Change In Position Research Articles

Visualization of the Postoperative Position of the Hydrus® Microstent Using Automatic 360° Gonioscopy.

Introduction: Glaucoma, one leading cause of irreversible vision loss worldwide, is primarily caused by elevated intraocular pressure (IOP). Recently, minimally invasive glaucoma surgeries (MIGSs) have become popular due to their shorter surgical times, tissue-sparing nature, and faster recovery. One such MIGS, the Hydrus® nickel-titanium alloy Microstent, helps lower IOP by improving aqueous humor outflow. The NIDEK GS-1 automated 360° gonioscope provides advanced imaging of the chamber angle for evaluation and documentation. The aim of this study was to test automated 360° gonioscopy for the detection of postoperative positional variations after Hydrus® Microstent implantation. This study is the largest to date to evaluate post-op positioning of the Hydrus® Microstent using the NIDEK GS-1. Materials and Methods: This study analyzed postoperative outcomes and stent location in eyes diagnosed with mild to moderate glaucoma that underwent Hydrus® Microstent implantation with or without phacoemulsification. Patients with prior IOP-lowering surgery or vitrectomy were excluded. Analyses of the postoperative Hydrus® Microstent position were based on the evaluation of automated 360° gonioscopy images. Results: Twenty-three eyes were included in the study, and all showed a reduction in IOP and a decrease in antiglaucomatous drop use postoperatively. Postoperative gonoscopic images showed variations in implant position. In all cases, the proximal inlet was clearly visible in the anterior chamber. The degree of protrusion into the anterior chamber was variable. The distal tip of the stent was visible behind the trabecular meshwork in Schlemm's canal in five cases, in the anterior chamber in one case, and not visible in seven cases. In no case did postoperative alterations in the position of the implant lead to explantation. Conclusions: This study demonstrated that the Hydrus® Microstent can effectively lower IOP even in the presence of postoperative positional variations. Automated 360° gonioscopy was found to be a useful tool to verify and document the postoperative position of the implant. Positional changes did not require device explantation in any of the cases evaluated.

A Method for Optimizing Terminal Sliding Mode Controller Parameters Based on a Multi-Strategy Improved Crayfish Algorithm

This paper proposes a parameter optimization method for a terminal sliding mode controller (TSMC) based on a multi-strategy improved crayfish algorithm (JLSCOA) to enhance the performance of ship dynamic positioning systems. The TSMC is designed for the “Xinhongzhuan” vessel of Dalian Maritime University. JLSCOA integrates subtractive averaging, Levy Flight, and sparrow search strategies to overcome the limitations of traditional crayfish algorithms. Compared to COA, WOA, and SSA algorithms, JLSCOA demonstrates superior optimization accuracy, convergence performance, and stability across 12 benchmark test functions. It achieves the optimal value in 83% of cases, outperforms the average in 83% of cases, and exhibits stronger robustness in 75% of cases. Simulations show that applying JLSCOA to TSMC parameter optimization significantly outperforms traditional non-optimized controllers, reducing the average time for three degrees of freedom position changes by over 300 s and nearly eliminating control force and velocity oscillations.

Experimental and Numerical Investigation on Attitude Adjustment Characteristics of Spacecraft with Impulse Thruster

AbstractThe spacecraft serves as an effective tool for the space exploration. The present study is devoted to investigate the yaw attitude adjustment motion of the spacecraft influenced by the reaction-jet control system. A novel spacecraft device with impulse thrusters is designed for the vacuum test. And a synchronous test system, equipped with high-speed cameras, is established to record the motion process of the spacecraft under the various initial setting conditions. Subsequently, a six degrees of the freedom exterior ballistic model is calculated considering the interior ballistic process in the impulse thruster. The experimental results confirm that the position change of the designed device’s center of mass aligns with expectation, and the prediction error of final attitude angle remains below 2%. Based on this foundation, the change rule of the impulse thrust under different main charge loads is explored. The non-linear impulse thrust needs to be coupled with the rotation motion to enhance calculation accuracy. And the position of the center of mass is investigated to illustrate the advantage of the designed spacecraft structure. Finally, the calculation of the ignition interval time required for each target attitude angle is conducted, providing the essential data for further optimization design research. The outcomes from this paper can offer valuable technical means for advancing studies on the spacecraft attitude control.

Research on Point Cloud Acquisition and Calibration of Deep Hole Inner Surfaces Based on Collimated Ring Laser Beams.

In this study, a ring light point cloud calibration technique based on collimated laser beams is developed, aiming to reduce errors caused by the position and attitude changes of traditional ring light measurement devices. This article details the generation mechanism of the ring beam and the principle of deep hole measurement. It introduces the collimated beam as a reference, building on traditional ring light measurement devices, to achieve the synchronous acquisition of the ring beam and collimated spot images by an industrial camera. The Steger algorithm is employed to accurately extract the coordinates of the point cloud contours of both the ring beam and the collimated spot. By analyzing the shape and position changes of the collimated spot contour, the spatial position and attitude of the measuring device are precisely determined. This technique is applied to the 3D reconstruction of the inner surface of deep holes, ensuring the accurate restoration of the spatial positional attitude of the ring beam by incorporating the spatial positional attitude parameters of the measuring device to precisely calibrate the cross-sectional point cloud coordinates. Experimental results with ring gauges and deep hole workpieces demonstrate that this technique effectively reduces the percentage of point cloud data outside the tolerance range, and improves the accuracy of the 3D reconstruction model by 6.287%, thereby verifying the accuracy and practicality of this technique.

Effect of body position during weaning from total liquid ventilation in piglets

ObjectiveTo determine if change in body position improves oxygen requirements and respiratory mechanics during the transition from total liquid ventilation (TLV) to gas ventilation. MethodsFourteen piglets underwent TLV, followed by a 2-hour weaning period under conventional gas ventilation. Subjects were randomized to the experimental group (Rotating – R), that was in prone position between the 10th and 30th minute of weaning, or to the static control group (Supine – S). ResultsOxygenation index was lower in the R group at 30 minutes in prone position than that in the S group (1.9 [1.6; 2.8] vs 3.5 [3.1; 5.1], p = 0.001). This difference disappeared when subjects resumed the supine position (4.2 [3.8; 4.7] and 4.7 [3.8; 5.4], p = 0.4, for the R and S groups, respectively). The change in body position did not affect respiratory system compliance or inspiratory capacity. ConclusionProne position improved oxygenation during weaning from TLV. The effect disappeared once piglets returned to the supine position.

THEPORE: A software package for modeling THErmo-PORo-elastic displacements

THEPORE (THErmo-POro-Elastic solutions) is an open source software to perform forward and inverse modeling of ground displacements induced by thermo-poro-elastic sources. The software, implemented in MATLAB, offers a library of analytical and semi-analytical solutions to compute ground displacements induced by thermo-poro-elastic deformation sources of different geometries, embedded in an elastic, homogeneous and isotropic half-space. The solutions have been verified against finite-element simulations. THEPORE includes also an inversion procedure of the deformation data to constrain the source parameters that better fit the observed signals.The software's functionality is showcased by inverting the GPS deformation data recorded on Vulcano Island at the onset of the 2021 unrest, in order to estimate the position and volume change of the source responsible for the observed deformations. The results encourage to consider THEPORE as a practical tool suitable for a fast preliminary estimation of the deformation source during a volcanic crisis.

Outcome of the novel description of arterial position changes after major liver resections: retrospective study.

After major liver resections, anatomical shifts due to liver parenchymal hypertrophy and organ displacement can happen. The aim of this study was to evaluate the impact of these anatomical changes on the main abdominal arteries (coeliac trunk and superior mesenteric artery) and on patient outcomes. All patients who underwent major liver resections (between January 2010 and July 2021) and who underwent preoperative and postoperative arterial-phase contrast-enhanced abdominal CT imaging were studied. Observed arterial position changes were classified into three groups: no position changes; class I position changes (vessel displacement with or without kinking with a vessel angle greater than 105°); and class II position changes (kinking less than or equal to 105°). The Mann-Whitney test and the Kruskal-Wallis test were used to compare continuous variables and the chi-squared test and Fisher's exact test were used to compare categorical variables. Univariable and multivariable logistic regression analyses were used to identify the risk factors for morbidity and mortality. A total of 265 patients (149 men and median age of 59 years) were enrolled. Arterial position changes were detected in a total of 145 patients (54.7%) (99 patients (37%) with class I position changes and 46 patients (18%) with class II position changes) and were observed more often after extended resection and right-sided resection (P < 0.001). Major complications were seen in 94 patients (35%) and the rate of mortality was 15% (40 patients died). Post-hepatectomy liver failure (P = 0.030), major complications (P < 0.001), and mortality (P = 0.004) occurred more frequently in patients with class II position changes. In multivariable analysis, arterial position change was an independent risk factor for post-hepatectomy liver failure (OR 2.86 (95% c.i. 1.06 to 7.72); P = 0.038), major complications (OR 2.10 (95% c.i. 1.12 to 3.93); P = 0.020), and mortality (OR 2.39 (95% c.i. 1.03 to 5.56); P = 0.042). Arterial position changes post-hepatectomy are observed in the majority of patients and are significantly related to postoperative morbidities and mortality.

Repeatability of alkaline inorganic phosphate quantification in the skeletal muscle using 31P-magnetic resonance spectroscopy at 3T.

The detection of a secondary inorganic phosphate (Pi) resonance, a possible marker of mitochondrial content in vivo, using phosphorus magnetic resonance spectroscopy (31P-MRS), poses technical challenges at 3Tesla (T). Overcoming these challenges is imperative for the integration of this biomarker into clinical research. To evaluate the repeatability and reliability of measuring resting skeletal muscle alkaline Pi (Pialk) using with 31P-MRS at 3 T. After an initial set of experiments on five subjects to optimize the sequence, resting 31P-MRS of the quadriceps muscles were acquired on two visits (~4days apart) using an intra-subjects design, from 13 sedentary to moderately active young male and female adults (22 ± 3years old) within a whole-body 3T MR system. Measurement variability attributed to changes in coil position, shimming procedure, and spectral analysis were quantified. 31P-MRS data were acquired with a 31P/-proton (1H) dual-tuned surface coil positioned on the quadriceps using a pulse-acquire sequence. Test-retest absolute and relative repeatability was analyzed using the coefficient of variation (CV) and intra-class correlation coefficients (ICC), respectively. After sequence parameter optimization, Pialk demonstrated high intra-subject repeatability (CV: 10.6 ± 5.4%, ICC: 0.80). Proximo-distal change in coil position along the length of the quadriceps introduced Pialk quantitation variability (CV: 28 ± 5%), due to magnetic field inhomogeneity with more distal coil locations. In contrast, Pialk measurement variability due to repeated shims from the same muscle volume (0.40 ± 0.09mM; CV: 6.6%), and automated spectral processing (0.37 ± 0.01mM; CV: 2.3%), was minor. The quantification of Pialk in skeletal muscle via surface coil 31P-MRS at 3T demonstrated excellent reproducibility. However, caution is advised against placing the coil at the distal part of the quadriceps to mitigate shimming inhomogeneity.

Prediction of rail wear band evolution under excitation by periodic track irregularities and its influence on vehicle dynamic performance

Periodic track irregularities (PTIs) are an important and sensitive source of vehicle vibration and have attracted considerable attention from railway researchers. However, previous studies have mainly focused on the irregularities themselves, with limited investigation of how the rail wear band (RWB) generated by PTIs excitation affects vehicle responses. To assess this, a three-dimensional rail wear prediction model is developed in this study to simulate the evolution of the RWB under PTIs conditions and then the effect of RWB excitation on the vehicle dynamic performance is investigated. The results show that the spatial trace of the rail contact points generated by the PTIs also exhibits clear periodic characteristics. Accordingly, the distribution pattern of the RWB also reflects these periodic features. The excitation of the periodic rail wear band (PRWB) has a negative effect on the vehicle running stability, especially when the vehicle is traveling at speeds that induce coupling resonance, which exacerbates the consequences. As the wear level of the PRWB increases, there is also an escalation in the vibration of the carbody. Furthermore, the amplitude of the change in the wheelset balance position resulting from variations in rail profile is found to serve as an effective descriptor for characterizing the wear intensity of PRWB, and the vibration amplitude of the carbody exhibits a clear linear correlation with PRWB excitation. The research results are helpful for understanding the relationship between PRWB excitation and vehicle vibration behavior and serve as a theoretical basis for track maintenance and profile optimization.

Changes in Skin Paddle Morphology after Autologous Breast Reconstruction

Background: Immediate autologous breast reconstruction (IABR) can provide favorable aesthetic outcomes after skin-sparing mastectomy. However, it is known that the morphology of the reconstructed breast changes over time. Therefore, it is necessary to be able to predict the likely amount of change preoperatively to reconstruct a symmetrical breast. In this study, we retrospectively examined the change in position and morphology of the skin paddle of the reconstructed breast over time. Methods: Thirty-five patients who underwent IABR after skin-sparing mastectomy for unilateral breast cancer were included. Three-dimensional images were obtained at 1 month and 12 months postoperatively to compare changes in the position and size of the skin paddle over time. Results: Significant increases were observed in the distance between the center of the skin paddle and the midpoint of the clavicle, the distance between the center of the skin paddle and the sternal notch, and projection. No significant change was observed in the distance between the inframammary fold and the center of the skin paddle. There was a significant increase in the area and short axis of the skin paddle. Conclusions: Our main findings were that the skin paddle shifts toward the outer caudal side after IABR and tends to become larger. When planning delayed nipple reconstruction with a local flap designed on a skin paddle, the paddle should be positioned slightly more mediocranially than the healthy nipple and should be narrower.

Abstract P156: Timing of Orthostatic Blood Pressure Changes is Associated with Orthostatic Symptoms in Very Old Adults: Findings from the ARIC Study.

Background: The timing of orthostatic changes in blood pressure (BP) and their associations with orthostatic symptoms among very old adults is undercharacterized. Objective: To determine the prevalence of distinct orthostatic BP patterns and their relationships with orthostatic symptoms. Methods: We measured three supine and six standing BP readings (timed at 0, 1, 2, 3, 4, and 5 minutes after standing) among ARIC participants (2021-2023). OH patterns (primary, initial, early, delayed, and sustained) were based on when a drop in BP (systolic ≥20 or diastolic ≥10 mmHg) occurred (see Figure for definitions). We quantified OH prevalence overall and by anti-hypertensive medication use and determined the associations of OH patterns with orthostatic symptoms, both concurrent with positional change and in the prior 30-days via logistic regression adjusted for age, sex, and Black race. Results: Of 1,044 participants (58.8% female, 16.5% Black, mean age 83.9±3.7 years), 24.5% had primary OH. Initial and early OH were more common than sustained and delayed OH. Participants using any hypertension medications had a higher prevalence of most types of OH ( Panel 1 ). Primary, early, and sustained OH were associated with orthostatic symptoms during the rise from supine to standing or when standing, while initial OH was associated with orthostatic symptoms only during the rise from supine to standing ( Panel 2 ). Sustained OH was associated with higher odds of prior light-headedness or dizziness and early OH with higher odds of prior imbalance. Conclusion: Clinicians should consider timing of BP changes when screening for OH and evaluating its contribution to orthostatic symptoms among very old adults.

Hyoid Position and Aging: A Comprehensive Analysis Using AI-assisted Segmentation of 282 Computed Tomography Scans.

With neck, aging the cervicomental angle becomes obtuse and may be influenced by hyoid bone aging. An understanding of hyoid position changes with aging will further our understanding of its role in neck contour changes. A 3D volumetric reconstruction of 282 neck computed tomography scans was performed. The cohort was categorized into three groups based on age: 20 years or older and younger than 40 years, 40 years or older and younger than 60 years, and 60 years or older and younger than 80 years. The vertical and horizontal hyoid distances in relation to the mandible were calculated for each patient. A total of 282 patients (153 women, 129 men) were included in the cohort. The age groups were evenly distributed in men and women. Mean hyoid vertical and horizontal distances differed between women and men in all age groups. There was a significant difference in the hyoid vertical distance between 20-39 years old to 40-59 years old in men (P < 0.01), and 20-39 years old to 60-79 years old in both genders (women P = 0.005, men P < 0.01). Hyoid horizontal distance was not affected by age and sex (age and sex: P > 0.05), but rather by body mass index (BMI). Every 5 BMI points corresponded to a forward movement of 2 mm. As individuals age, the hyoid bone descends in both sexes, and an increase in BMI is associated with forward movement. Additional studies are needed to assess the correlation of the hyoid position between upright and supine positions.

Effect of transcutaneous electrical nerve stimulation therapy on condylar position and myofascial pain in patients with temporomandibular joint disorders-A pilot clinical trial.

Temporomandibular joint disorders (TMD) are a type of disorder that affects the temporomandibular joint, muscles, and nerves leading to persistent facial pain. Transcutaneous electrical nerve stimulation (TENS) therapy is an alternative treatment for pain relief in TMD patients. The aim of the study was to assess the condylar position changes and pain levels occurring in TMD patients after TENS therapy. According to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) criteria, a total of seven patients with TMD were included in this study. Routine diagnostic investigations were taken for each patient along with joint vibration analysis (JVA), electromyography (EMG), and a cone beam computed tomography (CBCT) at rest position. Using the Dolphin software (version 11.95), the temporomandibular joint spaces were measured on the CBCT for the right and left sides individually for each patient. These patients were then subjected to TENS therapy, and an EMG reading was taken post-TENS therapy to evaluate the effect on muscle strain. A CBCT was taken after the TENS therapy to assess its effect on the condylar position. The statistical significance of the pre- and post-temporomandibular joint spaces and the EMG readings post-TENS therapy were assessed using paired t-tests, respectively. There was a change in the anterior, middle, and posterior dimensions observed radiographically, before and after TENS. However, the results were found to be statistically significant only in the anterior region on the right joint space (P = 0.03) and posterior region of the left joint space (P = 0.04). TENS therapy has been found to bring about a change in the condylar position and pain intensities by relieving inadvertent muscle activity in the temporomandibular region. Therefore, further studies with larger sample sizes and control are required to fully ascertain the role of inadvertent muscle activity on the TMJ.

Assessment of the Change in the Nasal Septum and Nasal Profile After Le Fort I With Cone Beam Computed Tomography.

This study aimed to determine the relationship between nasal changes and the amount of advancement, impaction, and downward movement of the maxilla after Le Fort I osteotomy. The study included 48 patients who underwent Le Fort I surgery and had pre- and postoperative cone-beam computed tomography records. Changes in the nasal septum were evaluated by measuring septal deviation angles and volumes. In addition, nasolabial angle and width of nasal and alar base were examined. Groups were determined according to the movement of point A (the deepest point on the curvature of the maxillary alveolar process), using a threshold of 1.5 mm for vertical movements and 4 mm for sagittal movements. This resulted in the comparison of 6 groups of 8 people each. Results are presented as mean and standard deviation or median and range depending on the data distribution. Significance level was accepted as P < 0.05. There were no significant differences for each group on its own septal deviation volume or angle values pre/postoperatively. Groups 3 and 5, which both had at least 1.5 mm of impaction, showed significant changes in both deviation angle and volume between the preoperative and postoperative measurements. Nasolabial angle did not show significant changes between groups. Alar base width and nasal width increase was significantly highest in Group 1, which has more than 4 mm sagittal movement and less than 1.5 mm vertical movement. Le Fort I osteotomy may lead to undesirable changes in the spatial positioning of the nasal septum. The results of this study suggest that maxillary advancement does not significantly impact septal deviation, whereas maxillary impaction increases the amount of deviation. In addition, nasal width and alar base width tended to increase, and the nasolabial angle tended to decrease slightly, regardless of the direction of movement of the maxilla after orthognathic surgery. Surgeons should consider increased nasal septal deviation risks when planning impaction of the maxilla. The soft tissue changes in the nose vary according to different directions and amounts of Le Fort I surgery.

Analysis of Electrooculogram in Detecting Eye Movements Associated with Brain Injury

Electrooculogram (EOG) has been a valuable clinical neurophysiology tool in the past five decades of the twentieth century. It facilitated understanding more about eye movement, which is clinically useful in identifying the neural substrate disrupted due to brain injuries. This is vital since accurate measurement of neural injuries has a direct bearing on a patient’s life. A number of neurological investigations, including neurological assessment and diagnosis, are done based on measuring eye movements. This essay focuses on using EOG technology and its benefits in identifying limitations of using physiological indices in individuals because of measurable ocular pathophysiological parameters. In the current essay, the major objective will be to discuss the EOG features, the EOG record in healthy individuals, and the relationship of EOG recordings to affected individuals following a neurological event. The eye-integrated EOG recorded from the front part of the face measures eye position change and shows an exponential decay of voltage due to its design, eye physiology, and the removal of corneal function slowly from the corneal electrode. This makes it the best choice to provide an eye position record with high accuracy that can be made available easily for clinicians. The rapid recordings obtained using transcranial electromagnetic stimulation could demonstrate that EOG has the potential to provide high pre-surgical planning utilities for brain tumor removal. This technology is also best for identifying physiological variability within an individual; the same concept can be extended to study brain injuries that trigger physiological changes in eye muscles. In effect, it potentially becomes a tool for personalized care wherein severity estimation for brain injuries would be based on measuring ocular function rather than the nature of the injury. Given its clinical potential, the present essay will review EOG technologies to assess eye pixel movement, its potential for clinical evaluation, physiological basis, and the research evidence regarding changes in EOG in affected individuals with brain injury. In this essay, the long-lasting and short-lasting EOG changes are presented as case studies of individuals diagnosed with PTA, hence demonstrating its clinical utility.

54283 Upward Brow Position Change After Treatment with AbobotulinumtoxinA in the Glabellar Lines

54283 Upward Brow Position Change After Treatment with AbobotulinumtoxinA in the Glabellar Lines

Altered expression of vesicular trafficking machinery in prostate cancer affects lysosomal dynamics and provides insight into the underlying biology and disease progression.

This study focuses on the role of lysosomal trafficking in prostate cancer, given the essential role of lysosomes in cellular homoeostasis. Lysosomal motility was evaluated using confocal laser scanning microscopy of LAMP-1-transfected prostate cells and spot-tracking analysis. Expression of lysosomal trafficking machinery was evaluated in patient cohort databases and through immunohistochemistry on tumour samples. The roles of vesicular trafficking machinery were evaluated through over-expression and siRNA. The effects of R1881 treatment on lysosome vesicular trafficking was evaluated by RNA sequencing, protein quantification and fixed- and live-cell microscopy. Altered regulation of lysosomal trafficking genes/proteins was observed in prostate cancer tissue, with significant correlations for co-expression of vesicular trafficking machinery in Gleason patterns. The expression of trafficking machinery was associated with poorer patient outcomes. R1881 treatment induced changes in lysosomal distribution, number, and expression of lysosomal vesicular trafficking machinery in hormone-sensitive prostate cancer cells. Manipulation of genes involved in lysosomal trafficking events induced changes in lysosome positioning and cell phenotype, as well as differential effects on cell migration, in non-malignant and prostate cancer cells. These findings provide novel insights into the altered regulation and functional impact of lysosomal vesicular trafficking in prostate cancer pathogenesis.

Assessing risk factors for elevated creatine kinase levels as an indicator of compartment syndrome following laparoscopic or robot-assisted colorectal cancer surgery in the lithotomy-trendelenburg position

BackgroundWell-leg compartment syndrome (WLCS) can occur due to compression and lower limb circulation disturbances caused by the surgical position during the procedure. Although rare, with an incidence of 1 in 3500 surgeries performed in the lithotomy position, it can lead to serious complications. Therefore, prevention and early diagnosis are critical. Symptoms of WLCS, such as leg pain, swelling, paresthesia, and serum creatine kinase (CK) levels are useful for diagnosis. This study aimed to investigate the risk factors for postoperative CK elevation in laparoscopic or robot-assisted colorectal cancer surgery performed in the lithotomy-Trendelenburg position.MethodsPostoperative CK levels were measured in 178 patients who underwent laparoscopic or robot-assisted colorectal cancer surgery between February 2022 and March 2023. We compared patient backgrounds, short-term outcomes, and thigh/calf circumferences between patients with CK levels ≥ 250 (n = 62) and those with CK levels < 250 (n = 116). We investigated risk factors for elevated CK levels using both univariate and multivariate analyses.ResultsFour patients with CK levels of 22405 U/L, 4685 U/L, 4050 U/L, and 3824 U/L reported symptoms, which improved with conservative treatment. The following independent prognostic factors were identified by multivariate analysis: male sex (odds ratio [OR], 4.403; 95% CI, 1.960 to 9.892), rectal surgery (OR, 2.779; 95% CI, 1.249 to 6.184), continuous head-down position duration ≥ 180 min (OR, 3.523; 95% CI, 1.552 to 7.997), and preoperative calf circumference ≥ 33 cm (OR, 2.482; 95% CI, 1.154 to 5.339).ConclusionsRisk factors for CK elevation after colorectal cancer surgery in the lithotomy position include male sex, rectal surgery, an extended continuous head-down position without position changes, and a larger preoperative calf circumference. This study highlights the potential importance of intraoperative position changes every 3 h for preventing elevated CK levels, although the preventive effect was not specifically examined.

Occlusal Plane, Mandibular Position and Dentoalveolar Changes during the Orthodontic Treatment with the Use of Mini-Screws.

This study aimed to describe the changes produced on the occlusal plane (OP), the mandibular position and the dentoalveolar compensations of patients with distalization of the maxillary/mandibular arch assisted by mini-screws (MS). A descriptive case-series study was performed using the digital lateral cephalograms (DLC) of nine patients who underwent orthodontic treatment and required the use of MS for a complete distalization of the maxillary/mandibular arch. Records were collected at three different times (T1-T2-T3) and digitally analyzed (variables: Skeletal diagnosis; maxillary occlusal plane; position of the maxilla/mandible; and dentoalveolar changes of the distalization arch tracing the longitudinal axis of incisors/molars regarding the palatal/mandibular plane). Findings show that the OP varied from T1-T2-T3 in all cases, indicating its stepping or flattening. ODI, APDI, SNA, SNB, and ANB changed minimally in all cases, without variations in the mandibular position or in the skeletal diagnosis. Dentoalveolar measurements also showed differences between T1-T2-T3. In summary, conventional orthodontic treatment modified the OP during the first phase of treatment. Moreover, the distalization mechanics with MS changed the OP and produced dentoalveolar changes, mainly in the inclination of incisors and molars. Other measures considered in the study did not change substantially.

Bobcat Optimization Algorithm: an effective bio-inspired metaheuristic algorithm for solving supply chain optimization problems

Supply chain efficiency is a major challenge in today’s business environment, where efficient resource allocation and coordination of activities are essential for competitive advantage. Traditional efficiency strategies often struggle for resources for the complex and dynamic network. In response, bio-inspired metaheuristic algorithms have emerged as powerful tools to solve these optimization problems. Referring to the random search nature of metaheuristic algorithms and emphasizing that no metaheuristic algorithm is the best optimizer for all optimization applications, the No Free Lunch (NFL) theorem encourages researchers to design newer algorithms to be able to provide more effective solutions to optimization problems. Motivated by the NFL theorem, the innovation and novelty of this paper is in designing a new meta-heuristic algorithm called Bobcat Optimization Algorithm (BOA) that imitates the natural behavior of bobcats in the wild. The basic inspiration of BOA is derived from the hunting strategy of bobcats during the attack towards the prey and the chase process between them. The theory of BOA is stated and then mathematically modeled in two phases (i) exploration based on the simulation of the bobcat’s position change while moving towards the prey and (ii) exploitation based on simulating the bobcat’s position change during the chase process to catch the prey. The performance of BOA is evaluated in optimization to handle the CEC 2017 test suite for problem dimensions equal to 10, 30, 50, and 100, as well as to address CEC 2020. The optimization results show that BOA has a high ability in exploration, exploitation, and balance them during the search process in order to achieve a suitable solution for optimization problems. The results obtained from BOA are compared with the performance of twelve well-known metaheuristic algorithms. The findings show that BOA has been successful in handling the CEC 2017 test suite in 89.65, 79.31, 93.10, and 89.65% of the functions for the problem dimension equal to 10, 30, 50, and 100, respectively. Also, the findings show that in order to handle the CEC 2020 test suite, BOA has been successful in 100% of the functions of this test suite. The statistical analysis confirms that BOA has a significant statistical superiority in the competition with the compared algorithms. Also, in order to analyze the efficiency of BOA in dealing with real world applications, twenty-two constrained optimization problems from CEC 2011 test suite and four engineering design problems have been selected. The findings show that BOA has been successful in 90.90% of CEC2011 test suite optimization problems and in 100% of engineering design problems. In addition, the efficiency of BOA to handle SCM applications has been challenged to solve ten case studies in the field of sustainable lot size optimization. The findings show that BOA has successfully provided superior performance in 100% of the case studies compared to competitor algorithms.