Changes In Axis Research Articles

Clinical Evaluation of Nd:YAG Capsulotomy on the Light-Adjustable Intraocular Lens.

To investigate the safety and refractive outcomes of neodymium-doped yttrium-aluminum-garnet (Nd:YAG) capsulotomy in pseudophakic eyes with the Light Adjustable Lens (LAL) both before and after completing the light delivery device (LDD) lock-in treatments. Private practice in Orange, California, USA. Retrospective, comparative study. Patients were divided into two groups according to the timing of their YAG capsulotomy (Group I underwent YAG capsulotomy before lock-in treatments and Group II underwent YAG capsulotomy upon completion of lock-in treatments). Sphere, cylinder, axis, spherical equivalent, uncorrected visual acuity, and best-corrected visual acuity were compared pre- and postoperatively using two-tailed paired t-tests. Postoperative data were measured one month after Nd:YAG capsulotomy. The alpha level (type I error) was set at 0.05. The LAL was successfully implanted in 485 eyes from January 2020 to March 2023. Ten eyes (0.02%) needed YAG capsulotomy prior to the completion of lock-in treatments (Group I) and 28 eyes (5.77%) needed YAG capsulotomy after the lock-in was completed (Group II). Postoperative BCVA significantly improved compared to preoperative values in both groups. Changes in sphere, cylinder, axis, SE, and UCVA pre- and postoperative measurements were not statistically significant (p > 0.05) in both groups. YAG capsulotomy can be safe and effective for patients with the LAL who develop PCO during the adjustment period. There were no significant changes in sphere, cylinder, axis, or spherical equivalence after YAG capsulotomy in both groups.

Rehabilitation in overweight and obesity as an integral part of pathogenetic therapy

Obesity is one of the most acute issues of medicine at the present stage due to the steady increase in morbidity, high risk of complications and comorbid conditions that entail significant financial costs. At the same time, many different etiopathogenetic factors are involved in the formation of obesity. The article presents a literature review concerning the main risk factors and etiologic aspects of the development of overweight and obesity in adults and children. The most relevant pathogenetic mechanisms are considered, including imbalance of adipokines (decrease in adiponectin level and increase in leptin content), formation of low activity chronic inflammation as a result of proinflammatory cytokines, changes in the features of neuroimmune-endocrine interactions, the impact of chronic stress on the human body, vitamin D deficiency, disorders of the “gut – brain” axis, quantitative and qualitative changes in the composition of intestinal microbiota. The main therapeutic approaches and surgical methods in the treatment of obesity are presented. The data available in the literature at the present stage on methods of rehabilitation of patients with obesity, as well as persons with excess body weight, indicating the need for a comprehensive approach and combination of lifestyle modification, physiotherapeutic methods, psychological counseling to achieve positive results are summarized.

Sensitivity of the magnetic axis to variations in the magnetic field

Lagrangian variational principles are used to locate the magnetic axis and to determine its sensitivity to variations in the magnetic field. Only the change in the magnetic field on axis is required to determine, to lowest order, the location of the new magnetic axis. Using a simple example, namely, the magnetic field produced by a set of current-carrying filaments (a.k.a. coils), the variation in the coil geometry that induces the largest change in the magnetic axis is determined using singular value decomposition.

Comparison of Crustal Stress and Strain Fields in the Himalaya–Tibet Region: Geodynamic Implications

The Himalaya–Tibet region represents a complex region of active deformation related to the ongoing India–Eurasia convergence process. To provide additional constraints on the active processes shaping this region, we used a comprehensive dataset of GNSS and focal mechanisms data and derived crustal strain and stress fields. The results allow the detection of features such as the arc-parallel extension along the Himalayan Arc and the coexistence of strike-slip and normal faulting across Tibet. We discuss our findings concerning the relevant geodynamic models proposed in the literature. While earlier studies largely emphasized the role of either compressional or extensional processes, our findings suggest a more complex interaction between them. In general, our study highlights the critical role of both surface and deep processes in shaping the geodynamic processes. The alignment between tectonic stress and strain rate patterns indicates that the crust is highly elastic and influenced by present-day tectonics. Stress and strain orientations show a clockwise rotation at 31°N, reflecting deep control by the underthrusted Indian Plate. South of this boundary, compression is driven by basal drag from the underthrusting Indian Plate, while northward, escape tectonics dominate, resulting in eastward movement of the Tibetan Plateau. Localized stretching along the Himalaya is likely driven by the oblique convergence resulting from the India–Eurasia collision generating a transtensional regime over the Main Himalayan Thrust. In Tibet, stress variations appear mainly related to changes in the vertical axis, driven by topographically induced stresses linked to the uniform elevation of the plateau. From a broader perspective, these findings improve the understanding of driving crustal forces in the Himalaya–Tibet region and provide insights into how large-scale geodynamics drives surface deformation. Additionally, they contribute to the ongoing debate regarding the applicability of the stress–strain comparison and offer a more comprehensive framework for future research in similar tectonic settings worldwide.

Exploring cardiac vector propagation in acute myocardial infarction: a spatial velocity perspective.

To objectively characterize the spatial-velocity dynamics of the QRS-loop in the vectorcardiogram (VCG) of patients with acute myocardial infarction (AMI). VCG was constructed as a space curve directly with three quasi-orthogonal leads I, aVF and V2 recorded by conventional ECG of 25healthy individuals and 50 AMI patients. Spatial velocity (SV) of the dynamic QRS loop, spatial distance (SD), and spatial magnitude (SM) were recorded, along with axis-specific component attributes of vector magnitude such as ΔX, ΔY, and ΔZ. Decreased SV (12-25%, p = 0.02) and SD (10-26%, p = 0.02) and altered spatial propagation patterns of ventricular vectors in AMI were recorded, with changes in specific axes based on infarct location. Significant vector changes were found in the Y-Axis in IWMI (p = 0.005) and X-Axis in cases of AWMI (p = 0.02), as compared to controls. There was no apparent alteration of SM in AMI. Decreased SV and SD without any significant alteration of SM indicates close approximation and clustering of the tips of the ventricular vector in AMI. This may be due to dilation, thinning, and stress of the ventricular wall in early post infarction ventricular remodeling, along with relative ischemia due to associated tachycardia and higher myocardial oxygen demand.

Growth Hormone, Hypothalamic Inflammation, and Aging.

While inflammation is a crucial response in injury repair and tissue regeneration, chronic inflammation is a prevalent feature in various chronic, non-communicable diseases such as obesity, diabetes, and cancer and in cardiovascular and neurodegenerative diseases. Long-term inflammation considerably affects disease prevalence, quality of life, and longevity. Our research indicates that the growth hormone/insulin-like growth factor 1 (GH/IGF-1) axis is a pivotal regulator of inflammation in some tissues, including the hypothalamus, which is a key player in systemic metabolism regulation. Moreover, the GH/IGF-1 axis is strongly linked to longevity, as GH- or GH receptor-deficient mice live approximately twice as long as wild-type animals and exhibit protection against aging-induced inflammation. Conversely, GH excess leads to increased neuroinflammation and reduced longevity. Our review studies the associations between the GH/IGF-1 axis, inflammation, and aging, with a particular focus on evidence suggesting that GH receptor signaling directly induces hypothalamic inflammation. This finding underscores the significant impact of changes in the GH axis on metabolism and on the predisposition to chronic, non-communicable diseases.

Behavior of RC Beams Under Two Points Load with Different Out-of-Plane Parts

Abstract This study focused on the out-of-plane beam behavior and the reduction caused by changes in the longitudinal axis and the out-of-plane span length in addition to the effect of adding torsion reinforcement. Five RC beams (150*200*2000) mm with constant cross section and reinforcement (except two with additional torsion reinforcement) were cast and tested under two points of monotonic load. The results showed that the existence of the out-of-plane part reduced the ultimate load by (80%), and the two out-of-plane span lengths (150mm and 300 mm) were different in behavior, that the outof-plane span (300 mm) behaved as under pure torsion while the (150 mm) behaved like under flexural and torsion loads. The worst case was for the beam with an out-of-plane part (150 mm), and the effect of adding torsion reinforcement enhanced the ultimate load by (80%) for the beam with an out-of-plane part (300 mm) whilst by (5%) for the beam with out-of-plane part (150mm).

Optimization of a Redundant Freedom Machining Toolpath for Scroll Profile Machining

The scroll disc is a critical functional component of the scroll compression mechanism, and its machining precision and quality directly impact the performance and longevity of the compressor. Current machining methods for scroll profiles face challenges in simultaneously achieving wide applicability, high precision, and high efficiency. This paper addresses issues related to unsmooth toolpaths of machine tool axes and high acceleration in the rotary axis during redundant degrees of freedom scroll profile machining. This paper proposes a toolpath optimization method for redundant axes, with optimization objectives focused on reducing the counts of directional changes in the linear axes and smoothing the trajectories of all axes. Experimental results demonstrate that the proposed method offers higher machining efficiency compared to traditional polar coordinate machining.

POSSIBILITIES OF AUTOREFKERATOMETRY

In modern ophthalmology, autorefkeratometry has long become a routine diagnostic study, without which it is impossible to imagine any examination. Computerized autorefkeratometers allow you to obtain a huge amount of information about the condition of the patient’s eye in a short time. At the same time, the information obtained is not always subjected to in-depth analysis.Refractometry data should be compared with keratometry data, compared with the indicators of the paired eye, and evaluate, if possible, the dynamics of changes and their tendency. Comparison of the obtained parameters with the average statistical indicators and the age norm make it possible to establish the presence of pathology that does not belong to the field of refractive errors. Thus, the occurrence of anisometropia with similar keratometry parameters suggests opacity of the lens or vitreous pathology. Direct astigmatism is typical for young people, and oblique or reverse astigmatism is typical for patients 65+. A shift in the irido-lens diaphragm is always accompanied by a change in refraction and its instability. Keratectasias are characterized by high variability in refraction and keratometry data, while sometimes maintaining high visual acuity that does not correspond to changes in optical power. Diopter syndrome is manifested by refractive transformations in accordance with changes in the anterior-posterior axis of the eye due to retinal edema. Dry eye syndrome can be manifested by noticeable refractive instability and errors in determining keratometric parameters.High-quality performance of autorefkeratometry, taking into account the nuances, and an in-depth analysis of the data obtained are necessary for making a diagnosis and assessing the dynamics of treatment of ocular pathology.

Efficacy and Predictive Factors Analysis of Androgen Deprivation Plus Novel Hormone Therapy as Neoadjuvant Treatment for High-Risk Prostate Cancer.

This investigation explored the clinical features, pathological outcomes, and biochemical recurrence (BCR) duration among high-risk prostate cancer (HRPC) patients who have undergone neoadjuvant therapy (NAT) in combination with radical prostatectomy (RP) and pelvic lymph node dissection (PLND). Additionally, we identified prognostic indicators that discern pathological complete response (pCR) or minimal residual disease (MRD) and BCR. In total, we examined 76 HRPC patients, who received NAT with either androgen deprivation therapy (ADT) plus apalutamide or ADT plus abiraterone, with subsequent RP and PLND. We conducted a genetic evaluation of patients receiving neoadjuvant apalutamide. Additionally, patient pathological outcomes, circulating prostate-specific antigen (PSA) response rates, and BCR duration were analyzed. Lastly, we employed uni- and multivariate analyses to screen for prognostic factors that govern pCR or MRD and BCR duration. Patient median age and median PSA at presentation were 69 years (IQR: 66-73), and 47.6 ng/mL (IQR: 24.1-105.75), respectively. We observed marked changes in pCR or MRD rates between the two cohorts. In particular, the ADT plus apalutamide cohort (51.5%) exhibited enhanced rates relative to the ADT plus abiraterone cohort (25.6%) (p = 0.03). The median BCR duration was substantially prolonged among neoadjuvant apalutamide cohort relative to the neoadjuvant abiraterone cohort (261 days vs. 76 days, p = 0.04). Using multivariate analysis, we revealed that the postintervention pre-RP PSA content (≤ 0.1 ng/mL vs. > 0.1 ng/mL) remained a substantial stand-alone indicator of pCR or MRD (odds ratio: 10.712, 95% CI: 2.725-42.105, p < 0.001). Furthermore, supplemental analyses revealed that the ADT plus apalutamide cohort exhibited an augmented serum response rate, which, in turn, reduced the post-intervention pre-RP PSA content. Based on our genetic profiling of the neoadjuvant apalutamide cohort demonstrated high-frequency deleterious changes in the AR axis (30.3%), followed by TP53 mutations (15.15%). Patients with defective AR axis experienced a remarkably shorter median BCR duration relative to patients with other or no genetic alterations (52.5 days vs. 286 and 336 days, respectively, p < 0.0001). Furthermore, using multivariate analysis, we demonstrated that achieving pCR or MRD (hazard ratio [HR]: 0.170, 95% CI: 0.061-0.477, p < 0.001) and presence of defective AR signaling (HR: 11.193, 95% CI: 3.499-35.806, p < 0.001) were strong stand-alone indicators of BCR. Herein, we demonstrated the superior performance of ADT plus apalutamide in achieving pCR or MRD and in extending BCR duration among HRPC patients. Post-intervention pre-RP PSA content as well as genetic shifts, especially in the AR axis, are critical indicators of patient pathological and clinical outcomes. These findings highlight the significance of genetic testing and PSA content monitoring in treating HRPC patients.

Defining Risk Factors for Medial Meniscus Posterior Root Repair Surgical Failure

Objectives To evaluate the risk factors for failure of a repair of the posterior root of the medial meniscus, including the patient's preoperative factors, factors related to surgery and rehabilitation, already excluding factors such as uncorrected varus axis deviation and changes advanced degenerative diseases in the medial compartment. Methods Patients who underwent repair of the posterior root of the medial meniscus were evaluated retrospectively, although with prospective data collection. Repair of the meniscal root was performed using an arthroscopic method, using stitches tying the meniscus using high-resistance suture threads or tapes and fixation through one or two transtibial tunnels in the anterior cortex of the tibia with a button or anchor. Results Among the 125 patients evaluated, considering the adopted failure criteria, 28 (22.4%) were considered repair failure and 97 (77.6%) were considered successful. Comparing the groups, patients who were considered to have repair failure presented as pre- and intra-operative factors a greater proportion of female patients (p=0.0004), higher BMI (p=0.0009), greater number of associated procedures at the time of root repair (0.02) and greater number of chondral injuries in the femur (0.0005). Patients who failed the repair underwent surgery with a greater number of stitches (p=0.02), although only repairs with 2 or 3 stitches were included, and had worse compliance with rehabilitation (p=0.0001). Conclusion Repairs of injuries to the posterior root of the medial meniscus with transtibial tunnel have 77.6% good results with an average follow-up of around 4 years. Female gender, high BMI, surgery to correct the axis or treatment of cartilage injury concomitant with root repair, more pronounced chondral injury in the femoral cartilage, repair with 3 stitches instead of 2, and poor patient compliance with rehabilitation were related factors of repair failure.

Clinical validation of the 2021 European Society of Cardiology guidelines on preexisting right bundle branch block in patients undergoing transcatheter aortic valve implantation.

Risk stratification of patients with right bundle branch block (RBBB) undergoing transcatheter aortic valve implantation (TAVI) remains challenging. This study aimed to evaluate the European Society of Cardiology (ESC) criteria for risk stratification of RBBB patients undergoing TAVI. We retrospectively analyzed prospectively enrolled patients with preexisting RBBB undergoing TAVI between 2011 and 2023. A surface 12-lead electrocardiogram was available before and after the procedure in all patients. The following ESC criteria were validated: ΔPR interval ≥20 ms, QRS axis change, and transient high-degree atrioventricular block (HAVB) <24 hours after TAVI. Preexisting RBBB was documented in 107 of 1410 patients (7.6%) undergoing TAVI. Mean age was 83 ± 5 years, 34% were female, and 66% received self-expandable valves. Of those 107 patients with preexisting RBBB, 36 (34%) had persistent HAVB lasting longer than 24 hours and received permanent pacemaker therapy. Of the remaining 71 patients, 16 patients (23%) had delayed HAVB during 30 days of follow-up. The ESC criteria identified 81% of patients (13/16) with delayed HAVB during 30-day follow-up while missing 3 patients (19%; 2.8% of the overall cohort). This resulted in a sensitivity of 81% and a negative predictive value of 92%. Meeting the ESC criteria bore a 6-fold increase in the odds for development of HAVB during 30-day follow-up (odds ratio, 6.5; 95% confidence interval, 1.84-30.8; P = .007). In this large cohort of patients with preexisting RBBB undergoing TAVI with contemporary prosthesis and implantation techniques, the ESC criteria-PR prolongation, QRS axis change, and transient HAVB-correctly identified 4 of 5 patients in whom HAVB developed during 30-day follow-up.

Clinical validation of the 2021 European Society of Cardiology guidelines on pre-existing right bundle branch block patients undergoing transcatheter aortic valve replacement

Abstract Introduction The management of patients with right bundle branch block (RBBB) undergoing transcatheter aortic valve replacement (TAVR) remains challenging. In these patients, the 2021 ESC guidelines recommend early pacemaker (PM) implantation in case of PR prolongation, QRS axis change or transient high-degree atrioventricular block (HAVB). However, evidence for the proposed criteria is scarce. Purpose Our aim was to evaluate the ESC recommendation for risk stratification of RBBB patients undergoing TAVR. Methods We retrospectively analyzed patients with pre-existing RBBB undergoing TAVR at our institution between 2011-2023. A surface 12-lead electrocardiogram (ECG) was available before and after procedure in all patients. The following, proposed ESC criteria were validated: ΔPR interval ≥ 20ms, QRS axis change or transient HAVB &amp;lt; 24 hours after TAVR. Results Of a total 1412 patients undergoing TAVR, 109 had pre-existing RBBB and were eligible for final analysis (mean age 83±5 years, 39% female). Of 109 RBBB patients, 36 (33%) developed persistent HAVB and received a permanent PM. Among the other 73 patients (67%), 17 patients (23%) suffered delayed HAVB during 30-days FU. When applying the ESC Guidelines, PM placement would have been indicated in 52% (38/73) of patients with RBBB after TAVR: due to transient HAVB in 17 (23%), due to PR prolongation ≥ 20ms in 19 (26%) and due to QRS axis change in 20 patients (27%). The proposed ESC criteria identified 82% of patients (14/17) with delayed HAVB during 30-day FU, while missing 3 patients (18%, 2.8% of overall cohort, Figure). This resulted in a sensitivity of 82% and a negative predictive value of 91%. Among the 17 patients with delayed HAVB, 12 patients (71%) displayed transient atrioventricular (AV) block within 24 hours after TAVR. Conclusion In this large cohort of RBBB patients undergoing TAVR with contemporary valves and techniques, the proposed ESC criteria of PR prolongation, QRS axis change or transient HAVB correctly identified 4/5 patients developing HAVB during 30-day FU. Prospective studies are warranted to confirm these findings.

8424 Complex Management Of Adrenal Insufficiency In Pregnancy: A Challenging Case

Abstract Disclosure: T. Avanessian: None. H. Alsamarraie: None. Background: Physiologic changes, including changes in the HPA axis and RAAS, during pregnancy pose challenges in the management of adrenal insufficiency in pregnant women. This case report discusses the management of adrenal insufficiency in a young primigravida female with Addison’s disease. Clinical Case: At 19.5 weeks of gestation, a 26-year-old primigravida, previously diagnosed with Addison’s disease 5 years ago, presented to an acute care center for syncopal episodes. The pregnancy had been complicated by persistent nausea and vomiting, labeled as hyperemesis gravidarum, and recurrent syncopal episodes, resulting in 6 ED visits and 3 hospitalizations, with symptoms improving each time after IV hydration and then returning within a few days. At presentation, the patient reported lightheadedness, sweating, palpitations, dyspnea, fatigue, nausea, vomiting, and a 10 lb weight loss since the beginning of pregnancy. The pre-pregnancy regimen was hydrocortisone 10 mg in the morning and 5 mg in the afternoon, with fludrocortisone 0.1mg daily. At 8 weeks of gestation, due to increased fatigue and hypotension, the hydrocortisone dose was doubled, while fludrocortisone was continued the same. During admission, blood pressure ranged from 67/37 to 90/56 mmHg, and heart rate ranged between 93-103 bpm. On labs, electrolytes were normal, and the serum renin level was elevated at 5.803 ng/ml/hr (0.167-5.380). Treatment included IV hydration and hydrocortisone 40 mg in the morning and 20 mg in the afternoon. Despite symptom improvement, blood pressure remained low. Thus, fludrocortisone was increased to 0.1 mg twice daily. Within 3 days, all symptoms improved, allowing for the down-titration of the hydrocortisone dose. The patient was discharged with hydrocortisone 30 mg at 8 AM, 10 mg at 3 PM, 5 mg at 7 PM, and fludrocortisone at 0.1 mg twice daily. Conclusion: Managing symptoms of adrenal insufficiency during pregnancy is challenging due to the overlap of symptoms and signs with physiologic manifestations of pregnancy. The use of biochemical testing is limited, given the physiological activation of RAAS and progressive increases in renin, CRH, ACTH (from both pituitary and placental sources), and cortisol during pregnancy. Monitoring mineralocorticoid requirements is further complicated by physiological changes in blood pressure and interstitial fluid status. While some literature suggests that adjusting fludrocortisone may not be necessary, as an increase in glucocorticoid dose can compensate, determining the correct dose of glucocorticoid and mineralocorticoid replacement should be tailored to each patient and their specific symptoms.

Ectopic Tooth Eruption – Integrative Literature Review

Ectopic eruption designates teeth that deviate from their normal eruption pattern. Its multifactorial etiology includes local and systemic factors, somatic disorders, and genetics. The objective of this study is to know the most common teeth that can present ectopic eruption, their prevalence, and associated clinical factors. A bibliographic search of scientific articles indexed in the PUBMED® and VHL databases was performed in September 2023, with the following descriptors: "Tooth Eruption; Ectopic; Dentistry". A total of 42 articles published in the last 5 years were found. Of these, 16 addressed ectopic eruptions and were included. The reviewed literature highlights the following clinical aspects: delayed eruption, partial appearance of the crown, changes in the eruption axis, transpositions, and gyro versions. The most affected teeth are the first permanent molars, with approximately 2 to 6%, and the canines with approximately 1.5 to 4.6%. It is essential to diagnose ectopic eruption early and identify the etiological factors, to obtain early treatment, preventing the development of this pathology and, consequently, the appearance of malocclusion.

Global R-wave peak time for diagnosis of left bundle branch capture

BackgroundQRS axis deviation and rS configuration in V6 affect the ability of V6 R-wave peak time (RWPT) criterion to discriminate capture type during left bundle branch area pacing (LBBAP). ObjectiveWe hypothesized that combining RWPTs from lateral leads: I, aVL, V5, and V6 may better reflect left ventricular activation time and that such a global RWPT may be insensitive to changes in QRS configuration. MethodsThe analysis included 519 electrocardiograms (ECGs) with nonselective left bundle branch pacing (nsLBBP) and 176 ECGs with left ventricular septal pacing (LVSP). Optimal RWPT cutoffs and area under the receiver operating curve (AUC) were determined for each lead and combinations of leads, to find the best RWPT criterion for discriminating nsLBBP from LVSP. Values were reported separately for healthy and diseased left conduction system groups. ResultsThe highest AUC of 97.1/89.2% was obtained for the global RWPT, which combined leads I and V6. The AUC for single-lead RWPT, was highest for lead I, followed by V6, V5, and aVL with AUC of 95.1/87.4%, 93.6/87.1%, 93.0/86.5%, and 84.8/74.6%, respectively. The global RWPT criterion was not affected by variations in QRS configuration, as V6 and I RWPTs often showed opposite responses to changes in axis. In contrast, all single-lead RWPT criteria were sensitive to axis deviation and QRS configuration. Diagnostically optimal RWPT cutoffs for global RWPT and lead I RWPT were 162.5/187.5 ms, and 81.5/90.5 ms, respectively. ConclusionThe global RWPT criterion allows a more accurate diagnosis of LBBAP capture type independent of QRS configuration and axis.

Gaseous Dynamical Friction on Elliptical Keplerian Orbits

We compute the gaseous dynamical friction force experienced by massive perturbers on elliptical Keplerian orbits. Using linear perturbation theory, we investigate the density wake morphology, dynamical friction force, and secular orbital evolution for massive single perturbers as well as equal-mass binaries embedded in a homogeneous, static medium. In all cases, the rate of change in the semimajor axis is found to be negative (as expected), whereas the rate of change in eccentricity is negative for strictly subsonic trajectories and positive for strictly supersonic trajectories. Transonic orbits can experience both positive and negative torques during the course of an orbit, with some growing in eccentricity and others circularizing. We observe all initial orbits becoming highly supersonic and eccentric (over sufficiently long timescales) due to a relentless semimajor axis decay increasing the Mach number and subsequent eccentricity driving. We compare our findings to previous studies for rectilinear and circular motion while also making our data for the evolution of Keplerian orbits available.

Comparison of Standard and Prone-Position Electrocardiograms in COVID-19 Patients With Pulmonary Complications: Correlations and Implications.

Previous research highlighted variability in electrocardiogram (ECG) readings across patient positions, particularly in the context of COVID-19 patients with pulmonary complications requiring prone positioning as part of the treatment. This study aimed to elucidate the effects of prone positioning on ECG parameters and explore its association with the severity of COVID-19. A prospective cohort study involved 60 patients diagnosed with COVID-19 and presenting pulmonary complications. ECGs were recorded in both supine and prone positions, and analyzed for various parameters including heart rate, QRS axis, and QTc interval. Clinical severity was assessed using APACHE II scores and SpO2/FiO2 ratios. Prone positioning led to an increase in heart rate (mean difference: 2.100, 95% CI: 0.471-3.729, p = 0.012), with minor shifts in the QRS axis. Heart rate and QRS axis demonstrated strong positive correlations between positions, with Pearson's correlation coefficients of 0.927 and 0.894, respectively. The study also found a significant association between prolonged QTc intervals in the prone position and elevated APACHE II scores, with a relative risk of 10.75 (95% CI: 1.82-63.64, p = 0.008). The prone positioning caused minor yet significant changes in heart rate and QRS axis. The correlation of prolonged QTc intervals in the prone position with higher APACHE II scores suggests the prognostic relevance of prone ECG in COVID-19 patients. However, further research is needed to fully understand the clinical implications and mechanisms of these findings.

Dynamical and Secular Stability of Mutually Inclined Planetary Systems

Multiple analytical, semi-analytical, and empirical stability criteria have been derived in the literature for two-planet systems. But, the dependence of the stability limit on the initial mutual inclination between the inner and outer orbits is not well modeled by previous stability criteria. Here, we derive a semi-analytical stability criteria for two-planet systems, at arbitrary inclinations, in which the inner planet is a test particle. Using perturbation theory we calculate the characteristic fractional change in the semimajor axis of the inner binary β = δ a 1/a 1 caused by perturbations from the companion. Stability criteria can be derived by setting a threshold on β. Focusing initially on circular orbits, we derive an analytical expression for β for coplanar prograde and retrograde orbits. For noncoplanar configurations, we evaluate a semi-analytical expression. We then generalize to orbits with arbitrary eccentricities and account for the secular effects. Our analytical and semi-analytical results are in excellent agreement with direct N-body simulations. In addition, we show that contours of β ∼ 0.01 can serve as criteria for stability. More specifically, we show that (1) retrograde orbits are generally more stable than prograde ones; (2) systems with intermediate mutual inclination are less stable due to von Ziepel–Lidov–Kozai (vZLK) dynamics; and (3) mean motion resonances (MMRs) can stabilize intermediate inclination secularly unstable regions in phase space, by quenching vZLK secular processes (4) MMRs can destabilize some of the dynamically stable regions. We also point out that these stability criteria can be used to constrain the orbital properties of observed systems and their age.

Hypothalamic-pituitary-adrenal axis function in the offspring of parents with bipolar disorder and the impact of the family environment: A pilot study of the Reducing Unwanted Stress in the Home (RUSH) prevention program

BackgroundThe home environment of offspring of parents with bipolar disorder (OBD) has been characterized by high levels of stress and disorganization, which may impact development of the hypothalamic-pituitary-adrenal (HPA) axis and their subsequent risk for affective disorders. The present study examined the effects of a family-based preventative intervention on the OBD’s HPA axis functioning and whether intervention-related changes in the home environment might have driven change in the HPA axis. MethodsFifty-five children (6–11 years) were recruited from families having a parent with bipolar disorder (n=26) or families having two parents with no current mental disorders (n=29). Only those families with a parent having bipolar disorder participated in the preventative intervention. Both groups completed assessments at baseline, post-prevention, 3-, and 6-months post-prevention. At each assessment, family organization, control, cohesion, conflict, and expressiveness, in addition to childhood internalizing problems, were measured, and offspring saliva samples were collected across two consecutive days. ResultsHierarchical Linear Modelling found no significant differences in HPA axis functioning between groups at baseline or across time. Improvements in family organization, however, were associated with elevations in participants’ cortisol awakening response (CAR; p =.004) and total daily output (p =.023), and a steepening of their diurnal slope (p =.003) across time. Similar findings were obtained for family cohesion with respect to CAR (p <.001) and, to a lesser degree, diurnal slope (p =.064). DiscussionHPA axis functioning did not differ between the OBD and healthy controls at baseline or in response to the preventative intervention. However, intervention-related improvements in family organization and, to a lesser degree, cohesion, were associated with adaptive changes in HPA functioning over time.