE guidelines. Methods A single-cycle snapshot audit was conducted on all surgical inpatients who had nasogastric tubes inserted over their admission across a single-centre district general hospital general surgery department. Data was collected on indication for NG tube insertion (drainage or feeding), length of initial tube insertion, whether pH testing was used to confirm position, and whether correct tube placement has been confirmed by a competent person through x-ray where indeterminate samples were tested from NG aspirate (pH > 5.5). Results A total of 15 patients had an NG tube inserted over their admission with mean age 77.3 years (range 47-97). 60% of patients had correctly documented confirmation of NG tube siting. 4/15 NG tubes were inserted for feeding purposes (26.7%), all of which were documented correctly. Only 45.5% of NG tubes for drainage were documented correctly and only 33.3% of all NG tubes had length of insertion documented. Where pH testing was inconclusive, a chest X-ray was requested for all patients and sufficiently documented by a doctor qualified to confirm position. No complications relating to NG tubes occurred across the audit study. Conclusions Implementation of improvement measures are warranted to improve overall adherence with NICE guidelines and prevent risk of incorrect confirmation of NG tube siting.

Using computed tomography to evaluate anatomic landmarks in taiwanese trauma patients for insertion of resuscitative endovascular balloon occlusion of the aorta: A retrospective cohort study.

Hemorrhage, particularly from non-compressible torso hemorrhage (NCTH) in the abdominopelvic region, is a leading cause of preventable trauma deaths. Resuscitative endovascular balloon occlusion of the aorta (REBOA), designed for aortic occlusion, has emerged as a tool for temporary hemorrhage control in recent years. However, attaining optimal REBOA placement in diverse demographic groups, such as Asian populations, may pose challenges owing to unique anatomical and physiological differences. This retrospective study analyzed trauma patients who underwent torso computed tomography (CT) at tertiary hospitals in Taiwan from January 2014 to January 2017. The OsiriX software was used to measure the endovascular lengths in the CT images. Among the 223 patients, the median vascular lengths and body measurements were higher in males. The optimal fixed insertion length was identified as 47.5cm for zone 1 with 99.43% accuracy and 25.5cm with 82.1% accuracy for zone 3. The landmark-guided method showed 100% accuracy for zone 1 when using the mid-sternum and 94.6% for zone 3 with the umbilicus as the guide with the distance between the umbilicus, xiphoid process, and pubic ramus. External validation confirmed the accuracy of the landmark-guided method. For zone 1 occlusions, a range of 44-48cm insertion length cross-referenced with the mid-sternal landmark is recommended. For zone 3 occlusions, using the umbilicus as a guide with the distance between the umbilicus, xiphoid process, and pubic ramus provided the highest accuracy.

Peripherally Inserted Central Catheter Tip Malposition in Neonates: A Comparison of Placement in the Head & Neck, Upper Extremity, and Lower Extremity

Background: While catheter lengths are determined based on guidelines, regional studies should be considered to ensure optimal catheter placement. Objectives: This study aimed to compare the incidence of tip malposition and the amount of catheter retraction required to achieve appropriate placement in peripherally inserted central catheters (PICC) inserted in the head and neck, upper extremities, and lower extremities to determine the optimal catheter placement site. Methods: This cross-sectional study was conducted in the Children's Medical Center NICU between 2020 and 2021. After the initial calculation of catheter insertion length based on guidelines, PICC placement was performed by two skilled nurses. The catheter position was then confirmed, and the amount of catheter retraction was compared for each group. Results: A total of 368 neonates were included in the study. The results showed a statistically significant higher incidence of catheter tip malposition in the upper extremity group (P-value = 0.004). The minimum amount of catheter retraction required to achieve proper placement was 1 cm. Conclusions: This study suggests that the formula for calculating the length of the catheter in the upper extremities should be adjusted. However, further studies are needed to confirm this.

Exploring aortic morphology and determining variable-distance insertion lengths for fluoroscopy-free resuscitative endovascular balloon occlusion of the aorta (REBOA)

Background (Rationale/Purpose/Objective)Resuscitative endovascular balloon occlusion of the aorta (REBOA) is used to temporary control non-compressible truncal hemorrhage (NCTH) as bridge to definitive surgical treatment. The dependence on radiography for safe balloon positioning is one factor that limits the extended use of REBOA in civilian and military pre-hospital settings. We aimed to determine standardized sex and age-based variable-distance catheter insertion lengths for accurate REBOA placement without initial fluoroscopic confirmation.MethodsContrast enhanced CT-scans from a representative sample of a Dutch non-trauma population were retrospectively analyzed. Intravascular distances were measured from the bilateral common femoral artery access points (FAAP) to the middle of the aortic occlusion zones and accompanying boundaries. Means and 95% confidence intervals for the distances from the FAAPs to the boundaries and mid-zone III were calculated for all (combined) sex and age-based subgroups. Optimal insertion lengths and potentially safe regions were determined for these groups. Bootstrap analysis was performed in combination with a 40-mm long balloon introduction simulation to determine error-rates and REBOA placement accuracy for the general population.ResultsIn total, 1354 non-trauma patients (694 females) were included. Vascular distances increased with age and were longer in males. The iliofemoral trajectory was 7 mm longer on the right side. The optimal zone I catheter insertion length would be 430 mm. Optimal zone III catheter insertion lengths showed up to 30 mm difference, ranging between 234 and 264 mm. Statistically significant and potentially clinically relevant differences were observed between the anatomical distances and necessary introduction depths for each subgroup.ConclusionThis is the first study to compare aortic morphology and intravascular distances between combined sex and age-based subgroups. As zone III length was consistent, length variability and elongation seem to mainly originate in the iliofemoral trajectory and zone II. The optimal zone I catheter insertion length would be 430 mm. Optimal zone III catheter insertion ranged between 234 and 264 mm. These standardized variable-distance insertion lengths could facilitate safer fluoroscopy-free REBOA in austere, pre-hospital settings.

Observational study of left bundle branch area pacing: implantation of the solia S lead using the selectra 3D sheath at an inclined angle

BackgroundLeft Bundle Branch Area Pacing (LBBaP) is a cardiac pacing technique designed to mimic the natural conduction system of the heart. Traditional right ventricular apical pacing has been associated with increased risks of heart failure and atrial fibrillation. This study investigates the stability and safety of LBBaP using the Selectra 3D sheath (Biotronik) with an inclined angle for implanting the Solia S lead (Biotronik, SE & Co, KG).MethodsA single-center retrospective study was conducted on 25 patients who underwent LBBaP implantation using the Selectra 3D sheath at our hospital. The procedure involved inserting the Solia S lead into the interventricular septum at an inclined angle. Surgical and postoperative data were collected, including the success rate, depth and angle of electrode insertion, complications, and follow-up data.ResultsThe success rate of LBBaP implantation was 92%. The length of electrode insertion into the interventricular septum ranged from 12 to 23.0 mm, with an average of 18.1 ± 3.08 mm. The angle formed between the electrode and the septum ranged from 0° to 57.3°, with an average of 35.14°±14.31°. During the 3-month follow-up period, pacing parameters remained stable, and no complications were reported.ConclusionsLBBaP implantation using the Selectra 3D sheath with an inclined angle for the Solia S implantation demonstrates stability and safety. The procedure boasts a high success rate and offers an effective option for LBBaP implantation.

Prediction of internal jugular vein catheter length inserted through the posterior approach of the sternocleidomastoid muscle.

This study aimed to determine an equation to estimate the optimal insertion length for catheter placement via the posterior approach of the sternocleidomastoid muscle in cancer patients. This retrospective study included patients with cancer who underwent infusion port implantation surgery in the Oncology Department of the 900th Hospital of Joint Logistic Support Force of the Chinese People Liberation Army from April 2017 to September 2023. Patient height (H), weight (W), chest length (C), and length of the internal jugular vein catheter (L) were collected from medical records. The patients were randomized 7:3 to the training and validation sets. Linear regression analyses were used in the training set to determine formulas to predict catheter length. The formula predictive value was analyzed using the Bland-Altman method in the validation set. This study included 336 patients, with a mean age of 58.27 ± 11.70 years, randomized in the training (n = 235) and validation (n = 101) sets. Linear regression analysis revealed that the equations for catheter length relative to H, body mass index (BMI), and C are L = 0.144 × H - 8.258 (R² = 0.608, P < .001), L = -0.103 × B + 17.384 (R² = 0.055, P < .001), and L = 0.477 × C + 1.769 (R² = 0.342, P < .001), respectively. The multivariable linear regression analysis showed that the equation between the length of the catheter and H and C was L = 0.131 × H + 0.086 × C-8.515 (R² = 0.614, P < .001). The Bland-Altman analysis in the validation set showed that the predicted values of internal jugular vein catheter length and the actual values showed good agreement. The optimal L might be determined by simple formulas based on patients H and C.

Neutron balance approach for inline critical rod position search calculation in Monte Carlo reactor analysis

The critical rod position search has been one of the issues in the Monte Carlo (MC) reactor analysis. This paper proposes a practical and simple approach for the critical rod position search based on the neutron balance equation and the monotonic relation between the control rod absorption rate and the total rod insertion length. The proposed method was implemented in an inline manner within the McCARD, the MC reactor design code, so that the critical rod position is calculated and updated for each fission source iteration. The numerical results in a typical fast reactor problem demonstrate the promising performance of the proposed method in the critical rod position search calculation. Furthermore, the cycle depletion calculation was performed to show the capability of the McCARD to simulate the rodded operation condition. By addressing the critical rod position search problem through the neutron balance approach, the applicability of the MC code in the advanced reactor design will be expanded.

Aortic valve cusp size and shape in dilated trileaflet aortic roots

ObjectivesThe objective of the study was to quantify the differences in cusp size and shape in patients with normal and dilated trileaflet aortic roots and in dilated roots with or without aortic regurgitation. MethodsA retrospective analysis of computed tomography studies in patients with normal and dilated trileaflet aortic roots was performed measuring root and cusp dimensions. Normal root size was defined as sinuses of Valsalva diameter less than 40 mm, dilated as 45 mm or greater. Root measurements normalized to basal ring diameter and cusp measurements normalized to geometric height were analyzed to assess the shape. Additionally, comparison of dilated roots with or without aortic regurgitation was made. ResultsWe analyzed 146 normal and 104 dilated aortic roots and 73 propensity-matched pairs. Dilated roots were larger in all dimensions and had increased ratio between commissural and basal ring diameter (1.58 ± 0.23 vs 1.11 ± 0.10, P < .001). Cusps in dilated roots were larger in all measured dimensions and were elongated with increased normalized cusp insertion length (3.64 ± 0.39 vs 3.26 ± 0.20, P < .001) and normalized free margin length (2.53 ± 0.30 vs 2.16 ± 0.19, P < .001). In patients with dilated root and no cusp prolapse (n = 83), those with moderate or severe aortic regurgitation had larger commissural diameter but similar cusp dimensions compared with those with no or mild aortic regurgitation. ConclusionsThe cusps in dilated roots elongate transversely and to a lesser degree radially. Functional aortic regurgitation is caused by extensive commissural dilatation and not by inadequate cusp adaptation.

Bilateral tensor fascia suralis muscles and unilateral accessory biceps femoris muscle: a cadaveric case study

PurposeThis study reports the findings of bilateral tensor fascia suralis muscles (TFS) and a unilateral accessory muscle belly of the biceps femoris (AMBF) in a 72-year-old female. Case reportThe findings were initially identified during educational dissection of the lower extremities by medical students. The AMBF and bilateral TFS were further dissected to identify their origins and insertions. The left TFS (length, 22.83 ± 0.05 cm; width, 6.24 ± 0.14 mm) originated from the biceps femoris long head muscle (BFLH) and inserted onto the crural fascia overlying the lateral head of gastrocnemius muscle. The right TFS (length, 114.89 ± 0.62 mm; width, 9.82 ± 0.11 mm) originated from the BFLH and inserted onto the crural fascia overlying the medial head of gastrocnemius muscle. The length of the crural fascia insertion was 76.26 ± 3.00 mm (left) and 127.69 ± 1.41 mm (right). An AMBF was present in the left lower limb, originating from the greater trochanter and inserting on the distal end of the BFLH. The common peroneal nerve passed deep to the AMBF, 20.3 cm inferior to the inferior border of the piriformis. ConclusionThis data characterizes a novel finding of bilateral TFS muscles with a unilateral AMBF.

Effect of Exhaust Pipe Size on Separation Efficiency of Cyclone Separator Used in Power Plant

In order to grasp the influence of exhaust pipe size on cyclone flow fields and improve the recovery and utilization rate of coal powder in power plant, the flow characteristics and the separation capacity of the fine coal powder separator in power plant were investigated through numerical simulation. The Reynolds stress model was employed to model the turbulent flow. The Eulerian-Lagrangian computational procedure was used to predict particles tracking in the cyclone. The particle trajectories were simulated using the discrete random walk. Five cyclone types with different insertion lengths of the exhaust pipe at the same other geometric dimensions were considered. It was found that tangential velocity played a dominant role in the radial distribution of particles, which was mainly represented by Rankine vortex. When the insertion length of the exhaust pipe was increased from 1638 mm to 5100 mm, the grade efficiency of 5–12 μm particles was increased by 19%, and the pressure drop reduced by 8%.

Outcomes of Utilizing Novel Versus Traditional Method of Length of Gastric Tube Insertion in Critically Ill Patients

Outcomes of Utilizing Novel Versus Traditional Method of Length of Gastric Tube Insertion in Critically Ill Patients

Blind versus endoscopy-guided postpyloric feeding tube placement in adults with ischemic stroke: A retrospective cohort study.

This study compared the one-time success rate of blind and endoscopy-guided postpyloric feeding tube placement after implementing a comprehensive nursing scheme of intestinal blind placement for patients with ischemic stroke. This retrospective cohort study included 179 patients with blind bedside placement and 118 with endoscopy-guided placement. The primary outcome was the one-time success rate of radiologically confirmed postpyloric placement. The secondary endpoints included the position of the tube tip, length of insertion, time of placement, and expenses. The safety endpoints were the incidence of complications caused by placement. The results showed that the method of tube placement did not significantly affect the outcome of the first tube placement (odds ratio [OR] = 0.41; 95% CI = 0.137-1.207; P = 0.105). Compared with endoscopy-guided placement, blind placement was half the cost. We also found that a history of abdominal surgery (OR = 0.003; 95% CI = 0.000-0.059; P < 0.001) and longer intensive care unit (ICU) days (OR = 0.94; 95% CI = 0.903-0.981; P = 0.004) were inversely associated with the one-time success rate. Our study suggested that blind intestinal feeding tube placement has an equivalent one-time success rate compared with endoscopy-guided placement in hospitalized patients with ischemic stroke if operators can be trained well. However, the expenses of endoscopy-guided placement were twice those of blind bedside methods. We also found that patients with abdominal surgery history and longer ICU stay were more likely to fail at the first placement. Further research is needed to replicate our single-center observations in a larger population of patients.

Neonatal Endotracheal Intubation: Comparison of Existing Formulae for Accuracy

Background There are several formulae proposed to calculate the ideal depth of insertion of the endotracheal tube (ETT) in neonates, none of which are universally accurate. Our objective is to identify the most accurate of these formulae and to determine the most suitable formula for babies weighing less than 1 kg. Methods This is a retro-prospective observational study conducted in a tertiary neonatal intensive care unit. All intubated babies, irrespective of their gestational age, were included in this study. Those with congenital airway anomalies or syndromes with involvement of the upper airway and those who required short-term ventilation restricted to the theatre complex were excluded. The ideal insertion depth was determined via a chest X-ray (CXR) with the ETT projecting between thoracic vertebrae 2 and 3. Predictions from eight formulae investigated in the Indian population were analysed using paired Wilcoxon tests and Bland–Altman plots. Results The sample size was 83, of which 16 weighed less than 1 kg. Neither weight-based nor naso-tragal length (NTL)-based formulae were universally accurate in the prediction of the ideal depth of insertion, and using either of the formulae resulted in a high rate of malpositioning. Amongst the NTL-based formulae, Tatwavedi and Singh’s adjustments worked better than the original. Conclusion The currently available formulae remain inaccurate in the prediction of the ideal length of insertion of ETT, more so in babies less than 1 kg in our study population.

Implant Fixture Fracture Related To Angulation Path Compounded By Implant Width

Accurate implant placement is vital to the proper function and life of not only the implant fixture but also the implant-restoration structural unit. Less than 1% of implant failures occur primarily due to fracture of the implant fixture. Though the principle of implant placement today is prosthetic-driven, proper implant fixture placement is fundamental to the life of the implant-prosthesis unit and includes factors such as selection of key factors such as expertise of dentist or specialist placing the implant fixture, length, and diameter, angulation or path of insertion, length and of implant fixture. Research indicates that among the factors listed, diameter and angulation or proposed path of insertion of the implant fixture play an important role in the long-term stability of the implant fixture. In this case report, we describe a patient who underwent implant therapy, bilaterally, in the mandible. Implant fixtures were placed in the region of missing tooth #19 and #30 which were previously extracted due to pulpal disease of carious origin. In both cases, a 5.0 mm diameter implant fixture was selected to replace the missing #19 and 30. The implant placed in the #19 region was placed with the ideal angulation and subsequently restored, while the implant fixture placed in the missing #30 location was inserted at an off-angle, then subsequently restored. Three years following restoration, the patient presented with a fractured implant replacing #30. This case report emphasizes the importance of selection of appropriate implant fixture features such as diameter and angulation for the long-term survival of the entire implant-prosthesis unit. As the report would further indicate, in the region of tooth #30, it was difficult to ascertain the cause of implant therapy failure. The case report also underpins the need to pay increased attention to all factors on an individual basis that essentially compound to improve the survivability of the implant-prosthesis unit.

In vitro evaluation of intersubject variability in pediatric intranasal drug delivery using nasal spray suspension products

Evaluation of the regional intranasal delivery of locally acting drugs in children is challenging. Anatomical nasal airway replicas potentially can provide a robust pre-clinical tool to test the performance of devices and formulations. However, there is often a challenge in identifying the nasal geometries that can reasonably be indicative of in vivo regional mass distribution of administered drug. This in vitro study was designed to investigate the regional intranasal drug delivery in 20 children, 2–11 years old (50% 2–6 years old and 50% female), using two commercially available suspension nasal spray products with different nozzle designs, plume characteristics, and active pharmaceutical ingredients. High-resolution computed tomography scans of the sinonasal region of pediatric human subjects with healthy nasal airways, reviewed and scored by a head and neck surgeon, were used to develop 20 three-dimensional (3D) replicas of the nasal airways. The 3D replicas were segmented into the two regions: anterior and posterior to the internal nasal valve (INV). They were then rapid prototyped in high clarity rigid plastic (Accura ClearVue). Each side of the septum of the 20 subjects was examined separately, resulting in 40 singular nasal cavities. A nozzle-specific spray tip holder was designed for each case to ensure consistent administration (insertion length, sagittal angle, and coronal angle) in all replicates. The wide range of posterior drug delivery observed in the forty geometries indicated significant intersubject variability in pediatric intranasal drug delivery. Three nasal geometries representing low, medium, and high levels of drug delivery to the target region, posterior to the INV, were chosen from the 40 nasal cavities. Our vision is that these three nasal geometries can potentially be beneficial in determining whether performance differences between test and reference nasal spray products are present that may affect their bioequivalence in children. They also may be useful when applied in parallel with similar adult nasal geometries, previously developed following a similar procedure, to provide additional insights into pediatric nasal drug delivery with innovator products in children in lieu of extending clinical studies to include pediatric subjects.

Quantitative 3D Analysis of Levator Ani Muscle Subdivisions in Nulliparous Women: MRI Feasibility Study.

The levator ani muscle (LAM) is crucial for pelvic floor stability, yet its quantitative MRI assessment is only a recent focus. Our study aims to standardize the quantitative analysis of the LAM morphology within the 3D Pelvic Inclination Correction System (3D-PICS). We analyzed 35 static MR datasets from nulliparous women examining the pubovisceral (PVM), iliococcygeal (ICM), coccygeal (COC), and puborectal muscle (PRM). The PVM consists of three origin-insertion pairs, namely the puboanal (PAM), puboperineal (PPM) and pubovaginal muscle (PVaM). The analysis included a quantitative examination of the morphology of LAM, focusing on the median location (x/y/z) (x: anterior-posterior, y: superior-inferior, z: left-right) of the origin and insertion points (a), angles (b) and lengths (c) of LAM. Inter-rater reliability was calculated. Interindividual variations in 3D coordinates among muscle subdivisions were shown. In all, 93% of all origin and insertion points were found within an SD of <8 mm. Angles to the xz-plane range between -15.4° (right PRM) and 40.7° (left PAM). The PRM is the largest pelvic muscle in static MRI. The ICC indicated moderate-to-good agreement between raters. The accurate morphometry of the LAM and its subdivisions, along with reliable inter-rater agreement, was demonstrated, enhancing the understanding of normal pelvic anatomy in young nulliparous women.

Effect of inside Surface Baffle Conditions on Just Drawdown Impeller Rotational Speed

The effect of inside surface baffle installation conditions on the minimum impeller rotational speed for just the drawdown of floating solid NJD was investigated. The inside surface baffle condition is the condition in which a partial baffle is placed with a clearance between the baffle and the vessel wall. In this study, a baffle with an insertion length of 0.2 times the liquid height was used. Moreover, the effect of baffle angle on NJD was investigated. The NJD was measured visually at least three times. The results showed that the effect of the radial installation position of the inside surface baffle on NJD depended on the impeller position. In addition, even baffles placed parallel to the tangential flow were found to decrease NJD.

Genome sequencing and analysis of black flounder (Paralichthys orbignyanus) reveals new insights into Pleuronectiformes genomic size and structure

Black flounder (Paralichthys orbignyanus, Pleuronectiformes) is a commercially significant marine fish with promising aquaculture potential in Argentina. Despite extensive studies on Black flounder aquaculture, its limited genetic information available hampers the crucial role genetics plays in the development of this activity. In this study, we first employed Illumina sequencing technology to sequence the entire genome of Black flounder. Utilizing two independent libraries—one from a female and another from a male—with 150 bp paired-end reads, a mean insert length of 350 bp, and over 35 X-fold coverage, we achieved assemblies resulting in a genome size of ~ 538 Mbp. Analysis of the assemblies revealed that more than 98% of the core genes were present, with more than 78% of them having more than 50% coverage. This indicates a somehow complete and accurate genome at the coding sequence level. This genome contains 25,231 protein-coding genes, 445 tRNAs, 3 rRNAs, and more than 1,500 non-coding RNAs of other types. Black flounder, along with pufferfishes, seahorses, pipefishes, and anabantid fish, displays a smaller genome compared to most other teleost groups. In vertebrates, the number of transposable elements (TEs) is often correlated with genome size. However, it remains unclear whether the sizes of introns and exons also play a role in determining genome size. Hence, to elucidate the potential factors contributing to this reduced genome size, we conducted a comparative genomic analysis between Black flounder and other teleost orders to determine if the small genomic size could be explained by repetitive elements or gene features, including the whole genome genes and introns sizes. We show that the smaller genome size of flounders can be attributed to several factors, including changes in the number of repetitive elements, and decreased gene size, particularly due to lower amount of very large and small introns. Thus, these components appear to be involved in the genome reduction in Black flounder. Despite these insights, the full implications and potential benefits of genome reduction in Black flounder for reproduction and aquaculture remain incompletely understood, necessitating further research.