Entry Location Research Articles

Numerical investigation on the water entry of curved wedge-shaped sections into waves

The water entry of structures with curved boundaries into waves can be frequently observed in actual operations as they are often exposed to harsh wave conditions. To investigate the problem, a numerical model which can simulate the water entry of complex objects into waves is developed in this paper. Under the framework of Cartesian grid, Volume of Fluid method combined with Piecewise Linear Interface Calculation (VOF-PLIC) are used to capture free surface. In addition, Volume of Solid Based Immersed Boundary Method (VOS-IB) is adopted to treat the body condition. Relaxation zones are applied to generate and absorb waves. After a careful validation, five curvatures and three entry locations are selected to investigate the influences of curvature and entry locations on slamming characteristics. Discoveries can be generally summarized as follows: 1) The arriving moment of force peak is not sensitive to the entry location, but is sensitive to the shape of curvatures because of its significant influence on flow separation. 2) The magnitude of force peak is always the smallest at wave peak, followed by calm water and wave trough, regardless of the shape of curvature. 3) The relative magnitude of the pressure on the left and right sides of body surface is influenced not only by the curvature but also by the entry location, and it changes during the water entry process. 4) Sequence of flow separation on the left and right sides of the body is determined by entry location, not by the curvature.

Overlying main roof breaking characteristic and its effect on the stability of gob-side entry

In this study, to figure out the deformation mechanism, a particle flow model was used to simulate the deformation of surrounding rock in a deeply buried entry. The fracture evolution, stress, and porosity of surrounding rock in the process of the main roof breaking, meanwhile, the displacement after entry being excavated were recorded and analyzed in the simulation. The results show that the main roof breaking is different from the ideally elastic–plastic simply supported beam for it has two more plastic zones on both sides of the beam and its support points tend to move. In addition, the stress reduction zone in the coal seam is about 10 m where the coal body and surrounding rock are almost completely broken and porosity is surprisingly increasing from 0.01 to 0.39 in coal and 0.23 in the main roof. The displacement concentrated on the ribs of entry, especially on the coal pillar. The continuous and large deformation that appears in the stress reduction zone results from the nearly completely broken state of the surrounding rock. The tradeoff between the stress reduction and the broken state of the surrounding rock should be considered when choosing the location of the gob-side entry.

The minimum wage and the locations of new business entries in China: Estimates based on a refined border approach

This paper studies how the local adjustments of minimum wage levels in China affect the locations of new business entries. We use a refined border approach to address the endogeneity concerns regarding local minimum wage levels and examine whether differential changes in minimum wage levels on both sides of a county border result in abrupt changes in business entries within short distances from the border. Our results suggest that a 10% increase in the minimum wage levels decreases business entries by 2.69%. This effect is magnified for industries that pay lower average salaries or employ a larger share of unskilled workers. The entry-discouraging effects of high minimum wage levels are stronger when closer to the border where the identification assumption of the border approach is the most likely to hold and gradually decrease as we expand the widths of the border areas. Moreover, although we expect businesses could move across county borders at relatively low costs to avoid high minimum wage levels, we find that business relocation is rare and does not significantly respond to changes in the cross-county difference in minimum wage levels.

Aeromechanical Optimization of Scalloping in Mixed Flow Turbines

Abstract Scalloping of radial and mixed-flow turbocharger turbine rotors has been commonplace for many years as a means of inertia reduction and stress relief. The interest in turbine rotor inertia reduction is driven by transient loading requirements of turbocharged internal combustion engines, as this is a key factor in the time taken to meet transient engine torque requirements. Due to the high-density materials used in turbine rotors, any material removal from the turbine wheel has a significant impact on turbocharger inertia, and thus the transient response of the engine. It is well known that scalloping reduces not only inertia, but also efficiency. This study aimed to identify if it was possible to produce a new scallop design which reduced the scalloping efficiency penalty without increasing inertia or compromising mechanical constraints. This was carried out with the aim of developing design recommendations for scalloping where a complete minimization of inertia is not the design goal. A multipoint, multi-physics numerical optimization, with constraints on inertia and back disc stress, was carried out to determine what efficiency benefit could be realized by aerodynamically designing mixed-flow turbine scalloping. An efficiency benefit was identified across the entire turbocharger operating line, with increased benefit at low engine load, whilst not exceeding the design constraints. Scalloping losses for the baseline design were found to be greatest at low engine load, where the turbine experienced a low expansion ratio, mass flow, and speed. This explains why an aerodynamic redesign yields the greatest benefit under those operating conditions. These performance predictions were experimentally validated on the cold flow test rig at Queen's University Belfast, with good agreement between simulated and measured data. To conclude the study, a detailed loss audit was carried out to identify key loss generating flow structures and to understand how changes in geometry affected the formation and development of these flow structures throughout the passage. A large vortex which entered the passage from the scalloped region and interacted with the tip leakage vortex along the suction surface of the blade was identified as the main source of loss due to scalloping. The optimized design was found to better control the location of entry of this vortex into the blade passage, thus reducing the associated loss and facilitating a performance improvement. Geometric design guidelines were then proposed based on these findings.

Prognostic Impact of Systemic Coagulation-Inflammation Index in AcuteType A Aortic Dissection Surgery.

A novel hematologic parameter, systemic coagulation-inflammation (SCI) index reflecting inflammation and coagulation pathways could be easily obtained from clinically routine laboratory findings. We hypothesize that the SCI index has prognostic implication in predicting operative mortality for patients with acute type A aortic dissection (ATAAD). This study aims to investigate the prognostic value of the SCI index and to establish an SCI-adding nomogram for mortality prediction in ATAAD patients. A total of 1,967 ATAAD patients surgically repaired were collected from 12 Chinese cardiovascular centers by the 5A (Additive Anti-inflammatory Action for Aortopathy & Arteriopathy [Multicenter Retrospective Study]) study III (2016-2020). SCI index was calculated as platelet count× fibrinogen/white blood cell count on admission. By adding SCI index, a nomogram was developed and evaluated for 90-day mortality prediction with conventional predictors via the Cox model with 10-fold cross-validation. Patients were stratified with low SCI (<40), middle SCI (40-100), or high SCI (>100). The 90-day survival rates increased with SCI index (low 86.9%; [95%CI: 84.9%-89.0%], middle 92.7% [95%CI: 90.9%-94.9%], and high 96.4% [95%CI: 94.2%-98.6%]; log-rank P< 0.001). SCI index is independently associated with 90-day mortality (adjusted hazard ratio: 0.549; 95%CI: 0.424-0.710; P< 0.001). The addition of SCI index provided significantly incremental prognostic value to base model including age, serum creatinine, DeBakey class, and location of intimal entry (area under the curve: 0.677; 95%CI: 0.641-0.716 vs 0.724; 95%CI: 0.685-0.760; P=0.002), which was confirmed by net reclassification improvement index (0.158; 95%CI: 0.065-0.235; P< 0.001) and integrated discrimination improvement index (0.070; 95%CI: 0.007-0.036; P< 0.001). SCI index is easily obtainable, performs moderately well as a predictor of short-term mortality in ATAAD patients, and may be useful for risk stratification in emergency settings. (Additive Anti-inflammatory Action for Aortopathy & Arteriopathy [Multicenter Retrospective Study] III NCT04918108).

7600 Identifying Risk Factors for Adhesion Formation in the Left Upper Quadrant - Preliminary Findings of a Prospective Study

<h3>Study Objective</h3> To identify risk factors for development of adhesions in the left upper quadrant (LUQ). <h3>Design</h3> Multi-site, prospective study approved by each institution's local institutional review board. <h3>Setting</h3> Two large academic tertiary referral centers. <h3>Patients or Participants</h3> All laparoscopic cases performed by study staff on adult patients were eligible. Cases were performed per standard protocol with entry approach and location per surgeon preference. Intraoperative photo documentation of four abdominal quadrants was obtained at the onset of each case, and additional areas as indicated. A data collection form was completed after each case to capture data on adhesiogenic events (such as prior surgeries, infections, endometriosis, radiation), time spent for adhesiolysis, route of entry, location and grade of adhesions, if present. <h3>Interventions</h3> No interventions were included in this study. The primary outcome of this study is the presence and severity of adhesions identified in the LUQ at the time of laparoscopy for benign gynecologic disease. <h3>Measurements and Main Results</h3> We present interval findings from study onset in 2019 until February 2022. A total of 520 laparoscopic cases have been collected, with an overall adhesion incidence of 59.4%. The overall incidence of adhesions present in the LUQ was 1.9%. Among patients with a history of gastric banding, sleeve gastrectomy, and Roux-en-Y bypass (n=24), there were 2 cases with adhesions in the LUQ (8.3%); one with filmy adhesions and one with dense cohesive adhesions between bowel and the anterior abdominal wall. These two patients had prior open gastric bypass and open gastric bypass revision with colectomy. No visceral or vascular injuries were noted when LUQ entry was performed. <h3>Conclusion</h3> Our early data suggests that the overall rate of adhesions in the LUQ is low, especially with prior laparoscopic gastric procedures. While a history of gastric surgery should not preclude abdominal entry in the LUQ, vigilance is important to avoid inadvertent injury to underlying structures.

Defining the safe corridor for transcondylar screw placement in the feline humeral condyle.

The aim of this study was to develop guidelines for the optimal location of drill entry and exit points for insertion of a transcondylar screw across the feline humeral condyle. Multiplanar reconstruction of feline elbow CT scans performed between 2016 and 2021 at one referral institution were reviewed. The optimum medial and lateral epicondylar entry and exit points for transcondylar screw placement were determined. These values were normalised to the humeral condylar diameter (HCD) for each elbow to determine the transcondylar screw placement guidelines. These guidelines were applied to each elbow and tolerance angles were determined in the transverse and frontal plane CT images to determine the safe corridor for screw placement. Twenty elbows from 12 cats were evaluated in this study. The guidelines for transcondylar screw placement were as follows: the medial entry/exit point was 0.38 × HCD cranial and 0.16 × HCD distal to the medial epicondyle, and the lateral entry/exit point was 0.3 × HCD cranial and 0.16 × HCD distal to the lateral epicondyle. Tolerance angles were statistically significantly (P <0.05) larger in both frontal (34.5% larger) and transverse (21.1% larger) planes when drilled from a lateral to medial direction compared with drilling from a medial to lateral direction. The guidelines determined from this study may aid clinicians in the placement of humeral transcondylar screws in cats. Where possible, drilling from a lateral to medial direction is recommended owing to the higher tolerance angles reducing the likelihood of articular surface damage. Further studies are warranted to determine whether these guidelines are clinically useful and result in the safe insertion of a transcondylar screw in the clinical setting.

Role of office layout typology in saving time and distance spent by users: Case of office buildings in Erbil city

Space organization and space layout in buildings are complex issues in architectural design. People spend most of their lives in offices, yet office buildings still get little attention. This paper examines the potential role of office space typologies in saving distance and time spent by users communicating between these spaces. The study adopts multiple methodologies to scrutinize users’ paths and track their movement. Diversity in methodologies provides a deep understanding of how spatial configurations of these spaces affect users’ movement. Three office buildings were selected in Erbil city to represent three different office space typologies. The study revealed the effective role of office space typologies in influencing the level of user satisfaction and comfort, concluding that the most influential factors in providing distances and time are circulation patterns, entry and exit locations that require considering function, organizational and administrative structure of building spaces, and balancing between horizontal and vertical accessibility.

Incidence of Misplaced Pedicle Screw in Free Hand Technique in Spine Fixation Patients

Objective: To evaluate the frequency of pedicle screw displacement during free-hand technique in spinal fixing Material &amp; Methods: This retrospective prospective study was carried out at Department of Neurosurgery Lady Reading Hospital Peshawar from June 2021 to December 2021. Total 90 patients were included. The screws were implanted utilising a free-hand placement technique. Facet joints and transverse processes were among the anatomical landmarks that were revealed. According to the level approached, the pedicle screw's entry location was selected. The insertion was done medially to the intersection of the origin of the transverse process and the lamina in the proximal thoracic spine and laterally to the pars interarticularis (T1 to T3). Results: 90 people in all were included in the trial. With a mean age of 37.5 years, the age varied from 15 to 60 years. Male to female ratio was 2:1, with 60 (66.7%) males and 30 (33.3%) females. Pedicle screws totaling 540 were inserted. 310 (57.4%) of the screws were placed at the lumbar spine, followed by 198 (36.7%) at the thoracic spine and 32 (5.9%) at the sacral spine. Conclusion: Pedicle screw cortical violation was found to be very high. Small pedicle breaches, however, have the potential to cause neurological lesions that can be reversed if the misaligned screws are fixed. Keywords: Freehand technique, Pedicle screw fixation, Spinal fracture

Comparing Vector-Borne Disease Surveillance and Response in Beijing and the Netherlands

Background:Climate change, environmental change, and globalization affect the geographical distribution of vector-borne diseases. Temperate regions should be prepared for emerging diseases and learn from each other’s experiences.Objective(s):The vector-borne disease preparedness in two regions, Beijing and the Netherlands, were compared in order understand their similarities and differences leading to learning points on this complex topic.Methods:A comparative study was performed using interviews with vector-borne disease experts from Beijing and the Netherlands and supplemented by literature.Findings:In Beijing, syndromic surveillance is a priority for the identification of suspected vector-borne disease cases. In the Netherlands, the main surveillance emphasis is on laboratory confirmed vector-borne disease cases. Vector-surveillance at potential points of entry and other high-risk locations is performed according to the International Health Regulation (2005) in both settings. Beijing controls invasive and native mosquitos, which is not the case in the Netherlands. In Beijing, vector surveillance is performed to measure mosquito density around hospitals, this is not observed in the Dutch setting. Health risks posed by ticks are a priority in urban areas in the Netherlands, and the public is educated in self-protection. In contrast, ticks seem to occur less often in Beijing’s urban areas.Conclusions:The vector-borne disease context framework allowed us to compare the vector-borne disease preparedness between Beijing and the Netherlands, despite differences in vector-borne disease challenges. We can learn valuable lessons concerning surveillance and early detection of emerging vector-borne diseases when comparing the preparedness between different regions.

Superiorly and transversely orienting the bicortical suspension device provides optimal anterolateral stability to the proximal tibiofibular joint: a finite-element study.

Instability of the proximal tibiofibular joint (PTFJ) can be treated with bicortical suspension (BCS) fixation. However, the ideal location, orientation, and configuration to apply one or two BCS devices are not clear. A finite-element model of the PTFJ was created from a female adult's CT dataset. Anterior and posterior ligaments at the PTFJ were modeled and suppressed to simulate stable and unstable joints. Fifty-six models simulated 56 device placements along guiding tunnel lines that connect eight entry locations on the fibular head to seven exit points on the anteromedial tibia. Doubling device stiffness created 56 more models. Combing any two placements created 1176 double-device configurations which were categorized to be crossed, divergent or parallel. Displacement of the fibular head relative to the fixed tibia under 100N anterolateral and posteromedial forces was assessed. Different placements had 2.1-27.9mm translation with 0.7-8.9° internal rotation under anterolateral loading, and 1.8-5.2mm translation with 6.1-7.9° external rotation under posteromedial loading. More transverse and superior orientations were associated with smaller anterolateral translation; more posterior and superior entry locations were associated with smaller internal rotation. The median (IQR) reductions in anterolateral translation by doubling device stiffness and by adding a second device were 0.8 (IQR 0.5-1.0) and 0.8 (IQR 0-6.1) mm, respectively. The type of double-device configurations had no significant effect on fibular motion. Surgeons should drill the guiding tunnel superiorly and transversely to ensure the optimal restoration of the PTFJ anterolateral stability.

Oblique Lateral Lumbar Interbody Fusion at L2-L5: Proposal of a New CT-based Preoperative Assessment to Minimize Risks

Objective: Oblique anterior to psoas (ATP) lumbar fusion is associated with advantages such as sufficient indirect decompression and restoration of lordosis. However, the ATP approach risks damaging the vascular elements anterior to the spine, and it requires a complicated left oblique surgical corridor that puts the contralateral neural elements at risk. Therefore, a thorough preoperative assessment of the location of entry into the disc space, a feasible trajectory to complete the intervertebral space procedure, and the possible retraction of the psoas muscle under these conditions are considered in this article.Methods: From January 2019 to January 2020, 160 lumbar CT scans were evaluated. Only 124 images from the L2-L3, L3-L4, and L4-L5 levels met the inclusion criteria. The length of the anterior vertebral line (AVL) and the middle-third of the disc in the anteroposterior axis were measured to localize the entry point (EP). The distance between the anterior arterial vessel (AV) and the EP was also measured. The trajectory commonly used to set the surgical instruments into the disc space was called α, and a new proposed trajectory termed β was calculated. The psoas cross-sectional area anterior to the β angle trajectory was measured to determine any possible retraction using this parameter. Results: The AVL-EP distances were L2-L3 11.49±0.89 mm, L3-L4 11.54±0.88 mm, and L4-L5 11.57±0.87 mm. The AV-EP lengths were 17.64±5.62 mm, 19.36±5.49 mm, and 16.48±6.47 mm at L2-L3, L3-L4, and L4-L5, respectively. The average α and β trajectory angles reported were 39.91º and 14.48º, respectively. Psoas muscle retraction was primarily noted at the L4-L5 level. Conclusion: This article’s proposed parameters represent a routine preoperative safety assessment in patients previously selected for oblique ATP lumbar fusion.

Numerical investigation of pollution transport around a single non-submerged spur dike

Industrial contaminants and chemicals adversely impact surface water quality and may lead to serious health risks to human and ecosystems. Rivers as one of the major surface water resources receive wastewaters and transport dissolved pollutions in water through Advection-Dispersion processes. A minimum distance known as the mixing length is required for complete mixing and dispersion of the pollutants. Since the concentration of pollutants often exceeds the self-purification capacity of rivers within this distance, reducing it decreases the negative impacts on the aquatic ecosystems. Creating turbulent flows with inherent mixing characteristics is an efficient measure in decreasing the mixing length. Spur dikes that are widely used in river engineering are able to reduce the mixing length by virtue of the turbulence made in a stream. Given the fact that entry of pollutants into the surface water is inevitable and the influence of spur dikes on the characteristics of pollution transport has not been meticulously investigated, this study aimed at the numerical simulation of pollution transport in a rectangular channel adjacent to a spur dike. We thus invoked Flow-3D to simulate flow and transport characteristics around an impermeable and non-submerged rectangular spur dike. The findings of this study enhance our understanding of spur dike effects on pollution transport. Notwithstanding the fact that the spur dike effectively decreased the mixing length of the pollution, the location of the pollutant entry also played a prominent role in reducing the length of this region.

Intramuscular Innervation of the Supraspinatus Muscle Assessed Using Sihler's Staining: Potential Application in Myofascial Pain Syndrome.

Despite the positive effects of botulinum neurotoxin (BoNT) injection into the neural arborized area, there is no anatomical evidence in the literature regarding the neural arborization of the supraspinatus muscle. The present study aimed to define the intramuscular neural arborized pattern of the supraspinatus muscle using the modified Sihler’s staining method to facilitate the establishment of safe and effective injection sites in patients with myofascial pain in the supraspinatus muscle. Seventeen supraspinatus muscles from 15 embalmed cadavers were dissected. Precise suprascapular nerve entry locations were also observed. Intramuscular neural arborization was visualized by Sihler’s staining. The supraspinatus muscle was divided into four portions named A, B, C, and D. The nerve entry points were observed in 88.2% (15 of 17 cases) of section B and 76.5% (13 of 17 cases) of section C of the supraspinatus muscle, respectively. The concentration of intramuscular neural arborization was highest in section B of the supraspinatus muscle, which was the center of the supraspinatus muscle. When the clinician performs a trigger point and a BoNT injection into the supraspinatus muscle, injection within the medial 25–75% of the supraspinatus muscle will lead to optimal results when using small amounts of BoNT and prevent undesirable paralysis.

Investigation into the problems of Proximal Femoral Nails (PFN) in the management of intertrochanteric fractures

Aim: An investigation into the problems of proximal femoral nails in the management of intertrochanteric fractures. Methods: This research comprised 50 patients with intertrochanteric fractures who received intramedullary fixation with PFN. The limb was adducted and held in traction. Under C-arm guidance, the entry location was seen, and a guide wire was passed over the fracture site. To repair the fracture, a short PFN with proximal and distal locking was inserted under C-arm guidance. Results: There were 33 men and 17 women. In 28 cases, the right side was implicated, whereas the left side was engaged in 22 patient. The average period of follow-up was 13 months. Closed reduction was used in 40 patients, whereas open reduction was used in 10 patients. Complications occurred in 15 of 50 individuals. All were early issues, and the causes of failure were investigated. Complications include a broken nail at the distal locking screw level (2%), screw back out (2%), perioperative proximal femur fracture (4%), inadequate fracture reduction (2%), varus distortion (4%), improper positioning of the distal locking screw (2%), placement of a single screw in the neck (4%), abductor lurch (4%), and Infection on the surface (4%).

VIPRE: A Tool Aiding the Design for Entry Probe Missions

Exploring planetary atmospheres uncovers important information as to how our solar system formed and evolved. While remote sensing is extensively used, some crucial observations require in situ measurements by an atmospheric probe. Given their scientific importance, probe missions to Saturn, Uranus, and Neptune are under consideration for the coming decades. In anticipation of future probe missions, the software tool Visualization of the Impact of PRobe Entry conditions on the science, mission and spacecraft design (VIPRE) was developed as proof-of-concept to facilitate selection of probe entry locations. Currently, there is no analytical way to identify which interplanetary trajectory from thousands of feasible launch opportunities is optimal for a considered mission concept. The search and decision process for that solution is complex and relies on the intuition of mission designers, who focus on a subset of trajectories to make the trade space manageable. The idea of VIPRE is (1) to generate a multidimensional data cube showing relevant engineering and science parameters simultaneously for thousands of trajectories, and (2) to visualize the data for all entry sites over the body’s envelope. VIPRE lays a foundation to make available the data for browsing in a 3D visualization to identify the best family of solutions for a given mission. This paper introduces the validated and verified core algorithms of VIPRE, published on GitHub Probst. VIPRE serves as a basic framework to be used and extended for different purposes. The paper further presents the motivation for the development and algorithms; it explains the computation and data visualization strategy; and gives a list of suggested functionalities to extend and further develop VIPRE to fully leverage its potential.

Early modern human migration into Sulawesi and Island adaptation in Wallacea

ABSTRACTMaritime migration and island adaptation by anatomically modern humans (AMH) are among the most significant current issues in Southeast Asian archaeology and directly related to their behavioural and technological advancement. In the center of this research hotspot are the Wallacean islands, situated between the Pleistocene landmasses of Sunda and Sahul. Two major migration routes have been suggested for the initial maritime migration from Sunda via Wallacea into Sahul, a northern route into the region of New Guinea and a southern route leading into northern Australia. Here, we report the outcomes of new archaeological research in Central Sulawesi, the most likely entry location for the northern route. Based on our latest findings and new C14 dates from Goa Topogaro 2, we discuss the evidence and timeline for the migration of early modern humans into the Wallacean islands and their adaptation to insular environments during the Late Pleistocene.

Unusual transorbital-penetrating intracranial injury by a metal bar: A case report

Introduction: The orbit has a fine bony structure and represents the most vulnerable structure in the cranium. Therefore, penetrating orbital injuries are often associated with traumatic brain injury. Although transorbital-penetrating intracranial injury is not commonly encountered in emergency medicine practice, this occurrence has the potential to cause severe and fatal brain injury. &#x0D; Case Report: In this study, we report the case of a 21-year-old male patient presented with an injury to his left orbit, caused by falling while holding a metal bar. A Local examination revealed a perforating injury at the entry location of a metallic bar (S-shaped) that penetrated his left orbit. CT imaging showed the appearance of a metallic foreign body that entered anterior superior to the left orbit, passed into the left half of the frontal sinus, and extended into the intracranial area. The metallic bar was removed by craniotomy. The patient fully recovered and was discharged on postoperative 9th day. &#x0D; Conclusion: The penetration of foreign bodies through the orbitofrontal region is rare but potentially life-threatening. An emergent surgical initiative is necessary to save the life of the patient. When managed in a timely and efficient manner, the associated mortality and morbidity can be reduced.

Identifying risk factors for abdominal adhesions: preliminary findings of a prospective study

The objective of this study is to identify relevant risk factors for development of abdominal and pelvic adhesions in women based on their prior medical and surgical history. The primary outcome of this study is the presence and severity of adhesions identified at the time of laparoscopy for benign gynecologic disease. This multi-site prospective study was approved by local IRB board. All laparoscopic cases performed by study staff on adult patients were eligible for inclusion. The anticipated study size is a minimum of 1,000 cases in an effort to account for more rare adhesion-promoting conditions. Cases were performed per standard protocol with entry approach and location per surgeon preference. Intraoperative photo documentation of four abdominal quadrants was obtained at the onset of each case. Following the case, a survey form was completed (Fig 1) to capture data on adhesiogenic events, time spent for adhesiolysis, route of entry, location, and grade of adhesions (Fig 2), if present. Herein we present interval findings from study onset in 2019 until 2021. A total of 490 laparoscopic cases have been collected, with an overall adhesion incidence of 58.98%. The most common prior inflammatory event was presence of endometriosis; among the endometriosis cases with no prior surgeries, the adhesion incidence was 61.29%. The most common preceding abdominal surgical event was a Cesarean section, with 82 patients having one or more prior Cesareans. Adhesions were present in 87.8% of cases with prior Cesarean, predominantly in the lower or midcentral abdomen and requiring on average 18.5 minutes of adhesiolysis; 44.4% of the adhesions were classified as filmy, 33.3% as dense, and 22.2% as cohesive. The second most common laparotomic procedure was abdominal myomectomy (n=22), of which 90.1% had adhesions predominantly in the central lower pelvis. There was a relatively even distribution of adhesion types, requiring an average of 24.4minutes of adhesiolysis. This is in contrast to the cases of laparoscopic myomectomy without prior abdominal surgery (n=10), of which 80% had adhesions noted in the lower or mid pelvis. These adhesions were filmy in 75% of the cases and required an average of 14.8 minutes for adhesiolysis. Our preliminary findings highlight the need for vigilance regarding anticipated intraabdominal adhesions. We anticipate that upon collecting a complete dataset, a model can be established for predicting risk factors for the development of abdominal adhesions. This project has important clinical implications and enables the provider to better counsel patients on rates of postoperative adhesion development, as well as guide operative decision-making for site of abdominal entry.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

On the minimum number of distinct eigenvalues of a threshold graph

For a graph G, we associate a family of real symmetric matrices, S(G), where for any A∈S(G), the location of the nonzero off-diagonal entries of A are governed by the adjacency structure of G. Let q(G) be the minimum number of distinct eigenvalues over all matrices in S(G). In this work, we give a characterization of all connected threshold graphs G with q(G)=2. Moreover, we study the values of q(G) for connected threshold graphs with trace 2, 3, n−2, n−3, where n is the order of threshold graph. The values of q(G) are determined for all connected threshold graphs with 7 and 8 vertices with two exceptions. Finally, a sharp upper bound for q(G) over all connected threshold graph G is given.