Primary Masses Research Articles

Anaesthesia Management of A Patient with Airway Obstruction Caused by Prosthetic Vascular Graft Invasion into the Tracheal Lumen.

Primary intratracheal masses causing luminal obstruction are relatively rare, posing a challenge for anaesthesiologists in airway management. This case report describes a distinctive airway management approach in a 71-year-old female patient with an aorta-carotid artery bypass graft that significantly obstructed the trachea. The patient presented with worsening shortness of breath, and a thoracic computed tomography scan revealed a 19.2 mm×9.9 mm×19.3 contrast-enhancing mass penetrating the right anterolateral tracheal wall, resulting in 80% occlusion of the tracheal lumen. Awake fiberoptic bronchoscopy (FOB)-guided nasotracheal intubation was performed following topical upper airway anaesthesia, with the patient positioned at a 30º head-up angle and slight right-up tilt to minimize discomfort. A 6.0 mm ID cuffed endotracheal tube was successfully placed under fiberoptic guidance distal to the intratracheal vascular graft but proximal to the carina. Intratracheal masses can lead to severe tracheal obstruction followed by progressive airway obstruction, which can be life-threatening when effective ventilation cannot be established after the induction of general anaesthesia. We recommend the use of awake FOB-guided intubation in such cases. Additionally, contingency plans should be prepared and meticulously prepared in the event of intubation or ventilation failure.

Improved diagnostic confidence using Super Resolution CEUS imaging in testicular lesions.

Ultrasound is the most used interdisciplinary non-ionizing imaging technique in clinical pathologies of the testis. The testis may be affected by a plethora of different disorders such as vasculopathies, trauma, infections and manifestations of primary and secondary malignant masses. Conventional ultrasound represents the basic imaging modality of choice to assess scrotal disorders. Contrast-enhanced ultrasound (CEUS) can provide further information to distinguish between benign and malignant testicular mass lesions. The recent introduction of Super Resolution CEUS Micro-Vascular Imaging (MVI SR) and Time of Arrival (TOA SR) parametric mapping compliments the information provided by conventional CEUS, since these two new post-processing techniques improve the visualization of microvascular structures with slow blood flow and provide high-resolution images of the peak contrast enhancement and temporal perfusion patterns. This paper gives a comprehensive overview of differential diagnoses of the testicular disorder and their corresponding sono-morphologic correlates based on representative cases of the Interdisciplinary Ultrasound Center of the University Hospital Munich.

Intra- and interobserver agreement in computed tomography localization of primary nonhematopoietic hepatic masses and comparison with surgical and histopathological outcomes in 21 cats.

Computed tomography (CT) is commonly used in the staging of hepatic masses and for liver lobectomy planning. Mass location is an important factor in determining the feasibility of resection, including surgical technique and the likelihood of surgical complications. The objectives of this retrospective descriptive cross-sectional, observer agreement, method comparison study were to assess the reliability of CT in correctly determining the hepatic division and lobar site of origin of feline primary nonhematopoietic hepatic masses, compared with surgically confirmed locations. Furthermore, it provides an overview of the types and locations of liver masses found in a cohort of cats. Pre- and postcontrast CT images of 21 cats were independently and simultaneously reviewed by two observers. Intra- and interobserver agreements and descriptive statistics on demographic and histological diagnoses were calculated. Based on surgical assessment, it was found that masses most frequently originated from the left hepatic division (13/24, 54%). The most frequent lobar origins were the left lateral (8/24, 33%), left medial (5/24, 21%), and right medial lobes (5/24, 21%). No masses were found originating from the right lateral lobe. CT correctly determined hepatic division and lobar origin in 76% of cases, with good-to-excellent intra- and interobserver agreement. The hepatic division had higher agreements overall for both observers. Most of the masses were benign (17/21, 81%), and the most prevalent histological diagnoses were biliary cystadenoma (11/21, 52%) and hepatocellular adenoma (6/21, 29%). Findings suggest that postcontrast CT is a reliable method for correctly determining hepatic mass division and lobar origin in cats.

The utility of next-generation sequencing in challenging liver FNA biopsies.

Fine-needle aspiration (FNA) biopsy is increasingly used for the diagnosis of hepatocellular masses. Because distinguishing well differentiated hepatocellular carcinoma (HCC) from other well differentiated hepatocellular lesions (e.g., large regenerative nodules or focal nodular hyperplasia) requires an assessment of architectural features, this may be challenging on FNA when intact tissue fragments are not sampled. Poorly differentiated HCC and intrahepatic cholangiocarcinoma (ICC) may exhibit overlapping pathologic features. Molecular testing can be helpful, because mutations in TERT promoter and CTNNB1 (β-catenin) are characteristic of HCC, whereas mutations in BAP1, IDH1/IDH2, and PBRM1 may favor ICC. The goal of this study was to assess the role of next-generation sequencing (NGS) in further subclassifying indeterminate liver lesions sampled by FNA. A retrospective review of liver cytology cases with NGS on cell block material was performed. Age, radiologic features, background hepatic disease and treatment, outcome, and NGS data were obtained from the electronic medical record. Twelve FNA biopsies that had cell blocks from clinically suspected primary hepatic masses were identified. The presence of a TERT promoter mutation supported a diagnosis of HCC for one well differentiated neoplasm. For three patients, the presence of mutations, such as IDH1, CDKN2A/CDKN2B, and BRAF, supported a diagnosis of ICC. Of the eight poorly differentiated carcinomas, NGS helped refine the diagnosis in six of eight cases, with one HCC, three ICCs, and two that had combined HCC-ICC, with two cases remaining unclassified. Molecular diagnostics can be helpful to distinguish HCC and ICC on FNA specimens, although a subset of primary hepatic tumors may remain unclassifiable.

Assessment of the diagnostic efficacy of radiological and functional evaluation of primary adrenal mass and its' surgical outcomes.

Objective of this study was to assess the diagnostic efficacy of the most commonly used radiological evaluation in form of contrast enhanced computed tomography of abdomen with adrenal protocol, basic functional evaluation and surgical outcomes of primary adrenal masses. We have retrospectively analysed the institutional records of 108, patients admitted from August 2017 to September 2023, who had underwent surgical intervention for their adrenal mass after thorough evaluation and stabilization. Flank pain was the most common symptoms in 44 (40.74%) patients. Non-functional adrenal adenoma was found in 36 (33.33%) patients. Pheochromocytoma was the most the common functional adrenal mass found in 24 (22.22%) patients. CECT abdomen had suggested features of malignancy in 16(14.81%) patients. In final histopathological report 26(24.07%) patients had pheochromocytoma and 12 (11.11%) patients had adrenocortical carcinoma. CECT abdomen had sensitivity of 75%, specificity of 95.6%. Plasma free metanephrines and normetanephrine analysis had shown sensitivity of 90%, specificity of 92.86%, aldosterone to renin ratio had sensitivity of 92%, specificity of 100%. Sensitivity and specificity of the low-dose dexamethasone suppression test and plasma dehydroepiandrosterone was 100% in our study. Eighty patients (74.07%) were operated with laparoscopic adrenalectomy, 20 (18.52%) patients with open adrenalectomy. Eight patients (7.41%) were converted from laparoscopic to open. Laparoscopic approach had significantly lesser mean operating time, lesser blood loss, lesser hospitalization and lesser post-operative complications. Radiological analysis and functional analysis has shown good sensitivity and high specificity. Laparoscopic approach has advantage of lesser operative time, lesser hospitalization and lesser post-operative complications.

Assessment of water mass distribution and intrusions of circumpolar deep water in the Amundsen Sea based on the ocean reanalysis product FOAM-GLOSEA5v13

The Amundsen Sea of West Antarctica is one of the regions of particularly interest to the oceanography community due to accelerated basal melting of its ice shelves. Quantitative estimates of the composition of water masses and their sources are essential for understanding the heat and salt budgets and the stability of ice shelves in this region. In this study, the water mass distributions on the Amundsen Sea continental shelf are estimated based on FOAM-GLOSEA5v13, a global oceanographic reanalysis product, using a modified statistical based optimal water mass analysis method. The reanalysis product effectively captures the signal of primary water masses, including the Winter Water (WW) and the Circumpolar Deep Water (CDW) below the Antarctic Summer Surface Water (SSW). The horizontal and vertical distributions and temporal evolution of three water mass endmembers (WW, CDW and DSW) and their mixing ratios are calculated, based on which an intrusion location detection method was established. Using the reanalysis product and intrusion detection method, all potential CDW intrusion sites along the shelf break are identified. Based on the reanalysis product, an intrusion site over the shelf break, away from major deep troughs was captured and confirmed by numerical particle tracking experiments.

The Redshift Evolution of the Binary Black Hole Mass Distribution from Dense Star Clusters

Gravitational-wave detectors are unveiling a population of binary black hole (BBH) mergers out to redshifts z ≈ 1, and are starting to constrain how the BBH population evolves with redshift. We present predictions for the redshift evolution of the BBH mass and spin distributions for systems originating from dense star clusters. Utilizing a grid of 144 state-of-the-art dynamical models for globular clusters, we demonstrate that BBH merger rates peak at higher redshifts for larger black hole primary masses M 1. Specifically, for M 1 ≳ 40 M ⊙, the BBH merger rate reaches its peak at redshift z ≈ 2.1, while for M 1 ≲ 20 M ⊙, the peak occurs at z ≈ 1.1, assuming that the cluster formation rate peaks at z = 2.2. The average BBH primary mass also increases from ∼10 M ⊙ at z = 0 to ∼30 M ⊙ at z = 10. We show that ∼20% BBHs contain massive remnants from next-generation mergers, with this fraction increasing (decreasing) for larger (smaller) primary masses. This difference is not large enough to significantly alter the effective spins of the BBH population originating from globular clusters, and we find that their effective spin distribution does not evolve across cosmic time. These findings can be used to distinguish BBHs from dense star clusters by future gravitational-wave observations.

Comparison of Diffusion MRI Findings of High-Graded Primary Brain Tumors and Metastatic Brain Tumors

Aim: Glioblastomas are the highest grade and most mortal primary brain tumors. Cerebral masses that occur with the metastasis of cancers of tissues other than brain are included in the differential diagnosis of glioblastomas. This study aimed to compare the diffusion-weighted imaging signal characteristics of primary and metastatic brain masses and to describe the findings that may be useful in the differential diagnosis. Material and Methods: Patients with pathologically diagnosed glioblastoma and patients with pathologically diagnosed metastases or radiologically diagnosed brain metastases were included in the study. Diffusion-weighted imaging signal properties in magnetic resonance imaging examinations obtained with a 1.5 Tesla scanner were retrospectively analyzed. The signal features and short and long diameters of the lesions were measured and compared in both patient groups. Results: A total of 54 patients, 24 glioblastomas, and 30 brain metastases were included in the study. The most common signal feature of diffusion-weighted imaging in the glioblastoma group was heterogeneous hyper- and hypointense areas observed in 20 (83.3%) patients. The most common signal feature in the metastasis group was the peripheral hyperintense ring and central hypointense signal in 16 (53.3%) patients. There was no significant relation found between the number of lesions and the primary brain tumor and metastases. Conclusion: Although only signal characteristics are used without quantitative assessment in diffusion-weighted imaging, it may be helpful in the differential diagnosis of primary and metastatic brain masses. It is important to remember that the masses in the two groups can have comparable signal properties.

Establishment, characterization, and biobanking of 36 pancreatic cancer organoids: prediction of metastasis in resectable pancreatic cancer

PurposeEarly dissemination of primary pancreatic ductal adenocarcinoma (PDAC) is the main cause of dismal prognosis as it highly limits possible treatment options. A number of PDAC patients experience distant metastasis even after treatment due to the metastatic clones. We aimed to demonstrate the molecular architecture of borderline resectable PDAC manifests cancer dissemination of PDAC.MethodsHere, 36 organoids isolated from primary tumor masses of PDAC patients with diverse metastatic statues are presented. Whole-exome sequencing and RNA sequencing were performed and drug responses to clinically relevant 18 compounds were assessed.ResultsOur results revealed that borderline resectable PDAC organoids exhibited distinct patterns according to their metastatic potency highlighted by multiple genetic and transcriptional factors and strong variances in drug responses.ConclusionsThese data suggest that the presence of metastatic PDAC can be identified by integrating molecular compositions and drug responses of borderline resectable PDAC.

68Ga-FAPI PET/CT as an Alternative to 18F-FDG PET/CT in the Imaging of Invasive Lobular Breast Carcinoma.

Accurate staging of invasive lobular carcinoma (ILC), a subtype of breast cancer, is vital for effective clinical management. Although 18F-FDG PET/CT is a commonly used tool, its efficacy varies across different histologic subtypes. To mitigate this challenge, our investigation delves into the potential utility of 68Ga-fibroblast activation protein inhibitor (FAPI) PET/CT as an alternative for staging ILC, aiming to address a significant research gap using a more expansive patient cohort than the smaller samples commonly found in the existing literature. Methods: In this retrospective analysis, women diagnosed with primary ILC of the breast underwent both 18F-FDG PET/CT and 68Ga-FAPI PET/CT. Both modalities were compared across all lesion locations with the used reference standard. The interval between scans was 1 wk, without any intervening treatments. Lesions were categorized visually, and tracer activity was analyzed using SUVmax, tumor-to-background uptake ratio, and uptake ratios. Both modalities were compared across various parameters, and statistical analysis was performed using SPSS 22.0. A P value of less than 0.05 was chosen to determine statistical significance. Results: The study included 23 female ILC patients (mean age, 51 y) with hormone-positive, human epidermal growth factor receptor type 2-negative tumors. Most (65%) had the luminal A subtype. 68Ga-FAPI PET/CT outperformed 18F-FDG PET/CT, with higher tumoral activity and tumor-to-background uptake ratios (P < 0.001). Primary tumors showed significantly increased uptake with 68Ga-FAPI PET/CT (P < 0.001), detecting additional foci, including multicentric cancer. Axillary lymph node metastases were more frequent and had higher uptake values with 68Ga-FAPI PET/CT (P = 0.012). Moreover, 68Ga-FAPI PET/CT identified more lesions, including bone and liver metastases. Pathologic features did not significantly correlate with imaging modalities, but a positive correlation was observed between peritumoral lymphocyte ratio and 68Ga-FAPI PET/CT-to-18F-FDG PET/CT uptake ratios (P = 0.026). Conclusion: This study underscores 68Ga-FAPI PET/CT's superiority over 18F-FDG PET/CT for ILC. 68Ga-FAPI PET/CT excels in detecting primary breast masses, axillary lymph nodes, and distant metastases; can complement 18F-FDG PET/CT in ILC; and holds potential as an alternative imaging method in future studies.

Modelling and simulation of MR damper characterization and uncertainty assessment in marine engine vibration isolation with FLPID control

ABSTRACT This paper meticulously examines the magneto-rheological (MR) damper to exploring its application in a semi-active isolator system. The MR damper’s distinctive capability to regulate damping force through an externally applied magnetic field is investigated via extensive experimental testing. Sinusoidal displacement inputs with varying electromagnet currents reveal a direct correlation between higher current levels and augmented MR damper forces. Validation of the experimental results is achieved through the Viscous Plus Dahl Model, showcasing its accuracy in capturing the damper’s hysteresis behavior. The study extends its scope to practical implementation by integrating the MR damper into a marine diesel engine system. A fuzzy logic-based self-tuning PID controller collaborates with the MR damper to establish a semi-active vibration isolator. The integrated model, encompassing primary and secondary masses, the engine, and the isolator with passive and semi-active systems, is rigorously analyzed. Experimental validation and theoretical simulations, aligned with data gathered from experiments, affirm the model’s fidelity in representing the MR damper. Simulation outcomes underscore the significant enhancement in vibration reduction characteristics of the semi-active isolator system compared to its passive counterpart, particularly evident in the improved performance of the 1200 kg engine under diverse operating conditions.

Two of a Kind: Comparing Big and Small Black Holes in Binaries with Gravitational Waves

When modeling the population of merging binary black holes, analyses have generally focused on characterizing the distribution of primary (i.e., more massive) black holes in the binary, while using simplistic prescriptions for the distribution of secondary masses. However, the secondary mass distribution and its relationship to the primary mass distribution provide a fundamental observational constraint on the formation history of coalescing binary black holes. If both black holes experience similar stellar evolutionary processes prior to collapse, as might be expected in dynamical formation channels, the primary and secondary mass distributions would show similar features. If they follow distinct evolutionary pathways (for example, due to binary interactions that break symmetry between the initially more massive and less massive stars), their mass distributions may differ. We present the first analysis of the binary black hole population that explicitly fits for the secondary mass distribution. We find that the data is consistent with a ∼30 M ⊙ peak existing only in the distribution of secondary rather than primary masses. This would have major implications for our understanding of the formation of these binaries. Alternatively, the data is consistent with the peak existing in both component mass distributions, a possibility not included in most previous studies. In either case, the peak is observed at 31.4−2.6+2.3M⊙ , which is shifted lower than the value obtained in previous analyses of the marginal primary mass distribution, placing this feature in further tension with expectations from a pulsational pair-instability supernova pileup.

Modified addition theorem on Kubelka-Munk transmission law for mass prediction of each primary in two-mixed cotton fiber blends

Unclear light propagation in mixed fibers has resulted in unachievable masses of primary fibers, in particular thin two-mixed fiber assemblies for decades. Hereby, a modified mixed medium addition theorem of the Kubelka-Munk transmission model is proposed to address this issue. This theorem was constructed by introducing a transfer function in the common ones on scattering coefficients, and such a transfer function takes both the mass proportion of each component and the reflectivity of mixed material into consideration. This opens up a new avenue for understanding the possible light mechanism of color mixed fiber assemblies. The proposed method demonstrated excellent accuracy in determining the primary masses of 48 specimens, with an average mean absolute error of only 2.23 mg. In comparison, the Lambert-Beer law yielded a much higher average mean absolute error of 8.66 for all types of blended samples. Such superiority was particularly obvious in white-black mixed samples, probably due to its comprised reflectance. In brief, this proposed theorem shows a high-quality prediction accuracy level in fiber mass and can be expanded to detect and control mixed fibers, as well as fiber length and uniformity detection through further study.

The dragon-II simulations – I. Evolution of single and binary compact objects in star clusters with up to 1 million stars

ABSTRACT We present the first results of the Dragon-II simulations, a suite of 19 N-body simulations of star clusters with up to 106 stars, with up to 33 per cent of them initially paired in binaries. In this work, we describe the main evolution of the clusters and their compact objects (COs). All Dragon-II clusters form in their centre a black hole (BH) subsystem with a density 10−100 times larger than the stellar density, with the cluster core containing $50{-}80~{{\rm per\ cent}}$ of the whole BH population. In all models, the BH average mass steeply decreases as a consequence of BH burning, reaching values 〈mBH〉 &amp;lt; 15 M⊙ within 10−30 relaxation times. Generally, our clusters retain only BHs lighter than 30 M⊙ over 30 relaxation times. Looser clusters retain a higher binary fraction, because in such environments binaries are less likely disrupted by dynamical encounters. We find that BH–main-sequence star binaries have properties similar to recently observed systems. Double CO binaries (DCOBs) ejected from the cluster exhibit larger mass ratios and heavier primary masses than ejected binaries hosting single CO binaries (SCOBs). Ejected SCOBs have BH masses mBH = 3−20 M⊙, definitely lower than those in DCOBs (mBH = 10−100 M⊙).

A A retrospective observational study in assesment of role of sonography in adnexal masses and its histopathological correlation in tertiary care centre.

Background- Adnexal masses (masses of the ovary, fallopian tube, or surrounding tissues) commonly are encountered by obstetrician–gynaecologist and often present diagnostic and management dilemmas. Types of adnexal mass ranges from benign ovarian and non-ovarian to primary and secondary malignant ovarian masses. Although most adnexal masses are benign, the main goal of the diagnostic evaluation is to exclude malignancy. Transvaginal ultrasonography remains the gold standard for evaluation of adnexal masses. The management of the adnexal masses varies according to age at presentation, whether benign or malignant, acute emergency or chronic presentation. Aim- The study aimed to determine the causes of adnexal masses and correlation of ultrasonographic and histopathologic findings of the adnexal masses. Methods- This is a retrospective observational study, performed in the Department of Obstetrics and Gynaecology, in tertiary care hospital. Operative and demographic details of patients operated for adnexal masses over a period of one year was obtained from case records of patient. Results- Among 90 cases studied, 86.66%(78) cases of adnexal masses was of ovarian origin followed by 11.66%(7) was of tubal origin. Among 90 cases of adnexal masses, 91.11%(82) cases were benign , 4.44%(4) were of borderline and malignant. Most common ovarian cause of adnexal mass was endometriotic cyst(22.22%) followed by serous cyst adenoma(20%) The highest sensitivity was found for follicular cyst (87.5%) followed by dermoid and serous cyst adenoma (83.33%). Malignancy was found in 8 cases among which 6 were correctly reported by USG resulting in sensitivity of 75%. Conclusion- It was concluded from the current study findings that sonography was primary modality and best screening tool for evaluation of pelvic masses. Ultrasound has high sensitivity for correctly diagnosing benign versus malignant pelvic lesions. Sonography was observed to be best modality to differentiate between solid and cystic pelvic masses.

Binary Vision: The Mass Distribution of Merging Binary Black Holes via Iterative Density Estimation

Binary black hole (BBH) systems detected via gravitational-wave emission are a recently opened astrophysical frontier with many unknowns and uncertainties. Accurate reconstruction of the binary distribution with as few assumptions as possible is desirable for inference of formation channels and environments. Most population analyses have, though, assumed a power law in binary mass ratio q, and/or assumed a universal q distribution regardless of primary mass. Methods based on kernel density estimation allow us to dispense with such assumptions and directly estimate the joint binary mass distribution. We deploy a self-consistent iterative method to estimate this full BBH mass distribution, finding local maxima in primary mass consistent with previous investigations and a secondary mass distribution with a partly independent structure, inconsistent both with a power law and with a constant function of q. We find a weaker preference for near-equal-mass binaries than in most previous investigations; instead, the secondary mass has its own “spectral lines” at slightly lower values than the primary, and we observe an anticorrelation between primary and secondary masses around the ∼10 M ⊙ peak.

Patterns and Clinico-Radiological Characteristics of Primary Liver Masses in Children Treated at a Tertiary Referral Hospital, in Ethiopia

Patterns and Clinico-Radiological Characteristics of Primary Liver Masses in Children Treated at a Tertiary Referral Hospital, in Ethiopia

The dominant mechanism(s) for populating the outskirts of star clusters with neutron star binaries

ABSTRACT It has been argued that heavy binaries composed of neutron stars (NSs) and millisecond pulsars (MSPs) can end up in the outskirts of star clusters via an interaction with a massive black hole (BH) binary expelling them from the core. We argue here, however, that this mechanism will rarely account for such observed objects. Only for primary masses ≲100 M⊙ and a narrow range of orbital separations should a BH–BH binary be both dynamically hard and produce a sufficiently low recoil velocity to retain the NS binary in the cluster. Hence, BH binaries are in general likely to eject NSs from clusters. We explore several alternative mechanisms that would cause NS/MSP binaries to be observed in the outskirts of their host clusters after a Hubble time. The most likely mechanism is a three-body interaction involving the NS/MSP binary and a normal star. We compare to Monte Carlo simulations of cluster evolution for the globular clusters NGC 6752 and 47 Tuc, and show that the models not only confirm that normal three-body interactions involving all stellar-mass objects are the dominant mechanism for putting NS/MSP binaries into the cluster outskirts, but also reproduce the observed NS/MSP binary radial distributions without needing to invoke the presence of a massive BH binary. Higher central densities and an episode of core collapse can broaden the radial distributions of NSs/MSPs and NS/MSP binaries due to three-body interactions, making these clusters more likely to host NSs in the cluster outskirts.

Mass Ratio Distribution of Hierarchical Triple Systems from the LAMOST-MRS Survey

Hierarchical triple-star systems consists of three components organized into an inner binary (M 1, M 2) and a more distant outer tertiary (M 3) star. The LAMOST Medium-Resolution Spectroscopic Survey has offered a great sample for the study of triple-system populations. We used the peak amplitude ratio method to obtain the mass ratio (q in, q out) of a triple system from its normalized spectrum. By calculating the cross-correlation function, we determined the correlation between the mass ratio q out (M 3/(M 1 + M 2)) and the amplitude ratio (A 3/(A 1 + A 2)). We derived a q in of 0.5–1.0 and a q out between 0.2 and 0.8. By fitting a power-law function of the corrected q in distribution, γ in is estimated to be −0.654 ± 2.915, 4.304 ± 1.125, and 11.371 ± 1.309 for A-, F-, and G-type stars. The derived γ in values increase as the mass decreases, indicating that less massive stars are more likely to have companion stars with similar masses. By fitting a power-law function of the corrected q out distribution, γ out is estimated to be −2.016 ± 0.172, −1.962 ± 0.853, and −1.238 ± 0.141 for G-, F-, and A-type stars, respectively. The γ out values show a trend of growth toward lower primary star masses.

The dynamical equations of a test particle in the restricted three-body problem with a triaxial primary and variable masses

The restricted three-body problem (R3BP) defines the motion of an infinitesimal mass moving under the gravitational attractions of two main masses, called primaries. In this paper, we examine the dynamical equations of a test body in the frame of the circular R3BP. Both primaries are assumed to vary their masses in accordance with the Unified Mestschersky law (UML) and their motion determined by the Gylden-Mestschersky problem (GMP). Further, the first primary is assumed to be a triaxial variable mass body. The potential between the primaries is deduced and in furtherance, the non-autonomous equations of motion of the model are derived. The derived equations are time varying and are thus transformed to the autonomized forms with constant coefficients using the Mestschersky transformation (MT), the UML, the particular integral and solutions of the GMP. We also use a transformation we introduced, which helps in converting the time dependent triaxiality of the bigger primary to one that is constant. The derived systems of equations with variable and constant coefficients can be used to model the long-term motion of satellites and planets in binary systems.